From: Tianyu Lan <[email protected]>
Hyper-V provides two kinds of Isolation VMs. VBS(Virtualization-based
security) and AMD SEV-SNP unenlightened Isolation VMs. This patchset
is to add support for these Isolation VM support in Linux.
The memory of these vms are encrypted and host can't access guest
memory directly. Hyper-V provides new host visibility hvcall and
the guest needs to call new hvcall to mark memory visible to host
before sharing memory with host. For security, all network/storage
stack memory should not be shared with host and so there is bounce
buffer requests.
Vmbus channel ring buffer already plays bounce buffer role because
all data from/to host needs to copy from/to between the ring buffer
and IO stack memory. So mark vmbus channel ring buffer visible.
For SNP isolation VM, guest needs to access the shared memory via
extra address space which is specified by Hyper-V CPUID HYPERV_CPUID_
ISOLATION_CONFIG. The access physical address of the shared memory
should be bounce buffer memory GPA plus with shared_gpa_boundary
reported by CPUID.
This patchset is rebased on the commit d9abdee of Linux mainline tree
and plus clean up patch from Borislav Petkov(https://lore.kernel.org/r/
YWRwxImd9Qcls/[email protected])
Change since v7
- Rework sev_es_ghcb_hv_call() and export it for Hyper-V
according to suggestion from Borislav Petkov.
Change since v6
- Add hv_set_mem_host_visibility() when CONFIG_HYPERV is no.
Fix compile error.
- Add comment to describe __set_memory_enc_pgtable().
- Split SEV change into patch "Expose __sev_es_ghcb_hv_call()
to call ghcb hv call out of sev code"
- Add comment about calling memunmap() in the non-snp IVM.
Change since v5
- Replace HVPFN_UP() with PFN_UP() in the __vmbus_establish_gpadl()
- Remove unused variable gpadl in the __vmbus_open() and vmbus_close_
internal()
- Clean gpadl_handle in the vmbus_teardown_gpadl().
- Adjust change layout in the asm/mshyperv.h to make
hv_is_synic_reg(), hv_get_register() and hv_set_register()
ahead of the #include of asm-generic/mshyperv.h
- Change vmbus_connection.monitor_pages_pa type from unsigned
long to phys_addr_t
Change since v4:
- Hide hv_mark_gpa_visibility() and set memory visibility via
set_memory_encrypted/decrypted()
- Change gpadl handle in netvsc and uio driver from u32 to
struct vmbus_gpadl.
- Change vmbus_establish_gpadl()'s gpadl_handle parameter
to vmbus_gpadl data structure.
- Remove hv_get_simp(), hv_get_siefp() hv_get_synint_*()
helper function. Move the logic into hv_get/set_register().
- Use scsi_dma_map/unmap() instead of dma_map/unmap_sg() in storvsc driver.
- Allocate rx/tx ring buffer via alloc_pages() in Isolation VM
Change since V3:
- Initalize GHCB page in the cpu init callbac.
- Change vmbus_teardown_gpadl() parameter in order to
mask the memory back to non-visible to host.
- Merge hv_ringbuffer_post_init() into hv_ringbuffer_init().
- Keep Hyper-V bounce buffer size as same as AMD SEV VM
- Use dma_map_sg() instead of dm_map_page() in the storvsc driver.
Change since V2:
- Drop x86_set_memory_enc static call and use platform check
in the __set_memory_enc_dec() to run platform callback of
set memory encrypted or decrypted.
Change since V1:
- Introduce x86_set_memory_enc static call and so platforms can
override __set_memory_enc_dec() with their implementation
- Introduce sev_es_ghcb_hv_call_simple() and share code
between SEV and Hyper-V code.
- Not remap monitor pages in the non-SNP isolation VM
- Make swiotlb_init_io_tlb_mem() return error code and return
error when dma_map_decrypted() fails.
Change since RFC V4:
- Introduce dma map decrypted function to remap bounce buffer
and provide dma map decrypted ops for platform to hook callback.
- Split swiotlb and dma map decrypted change into two patches
- Replace vstart with vaddr in swiotlb changes.
Change since RFC v3:
- Add interface set_memory_decrypted_map() to decrypt memory and
map bounce buffer in extra address space
- Remove swiotlb remap function and store the remap address
returned by set_memory_decrypted_map() in swiotlb mem data structure.
- Introduce hv_set_mem_enc() to make code more readable in the __set_memory_enc_dec().
Change since RFC v2:
- Remove not UIO driver in Isolation VM patch
- Use vmap_pfn() to replace ioremap_page_range function in
order to avoid exposing symbol ioremap_page_range() and
ioremap_page_range()
- Call hv set mem host visibility hvcall in set_memory_encrypted/decrypted()
- Enable swiotlb force mode instead of adding Hyper-V dma map/unmap hook
- Fix code style
Tianyu Lan (9):
x86/hyperv: Initialize GHCB page in Isolation VM
x86/hyperv: Initialize shared memory boundary in the Isolation VM.
x86/hyperv: Add new hvcall guest address host visibility support
Drivers: hv: vmbus: Mark vmbus ring buffer visible to host in
Isolation VM
x86/sev-es: Expose sev_es_ghcb_hv_call() to call ghcb hv call out of
sev code
x86/hyperv: Add Write/Read MSR registers via ghcb page
x86/hyperv: Add ghcb hvcall support for SNP VM
Drivers: hv: vmbus: Add SNP support for VMbus channel initiate
message
Drivers: hv : vmbus: Initialize VMbus ring buffer for Isolation VM
arch/x86/hyperv/Makefile | 2 +-
arch/x86/hyperv/hv_init.c | 78 ++++++--
arch/x86/hyperv/ivm.c | 286 +++++++++++++++++++++++++++++
arch/x86/include/asm/hyperv-tlfs.h | 17 ++
arch/x86/include/asm/mshyperv.h | 64 +++++--
arch/x86/include/asm/sev.h | 12 ++
arch/x86/kernel/cpu/mshyperv.c | 5 +
arch/x86/kernel/sev-shared.c | 26 ++-
arch/x86/kernel/sev.c | 13 +-
arch/x86/mm/pat/set_memory.c | 23 ++-
drivers/hv/Kconfig | 1 +
drivers/hv/channel.c | 72 +++++---
drivers/hv/connection.c | 101 +++++++++-
drivers/hv/hv.c | 82 +++++++--
drivers/hv/hv_common.c | 12 ++
drivers/hv/hyperv_vmbus.h | 2 +
drivers/hv/ring_buffer.c | 55 ++++--
drivers/net/hyperv/hyperv_net.h | 5 +-
drivers/net/hyperv/netvsc.c | 15 +-
drivers/uio/uio_hv_generic.c | 18 +-
include/asm-generic/hyperv-tlfs.h | 1 +
include/asm-generic/mshyperv.h | 20 +-
include/linux/hyperv.h | 12 +-
23 files changed, 783 insertions(+), 139 deletions(-)
create mode 100644 arch/x86/hyperv/ivm.c
--
2.25.1
From: Tianyu Lan <[email protected]>
Hyperv exposes GHCB page via SEV ES GHCB MSR for SNP guest
to communicate with hypervisor. Map GHCB page for all
cpus to read/write MSR register and submit hvcall request
via ghcb page.
Signed-off-by: Tianyu Lan <[email protected]>
---
Change since v4:
* Fix typo comment
Chagne since v3:
* Rename ghcb_base to hv_ghcb_pg and move it out of
struct ms_hyperv_info.
* Allocate hv_ghcb_pg before cpuhp_setup_state() and leverage
hv_cpu_init() to initialize ghcb page.
---
arch/x86/hyperv/hv_init.c | 68 +++++++++++++++++++++++++++++----
arch/x86/include/asm/mshyperv.h | 4 ++
arch/x86/kernel/cpu/mshyperv.c | 3 ++
include/asm-generic/mshyperv.h | 6 +++
4 files changed, 74 insertions(+), 7 deletions(-)
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 708a2712a516..a7e922755ad1 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -20,6 +20,7 @@
#include <linux/kexec.h>
#include <linux/version.h>
#include <linux/vmalloc.h>
+#include <linux/io.h>
#include <linux/mm.h>
#include <linux/hyperv.h>
#include <linux/slab.h>
@@ -36,12 +37,42 @@ EXPORT_SYMBOL_GPL(hv_current_partition_id);
void *hv_hypercall_pg;
EXPORT_SYMBOL_GPL(hv_hypercall_pg);
+void __percpu **hv_ghcb_pg;
+
/* Storage to save the hypercall page temporarily for hibernation */
static void *hv_hypercall_pg_saved;
struct hv_vp_assist_page **hv_vp_assist_page;
EXPORT_SYMBOL_GPL(hv_vp_assist_page);
+static int hyperv_init_ghcb(void)
+{
+ u64 ghcb_gpa;
+ void *ghcb_va;
+ void **ghcb_base;
+
+ if (!hv_isolation_type_snp())
+ return 0;
+
+ if (!hv_ghcb_pg)
+ return -EINVAL;
+
+ /*
+ * GHCB page is allocated by paravisor. The address
+ * returned by MSR_AMD64_SEV_ES_GHCB is above shared
+ * memory boundary and map it here.
+ */
+ rdmsrl(MSR_AMD64_SEV_ES_GHCB, ghcb_gpa);
+ ghcb_va = memremap(ghcb_gpa, HV_HYP_PAGE_SIZE, MEMREMAP_WB);
+ if (!ghcb_va)
+ return -ENOMEM;
+
+ ghcb_base = (void **)this_cpu_ptr(hv_ghcb_pg);
+ *ghcb_base = ghcb_va;
+
+ return 0;
+}
+
static int hv_cpu_init(unsigned int cpu)
{
union hv_vp_assist_msr_contents msr = { 0 };
@@ -85,7 +116,7 @@ static int hv_cpu_init(unsigned int cpu)
}
}
- return 0;
+ return hyperv_init_ghcb();
}
static void (*hv_reenlightenment_cb)(void);
@@ -177,6 +208,14 @@ static int hv_cpu_die(unsigned int cpu)
{
struct hv_reenlightenment_control re_ctrl;
unsigned int new_cpu;
+ void **ghcb_va;
+
+ if (hv_ghcb_pg) {
+ ghcb_va = (void **)this_cpu_ptr(hv_ghcb_pg);
+ if (*ghcb_va)
+ memunmap(*ghcb_va);
+ *ghcb_va = NULL;
+ }
hv_common_cpu_die(cpu);
@@ -366,10 +405,16 @@ void __init hyperv_init(void)
goto common_free;
}
+ if (hv_isolation_type_snp()) {
+ hv_ghcb_pg = alloc_percpu(void *);
+ if (!hv_ghcb_pg)
+ goto free_vp_assist_page;
+ }
+
cpuhp = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/hyperv_init:online",
hv_cpu_init, hv_cpu_die);
if (cpuhp < 0)
- goto free_vp_assist_page;
+ goto free_ghcb_page;
/*
* Setup the hypercall page and enable hypercalls.
@@ -383,10 +428,8 @@ void __init hyperv_init(void)
VMALLOC_END, GFP_KERNEL, PAGE_KERNEL_ROX,
VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
__builtin_return_address(0));
- if (hv_hypercall_pg == NULL) {
- wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
- goto remove_cpuhp_state;
- }
+ if (hv_hypercall_pg == NULL)
+ goto clean_guest_os_id;
rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
hypercall_msr.enable = 1;
@@ -456,8 +499,11 @@ void __init hyperv_init(void)
hv_query_ext_cap(0);
return;
-remove_cpuhp_state:
+clean_guest_os_id:
+ wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
cpuhp_remove_state(cpuhp);
+free_ghcb_page:
+ free_percpu(hv_ghcb_pg);
free_vp_assist_page:
kfree(hv_vp_assist_page);
hv_vp_assist_page = NULL;
@@ -559,3 +605,11 @@ bool hv_is_isolation_supported(void)
{
return hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE;
}
+
+DEFINE_STATIC_KEY_FALSE(isolation_type_snp);
+
+bool hv_isolation_type_snp(void)
+{
+ return static_branch_unlikely(&isolation_type_snp);
+}
+EXPORT_SYMBOL_GPL(hv_isolation_type_snp);
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index adccbc209169..37739a277ac6 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -11,6 +11,8 @@
#include <asm/paravirt.h>
#include <asm/mshyperv.h>
+DECLARE_STATIC_KEY_FALSE(isolation_type_snp);
+
typedef int (*hyperv_fill_flush_list_func)(
struct hv_guest_mapping_flush_list *flush,
void *data);
@@ -39,6 +41,8 @@ extern void *hv_hypercall_pg;
extern u64 hv_current_partition_id;
+extern void __percpu **hv_ghcb_pg;
+
int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages);
int hv_call_add_logical_proc(int node, u32 lp_index, u32 acpi_id);
int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags);
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index e095c28d27ae..b09ade389040 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -316,6 +316,9 @@ static void __init ms_hyperv_init_platform(void)
pr_info("Hyper-V: Isolation Config: Group A 0x%x, Group B 0x%x\n",
ms_hyperv.isolation_config_a, ms_hyperv.isolation_config_b);
+
+ if (hv_get_isolation_type() == HV_ISOLATION_TYPE_SNP)
+ static_branch_enable(&isolation_type_snp);
}
if (hv_max_functions_eax >= HYPERV_CPUID_NESTED_FEATURES) {
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index d3eae6cdbacb..2d88aa855f7e 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -254,12 +254,18 @@ bool hv_is_hyperv_initialized(void);
bool hv_is_hibernation_supported(void);
enum hv_isolation_type hv_get_isolation_type(void);
bool hv_is_isolation_supported(void);
+bool hv_isolation_type_snp(void);
void hyperv_cleanup(void);
bool hv_query_ext_cap(u64 cap_query);
#else /* CONFIG_HYPERV */
static inline bool hv_is_hyperv_initialized(void) { return false; }
static inline bool hv_is_hibernation_supported(void) { return false; }
static inline void hyperv_cleanup(void) {}
+static inline bool hv_is_isolation_supported(void) { return false; }
+static inline enum hv_isolation_type hv_get_isolation_type(void)
+{
+ return HV_ISOLATION_TYPE_NONE;
+}
#endif /* CONFIG_HYPERV */
#endif
--
2.25.1
From: Tianyu Lan <[email protected]>
Add new hvcall guest address host visibility support to mark
memory visible to host. Call it inside set_memory_decrypted
/encrypted(). Add HYPERVISOR feature check in the
hv_is_isolation_supported() to optimize in non-virtualization
environment.
Acked-by: Dave Hansen <[email protected]>
Signed-off-by: Tianyu Lan <[email protected]>
---
Change since v6:
* Add hv_set_mem_host_visibility() when CONFIG_HYPERV is no.
Fix compile error.
* Add comment to describe __set_memory_enc_pgtable().
Change since v4:
* Fix typo in the comment
* Make hv_mark_gpa_visibility() to be a static function
* Merge __hv_set_mem_host_visibility() and hv_set_mem_host_visibility()
Change since v3:
* Fix error code handle in the __hv_set_mem_host_visibility().
* Move HvCallModifySparseGpaPageHostVisibility near to enum
hv_mem_host_visibility.
Change since v2:
* Rework __set_memory_enc_dec() and call Hyper-V and AMD function
according to platform check.
Change since v1:
* Use new staic call x86_set_memory_enc to avoid add Hyper-V
specific check in the set_memory code.
---
arch/x86/hyperv/Makefile | 2 +-
arch/x86/hyperv/hv_init.c | 6 ++
arch/x86/hyperv/ivm.c | 105 +++++++++++++++++++++++++++++
arch/x86/include/asm/hyperv-tlfs.h | 17 +++++
arch/x86/include/asm/mshyperv.h | 7 +-
arch/x86/mm/pat/set_memory.c | 23 +++++--
include/asm-generic/hyperv-tlfs.h | 1 +
7 files changed, 154 insertions(+), 7 deletions(-)
create mode 100644 arch/x86/hyperv/ivm.c
diff --git a/arch/x86/hyperv/Makefile b/arch/x86/hyperv/Makefile
index 48e2c51464e8..5d2de10809ae 100644
--- a/arch/x86/hyperv/Makefile
+++ b/arch/x86/hyperv/Makefile
@@ -1,5 +1,5 @@
# SPDX-License-Identifier: GPL-2.0-only
-obj-y := hv_init.o mmu.o nested.o irqdomain.o
+obj-y := hv_init.o mmu.o nested.o irqdomain.o ivm.o
obj-$(CONFIG_X86_64) += hv_apic.o hv_proc.o
ifdef CONFIG_X86_64
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index a7e922755ad1..d57df6825527 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -603,6 +603,12 @@ EXPORT_SYMBOL_GPL(hv_get_isolation_type);
bool hv_is_isolation_supported(void)
{
+ if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
+ return false;
+
+ if (!hypervisor_is_type(X86_HYPER_MS_HYPERV))
+ return false;
+
return hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE;
}
diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
new file mode 100644
index 000000000000..79e7fb83472a
--- /dev/null
+++ b/arch/x86/hyperv/ivm.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Hyper-V Isolation VM interface with paravisor and hypervisor
+ *
+ * Author:
+ * Tianyu Lan <[email protected]>
+ */
+
+#include <linux/hyperv.h>
+#include <linux/types.h>
+#include <linux/bitfield.h>
+#include <linux/slab.h>
+#include <asm/io.h>
+#include <asm/mshyperv.h>
+
+/*
+ * hv_mark_gpa_visibility - Set pages visible to host via hvcall.
+ *
+ * In Isolation VM, all guest memory is encrypted from host and guest
+ * needs to set memory visible to host via hvcall before sharing memory
+ * with host.
+ */
+static int hv_mark_gpa_visibility(u16 count, const u64 pfn[],
+ enum hv_mem_host_visibility visibility)
+{
+ struct hv_gpa_range_for_visibility **input_pcpu, *input;
+ u16 pages_processed;
+ u64 hv_status;
+ unsigned long flags;
+
+ /* no-op if partition isolation is not enabled */
+ if (!hv_is_isolation_supported())
+ return 0;
+
+ if (count > HV_MAX_MODIFY_GPA_REP_COUNT) {
+ pr_err("Hyper-V: GPA count:%d exceeds supported:%lu\n", count,
+ HV_MAX_MODIFY_GPA_REP_COUNT);
+ return -EINVAL;
+ }
+
+ local_irq_save(flags);
+ input_pcpu = (struct hv_gpa_range_for_visibility **)
+ this_cpu_ptr(hyperv_pcpu_input_arg);
+ input = *input_pcpu;
+ if (unlikely(!input)) {
+ local_irq_restore(flags);
+ return -EINVAL;
+ }
+
+ input->partition_id = HV_PARTITION_ID_SELF;
+ input->host_visibility = visibility;
+ input->reserved0 = 0;
+ input->reserved1 = 0;
+ memcpy((void *)input->gpa_page_list, pfn, count * sizeof(*pfn));
+ hv_status = hv_do_rep_hypercall(
+ HVCALL_MODIFY_SPARSE_GPA_PAGE_HOST_VISIBILITY, count,
+ 0, input, &pages_processed);
+ local_irq_restore(flags);
+
+ if (hv_result_success(hv_status))
+ return 0;
+ else
+ return -EFAULT;
+}
+
+/*
+ * hv_set_mem_host_visibility - Set specified memory visible to host.
+ *
+ * In Isolation VM, all guest memory is encrypted from host and guest
+ * needs to set memory visible to host via hvcall before sharing memory
+ * with host. This function works as wrap of hv_mark_gpa_visibility()
+ * with memory base and size.
+ */
+int hv_set_mem_host_visibility(unsigned long kbuffer, int pagecount, bool visible)
+{
+ enum hv_mem_host_visibility visibility = visible ?
+ VMBUS_PAGE_VISIBLE_READ_WRITE : VMBUS_PAGE_NOT_VISIBLE;
+ u64 *pfn_array;
+ int ret = 0;
+ int i, pfn;
+
+ if (!hv_is_isolation_supported() || !hv_hypercall_pg)
+ return 0;
+
+ pfn_array = kmalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
+ if (!pfn_array)
+ return -ENOMEM;
+
+ for (i = 0, pfn = 0; i < pagecount; i++) {
+ pfn_array[pfn] = virt_to_hvpfn((void *)kbuffer + i * HV_HYP_PAGE_SIZE);
+ pfn++;
+
+ if (pfn == HV_MAX_MODIFY_GPA_REP_COUNT || i == pagecount - 1) {
+ ret = hv_mark_gpa_visibility(pfn, pfn_array,
+ visibility);
+ if (ret)
+ goto err_free_pfn_array;
+ pfn = 0;
+ }
+ }
+
+ err_free_pfn_array:
+ kfree(pfn_array);
+ return ret;
+}
diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index 2322d6bd5883..381e88122a5f 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -276,6 +276,23 @@ enum hv_isolation_type {
#define HV_X64_MSR_TIME_REF_COUNT HV_REGISTER_TIME_REF_COUNT
#define HV_X64_MSR_REFERENCE_TSC HV_REGISTER_REFERENCE_TSC
+/* Hyper-V memory host visibility */
+enum hv_mem_host_visibility {
+ VMBUS_PAGE_NOT_VISIBLE = 0,
+ VMBUS_PAGE_VISIBLE_READ_ONLY = 1,
+ VMBUS_PAGE_VISIBLE_READ_WRITE = 3
+};
+
+/* HvCallModifySparseGpaPageHostVisibility hypercall */
+#define HV_MAX_MODIFY_GPA_REP_COUNT ((PAGE_SIZE / sizeof(u64)) - 2)
+struct hv_gpa_range_for_visibility {
+ u64 partition_id;
+ u32 host_visibility:2;
+ u32 reserved0:30;
+ u32 reserved1;
+ u64 gpa_page_list[HV_MAX_MODIFY_GPA_REP_COUNT];
+} __packed;
+
/*
* Declare the MSR used to setup pages used to communicate with the hypervisor.
*/
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 37739a277ac6..f3154ca41ac4 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -192,7 +192,7 @@ struct irq_domain *hv_create_pci_msi_domain(void);
int hv_map_ioapic_interrupt(int ioapic_id, bool level, int vcpu, int vector,
struct hv_interrupt_entry *entry);
int hv_unmap_ioapic_interrupt(int ioapic_id, struct hv_interrupt_entry *entry);
-
+int hv_set_mem_host_visibility(unsigned long addr, int numpages, bool visible);
#else /* CONFIG_HYPERV */
static inline void hyperv_init(void) {}
static inline void hyperv_setup_mmu_ops(void) {}
@@ -209,6 +209,11 @@ static inline int hyperv_flush_guest_mapping_range(u64 as,
{
return -1;
}
+static inline int hv_set_mem_host_visibility(unsigned long addr, int numpages,
+ bool visible)
+{
+ return -1;
+}
#endif /* CONFIG_HYPERV */
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index ad8a5c586a35..525f682ab150 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -29,6 +29,8 @@
#include <asm/proto.h>
#include <asm/memtype.h>
#include <asm/set_memory.h>
+#include <asm/hyperv-tlfs.h>
+#include <asm/mshyperv.h>
#include "../mm_internal.h"
@@ -1980,15 +1982,15 @@ int set_memory_global(unsigned long addr, int numpages)
__pgprot(_PAGE_GLOBAL), 0);
}
-static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
+/*
+ * __set_memory_enc_pgtable() is used for the hypervisors that get
+ * informed about "encryption" status via page tables.
+ */
+static int __set_memory_enc_pgtable(unsigned long addr, int numpages, bool enc)
{
struct cpa_data cpa;
int ret;
- /* Nothing to do if memory encryption is not active */
- if (!mem_encrypt_active())
- return 0;
-
/* Should not be working on unaligned addresses */
if (WARN_ONCE(addr & ~PAGE_MASK, "misaligned address: %#lx\n", addr))
addr &= PAGE_MASK;
@@ -2023,6 +2025,17 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
return ret;
}
+static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
+{
+ if (hv_is_isolation_supported())
+ return hv_set_mem_host_visibility(addr, numpages, !enc);
+
+ if (mem_encrypt_active())
+ return __set_memory_enc_pgtable(addr, numpages, enc);
+
+ return 0;
+}
+
int set_memory_encrypted(unsigned long addr, int numpages)
{
return __set_memory_enc_dec(addr, numpages, true);
diff --git a/include/asm-generic/hyperv-tlfs.h b/include/asm-generic/hyperv-tlfs.h
index 56348a541c50..8ed6733d5146 100644
--- a/include/asm-generic/hyperv-tlfs.h
+++ b/include/asm-generic/hyperv-tlfs.h
@@ -158,6 +158,7 @@ struct ms_hyperv_tsc_page {
#define HVCALL_RETARGET_INTERRUPT 0x007e
#define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE 0x00af
#define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_LIST 0x00b0
+#define HVCALL_MODIFY_SPARSE_GPA_PAGE_HOST_VISIBILITY 0x00db
/* Extended hypercalls */
#define HV_EXT_CALL_QUERY_CAPABILITIES 0x8001
--
2.25.1
From: Tianyu Lan <[email protected]>
Mark vmbus ring buffer visible with set_memory_decrypted() when
establish gpadl handle.
Signed-off-by: Tianyu Lan <[email protected]>
---
Change since v5:
* Replace HVPFN_UP() with PFN_UP() in the __vmbus_establish_gpadl()
* Remove unused variable gpadl in the __vmbus_open() and vmbus_close_
internal()
* Clean gpadl_handle in the vmbus_teardown_gpadl().
Change since v4
* Change gpadl handle in netvsc and uio driver from u32 to
struct vmbus_gpadl.
* Change vmbus_establish_gpadl()'s gpadl_handle parameter
to vmbus_gpadl data structure.
Change since v3:
* Change vmbus_teardown_gpadl() parameter and put gpadl handle,
buffer and buffer size in the struct vmbus_gpadl.
---
drivers/hv/channel.c | 53 +++++++++++++++++++++++----------
drivers/net/hyperv/hyperv_net.h | 5 ++--
drivers/net/hyperv/netvsc.c | 15 +++++-----
drivers/uio/uio_hv_generic.c | 18 +++++------
include/linux/hyperv.h | 12 ++++++--
5 files changed, 65 insertions(+), 38 deletions(-)
diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index f3761c73b074..b37ff4a39224 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -17,6 +17,7 @@
#include <linux/hyperv.h>
#include <linux/uio.h>
#include <linux/interrupt.h>
+#include <linux/set_memory.h>
#include <asm/page.h>
#include <asm/mshyperv.h>
@@ -456,7 +457,7 @@ static int create_gpadl_header(enum hv_gpadl_type type, void *kbuffer,
static int __vmbus_establish_gpadl(struct vmbus_channel *channel,
enum hv_gpadl_type type, void *kbuffer,
u32 size, u32 send_offset,
- u32 *gpadl_handle)
+ struct vmbus_gpadl *gpadl)
{
struct vmbus_channel_gpadl_header *gpadlmsg;
struct vmbus_channel_gpadl_body *gpadl_body;
@@ -474,6 +475,15 @@ static int __vmbus_establish_gpadl(struct vmbus_channel *channel,
if (ret)
return ret;
+ ret = set_memory_decrypted((unsigned long)kbuffer,
+ PFN_UP(size));
+ if (ret) {
+ dev_warn(&channel->device_obj->device,
+ "Failed to set host visibility for new GPADL %d.\n",
+ ret);
+ return ret;
+ }
+
init_completion(&msginfo->waitevent);
msginfo->waiting_channel = channel;
@@ -537,7 +547,10 @@ static int __vmbus_establish_gpadl(struct vmbus_channel *channel,
}
/* At this point, we received the gpadl created msg */
- *gpadl_handle = gpadlmsg->gpadl;
+ gpadl->gpadl_handle = gpadlmsg->gpadl;
+ gpadl->buffer = kbuffer;
+ gpadl->size = size;
+
cleanup:
spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
@@ -549,6 +562,11 @@ static int __vmbus_establish_gpadl(struct vmbus_channel *channel,
}
kfree(msginfo);
+
+ if (ret)
+ set_memory_encrypted((unsigned long)kbuffer,
+ PFN_UP(size));
+
return ret;
}
@@ -561,10 +579,10 @@ static int __vmbus_establish_gpadl(struct vmbus_channel *channel,
* @gpadl_handle: some funky thing
*/
int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
- u32 size, u32 *gpadl_handle)
+ u32 size, struct vmbus_gpadl *gpadl)
{
return __vmbus_establish_gpadl(channel, HV_GPADL_BUFFER, kbuffer, size,
- 0U, gpadl_handle);
+ 0U, gpadl);
}
EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
@@ -675,7 +693,7 @@ static int __vmbus_open(struct vmbus_channel *newchannel,
goto error_clean_ring;
/* Establish the gpadl for the ring buffer */
- newchannel->ringbuffer_gpadlhandle = 0;
+ newchannel->ringbuffer_gpadlhandle.gpadl_handle = 0;
err = __vmbus_establish_gpadl(newchannel, HV_GPADL_RING,
page_address(newchannel->ringbuffer_page),
@@ -701,7 +719,8 @@ static int __vmbus_open(struct vmbus_channel *newchannel,
open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
open_msg->openid = newchannel->offermsg.child_relid;
open_msg->child_relid = newchannel->offermsg.child_relid;
- open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
+ open_msg->ringbuffer_gpadlhandle
+ = newchannel->ringbuffer_gpadlhandle.gpadl_handle;
/*
* The unit of ->downstream_ringbuffer_pageoffset is HV_HYP_PAGE and
* the unit of ->ringbuffer_send_offset (i.e. send_pages) is PAGE, so
@@ -759,8 +778,7 @@ static int __vmbus_open(struct vmbus_channel *newchannel,
error_free_info:
kfree(open_info);
error_free_gpadl:
- vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
- newchannel->ringbuffer_gpadlhandle = 0;
+ vmbus_teardown_gpadl(newchannel, &newchannel->ringbuffer_gpadlhandle);
error_clean_ring:
hv_ringbuffer_cleanup(&newchannel->outbound);
hv_ringbuffer_cleanup(&newchannel->inbound);
@@ -806,7 +824,7 @@ EXPORT_SYMBOL_GPL(vmbus_open);
/*
* vmbus_teardown_gpadl -Teardown the specified GPADL handle
*/
-int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
+int vmbus_teardown_gpadl(struct vmbus_channel *channel, struct vmbus_gpadl *gpadl)
{
struct vmbus_channel_gpadl_teardown *msg;
struct vmbus_channel_msginfo *info;
@@ -825,7 +843,7 @@ int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
msg->child_relid = channel->offermsg.child_relid;
- msg->gpadl = gpadl_handle;
+ msg->gpadl = gpadl->gpadl_handle;
spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
list_add_tail(&info->msglistentry,
@@ -845,6 +863,8 @@ int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
wait_for_completion(&info->waitevent);
+ gpadl->gpadl_handle = 0;
+
post_msg_err:
/*
* If the channel has been rescinded;
@@ -859,6 +879,12 @@ int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
kfree(info);
+
+ ret = set_memory_encrypted((unsigned long)gpadl->buffer,
+ PFN_UP(gpadl->size));
+ if (ret)
+ pr_warn("Fail to set mem host visibility in GPADL teardown %d.\n", ret);
+
return ret;
}
EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
@@ -933,9 +959,8 @@ static int vmbus_close_internal(struct vmbus_channel *channel)
}
/* Tear down the gpadl for the channel's ring buffer */
- else if (channel->ringbuffer_gpadlhandle) {
- ret = vmbus_teardown_gpadl(channel,
- channel->ringbuffer_gpadlhandle);
+ else if (channel->ringbuffer_gpadlhandle.gpadl_handle) {
+ ret = vmbus_teardown_gpadl(channel, &channel->ringbuffer_gpadlhandle);
if (ret) {
pr_err("Close failed: teardown gpadl return %d\n", ret);
/*
@@ -943,8 +968,6 @@ static int vmbus_close_internal(struct vmbus_channel *channel)
* it is perhaps better to leak memory.
*/
}
-
- channel->ringbuffer_gpadlhandle = 0;
}
if (!ret)
diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index bc48855dff10..315278a7cf88 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -1075,14 +1075,15 @@ struct netvsc_device {
/* Receive buffer allocated by us but manages by NetVSP */
void *recv_buf;
u32 recv_buf_size; /* allocated bytes */
- u32 recv_buf_gpadl_handle;
+ struct vmbus_gpadl recv_buf_gpadl_handle;
u32 recv_section_cnt;
u32 recv_section_size;
u32 recv_completion_cnt;
/* Send buffer allocated by us */
void *send_buf;
- u32 send_buf_gpadl_handle;
+ u32 send_buf_size;
+ struct vmbus_gpadl send_buf_gpadl_handle;
u32 send_section_cnt;
u32 send_section_size;
unsigned long *send_section_map;
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 7bd935412853..396bc1c204e6 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -278,9 +278,9 @@ static void netvsc_teardown_recv_gpadl(struct hv_device *device,
{
int ret;
- if (net_device->recv_buf_gpadl_handle) {
+ if (net_device->recv_buf_gpadl_handle.gpadl_handle) {
ret = vmbus_teardown_gpadl(device->channel,
- net_device->recv_buf_gpadl_handle);
+ &net_device->recv_buf_gpadl_handle);
/* If we failed here, we might as well return and have a leak
* rather than continue and a bugchk
@@ -290,7 +290,6 @@ static void netvsc_teardown_recv_gpadl(struct hv_device *device,
"unable to teardown receive buffer's gpadl\n");
return;
}
- net_device->recv_buf_gpadl_handle = 0;
}
}
@@ -300,9 +299,9 @@ static void netvsc_teardown_send_gpadl(struct hv_device *device,
{
int ret;
- if (net_device->send_buf_gpadl_handle) {
+ if (net_device->send_buf_gpadl_handle.gpadl_handle) {
ret = vmbus_teardown_gpadl(device->channel,
- net_device->send_buf_gpadl_handle);
+ &net_device->send_buf_gpadl_handle);
/* If we failed here, we might as well return and have a leak
* rather than continue and a bugchk
@@ -312,7 +311,6 @@ static void netvsc_teardown_send_gpadl(struct hv_device *device,
"unable to teardown send buffer's gpadl\n");
return;
}
- net_device->send_buf_gpadl_handle = 0;
}
}
@@ -380,7 +378,7 @@ static int netvsc_init_buf(struct hv_device *device,
memset(init_packet, 0, sizeof(struct nvsp_message));
init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
init_packet->msg.v1_msg.send_recv_buf.
- gpadl_handle = net_device->recv_buf_gpadl_handle;
+ gpadl_handle = net_device->recv_buf_gpadl_handle.gpadl_handle;
init_packet->msg.v1_msg.
send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
@@ -463,6 +461,7 @@ static int netvsc_init_buf(struct hv_device *device,
ret = -ENOMEM;
goto cleanup;
}
+ net_device->send_buf_size = buf_size;
/* Establish the gpadl handle for this buffer on this
* channel. Note: This call uses the vmbus connection rather
@@ -482,7 +481,7 @@ static int netvsc_init_buf(struct hv_device *device,
memset(init_packet, 0, sizeof(struct nvsp_message));
init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;
init_packet->msg.v1_msg.send_send_buf.gpadl_handle =
- net_device->send_buf_gpadl_handle;
+ net_device->send_buf_gpadl_handle.gpadl_handle;
init_packet->msg.v1_msg.send_send_buf.id = NETVSC_SEND_BUFFER_ID;
trace_nvsp_send(ndev, init_packet);
diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
index 652fe2547587..c08a6cfd119f 100644
--- a/drivers/uio/uio_hv_generic.c
+++ b/drivers/uio/uio_hv_generic.c
@@ -58,11 +58,11 @@ struct hv_uio_private_data {
atomic_t refcnt;
void *recv_buf;
- u32 recv_gpadl;
+ struct vmbus_gpadl recv_gpadl;
char recv_name[32]; /* "recv_4294967295" */
void *send_buf;
- u32 send_gpadl;
+ struct vmbus_gpadl send_gpadl;
char send_name[32];
};
@@ -179,15 +179,13 @@ hv_uio_new_channel(struct vmbus_channel *new_sc)
static void
hv_uio_cleanup(struct hv_device *dev, struct hv_uio_private_data *pdata)
{
- if (pdata->send_gpadl) {
- vmbus_teardown_gpadl(dev->channel, pdata->send_gpadl);
- pdata->send_gpadl = 0;
+ if (pdata->send_gpadl.gpadl_handle) {
+ vmbus_teardown_gpadl(dev->channel, &pdata->send_gpadl);
vfree(pdata->send_buf);
}
- if (pdata->recv_gpadl) {
- vmbus_teardown_gpadl(dev->channel, pdata->recv_gpadl);
- pdata->recv_gpadl = 0;
+ if (pdata->recv_gpadl.gpadl_handle) {
+ vmbus_teardown_gpadl(dev->channel, &pdata->recv_gpadl);
vfree(pdata->recv_buf);
}
}
@@ -303,7 +301,7 @@ hv_uio_probe(struct hv_device *dev,
/* put Global Physical Address Label in name */
snprintf(pdata->recv_name, sizeof(pdata->recv_name),
- "recv:%u", pdata->recv_gpadl);
+ "recv:%u", pdata->recv_gpadl.gpadl_handle);
pdata->info.mem[RECV_BUF_MAP].name = pdata->recv_name;
pdata->info.mem[RECV_BUF_MAP].addr
= (uintptr_t)pdata->recv_buf;
@@ -324,7 +322,7 @@ hv_uio_probe(struct hv_device *dev,
}
snprintf(pdata->send_name, sizeof(pdata->send_name),
- "send:%u", pdata->send_gpadl);
+ "send:%u", pdata->send_gpadl.gpadl_handle);
pdata->info.mem[SEND_BUF_MAP].name = pdata->send_name;
pdata->info.mem[SEND_BUF_MAP].addr
= (uintptr_t)pdata->send_buf;
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index ddc8713ce57b..a9e0bc3b1511 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -803,6 +803,12 @@ struct vmbus_device {
#define VMBUS_DEFAULT_MAX_PKT_SIZE 4096
+struct vmbus_gpadl {
+ u32 gpadl_handle;
+ u32 size;
+ void *buffer;
+};
+
struct vmbus_channel {
struct list_head listentry;
@@ -822,7 +828,7 @@ struct vmbus_channel {
bool rescind_ref; /* got rescind msg, got channel reference */
struct completion rescind_event;
- u32 ringbuffer_gpadlhandle;
+ struct vmbus_gpadl ringbuffer_gpadlhandle;
/* Allocated memory for ring buffer */
struct page *ringbuffer_page;
@@ -1192,10 +1198,10 @@ extern int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
extern int vmbus_establish_gpadl(struct vmbus_channel *channel,
void *kbuffer,
u32 size,
- u32 *gpadl_handle);
+ struct vmbus_gpadl *gpadl);
extern int vmbus_teardown_gpadl(struct vmbus_channel *channel,
- u32 gpadl_handle);
+ struct vmbus_gpadl *gpadl);
void vmbus_reset_channel_cb(struct vmbus_channel *channel);
--
2.25.1
From: Tianyu Lan <[email protected]>
Hyper-V needs to call ghcb hv call to write/read MSR in Isolation VM.
So expose sev_es_ghcb_hv_call() to call it in the Hyper-V code.
Hyper-V Isolation VM is unenlightened guests and run a paravisor in the
VMPL0 for communicating and GHCB pages are being allocated and set up by
that paravisor. Linux gets ghcb page pa via MSR_AMD64_SEV_ES_GHCB
from paravisor and should not change it. Add set_ghcb_msr parameter for
sev_es_ghcb_hv_call() and not set ghcb page pa when it's false.
Signed-off-by: Tianyu Lan <[email protected]>
---
arch/x86/include/asm/sev.h | 12 ++++++++++++
arch/x86/kernel/sev-shared.c | 26 +++++++++++++++++---------
arch/x86/kernel/sev.c | 13 +++++++------
3 files changed, 36 insertions(+), 15 deletions(-)
diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index fa5cd05d3b5b..5b7f7e2b81f7 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -81,12 +81,24 @@ static __always_inline void sev_es_nmi_complete(void)
__sev_es_nmi_complete();
}
extern int __init sev_es_efi_map_ghcbs(pgd_t *pgd);
+extern enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
+ bool set_ghcb_msr,
+ struct es_em_ctxt *ctxt,
+ u64 exit_code, u64 exit_info_1,
+ u64 exit_info_2);
#else
static inline void sev_es_ist_enter(struct pt_regs *regs) { }
static inline void sev_es_ist_exit(void) { }
static inline int sev_es_setup_ap_jump_table(struct real_mode_header *rmh) { return 0; }
static inline void sev_es_nmi_complete(void) { }
static inline int sev_es_efi_map_ghcbs(pgd_t *pgd) { return 0; }
+static inline enum
+es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
+ bool set_ghcb_msr, u64 exit_code,
+ u64 exit_info_1, u64 exit_info_2)
+{
+ return ES_VMM_ERROR;
+}
#endif
#endif
diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c
index ea9abd69237e..368ed36971e3 100644
--- a/arch/x86/kernel/sev-shared.c
+++ b/arch/x86/kernel/sev-shared.c
@@ -124,10 +124,9 @@ static enum es_result verify_exception_info(struct ghcb *ghcb, struct es_em_ctxt
return ES_VMM_ERROR;
}
-static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
- struct es_em_ctxt *ctxt,
- u64 exit_code, u64 exit_info_1,
- u64 exit_info_2)
+enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb, bool set_ghcb_msr,
+ struct es_em_ctxt *ctxt, u64 exit_code,
+ u64 exit_info_1, u64 exit_info_2)
{
/* Fill in protocol and format specifiers */
ghcb->protocol_version = GHCB_PROTOCOL_MAX;
@@ -137,7 +136,15 @@ static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
ghcb_set_sw_exit_info_1(ghcb, exit_info_1);
ghcb_set_sw_exit_info_2(ghcb, exit_info_2);
- sev_es_wr_ghcb_msr(__pa(ghcb));
+ /*
+ * Hyper-V unenlightened guests use a paravisor for communicating and
+ * GHCB pages are being allocated and set up by that paravisor. Linux
+ * should not change ghcb page pa in such case and so add set_ghcb_msr
+ * parameter.
+ */
+ if (set_ghcb_msr)
+ sev_es_wr_ghcb_msr(__pa(ghcb));
+
VMGEXIT();
return verify_exception_info(ghcb, ctxt);
@@ -417,7 +424,7 @@ static enum es_result vc_handle_ioio(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
*/
sw_scratch = __pa(ghcb) + offsetof(struct ghcb, shared_buffer);
ghcb_set_sw_scratch(ghcb, sw_scratch);
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO,
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_IOIO,
exit_info_1, exit_info_2);
if (ret != ES_OK)
return ret;
@@ -459,7 +466,8 @@ static enum es_result vc_handle_ioio(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
ghcb_set_rax(ghcb, rax);
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO, exit_info_1, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt,
+ SVM_EXIT_IOIO, exit_info_1, 0);
if (ret != ES_OK)
return ret;
@@ -490,7 +498,7 @@ static enum es_result vc_handle_cpuid(struct ghcb *ghcb,
/* xgetbv will cause #GP - use reset value for xcr0 */
ghcb_set_xcr0(ghcb, 1);
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_CPUID, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_CPUID, 0, 0);
if (ret != ES_OK)
return ret;
@@ -515,7 +523,7 @@ static enum es_result vc_handle_rdtsc(struct ghcb *ghcb,
bool rdtscp = (exit_code == SVM_EXIT_RDTSCP);
enum es_result ret;
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, exit_code, 0, 0);
if (ret != ES_OK)
return ret;
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index a6895e440bc3..bb62a1d15d6c 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -648,7 +648,8 @@ static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
ghcb_set_rdx(ghcb, regs->dx);
}
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_MSR, exit_info_1, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_MSR,
+ exit_info_1, 0);
if ((ret == ES_OK) && (!exit_info_1)) {
regs->ax = ghcb->save.rax;
@@ -867,7 +868,7 @@ static enum es_result vc_do_mmio(struct ghcb *ghcb, struct es_em_ctxt *ctxt,
ghcb_set_sw_scratch(ghcb, ghcb_pa + offsetof(struct ghcb, shared_buffer));
- return sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, exit_info_1, exit_info_2);
+ return sev_es_ghcb_hv_call(ghcb, true, ctxt, exit_code, exit_info_1, exit_info_2);
}
static enum es_result vc_handle_mmio_twobyte_ops(struct ghcb *ghcb,
@@ -1117,7 +1118,7 @@ static enum es_result vc_handle_dr7_write(struct ghcb *ghcb,
/* Using a value of 0 for ExitInfo1 means RAX holds the value */
ghcb_set_rax(ghcb, val);
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WRITE_DR7, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_WRITE_DR7, 0, 0);
if (ret != ES_OK)
return ret;
@@ -1147,7 +1148,7 @@ static enum es_result vc_handle_dr7_read(struct ghcb *ghcb,
static enum es_result vc_handle_wbinvd(struct ghcb *ghcb,
struct es_em_ctxt *ctxt)
{
- return sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WBINVD, 0, 0);
+ return sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_WBINVD, 0, 0);
}
static enum es_result vc_handle_rdpmc(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
@@ -1156,7 +1157,7 @@ static enum es_result vc_handle_rdpmc(struct ghcb *ghcb, struct es_em_ctxt *ctxt
ghcb_set_rcx(ghcb, ctxt->regs->cx);
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_RDPMC, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_RDPMC, 0, 0);
if (ret != ES_OK)
return ret;
@@ -1197,7 +1198,7 @@ static enum es_result vc_handle_vmmcall(struct ghcb *ghcb,
if (x86_platform.hyper.sev_es_hcall_prepare)
x86_platform.hyper.sev_es_hcall_prepare(ghcb, ctxt->regs);
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_VMMCALL, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_VMMCALL, 0, 0);
if (ret != ES_OK)
return ret;
--
2.25.1
From: Tianyu Lan <[email protected]>
hyperv provides ghcb hvcall to handle VMBus
HVCALL_SIGNAL_EVENT and HVCALL_POST_MESSAGE
msg in SNP Isolation VM. Add such support.
Signed-off-by: Tianyu Lan <[email protected]>
---
Change since v3:
* Add hv_ghcb_hypercall() stub function to avoid
compile error for ARM.
---
arch/x86/hyperv/ivm.c | 74 ++++++++++++++++++++++++++++++++++
drivers/hv/connection.c | 6 ++-
drivers/hv/hv.c | 8 +++-
drivers/hv/hv_common.c | 6 +++
include/asm-generic/mshyperv.h | 1 +
5 files changed, 93 insertions(+), 2 deletions(-)
diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
index 925cbc3e7601..260fcba97914 100644
--- a/arch/x86/hyperv/ivm.c
+++ b/arch/x86/hyperv/ivm.c
@@ -18,10 +18,84 @@
#include <asm/mshyperv.h>
#include <asm/hypervisor.h>
+#define GHCB_USAGE_HYPERV_CALL 1
+
union hv_ghcb {
struct ghcb ghcb;
+ struct {
+ u64 hypercalldata[509];
+ u64 outputgpa;
+ union {
+ union {
+ struct {
+ u32 callcode : 16;
+ u32 isfast : 1;
+ u32 reserved1 : 14;
+ u32 isnested : 1;
+ u32 countofelements : 12;
+ u32 reserved2 : 4;
+ u32 repstartindex : 12;
+ u32 reserved3 : 4;
+ };
+ u64 asuint64;
+ } hypercallinput;
+ union {
+ struct {
+ u16 callstatus;
+ u16 reserved1;
+ u32 elementsprocessed : 12;
+ u32 reserved2 : 20;
+ };
+ u64 asunit64;
+ } hypercalloutput;
+ };
+ u64 reserved2;
+ } hypercall;
} __packed __aligned(HV_HYP_PAGE_SIZE);
+u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size)
+{
+ union hv_ghcb *hv_ghcb;
+ void **ghcb_base;
+ unsigned long flags;
+ u64 status;
+
+ if (!hv_ghcb_pg)
+ return -EFAULT;
+
+ WARN_ON(in_nmi());
+
+ local_irq_save(flags);
+ ghcb_base = (void **)this_cpu_ptr(hv_ghcb_pg);
+ hv_ghcb = (union hv_ghcb *)*ghcb_base;
+ if (!hv_ghcb) {
+ local_irq_restore(flags);
+ return -EFAULT;
+ }
+
+ hv_ghcb->ghcb.protocol_version = GHCB_PROTOCOL_MAX;
+ hv_ghcb->ghcb.ghcb_usage = GHCB_USAGE_HYPERV_CALL;
+
+ hv_ghcb->hypercall.outputgpa = (u64)output;
+ hv_ghcb->hypercall.hypercallinput.asuint64 = 0;
+ hv_ghcb->hypercall.hypercallinput.callcode = control;
+
+ if (input_size)
+ memcpy(hv_ghcb->hypercall.hypercalldata, input, input_size);
+
+ VMGEXIT();
+
+ hv_ghcb->ghcb.ghcb_usage = 0xffffffff;
+ memset(hv_ghcb->ghcb.save.valid_bitmap, 0,
+ sizeof(hv_ghcb->ghcb.save.valid_bitmap));
+
+ status = hv_ghcb->hypercall.hypercalloutput.callstatus;
+
+ local_irq_restore(flags);
+
+ return status;
+}
+
void hv_ghcb_msr_write(u64 msr, u64 value)
{
union hv_ghcb *hv_ghcb;
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 5e479d54918c..8820ae68f20f 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -447,6 +447,10 @@ void vmbus_set_event(struct vmbus_channel *channel)
++channel->sig_events;
- hv_do_fast_hypercall8(HVCALL_SIGNAL_EVENT, channel->sig_event);
+ if (hv_isolation_type_snp())
+ hv_ghcb_hypercall(HVCALL_SIGNAL_EVENT, &channel->sig_event,
+ NULL, sizeof(channel->sig_event));
+ else
+ hv_do_fast_hypercall8(HVCALL_SIGNAL_EVENT, channel->sig_event);
}
EXPORT_SYMBOL_GPL(vmbus_set_event);
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 943392db9e8a..4d6480d57546 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -98,7 +98,13 @@ int hv_post_message(union hv_connection_id connection_id,
aligned_msg->payload_size = payload_size;
memcpy((void *)aligned_msg->payload, payload, payload_size);
- status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL);
+ if (hv_isolation_type_snp())
+ status = hv_ghcb_hypercall(HVCALL_POST_MESSAGE,
+ (void *)aligned_msg, NULL,
+ sizeof(*aligned_msg));
+ else
+ status = hv_do_hypercall(HVCALL_POST_MESSAGE,
+ aligned_msg, NULL);
/* Preemption must remain disabled until after the hypercall
* so some other thread can't get scheduled onto this cpu and
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index 1fc82d237161..7be173a99f27 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -289,3 +289,9 @@ void __weak hyperv_cleanup(void)
{
}
EXPORT_SYMBOL_GPL(hyperv_cleanup);
+
+u64 __weak hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size)
+{
+ return HV_STATUS_INVALID_PARAMETER;
+}
+EXPORT_SYMBOL_GPL(hv_ghcb_hypercall);
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 6d3ba902ebb0..3e2248ac328e 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -266,6 +266,7 @@ bool hv_is_hibernation_supported(void);
enum hv_isolation_type hv_get_isolation_type(void);
bool hv_is_isolation_supported(void);
bool hv_isolation_type_snp(void);
+u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size);
void hyperv_cleanup(void);
bool hv_query_ext_cap(u64 cap_query);
#else /* CONFIG_HYPERV */
--
2.25.1
From: Tianyu Lan <[email protected]>
The monitor pages in the CHANNELMSG_INITIATE_CONTACT msg are shared
with host in Isolation VM and so it's necessary to use hvcall to set
them visible to host. In Isolation VM with AMD SEV SNP, the access
address should be in the extra space which is above shared gpa
boundary. So remap these pages into the extra address(pa +
shared_gpa_boundary).
Introduce monitor_pages_original[] in the struct vmbus_connection
to store monitor page virtual address returned by hv_alloc_hyperv_
zeroed_page() and free monitor page via monitor_pages_original in
the vmbus_disconnect(). The monitor_pages[] is to used to access
monitor page and it is initialized to be equal with monitor_pages_
original. The monitor_pages[] will be overridden in the isolation VM
with va of extra address. Introduce monitor_pages_pa[] to store
monitor pages' physical address and use it to populate pa in the
initiate msg.
Signed-off-by: Tianyu Lan <[email protected]>
---
Change since v6:
* Add comment about calling memunmap() in the non-snp IVM.
Change since v5:
* change vmbus_connection.monitor_pages_pa type from
unsigned long to phys_addr_t
* Plus vmbus_connection.monitor_pages_pa with ms_hyperv.
shared_gpa_boundary only in the IVM with AMD SEV.
Change since v4:
* Introduce monitor_pages_pa[] to store monitor pages' physical
address and use it to populate pa in the initiate msg.
* Move code of mapping moniter pages in extra address into
vmbus_connect().
Change since v3:
* Rename monitor_pages_va with monitor_pages_original
* free monitor page via monitor_pages_original and
monitor_pages is used to access monitor page.
Change since v1:
* Not remap monitor pages in the non-SNP isolation VM.
---
drivers/hv/connection.c | 95 ++++++++++++++++++++++++++++++++++++---
drivers/hv/hyperv_vmbus.h | 2 +
2 files changed, 91 insertions(+), 6 deletions(-)
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 8820ae68f20f..a3d8be8d6cfb 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -19,6 +19,8 @@
#include <linux/vmalloc.h>
#include <linux/hyperv.h>
#include <linux/export.h>
+#include <linux/io.h>
+#include <linux/set_memory.h>
#include <asm/mshyperv.h>
#include "hyperv_vmbus.h"
@@ -102,8 +104,9 @@ int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version)
vmbus_connection.msg_conn_id = VMBUS_MESSAGE_CONNECTION_ID;
}
- msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages[0]);
- msg->monitor_page2 = virt_to_phys(vmbus_connection.monitor_pages[1]);
+ msg->monitor_page1 = vmbus_connection.monitor_pages_pa[0];
+ msg->monitor_page2 = vmbus_connection.monitor_pages_pa[1];
+
msg->target_vcpu = hv_cpu_number_to_vp_number(VMBUS_CONNECT_CPU);
/*
@@ -216,6 +219,65 @@ int vmbus_connect(void)
goto cleanup;
}
+ vmbus_connection.monitor_pages_original[0]
+ = vmbus_connection.monitor_pages[0];
+ vmbus_connection.monitor_pages_original[1]
+ = vmbus_connection.monitor_pages[1];
+ vmbus_connection.monitor_pages_pa[0]
+ = virt_to_phys(vmbus_connection.monitor_pages[0]);
+ vmbus_connection.monitor_pages_pa[1]
+ = virt_to_phys(vmbus_connection.monitor_pages[1]);
+
+ if (hv_is_isolation_supported()) {
+ ret = set_memory_decrypted((unsigned long)
+ vmbus_connection.monitor_pages[0],
+ 1);
+ ret |= set_memory_decrypted((unsigned long)
+ vmbus_connection.monitor_pages[1],
+ 1);
+ if (ret)
+ goto cleanup;
+
+ /*
+ * Isolation VM with AMD SNP needs to access monitor page via
+ * address space above shared gpa boundary.
+ */
+ if (hv_isolation_type_snp()) {
+ vmbus_connection.monitor_pages_pa[0] +=
+ ms_hyperv.shared_gpa_boundary;
+ vmbus_connection.monitor_pages_pa[1] +=
+ ms_hyperv.shared_gpa_boundary;
+
+ vmbus_connection.monitor_pages[0]
+ = memremap(vmbus_connection.monitor_pages_pa[0],
+ HV_HYP_PAGE_SIZE,
+ MEMREMAP_WB);
+ if (!vmbus_connection.monitor_pages[0]) {
+ ret = -ENOMEM;
+ goto cleanup;
+ }
+
+ vmbus_connection.monitor_pages[1]
+ = memremap(vmbus_connection.monitor_pages_pa[1],
+ HV_HYP_PAGE_SIZE,
+ MEMREMAP_WB);
+ if (!vmbus_connection.monitor_pages[1]) {
+ ret = -ENOMEM;
+ goto cleanup;
+ }
+ }
+
+ /*
+ * Set memory host visibility hvcall smears memory
+ * and so zero monitor pages here.
+ */
+ memset(vmbus_connection.monitor_pages[0], 0x00,
+ HV_HYP_PAGE_SIZE);
+ memset(vmbus_connection.monitor_pages[1], 0x00,
+ HV_HYP_PAGE_SIZE);
+
+ }
+
msginfo = kzalloc(sizeof(*msginfo) +
sizeof(struct vmbus_channel_initiate_contact),
GFP_KERNEL);
@@ -303,10 +365,31 @@ void vmbus_disconnect(void)
vmbus_connection.int_page = NULL;
}
- hv_free_hyperv_page((unsigned long)vmbus_connection.monitor_pages[0]);
- hv_free_hyperv_page((unsigned long)vmbus_connection.monitor_pages[1]);
- vmbus_connection.monitor_pages[0] = NULL;
- vmbus_connection.monitor_pages[1] = NULL;
+ if (hv_is_isolation_supported()) {
+ /*
+ * memunmap() checks input address is ioremap address or not
+ * inside. It doesn't unmap any thing in the non-SNP CVM and
+ * so not check CVM type here.
+ */
+ memunmap(vmbus_connection.monitor_pages[0]);
+ memunmap(vmbus_connection.monitor_pages[1]);
+
+ set_memory_encrypted((unsigned long)
+ vmbus_connection.monitor_pages_original[0],
+ 1);
+ set_memory_encrypted((unsigned long)
+ vmbus_connection.monitor_pages_original[1],
+ 1);
+ }
+
+ hv_free_hyperv_page((unsigned long)
+ vmbus_connection.monitor_pages_original[0]);
+ hv_free_hyperv_page((unsigned long)
+ vmbus_connection.monitor_pages_original[1]);
+ vmbus_connection.monitor_pages_original[0] =
+ vmbus_connection.monitor_pages[0] = NULL;
+ vmbus_connection.monitor_pages_original[1] =
+ vmbus_connection.monitor_pages[1] = NULL;
}
/*
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 42f3d9d123a1..d0a5232a1c3e 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -240,6 +240,8 @@ struct vmbus_connection {
* is child->parent notification
*/
struct hv_monitor_page *monitor_pages[2];
+ void *monitor_pages_original[2];
+ phys_addr_t monitor_pages_pa[2];
struct list_head chn_msg_list;
spinlock_t channelmsg_lock;
--
2.25.1
From: Tianyu Lan <[email protected]>
Hyper-V exposes shared memory boundary via cpuid
HYPERV_CPUID_ISOLATION_CONFIG and store it in the
shared_gpa_boundary of ms_hyperv struct. This prepares
to share memory with host for SNP guest.
Signed-off-by: Tianyu Lan <[email protected]>
---
Change since v4:
* Rename reserve field.
Change since v3:
* user BIT_ULL to get shared_gpa_boundary
* Rename field Reserved* to reserved
---
arch/x86/kernel/cpu/mshyperv.c | 2 ++
include/asm-generic/mshyperv.h | 12 +++++++++++-
2 files changed, 13 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index b09ade389040..4794b716ec79 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -313,6 +313,8 @@ static void __init ms_hyperv_init_platform(void)
if (ms_hyperv.priv_high & HV_ISOLATION) {
ms_hyperv.isolation_config_a = cpuid_eax(HYPERV_CPUID_ISOLATION_CONFIG);
ms_hyperv.isolation_config_b = cpuid_ebx(HYPERV_CPUID_ISOLATION_CONFIG);
+ ms_hyperv.shared_gpa_boundary =
+ BIT_ULL(ms_hyperv.shared_gpa_boundary_bits);
pr_info("Hyper-V: Isolation Config: Group A 0x%x, Group B 0x%x\n",
ms_hyperv.isolation_config_a, ms_hyperv.isolation_config_b);
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 2d88aa855f7e..a8ac497167d2 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -35,7 +35,17 @@ struct ms_hyperv_info {
u32 max_vp_index;
u32 max_lp_index;
u32 isolation_config_a;
- u32 isolation_config_b;
+ union {
+ u32 isolation_config_b;
+ struct {
+ u32 cvm_type : 4;
+ u32 reserved1 : 1;
+ u32 shared_gpa_boundary_active : 1;
+ u32 shared_gpa_boundary_bits : 6;
+ u32 reserved2 : 20;
+ };
+ };
+ u64 shared_gpa_boundary;
};
extern struct ms_hyperv_info ms_hyperv;
--
2.25.1
From: Tianyu Lan <[email protected]>
VMbus ring buffer are shared with host and it's need to
be accessed via extra address space of Isolation VM with
AMD SNP support. This patch is to map the ring buffer
address in extra address space via vmap_pfn(). Hyperv set
memory host visibility hvcall smears data in the ring buffer
and so reset the ring buffer memory to zero after mapping.
Signed-off-by: Tianyu Lan <[email protected]>
---
Change since v4:
* Use PFN_DOWN instead of HVPFN_DOWN in the hv_ringbuffer_init()
Change since v3:
* Remove hv_ringbuffer_post_init(), merge map
operation for Isolation VM into hv_ringbuffer_init()
* Call hv_ringbuffer_init() after __vmbus_establish_gpadl().
---
drivers/hv/Kconfig | 1 +
drivers/hv/channel.c | 19 +++++++-------
drivers/hv/ring_buffer.c | 55 ++++++++++++++++++++++++++++++----------
3 files changed, 53 insertions(+), 22 deletions(-)
diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
index d1123ceb38f3..dd12af20e467 100644
--- a/drivers/hv/Kconfig
+++ b/drivers/hv/Kconfig
@@ -8,6 +8,7 @@ config HYPERV
|| (ARM64 && !CPU_BIG_ENDIAN))
select PARAVIRT
select X86_HV_CALLBACK_VECTOR if X86
+ select VMAP_PFN
help
Select this option to run Linux as a Hyper-V client operating
system.
diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index b37ff4a39224..dc5c35210c16 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -683,15 +683,6 @@ static int __vmbus_open(struct vmbus_channel *newchannel,
if (!newchannel->max_pkt_size)
newchannel->max_pkt_size = VMBUS_DEFAULT_MAX_PKT_SIZE;
- err = hv_ringbuffer_init(&newchannel->outbound, page, send_pages, 0);
- if (err)
- goto error_clean_ring;
-
- err = hv_ringbuffer_init(&newchannel->inbound, &page[send_pages],
- recv_pages, newchannel->max_pkt_size);
- if (err)
- goto error_clean_ring;
-
/* Establish the gpadl for the ring buffer */
newchannel->ringbuffer_gpadlhandle.gpadl_handle = 0;
@@ -703,6 +694,16 @@ static int __vmbus_open(struct vmbus_channel *newchannel,
if (err)
goto error_clean_ring;
+ err = hv_ringbuffer_init(&newchannel->outbound,
+ page, send_pages, 0);
+ if (err)
+ goto error_free_gpadl;
+
+ err = hv_ringbuffer_init(&newchannel->inbound, &page[send_pages],
+ recv_pages, newchannel->max_pkt_size);
+ if (err)
+ goto error_free_gpadl;
+
/* Create and init the channel open message */
open_info = kzalloc(sizeof(*open_info) +
sizeof(struct vmbus_channel_open_channel),
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index 314015d9e912..931802ae985c 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -17,6 +17,8 @@
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/prefetch.h>
+#include <linux/io.h>
+#include <asm/mshyperv.h>
#include "hyperv_vmbus.h"
@@ -183,8 +185,10 @@ void hv_ringbuffer_pre_init(struct vmbus_channel *channel)
int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
struct page *pages, u32 page_cnt, u32 max_pkt_size)
{
- int i;
struct page **pages_wraparound;
+ unsigned long *pfns_wraparound;
+ u64 pfn;
+ int i;
BUILD_BUG_ON((sizeof(struct hv_ring_buffer) != PAGE_SIZE));
@@ -192,23 +196,48 @@ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
* First page holds struct hv_ring_buffer, do wraparound mapping for
* the rest.
*/
- pages_wraparound = kcalloc(page_cnt * 2 - 1, sizeof(struct page *),
- GFP_KERNEL);
- if (!pages_wraparound)
- return -ENOMEM;
+ if (hv_isolation_type_snp()) {
+ pfn = page_to_pfn(pages) +
+ PFN_DOWN(ms_hyperv.shared_gpa_boundary);
+
+ pfns_wraparound = kcalloc(page_cnt * 2 - 1,
+ sizeof(unsigned long), GFP_KERNEL);
+ if (!pfns_wraparound)
+ return -ENOMEM;
+
+ pfns_wraparound[0] = pfn;
+ for (i = 0; i < 2 * (page_cnt - 1); i++)
+ pfns_wraparound[i + 1] = pfn + i % (page_cnt - 1) + 1;
- pages_wraparound[0] = pages;
- for (i = 0; i < 2 * (page_cnt - 1); i++)
- pages_wraparound[i + 1] = &pages[i % (page_cnt - 1) + 1];
+ ring_info->ring_buffer = (struct hv_ring_buffer *)
+ vmap_pfn(pfns_wraparound, page_cnt * 2 - 1,
+ PAGE_KERNEL);
+ kfree(pfns_wraparound);
- ring_info->ring_buffer = (struct hv_ring_buffer *)
- vmap(pages_wraparound, page_cnt * 2 - 1, VM_MAP, PAGE_KERNEL);
+ if (!ring_info->ring_buffer)
+ return -ENOMEM;
+
+ /* Zero ring buffer after setting memory host visibility. */
+ memset(ring_info->ring_buffer, 0x00, PAGE_SIZE * page_cnt);
+ } else {
+ pages_wraparound = kcalloc(page_cnt * 2 - 1,
+ sizeof(struct page *),
+ GFP_KERNEL);
+
+ pages_wraparound[0] = pages;
+ for (i = 0; i < 2 * (page_cnt - 1); i++)
+ pages_wraparound[i + 1] =
+ &pages[i % (page_cnt - 1) + 1];
- kfree(pages_wraparound);
+ ring_info->ring_buffer = (struct hv_ring_buffer *)
+ vmap(pages_wraparound, page_cnt * 2 - 1, VM_MAP,
+ PAGE_KERNEL);
+ kfree(pages_wraparound);
+ if (!ring_info->ring_buffer)
+ return -ENOMEM;
+ }
- if (!ring_info->ring_buffer)
- return -ENOMEM;
ring_info->ring_buffer->read_index =
ring_info->ring_buffer->write_index = 0;
--
2.25.1
From: Tianyu Lan <[email protected]>
Hyperv provides GHCB protocol to write Synthetic Interrupt
Controller MSR registers in Isolation VM with AMD SEV SNP
and these registers are emulated by hypervisor directly.
Hyperv requires to write SINTx MSR registers twice. First
writes MSR via GHCB page to communicate with hypervisor
and then writes wrmsr instruction to talk with paravisor
which runs in VMPL0. Guest OS ID MSR also needs to be set
via GHCB page.
Signed-off-by: Tianyu Lan <[email protected]>
---
Change since v6:
* Spilt sev-es code into separate patch
* Add hv_get/set_register() dummy function under CONFIG_HYPERV
is not selected to fix compile error.
Change since v5:
* Adjust change layout in the asm/mshyperv.h
to make hv_is_synic_reg(), hv_get_register()
and hv_set_register() ahead of the #include
of asm-generic/mshyperv.h
* Remove Spurious blank line
Change since v4:
* Remove hv_get_simp(), hv_get_siefp() hv_get_synint_*()
helper function. Move the logic into hv_get/set_register().
Change since v3:
* Pass old_msg_type to hv_signal_eom() as parameter.
* Use HV_REGISTER_* marcro instead of HV_X64_MSR_*
* Add hv_isolation_type_snp() weak function.
* Add maros to set syinc register in ARM code.
Change since v1:
* Introduce sev_es_ghcb_hv_call_simple() and share code
between SEV and Hyper-V code.
---
arch/x86/hyperv/hv_init.c | 36 +++--------
arch/x86/hyperv/ivm.c | 107 ++++++++++++++++++++++++++++++++
arch/x86/include/asm/mshyperv.h | 57 ++++++++++++-----
drivers/hv/hv.c | 74 +++++++++++++++++-----
drivers/hv/hv_common.c | 6 ++
include/asm-generic/mshyperv.h | 1 +
6 files changed, 222 insertions(+), 59 deletions(-)
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index d57df6825527..a16a83e46a30 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -37,7 +37,7 @@ EXPORT_SYMBOL_GPL(hv_current_partition_id);
void *hv_hypercall_pg;
EXPORT_SYMBOL_GPL(hv_hypercall_pg);
-void __percpu **hv_ghcb_pg;
+union hv_ghcb __percpu **hv_ghcb_pg;
/* Storage to save the hypercall page temporarily for hibernation */
static void *hv_hypercall_pg_saved;
@@ -406,7 +406,7 @@ void __init hyperv_init(void)
}
if (hv_isolation_type_snp()) {
- hv_ghcb_pg = alloc_percpu(void *);
+ hv_ghcb_pg = alloc_percpu(union hv_ghcb *);
if (!hv_ghcb_pg)
goto free_vp_assist_page;
}
@@ -424,6 +424,9 @@ void __init hyperv_init(void)
guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0);
wrmsrl(HV_X64_MSR_GUEST_OS_ID, guest_id);
+ /* Hyper-V requires to write guest os id via ghcb in SNP IVM. */
+ hv_ghcb_msr_write(HV_X64_MSR_GUEST_OS_ID, guest_id);
+
hv_hypercall_pg = __vmalloc_node_range(PAGE_SIZE, 1, VMALLOC_START,
VMALLOC_END, GFP_KERNEL, PAGE_KERNEL_ROX,
VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
@@ -501,6 +504,7 @@ void __init hyperv_init(void)
clean_guest_os_id:
wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
+ hv_ghcb_msr_write(HV_X64_MSR_GUEST_OS_ID, 0);
cpuhp_remove_state(cpuhp);
free_ghcb_page:
free_percpu(hv_ghcb_pg);
@@ -522,6 +526,7 @@ void hyperv_cleanup(void)
/* Reset our OS id */
wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
+ hv_ghcb_msr_write(HV_X64_MSR_GUEST_OS_ID, 0);
/*
* Reset hypercall page reference before reset the page,
@@ -592,30 +597,3 @@ bool hv_is_hyperv_initialized(void)
return hypercall_msr.enable;
}
EXPORT_SYMBOL_GPL(hv_is_hyperv_initialized);
-
-enum hv_isolation_type hv_get_isolation_type(void)
-{
- if (!(ms_hyperv.priv_high & HV_ISOLATION))
- return HV_ISOLATION_TYPE_NONE;
- return FIELD_GET(HV_ISOLATION_TYPE, ms_hyperv.isolation_config_b);
-}
-EXPORT_SYMBOL_GPL(hv_get_isolation_type);
-
-bool hv_is_isolation_supported(void)
-{
- if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
- return false;
-
- if (!hypervisor_is_type(X86_HYPER_MS_HYPERV))
- return false;
-
- return hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE;
-}
-
-DEFINE_STATIC_KEY_FALSE(isolation_type_snp);
-
-bool hv_isolation_type_snp(void)
-{
- return static_branch_unlikely(&isolation_type_snp);
-}
-EXPORT_SYMBOL_GPL(hv_isolation_type_snp);
diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
index 79e7fb83472a..925cbc3e7601 100644
--- a/arch/x86/hyperv/ivm.c
+++ b/arch/x86/hyperv/ivm.c
@@ -6,12 +6,119 @@
* Tianyu Lan <[email protected]>
*/
+#include <linux/types.h>
+#include <linux/bitfield.h>
#include <linux/hyperv.h>
#include <linux/types.h>
#include <linux/bitfield.h>
#include <linux/slab.h>
+#include <asm/svm.h>
+#include <asm/sev.h>
#include <asm/io.h>
#include <asm/mshyperv.h>
+#include <asm/hypervisor.h>
+
+union hv_ghcb {
+ struct ghcb ghcb;
+} __packed __aligned(HV_HYP_PAGE_SIZE);
+
+void hv_ghcb_msr_write(u64 msr, u64 value)
+{
+ union hv_ghcb *hv_ghcb;
+ void **ghcb_base;
+ unsigned long flags;
+ struct es_em_ctxt ctxt;
+
+ if (!hv_ghcb_pg)
+ return;
+
+ WARN_ON(in_nmi());
+
+ local_irq_save(flags);
+ ghcb_base = (void **)this_cpu_ptr(hv_ghcb_pg);
+ hv_ghcb = (union hv_ghcb *)*ghcb_base;
+ if (!hv_ghcb) {
+ local_irq_restore(flags);
+ return;
+ }
+
+ ghcb_set_rcx(&hv_ghcb->ghcb, msr);
+ ghcb_set_rax(&hv_ghcb->ghcb, lower_32_bits(value));
+ ghcb_set_rdx(&hv_ghcb->ghcb, upper_32_bits(value));
+
+ if (sev_es_ghcb_hv_call(&hv_ghcb->ghcb, false, &ctxt,
+ SVM_EXIT_MSR, 1, 0))
+ pr_warn("Fail to write msr via ghcb %llx.\n", msr);
+
+ local_irq_restore(flags);
+}
+
+void hv_ghcb_msr_read(u64 msr, u64 *value)
+{
+ union hv_ghcb *hv_ghcb;
+ void **ghcb_base;
+ unsigned long flags;
+ struct es_em_ctxt ctxt;
+
+ /* Check size of union hv_ghcb here. */
+ BUILD_BUG_ON(sizeof(union hv_ghcb) != HV_HYP_PAGE_SIZE);
+
+ if (!hv_ghcb_pg)
+ return;
+
+ WARN_ON(in_nmi());
+
+ local_irq_save(flags);
+ ghcb_base = (void **)this_cpu_ptr(hv_ghcb_pg);
+ hv_ghcb = (union hv_ghcb *)*ghcb_base;
+ if (!hv_ghcb) {
+ local_irq_restore(flags);
+ return;
+ }
+
+ ghcb_set_rcx(&hv_ghcb->ghcb, msr);
+ if (sev_es_ghcb_hv_call(&hv_ghcb->ghcb, false, &ctxt,
+ SVM_EXIT_MSR, 0, 0))
+ pr_warn("Fail to read msr via ghcb %llx.\n", msr);
+ else
+ *value = (u64)lower_32_bits(hv_ghcb->ghcb.save.rax)
+ | ((u64)lower_32_bits(hv_ghcb->ghcb.save.rdx) << 32);
+ local_irq_restore(flags);
+}
+
+enum hv_isolation_type hv_get_isolation_type(void)
+{
+ if (!(ms_hyperv.priv_high & HV_ISOLATION))
+ return HV_ISOLATION_TYPE_NONE;
+ return FIELD_GET(HV_ISOLATION_TYPE, ms_hyperv.isolation_config_b);
+}
+EXPORT_SYMBOL_GPL(hv_get_isolation_type);
+
+/*
+ * hv_is_isolation_supported - Check system runs in the Hyper-V
+ * isolation VM.
+ */
+bool hv_is_isolation_supported(void)
+{
+ if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
+ return false;
+
+ if (!hypervisor_is_type(X86_HYPER_MS_HYPERV))
+ return false;
+
+ return hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE;
+}
+
+DEFINE_STATIC_KEY_FALSE(isolation_type_snp);
+
+/*
+ * hv_isolation_type_snp - Check system runs in the AMD SEV-SNP based
+ * isolation VM.
+ */
+bool hv_isolation_type_snp(void)
+{
+ return static_branch_unlikely(&isolation_type_snp);
+}
/*
* hv_mark_gpa_visibility - Set pages visible to host via hvcall.
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index f3154ca41ac4..eb1ba33da113 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -11,25 +11,14 @@
#include <asm/paravirt.h>
#include <asm/mshyperv.h>
+union hv_ghcb;
+
DECLARE_STATIC_KEY_FALSE(isolation_type_snp);
typedef int (*hyperv_fill_flush_list_func)(
struct hv_guest_mapping_flush_list *flush,
void *data);
-static inline void hv_set_register(unsigned int reg, u64 value)
-{
- wrmsrl(reg, value);
-}
-
-static inline u64 hv_get_register(unsigned int reg)
-{
- u64 value;
-
- rdmsrl(reg, value);
- return value;
-}
-
#define hv_get_raw_timer() rdtsc_ordered()
void hyperv_vector_handler(struct pt_regs *regs);
@@ -41,7 +30,7 @@ extern void *hv_hypercall_pg;
extern u64 hv_current_partition_id;
-extern void __percpu **hv_ghcb_pg;
+extern union hv_ghcb __percpu **hv_ghcb_pg;
int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages);
int hv_call_add_logical_proc(int node, u32 lp_index, u32 acpi_id);
@@ -193,6 +182,44 @@ int hv_map_ioapic_interrupt(int ioapic_id, bool level, int vcpu, int vector,
struct hv_interrupt_entry *entry);
int hv_unmap_ioapic_interrupt(int ioapic_id, struct hv_interrupt_entry *entry);
int hv_set_mem_host_visibility(unsigned long addr, int numpages, bool visible);
+void hv_ghcb_msr_write(u64 msr, u64 value);
+void hv_ghcb_msr_read(u64 msr, u64 *value);
+
+extern bool hv_isolation_type_snp(void);
+
+static inline bool hv_is_synic_reg(unsigned int reg)
+{
+ if ((reg >= HV_REGISTER_SCONTROL) &&
+ (reg <= HV_REGISTER_SINT15))
+ return true;
+ return false;
+}
+
+static inline u64 hv_get_register(unsigned int reg)
+{
+ u64 value;
+
+ if (hv_is_synic_reg(reg) && hv_isolation_type_snp())
+ hv_ghcb_msr_read(reg, &value);
+ else
+ rdmsrl(reg, value);
+ return value;
+}
+
+static inline void hv_set_register(unsigned int reg, u64 value)
+{
+ if (hv_is_synic_reg(reg) && hv_isolation_type_snp()) {
+ hv_ghcb_msr_write(reg, value);
+
+ /* Write proxy bit via wrmsl instruction */
+ if (reg >= HV_REGISTER_SINT0 &&
+ reg <= HV_REGISTER_SINT15)
+ wrmsrl(reg, value | 1 << 20);
+ } else {
+ wrmsrl(reg, value);
+ }
+}
+
#else /* CONFIG_HYPERV */
static inline void hyperv_init(void) {}
static inline void hyperv_setup_mmu_ops(void) {}
@@ -209,6 +236,8 @@ static inline int hyperv_flush_guest_mapping_range(u64 as,
{
return -1;
}
+static inline void hv_set_register(unsigned int reg, u64 value) { }
+static inline u64 hv_get_register(unsigned int reg) { return 0; }
static inline int hv_set_mem_host_visibility(unsigned long addr, int numpages,
bool visible)
{
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index e83507f49676..943392db9e8a 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -8,6 +8,7 @@
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/slab.h>
@@ -136,17 +137,24 @@ int hv_synic_alloc(void)
tasklet_init(&hv_cpu->msg_dpc,
vmbus_on_msg_dpc, (unsigned long) hv_cpu);
- hv_cpu->synic_message_page =
- (void *)get_zeroed_page(GFP_ATOMIC);
- if (hv_cpu->synic_message_page == NULL) {
- pr_err("Unable to allocate SYNIC message page\n");
- goto err;
- }
+ /*
+ * Synic message and event pages are allocated by paravisor.
+ * Skip these pages allocation here.
+ */
+ if (!hv_isolation_type_snp()) {
+ hv_cpu->synic_message_page =
+ (void *)get_zeroed_page(GFP_ATOMIC);
+ if (hv_cpu->synic_message_page == NULL) {
+ pr_err("Unable to allocate SYNIC message page\n");
+ goto err;
+ }
- hv_cpu->synic_event_page = (void *)get_zeroed_page(GFP_ATOMIC);
- if (hv_cpu->synic_event_page == NULL) {
- pr_err("Unable to allocate SYNIC event page\n");
- goto err;
+ hv_cpu->synic_event_page =
+ (void *)get_zeroed_page(GFP_ATOMIC);
+ if (hv_cpu->synic_event_page == NULL) {
+ pr_err("Unable to allocate SYNIC event page\n");
+ goto err;
+ }
}
hv_cpu->post_msg_page = (void *)get_zeroed_page(GFP_ATOMIC);
@@ -201,16 +209,35 @@ void hv_synic_enable_regs(unsigned int cpu)
/* Setup the Synic's message page */
simp.as_uint64 = hv_get_register(HV_REGISTER_SIMP);
simp.simp_enabled = 1;
- simp.base_simp_gpa = virt_to_phys(hv_cpu->synic_message_page)
- >> HV_HYP_PAGE_SHIFT;
+
+ if (hv_isolation_type_snp()) {
+ hv_cpu->synic_message_page
+ = memremap(simp.base_simp_gpa << HV_HYP_PAGE_SHIFT,
+ HV_HYP_PAGE_SIZE, MEMREMAP_WB);
+ if (!hv_cpu->synic_message_page)
+ pr_err("Fail to map syinc message page.\n");
+ } else {
+ simp.base_simp_gpa = virt_to_phys(hv_cpu->synic_message_page)
+ >> HV_HYP_PAGE_SHIFT;
+ }
hv_set_register(HV_REGISTER_SIMP, simp.as_uint64);
/* Setup the Synic's event page */
siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP);
siefp.siefp_enabled = 1;
- siefp.base_siefp_gpa = virt_to_phys(hv_cpu->synic_event_page)
- >> HV_HYP_PAGE_SHIFT;
+
+ if (hv_isolation_type_snp()) {
+ hv_cpu->synic_event_page =
+ memremap(siefp.base_siefp_gpa << HV_HYP_PAGE_SHIFT,
+ HV_HYP_PAGE_SIZE, MEMREMAP_WB);
+
+ if (!hv_cpu->synic_event_page)
+ pr_err("Fail to map syinc event page.\n");
+ } else {
+ siefp.base_siefp_gpa = virt_to_phys(hv_cpu->synic_event_page)
+ >> HV_HYP_PAGE_SHIFT;
+ }
hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64);
@@ -257,6 +284,8 @@ int hv_synic_init(unsigned int cpu)
*/
void hv_synic_disable_regs(unsigned int cpu)
{
+ struct hv_per_cpu_context *hv_cpu
+ = per_cpu_ptr(hv_context.cpu_context, cpu);
union hv_synic_sint shared_sint;
union hv_synic_simp simp;
union hv_synic_siefp siefp;
@@ -273,14 +302,27 @@ void hv_synic_disable_regs(unsigned int cpu)
shared_sint.as_uint64);
simp.as_uint64 = hv_get_register(HV_REGISTER_SIMP);
+ /*
+ * In Isolation VM, sim and sief pages are allocated by
+ * paravisor. These pages also will be used by kdump
+ * kernel. So just reset enable bit here and keep page
+ * addresses.
+ */
simp.simp_enabled = 0;
- simp.base_simp_gpa = 0;
+ if (hv_isolation_type_snp())
+ memunmap(hv_cpu->synic_message_page);
+ else
+ simp.base_simp_gpa = 0;
hv_set_register(HV_REGISTER_SIMP, simp.as_uint64);
siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP);
siefp.siefp_enabled = 0;
- siefp.base_siefp_gpa = 0;
+
+ if (hv_isolation_type_snp())
+ memunmap(hv_cpu->synic_event_page);
+ else
+ siefp.base_siefp_gpa = 0;
hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64);
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index c0d9048a4112..1fc82d237161 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -249,6 +249,12 @@ bool __weak hv_is_isolation_supported(void)
}
EXPORT_SYMBOL_GPL(hv_is_isolation_supported);
+bool __weak hv_isolation_type_snp(void)
+{
+ return false;
+}
+EXPORT_SYMBOL_GPL(hv_isolation_type_snp);
+
void __weak hv_setup_vmbus_handler(void (*handler)(void))
{
}
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index a8ac497167d2..6d3ba902ebb0 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -54,6 +54,7 @@ extern void __percpu **hyperv_pcpu_output_arg;
extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);
+extern bool hv_isolation_type_snp(void);
/* Helper functions that provide a consistent pattern for checking Hyper-V hypercall status. */
static inline int hv_result(u64 status)
--
2.25.1
On Thu, Oct 21, 2021 at 11:41:05AM -0400, Tianyu Lan wrote:
> diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c
> index ea9abd69237e..368ed36971e3 100644
> --- a/arch/x86/kernel/sev-shared.c
> +++ b/arch/x86/kernel/sev-shared.c
> @@ -124,10 +124,9 @@ static enum es_result verify_exception_info(struct ghcb *ghcb, struct es_em_ctxt
> return ES_VMM_ERROR;
> }
>
> -static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
> - struct es_em_ctxt *ctxt,
> - u64 exit_code, u64 exit_info_1,
> - u64 exit_info_2)
> +enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb, bool set_ghcb_msr,
> + struct es_em_ctxt *ctxt, u64 exit_code,
> + u64 exit_info_1, u64 exit_info_2)
> {
> /* Fill in protocol and format specifiers */
> ghcb->protocol_version = GHCB_PROTOCOL_MAX;
> @@ -137,7 +136,15 @@ static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
> ghcb_set_sw_exit_info_1(ghcb, exit_info_1);
> ghcb_set_sw_exit_info_2(ghcb, exit_info_2);
>
> - sev_es_wr_ghcb_msr(__pa(ghcb));
> + /*
> + * Hyper-V unenlightened guests use a paravisor for communicating and
> + * GHCB pages are being allocated and set up by that paravisor. Linux
> + * should not change ghcb page pa in such case and so add set_ghcb_msr
"... not change the GHCB page's physical address."
Remove the "so add... " rest.
Otherwise, LGTM.
Do you want me to take it through the tip tree?
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
From: Tianyu Lan <[email protected]>
Hyper-V needs to call ghcb hv call to write/read MSR in Isolation VM.
So expose sev_es_ghcb_hv_call() to call it in the Hyper-V code.
Hyper-V Isolation VM is unenlightened guests and run a paravisor in the
VMPL0 for communicating and GHCB pages are being allocated and set up by
that paravisor. Linux gets ghcb page pa via MSR_AMD64_SEV_ES_GHCB
from paravisor and should not change it. Add set_ghcb_msr parameter for
sev_es_ghcb_hv_call() and not set ghcb page pa when it's false.
Signed-off-by: Tianyu Lan <[email protected]>
---
Change since v8:
Fix commit in the sev_es_ghcb_hv_call().
arch/x86/include/asm/sev.h | 12 ++++++++++++
arch/x86/kernel/sev-shared.c | 25 ++++++++++++++++---------
arch/x86/kernel/sev.c | 13 +++++++------
3 files changed, 35 insertions(+), 15 deletions(-)
diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index fa5cd05d3b5b..5b7f7e2b81f7 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -81,12 +81,24 @@ static __always_inline void sev_es_nmi_complete(void)
__sev_es_nmi_complete();
}
extern int __init sev_es_efi_map_ghcbs(pgd_t *pgd);
+extern enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
+ bool set_ghcb_msr,
+ struct es_em_ctxt *ctxt,
+ u64 exit_code, u64 exit_info_1,
+ u64 exit_info_2);
#else
static inline void sev_es_ist_enter(struct pt_regs *regs) { }
static inline void sev_es_ist_exit(void) { }
static inline int sev_es_setup_ap_jump_table(struct real_mode_header *rmh) { return 0; }
static inline void sev_es_nmi_complete(void) { }
static inline int sev_es_efi_map_ghcbs(pgd_t *pgd) { return 0; }
+static inline enum
+es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
+ bool set_ghcb_msr, u64 exit_code,
+ u64 exit_info_1, u64 exit_info_2)
+{
+ return ES_VMM_ERROR;
+}
#endif
#endif
diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c
index ea9abd69237e..e1863a6d76b8 100644
--- a/arch/x86/kernel/sev-shared.c
+++ b/arch/x86/kernel/sev-shared.c
@@ -124,10 +124,9 @@ static enum es_result verify_exception_info(struct ghcb *ghcb, struct es_em_ctxt
return ES_VMM_ERROR;
}
-static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
- struct es_em_ctxt *ctxt,
- u64 exit_code, u64 exit_info_1,
- u64 exit_info_2)
+enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb, bool set_ghcb_msr,
+ struct es_em_ctxt *ctxt, u64 exit_code,
+ u64 exit_info_1, u64 exit_info_2)
{
/* Fill in protocol and format specifiers */
ghcb->protocol_version = GHCB_PROTOCOL_MAX;
@@ -137,7 +136,14 @@ static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
ghcb_set_sw_exit_info_1(ghcb, exit_info_1);
ghcb_set_sw_exit_info_2(ghcb, exit_info_2);
- sev_es_wr_ghcb_msr(__pa(ghcb));
+ /*
+ * Hyper-V unenlightened guests use a paravisor for communicating and
+ * GHCB pages are being allocated and set up by that paravisor. Linux
+ * should not change the GHCB page's physical address.
+ */
+ if (set_ghcb_msr)
+ sev_es_wr_ghcb_msr(__pa(ghcb));
+
VMGEXIT();
return verify_exception_info(ghcb, ctxt);
@@ -417,7 +423,7 @@ static enum es_result vc_handle_ioio(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
*/
sw_scratch = __pa(ghcb) + offsetof(struct ghcb, shared_buffer);
ghcb_set_sw_scratch(ghcb, sw_scratch);
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO,
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_IOIO,
exit_info_1, exit_info_2);
if (ret != ES_OK)
return ret;
@@ -459,7 +465,8 @@ static enum es_result vc_handle_ioio(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
ghcb_set_rax(ghcb, rax);
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO, exit_info_1, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt,
+ SVM_EXIT_IOIO, exit_info_1, 0);
if (ret != ES_OK)
return ret;
@@ -490,7 +497,7 @@ static enum es_result vc_handle_cpuid(struct ghcb *ghcb,
/* xgetbv will cause #GP - use reset value for xcr0 */
ghcb_set_xcr0(ghcb, 1);
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_CPUID, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_CPUID, 0, 0);
if (ret != ES_OK)
return ret;
@@ -515,7 +522,7 @@ static enum es_result vc_handle_rdtsc(struct ghcb *ghcb,
bool rdtscp = (exit_code == SVM_EXIT_RDTSCP);
enum es_result ret;
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, exit_code, 0, 0);
if (ret != ES_OK)
return ret;
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index a6895e440bc3..bb62a1d15d6c 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -648,7 +648,8 @@ static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
ghcb_set_rdx(ghcb, regs->dx);
}
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_MSR, exit_info_1, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_MSR,
+ exit_info_1, 0);
if ((ret == ES_OK) && (!exit_info_1)) {
regs->ax = ghcb->save.rax;
@@ -867,7 +868,7 @@ static enum es_result vc_do_mmio(struct ghcb *ghcb, struct es_em_ctxt *ctxt,
ghcb_set_sw_scratch(ghcb, ghcb_pa + offsetof(struct ghcb, shared_buffer));
- return sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, exit_info_1, exit_info_2);
+ return sev_es_ghcb_hv_call(ghcb, true, ctxt, exit_code, exit_info_1, exit_info_2);
}
static enum es_result vc_handle_mmio_twobyte_ops(struct ghcb *ghcb,
@@ -1117,7 +1118,7 @@ static enum es_result vc_handle_dr7_write(struct ghcb *ghcb,
/* Using a value of 0 for ExitInfo1 means RAX holds the value */
ghcb_set_rax(ghcb, val);
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WRITE_DR7, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_WRITE_DR7, 0, 0);
if (ret != ES_OK)
return ret;
@@ -1147,7 +1148,7 @@ static enum es_result vc_handle_dr7_read(struct ghcb *ghcb,
static enum es_result vc_handle_wbinvd(struct ghcb *ghcb,
struct es_em_ctxt *ctxt)
{
- return sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WBINVD, 0, 0);
+ return sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_WBINVD, 0, 0);
}
static enum es_result vc_handle_rdpmc(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
@@ -1156,7 +1157,7 @@ static enum es_result vc_handle_rdpmc(struct ghcb *ghcb, struct es_em_ctxt *ctxt
ghcb_set_rcx(ghcb, ctxt->regs->cx);
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_RDPMC, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_RDPMC, 0, 0);
if (ret != ES_OK)
return ret;
@@ -1197,7 +1198,7 @@ static enum es_result vc_handle_vmmcall(struct ghcb *ghcb,
if (x86_platform.hyper.sev_es_hcall_prepare)
x86_platform.hyper.sev_es_hcall_prepare(ghcb, ctxt->regs);
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_VMMCALL, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_VMMCALL, 0, 0);
if (ret != ES_OK)
return ret;
--
2.25.1
On 10/22/2021 12:22 AM, Borislav Petkov wrote:
> On Thu, Oct 21, 2021 at 11:41:05AM -0400, Tianyu Lan wrote:
>> diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c
>> index ea9abd69237e..368ed36971e3 100644
>> --- a/arch/x86/kernel/sev-shared.c
>> +++ b/arch/x86/kernel/sev-shared.c
>> @@ -124,10 +124,9 @@ static enum es_result verify_exception_info(struct ghcb *ghcb, struct es_em_ctxt
>> return ES_VMM_ERROR;
>> }
>>
>> -static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
>> - struct es_em_ctxt *ctxt,
>> - u64 exit_code, u64 exit_info_1,
>> - u64 exit_info_2)
>> +enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb, bool set_ghcb_msr,
>> + struct es_em_ctxt *ctxt, u64 exit_code,
>> + u64 exit_info_1, u64 exit_info_2)
>> {
>> /* Fill in protocol and format specifiers */
>> ghcb->protocol_version = GHCB_PROTOCOL_MAX;
>> @@ -137,7 +136,15 @@ static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
>> ghcb_set_sw_exit_info_1(ghcb, exit_info_1);
>> ghcb_set_sw_exit_info_2(ghcb, exit_info_2);
>>
>> - sev_es_wr_ghcb_msr(__pa(ghcb));
>> + /*
>> + * Hyper-V unenlightened guests use a paravisor for communicating and
>> + * GHCB pages are being allocated and set up by that paravisor. Linux
>> + * should not change ghcb page pa in such case and so add set_ghcb_msr
>
> "... not change the GHCB page's physical address."
>
> Remove the "so add... " rest.
>
> Otherwise, LGTM.
>
> Do you want me to take it through the tip tree?
Yes, please and this patch is based on the your clean up patch which is
already in the tip sev branch.
From: Tianyu Lan <[email protected]>
Hyperv provides GHCB protocol to write Synthetic Interrupt
Controller MSR registers in Isolation VM with AMD SEV SNP
and these registers are emulated by hypervisor directly.
Hyperv requires to write SINTx MSR registers twice. First
writes MSR via GHCB page to communicate with hypervisor
and then writes wrmsr instruction to talk with paravisor
which runs in VMPL0. Guest OS ID MSR also needs to be set
via GHCB page.
Signed-off-by: Tianyu Lan <[email protected]>
---
Change since v8:
* Export hv_ghcb_msr_write/read() to fix compile error.
Change since v6:
* Spilt sev-es code into separate patch
* Add hv_get/set_register() dummy function under CONFIG_HYPERV
is not selected to fix compile error.
Change since v5:
* Adjust change layout in the asm/mshyperv.h
to make hv_is_synic_reg(), hv_get_register()
and hv_set_register() ahead of the #include
of asm-generic/mshyperv.h
* Remove Spurious blank line
Change since v4:
* Remove hv_get_simp(), hv_get_siefp() hv_get_synint_*()
helper function. Move the logic into hv_get/set_register().
Change since v3:
* Pass old_msg_type to hv_signal_eom() as parameter.
* Use HV_REGISTER_* marcro instead of HV_X64_MSR_*
* Add hv_isolation_type_snp() weak function.
* Add maros to set syinc register in ARM code.
Change since v1:
* Introduce sev_es_ghcb_hv_call_simple() and share code
between SEV and Hyper-V code.
---
arch/x86/hyperv/hv_init.c | 36 ++---------
arch/x86/hyperv/ivm.c | 109 ++++++++++++++++++++++++++++++++
arch/x86/include/asm/mshyperv.h | 57 +++++++++++++----
drivers/hv/hv.c | 74 +++++++++++++++++-----
drivers/hv/hv_common.c | 6 ++
include/asm-generic/mshyperv.h | 1 +
6 files changed, 224 insertions(+), 59 deletions(-)
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index d57df6825527..a16a83e46a30 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -37,7 +37,7 @@ EXPORT_SYMBOL_GPL(hv_current_partition_id);
void *hv_hypercall_pg;
EXPORT_SYMBOL_GPL(hv_hypercall_pg);
-void __percpu **hv_ghcb_pg;
+union hv_ghcb __percpu **hv_ghcb_pg;
/* Storage to save the hypercall page temporarily for hibernation */
static void *hv_hypercall_pg_saved;
@@ -406,7 +406,7 @@ void __init hyperv_init(void)
}
if (hv_isolation_type_snp()) {
- hv_ghcb_pg = alloc_percpu(void *);
+ hv_ghcb_pg = alloc_percpu(union hv_ghcb *);
if (!hv_ghcb_pg)
goto free_vp_assist_page;
}
@@ -424,6 +424,9 @@ void __init hyperv_init(void)
guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0);
wrmsrl(HV_X64_MSR_GUEST_OS_ID, guest_id);
+ /* Hyper-V requires to write guest os id via ghcb in SNP IVM. */
+ hv_ghcb_msr_write(HV_X64_MSR_GUEST_OS_ID, guest_id);
+
hv_hypercall_pg = __vmalloc_node_range(PAGE_SIZE, 1, VMALLOC_START,
VMALLOC_END, GFP_KERNEL, PAGE_KERNEL_ROX,
VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
@@ -501,6 +504,7 @@ void __init hyperv_init(void)
clean_guest_os_id:
wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
+ hv_ghcb_msr_write(HV_X64_MSR_GUEST_OS_ID, 0);
cpuhp_remove_state(cpuhp);
free_ghcb_page:
free_percpu(hv_ghcb_pg);
@@ -522,6 +526,7 @@ void hyperv_cleanup(void)
/* Reset our OS id */
wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
+ hv_ghcb_msr_write(HV_X64_MSR_GUEST_OS_ID, 0);
/*
* Reset hypercall page reference before reset the page,
@@ -592,30 +597,3 @@ bool hv_is_hyperv_initialized(void)
return hypercall_msr.enable;
}
EXPORT_SYMBOL_GPL(hv_is_hyperv_initialized);
-
-enum hv_isolation_type hv_get_isolation_type(void)
-{
- if (!(ms_hyperv.priv_high & HV_ISOLATION))
- return HV_ISOLATION_TYPE_NONE;
- return FIELD_GET(HV_ISOLATION_TYPE, ms_hyperv.isolation_config_b);
-}
-EXPORT_SYMBOL_GPL(hv_get_isolation_type);
-
-bool hv_is_isolation_supported(void)
-{
- if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
- return false;
-
- if (!hypervisor_is_type(X86_HYPER_MS_HYPERV))
- return false;
-
- return hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE;
-}
-
-DEFINE_STATIC_KEY_FALSE(isolation_type_snp);
-
-bool hv_isolation_type_snp(void)
-{
- return static_branch_unlikely(&isolation_type_snp);
-}
-EXPORT_SYMBOL_GPL(hv_isolation_type_snp);
diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
index 79e7fb83472a..e2ab3e06f85a 100644
--- a/arch/x86/hyperv/ivm.c
+++ b/arch/x86/hyperv/ivm.c
@@ -6,12 +6,121 @@
* Tianyu Lan <[email protected]>
*/
+#include <linux/types.h>
+#include <linux/bitfield.h>
#include <linux/hyperv.h>
#include <linux/types.h>
#include <linux/bitfield.h>
#include <linux/slab.h>
+#include <asm/svm.h>
+#include <asm/sev.h>
#include <asm/io.h>
#include <asm/mshyperv.h>
+#include <asm/hypervisor.h>
+
+union hv_ghcb {
+ struct ghcb ghcb;
+} __packed __aligned(HV_HYP_PAGE_SIZE);
+
+void hv_ghcb_msr_write(u64 msr, u64 value)
+{
+ union hv_ghcb *hv_ghcb;
+ void **ghcb_base;
+ unsigned long flags;
+ struct es_em_ctxt ctxt;
+
+ if (!hv_ghcb_pg)
+ return;
+
+ WARN_ON(in_nmi());
+
+ local_irq_save(flags);
+ ghcb_base = (void **)this_cpu_ptr(hv_ghcb_pg);
+ hv_ghcb = (union hv_ghcb *)*ghcb_base;
+ if (!hv_ghcb) {
+ local_irq_restore(flags);
+ return;
+ }
+
+ ghcb_set_rcx(&hv_ghcb->ghcb, msr);
+ ghcb_set_rax(&hv_ghcb->ghcb, lower_32_bits(value));
+ ghcb_set_rdx(&hv_ghcb->ghcb, upper_32_bits(value));
+
+ if (sev_es_ghcb_hv_call(&hv_ghcb->ghcb, false, &ctxt,
+ SVM_EXIT_MSR, 1, 0))
+ pr_warn("Fail to write msr via ghcb %llx.\n", msr);
+
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL_GPL(hv_ghcb_msr_write);
+
+void hv_ghcb_msr_read(u64 msr, u64 *value)
+{
+ union hv_ghcb *hv_ghcb;
+ void **ghcb_base;
+ unsigned long flags;
+ struct es_em_ctxt ctxt;
+
+ /* Check size of union hv_ghcb here. */
+ BUILD_BUG_ON(sizeof(union hv_ghcb) != HV_HYP_PAGE_SIZE);
+
+ if (!hv_ghcb_pg)
+ return;
+
+ WARN_ON(in_nmi());
+
+ local_irq_save(flags);
+ ghcb_base = (void **)this_cpu_ptr(hv_ghcb_pg);
+ hv_ghcb = (union hv_ghcb *)*ghcb_base;
+ if (!hv_ghcb) {
+ local_irq_restore(flags);
+ return;
+ }
+
+ ghcb_set_rcx(&hv_ghcb->ghcb, msr);
+ if (sev_es_ghcb_hv_call(&hv_ghcb->ghcb, false, &ctxt,
+ SVM_EXIT_MSR, 0, 0))
+ pr_warn("Fail to read msr via ghcb %llx.\n", msr);
+ else
+ *value = (u64)lower_32_bits(hv_ghcb->ghcb.save.rax)
+ | ((u64)lower_32_bits(hv_ghcb->ghcb.save.rdx) << 32);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL_GPL(hv_ghcb_msr_read);
+
+enum hv_isolation_type hv_get_isolation_type(void)
+{
+ if (!(ms_hyperv.priv_high & HV_ISOLATION))
+ return HV_ISOLATION_TYPE_NONE;
+ return FIELD_GET(HV_ISOLATION_TYPE, ms_hyperv.isolation_config_b);
+}
+EXPORT_SYMBOL_GPL(hv_get_isolation_type);
+
+/*
+ * hv_is_isolation_supported - Check system runs in the Hyper-V
+ * isolation VM.
+ */
+bool hv_is_isolation_supported(void)
+{
+ if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
+ return false;
+
+ if (!hypervisor_is_type(X86_HYPER_MS_HYPERV))
+ return false;
+
+ return hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE;
+}
+
+DEFINE_STATIC_KEY_FALSE(isolation_type_snp);
+
+/*
+ * hv_isolation_type_snp - Check system runs in the AMD SEV-SNP based
+ * isolation VM.
+ */
+bool hv_isolation_type_snp(void)
+{
+ return static_branch_unlikely(&isolation_type_snp);
+}
/*
* hv_mark_gpa_visibility - Set pages visible to host via hvcall.
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index f3154ca41ac4..eb1ba33da113 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -11,25 +11,14 @@
#include <asm/paravirt.h>
#include <asm/mshyperv.h>
+union hv_ghcb;
+
DECLARE_STATIC_KEY_FALSE(isolation_type_snp);
typedef int (*hyperv_fill_flush_list_func)(
struct hv_guest_mapping_flush_list *flush,
void *data);
-static inline void hv_set_register(unsigned int reg, u64 value)
-{
- wrmsrl(reg, value);
-}
-
-static inline u64 hv_get_register(unsigned int reg)
-{
- u64 value;
-
- rdmsrl(reg, value);
- return value;
-}
-
#define hv_get_raw_timer() rdtsc_ordered()
void hyperv_vector_handler(struct pt_regs *regs);
@@ -41,7 +30,7 @@ extern void *hv_hypercall_pg;
extern u64 hv_current_partition_id;
-extern void __percpu **hv_ghcb_pg;
+extern union hv_ghcb __percpu **hv_ghcb_pg;
int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages);
int hv_call_add_logical_proc(int node, u32 lp_index, u32 acpi_id);
@@ -193,6 +182,44 @@ int hv_map_ioapic_interrupt(int ioapic_id, bool level, int vcpu, int vector,
struct hv_interrupt_entry *entry);
int hv_unmap_ioapic_interrupt(int ioapic_id, struct hv_interrupt_entry *entry);
int hv_set_mem_host_visibility(unsigned long addr, int numpages, bool visible);
+void hv_ghcb_msr_write(u64 msr, u64 value);
+void hv_ghcb_msr_read(u64 msr, u64 *value);
+
+extern bool hv_isolation_type_snp(void);
+
+static inline bool hv_is_synic_reg(unsigned int reg)
+{
+ if ((reg >= HV_REGISTER_SCONTROL) &&
+ (reg <= HV_REGISTER_SINT15))
+ return true;
+ return false;
+}
+
+static inline u64 hv_get_register(unsigned int reg)
+{
+ u64 value;
+
+ if (hv_is_synic_reg(reg) && hv_isolation_type_snp())
+ hv_ghcb_msr_read(reg, &value);
+ else
+ rdmsrl(reg, value);
+ return value;
+}
+
+static inline void hv_set_register(unsigned int reg, u64 value)
+{
+ if (hv_is_synic_reg(reg) && hv_isolation_type_snp()) {
+ hv_ghcb_msr_write(reg, value);
+
+ /* Write proxy bit via wrmsl instruction */
+ if (reg >= HV_REGISTER_SINT0 &&
+ reg <= HV_REGISTER_SINT15)
+ wrmsrl(reg, value | 1 << 20);
+ } else {
+ wrmsrl(reg, value);
+ }
+}
+
#else /* CONFIG_HYPERV */
static inline void hyperv_init(void) {}
static inline void hyperv_setup_mmu_ops(void) {}
@@ -209,6 +236,8 @@ static inline int hyperv_flush_guest_mapping_range(u64 as,
{
return -1;
}
+static inline void hv_set_register(unsigned int reg, u64 value) { }
+static inline u64 hv_get_register(unsigned int reg) { return 0; }
static inline int hv_set_mem_host_visibility(unsigned long addr, int numpages,
bool visible)
{
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index e83507f49676..943392db9e8a 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -8,6 +8,7 @@
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/slab.h>
@@ -136,17 +137,24 @@ int hv_synic_alloc(void)
tasklet_init(&hv_cpu->msg_dpc,
vmbus_on_msg_dpc, (unsigned long) hv_cpu);
- hv_cpu->synic_message_page =
- (void *)get_zeroed_page(GFP_ATOMIC);
- if (hv_cpu->synic_message_page == NULL) {
- pr_err("Unable to allocate SYNIC message page\n");
- goto err;
- }
+ /*
+ * Synic message and event pages are allocated by paravisor.
+ * Skip these pages allocation here.
+ */
+ if (!hv_isolation_type_snp()) {
+ hv_cpu->synic_message_page =
+ (void *)get_zeroed_page(GFP_ATOMIC);
+ if (hv_cpu->synic_message_page == NULL) {
+ pr_err("Unable to allocate SYNIC message page\n");
+ goto err;
+ }
- hv_cpu->synic_event_page = (void *)get_zeroed_page(GFP_ATOMIC);
- if (hv_cpu->synic_event_page == NULL) {
- pr_err("Unable to allocate SYNIC event page\n");
- goto err;
+ hv_cpu->synic_event_page =
+ (void *)get_zeroed_page(GFP_ATOMIC);
+ if (hv_cpu->synic_event_page == NULL) {
+ pr_err("Unable to allocate SYNIC event page\n");
+ goto err;
+ }
}
hv_cpu->post_msg_page = (void *)get_zeroed_page(GFP_ATOMIC);
@@ -201,16 +209,35 @@ void hv_synic_enable_regs(unsigned int cpu)
/* Setup the Synic's message page */
simp.as_uint64 = hv_get_register(HV_REGISTER_SIMP);
simp.simp_enabled = 1;
- simp.base_simp_gpa = virt_to_phys(hv_cpu->synic_message_page)
- >> HV_HYP_PAGE_SHIFT;
+
+ if (hv_isolation_type_snp()) {
+ hv_cpu->synic_message_page
+ = memremap(simp.base_simp_gpa << HV_HYP_PAGE_SHIFT,
+ HV_HYP_PAGE_SIZE, MEMREMAP_WB);
+ if (!hv_cpu->synic_message_page)
+ pr_err("Fail to map syinc message page.\n");
+ } else {
+ simp.base_simp_gpa = virt_to_phys(hv_cpu->synic_message_page)
+ >> HV_HYP_PAGE_SHIFT;
+ }
hv_set_register(HV_REGISTER_SIMP, simp.as_uint64);
/* Setup the Synic's event page */
siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP);
siefp.siefp_enabled = 1;
- siefp.base_siefp_gpa = virt_to_phys(hv_cpu->synic_event_page)
- >> HV_HYP_PAGE_SHIFT;
+
+ if (hv_isolation_type_snp()) {
+ hv_cpu->synic_event_page =
+ memremap(siefp.base_siefp_gpa << HV_HYP_PAGE_SHIFT,
+ HV_HYP_PAGE_SIZE, MEMREMAP_WB);
+
+ if (!hv_cpu->synic_event_page)
+ pr_err("Fail to map syinc event page.\n");
+ } else {
+ siefp.base_siefp_gpa = virt_to_phys(hv_cpu->synic_event_page)
+ >> HV_HYP_PAGE_SHIFT;
+ }
hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64);
@@ -257,6 +284,8 @@ int hv_synic_init(unsigned int cpu)
*/
void hv_synic_disable_regs(unsigned int cpu)
{
+ struct hv_per_cpu_context *hv_cpu
+ = per_cpu_ptr(hv_context.cpu_context, cpu);
union hv_synic_sint shared_sint;
union hv_synic_simp simp;
union hv_synic_siefp siefp;
@@ -273,14 +302,27 @@ void hv_synic_disable_regs(unsigned int cpu)
shared_sint.as_uint64);
simp.as_uint64 = hv_get_register(HV_REGISTER_SIMP);
+ /*
+ * In Isolation VM, sim and sief pages are allocated by
+ * paravisor. These pages also will be used by kdump
+ * kernel. So just reset enable bit here and keep page
+ * addresses.
+ */
simp.simp_enabled = 0;
- simp.base_simp_gpa = 0;
+ if (hv_isolation_type_snp())
+ memunmap(hv_cpu->synic_message_page);
+ else
+ simp.base_simp_gpa = 0;
hv_set_register(HV_REGISTER_SIMP, simp.as_uint64);
siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP);
siefp.siefp_enabled = 0;
- siefp.base_siefp_gpa = 0;
+
+ if (hv_isolation_type_snp())
+ memunmap(hv_cpu->synic_event_page);
+ else
+ siefp.base_siefp_gpa = 0;
hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64);
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index c0d9048a4112..1fc82d237161 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -249,6 +249,12 @@ bool __weak hv_is_isolation_supported(void)
}
EXPORT_SYMBOL_GPL(hv_is_isolation_supported);
+bool __weak hv_isolation_type_snp(void)
+{
+ return false;
+}
+EXPORT_SYMBOL_GPL(hv_isolation_type_snp);
+
void __weak hv_setup_vmbus_handler(void (*handler)(void))
{
}
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index a8ac497167d2..6d3ba902ebb0 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -54,6 +54,7 @@ extern void __percpu **hyperv_pcpu_output_arg;
extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);
+extern bool hv_isolation_type_snp(void);
/* Helper functions that provide a consistent pattern for checking Hyper-V hypercall status. */
static inline int hv_result(u64 status)
--
2.25.1
From: Tianyu Lan <[email protected]> Sent: Thursday, October 21, 2021 8:41 AM
>
> Hyper-V provides two kinds of Isolation VMs. VBS(Virtualization-based
> security) and AMD SEV-SNP unenlightened Isolation VMs. This patchset
> is to add support for these Isolation VM support in Linux.
>
> The memory of these vms are encrypted and host can't access guest
> memory directly. Hyper-V provides new host visibility hvcall and
> the guest needs to call new hvcall to mark memory visible to host
> before sharing memory with host. For security, all network/storage
> stack memory should not be shared with host and so there is bounce
> buffer requests.
>
> Vmbus channel ring buffer already plays bounce buffer role because
> all data from/to host needs to copy from/to between the ring buffer
> and IO stack memory. So mark vmbus channel ring buffer visible.
>
> For SNP isolation VM, guest needs to access the shared memory via
> extra address space which is specified by Hyper-V CPUID HYPERV_CPUID_
> ISOLATION_CONFIG. The access physical address of the shared memory
> should be bounce buffer memory GPA plus with shared_gpa_boundary
> reported by CPUID.
>
> This patchset is rebased on the commit d9abdee of Linux mainline tree
> and plus clean up patch from Borislav
> Petkov
>
> Change since v7
> - Rework sev_es_ghcb_hv_call() and export it for Hyper-V
> according to suggestion from Borislav Petkov.
>
> Change since v6
> - Add hv_set_mem_host_visibility() when CONFIG_HYPERV is no.
> Fix compile error.
> - Add comment to describe __set_memory_enc_pgtable().
> - Split SEV change into patch "Expose __sev_es_ghcb_hv_call()
> to call ghcb hv call out of sev code"
> - Add comment about calling memunmap() in the non-snp IVM.
>
> Change since v5
> - Replace HVPFN_UP() with PFN_UP() in the __vmbus_establish_gpadl()
> - Remove unused variable gpadl in the __vmbus_open() and vmbus_close_
> internal()
> - Clean gpadl_handle in the vmbus_teardown_gpadl().
> - Adjust change layout in the asm/mshyperv.h to make
> hv_is_synic_reg(), hv_get_register() and hv_set_register()
> ahead of the #include of asm-generic/mshyperv.h
> - Change vmbus_connection.monitor_pages_pa type from unsigned
> long to phys_addr_t
>
> Change since v4:
> - Hide hv_mark_gpa_visibility() and set memory visibility via
> set_memory_encrypted/decrypted()
> - Change gpadl handle in netvsc and uio driver from u32 to
> struct vmbus_gpadl.
> - Change vmbus_establish_gpadl()'s gpadl_handle parameter
> to vmbus_gpadl data structure.
> - Remove hv_get_simp(), hv_get_siefp() hv_get_synint_*()
> helper function. Move the logic into hv_get/set_register().
> - Use scsi_dma_map/unmap() instead of dma_map/unmap_sg() in storvsc driver.
> - Allocate rx/tx ring buffer via alloc_pages() in Isolation VM
>
> Change since V3:
> - Initalize GHCB page in the cpu init callbac.
> - Change vmbus_teardown_gpadl() parameter in order to
> mask the memory back to non-visible to host.
> - Merge hv_ringbuffer_post_init() into hv_ringbuffer_init().
> - Keep Hyper-V bounce buffer size as same as AMD SEV VM
> - Use dma_map_sg() instead of dm_map_page() in the storvsc driver.
>
> Change since V2:
> - Drop x86_set_memory_enc static call and use platform check
> in the __set_memory_enc_dec() to run platform callback of
> set memory encrypted or decrypted.
>
> Change since V1:
> - Introduce x86_set_memory_enc static call and so platforms can
> override __set_memory_enc_dec() with their implementation
> - Introduce sev_es_ghcb_hv_call_simple() and share code
> between SEV and Hyper-V code.
> - Not remap monitor pages in the non-SNP isolation VM
> - Make swiotlb_init_io_tlb_mem() return error code and return
> error when dma_map_decrypted() fails.
>
> Change since RFC V4:
> - Introduce dma map decrypted function to remap bounce buffer
> and provide dma map decrypted ops for platform to hook callback.
> - Split swiotlb and dma map decrypted change into two patches
> - Replace vstart with vaddr in swiotlb changes.
>
> Change since RFC v3:
> - Add interface set_memory_decrypted_map() to decrypt memory and
> map bounce buffer in extra address space
> - Remove swiotlb remap function and store the remap address
> returned by set_memory_decrypted_map() in swiotlb mem data structure.
> - Introduce hv_set_mem_enc() to make code more readable in the __set_memory_enc_dec().
>
> Change since RFC v2:
> - Remove not UIO driver in Isolation VM patch
> - Use vmap_pfn() to replace ioremap_page_range function in
> order to avoid exposing symbol ioremap_page_range() and
> ioremap_page_range()
> - Call hv set mem host visibility hvcall in set_memory_encrypted/decrypted()
> - Enable swiotlb force mode instead of adding Hyper-V dma map/unmap hook
> - Fix code style
>
> Tianyu Lan (9):
> x86/hyperv: Initialize GHCB page in Isolation VM
> x86/hyperv: Initialize shared memory boundary in the Isolation VM.
> x86/hyperv: Add new hvcall guest address host visibility support
> Drivers: hv: vmbus: Mark vmbus ring buffer visible to host in
> Isolation VM
> x86/sev-es: Expose sev_es_ghcb_hv_call() to call ghcb hv call out of
> sev code
> x86/hyperv: Add Write/Read MSR registers via ghcb page
> x86/hyperv: Add ghcb hvcall support for SNP VM
> Drivers: hv: vmbus: Add SNP support for VMbus channel initiate
> message
> Drivers: hv : vmbus: Initialize VMbus ring buffer for Isolation VM
>
> arch/x86/hyperv/Makefile | 2 +-
> arch/x86/hyperv/hv_init.c | 78 ++++++--
> arch/x86/hyperv/ivm.c | 286 +++++++++++++++++++++++++++++
> arch/x86/include/asm/hyperv-tlfs.h | 17 ++
> arch/x86/include/asm/mshyperv.h | 64 +++++--
> arch/x86/include/asm/sev.h | 12 ++
> arch/x86/kernel/cpu/mshyperv.c | 5 +
> arch/x86/kernel/sev-shared.c | 26 ++-
> arch/x86/kernel/sev.c | 13 +-
> arch/x86/mm/pat/set_memory.c | 23 ++-
> drivers/hv/Kconfig | 1 +
> drivers/hv/channel.c | 72 +++++---
> drivers/hv/connection.c | 101 +++++++++-
> drivers/hv/hv.c | 82 +++++++--
> drivers/hv/hv_common.c | 12 ++
> drivers/hv/hyperv_vmbus.h | 2 +
> drivers/hv/ring_buffer.c | 55 ++++--
> drivers/net/hyperv/hyperv_net.h | 5 +-
> drivers/net/hyperv/netvsc.c | 15 +-
> drivers/uio/uio_hv_generic.c | 18 +-
> include/asm-generic/hyperv-tlfs.h | 1 +
> include/asm-generic/mshyperv.h | 20 +-
> include/linux/hyperv.h | 12 +-
> 23 files changed, 783 insertions(+), 139 deletions(-)
> create mode 100644 arch/x86/hyperv/ivm.c
>
> --
> 2.25.1
For the entire series, modulo a minor missing argument error in a
declaration in Patch 5 that I noted separately,
Reviewed-by: Michael Kelley <[email protected]>
From: Tianyu Lan <[email protected]> Sent: Friday, October 22, 2021 6:37 AM
>
> Hyper-V needs to call ghcb hv call to write/read MSR in Isolation VM.
> So expose sev_es_ghcb_hv_call() to call it in the Hyper-V code.
>
> Hyper-V Isolation VM is unenlightened guests and run a paravisor in the
> VMPL0 for communicating and GHCB pages are being allocated and set up by
> that paravisor. Linux gets ghcb page pa via MSR_AMD64_SEV_ES_GHCB
> from paravisor and should not change it. Add set_ghcb_msr parameter for
> sev_es_ghcb_hv_call() and not set ghcb page pa when it's false.
>
> Signed-off-by: Tianyu Lan <[email protected]>
> ---
> Change since v8:
> Fix commit in the sev_es_ghcb_hv_call().
>
> arch/x86/include/asm/sev.h | 12 ++++++++++++
> arch/x86/kernel/sev-shared.c | 25 ++++++++++++++++---------
> arch/x86/kernel/sev.c | 13 +++++++------
> 3 files changed, 35 insertions(+), 15 deletions(-)
>
> diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
> index fa5cd05d3b5b..5b7f7e2b81f7 100644
> --- a/arch/x86/include/asm/sev.h
> +++ b/arch/x86/include/asm/sev.h
> @@ -81,12 +81,24 @@ static __always_inline void sev_es_nmi_complete(void)
> __sev_es_nmi_complete();
> }
> extern int __init sev_es_efi_map_ghcbs(pgd_t *pgd);
> +extern enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
> + bool set_ghcb_msr,
> + struct es_em_ctxt *ctxt,
> + u64 exit_code, u64 exit_info_1,
> + u64 exit_info_2);
> #else
> static inline void sev_es_ist_enter(struct pt_regs *regs) { }
> static inline void sev_es_ist_exit(void) { }
> static inline int sev_es_setup_ap_jump_table(struct real_mode_header *rmh) { return 0; }
> static inline void sev_es_nmi_complete(void) { }
> static inline int sev_es_efi_map_ghcbs(pgd_t *pgd) { return 0; }
> +static inline enum
> +es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
> + bool set_ghcb_msr, u64 exit_code,
The "struct es_em_ctxt *ctxt" argument is missing from this declaration,
which would presumably produce a compile error.
> + u64 exit_info_1, u64 exit_info_2)
> +{
> + return ES_VMM_ERROR;
> +}
> #endif
>
> #endif
On Fri, Oct 22, 2021 at 08:58:00PM +0000, Michael Kelley wrote:
> > static inline void sev_es_ist_enter(struct pt_regs *regs) { }
> > static inline void sev_es_ist_exit(void) { }
> > static inline int sev_es_setup_ap_jump_table(struct real_mode_header *rmh) { return 0; }
> > static inline void sev_es_nmi_complete(void) { }
> > static inline int sev_es_efi_map_ghcbs(pgd_t *pgd) { return 0; }
> > +static inline enum
> > +es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
> > + bool set_ghcb_msr, u64 exit_code,
>
> The "struct es_em_ctxt *ctxt" argument is missing from this declaration,
> which would presumably produce a compile error.
Which raises the more important question: that ivm.c thing which is
going to be that function's user gets enabled unconditionally in
HyperV's Makefile so maybe you guys wanna consider perhaps making that
isolation VM functionality dependent on CONFIG_AMD_MEM_ENCRYPT because
without it, it would be useless.
And if you add that dependency, you probably won't need the stub as
outside of AMD SEV, nothing else will be using that function.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
On 10/25/2021 7:24 PM, Borislav Petkov wrote:
> On Mon, Oct 25, 2021 at 11:20:33AM +0000, Wei Liu wrote:
>> Borislav, please take the whole series via the tip tree if possible.
>> That's perhaps the easiest thing for both of us because the rest of the
>> series depends on this patch. Or else I will have to base hyperv-next on
>> the tip tree once you merge this patch.
>>
>> Let me know what you think.
>
> You'll be able to simply merge the tip/x86/sev branch which will have it
> and then base everything ontop.
>
> However, there's still a question open - see my reply to Michael.
Hi Boris:
I just sent out v9 version and compile hv ghcb related functions
when CONFIG_AMD_MEM_ENCRYPT is selected. The sev_es_ghcb_hv_call() stub
is not necessary in the series and remove it. Please have a look and
give your ack if it's ok. Then Wei can merge it through Hyper-V next
branch.
Thanks.
On Fri, Oct 22, 2021 at 09:39:48PM +0800, Tianyu Lan wrote:
> On 10/22/2021 12:22 AM, Borislav Petkov wrote:
> > On Thu, Oct 21, 2021 at 11:41:05AM -0400, Tianyu Lan wrote:
> > > diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c
> > > index ea9abd69237e..368ed36971e3 100644
> > > --- a/arch/x86/kernel/sev-shared.c
> > > +++ b/arch/x86/kernel/sev-shared.c
> > > @@ -124,10 +124,9 @@ static enum es_result verify_exception_info(struct ghcb *ghcb, struct es_em_ctxt
> > > return ES_VMM_ERROR;
> > > }
> > > -static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
> > > - struct es_em_ctxt *ctxt,
> > > - u64 exit_code, u64 exit_info_1,
> > > - u64 exit_info_2)
> > > +enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb, bool set_ghcb_msr,
> > > + struct es_em_ctxt *ctxt, u64 exit_code,
> > > + u64 exit_info_1, u64 exit_info_2)
> > > {
> > > /* Fill in protocol and format specifiers */
> > > ghcb->protocol_version = GHCB_PROTOCOL_MAX;
> > > @@ -137,7 +136,15 @@ static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
> > > ghcb_set_sw_exit_info_1(ghcb, exit_info_1);
> > > ghcb_set_sw_exit_info_2(ghcb, exit_info_2);
> > > - sev_es_wr_ghcb_msr(__pa(ghcb));
> > > + /*
> > > + * Hyper-V unenlightened guests use a paravisor for communicating and
> > > + * GHCB pages are being allocated and set up by that paravisor. Linux
> > > + * should not change ghcb page pa in such case and so add set_ghcb_msr
> >
> > "... not change the GHCB page's physical address."
> >
> > Remove the "so add... " rest.
> >
> > Otherwise, LGTM.
> >
> > Do you want me to take it through the tip tree?
>
> Yes, please and this patch is based on the your clean up patch which is
> already in the tip sev branch.
Borislav, please take the whole series via the tip tree if possible.
That's perhaps the easiest thing for both of us because the rest of the
series depends on this patch. Or else I will have to base hyperv-next on
the tip tree once you merge this patch.
Let me know what you think.
Thanks,
Wei.
On Mon, Oct 25, 2021 at 11:20:33AM +0000, Wei Liu wrote:
> Borislav, please take the whole series via the tip tree if possible.
> That's perhaps the easiest thing for both of us because the rest of the
> series depends on this patch. Or else I will have to base hyperv-next on
> the tip tree once you merge this patch.
>
> Let me know what you think.
You'll be able to simply merge the tip/x86/sev branch which will have it
and then base everything ontop.
However, there's still a question open - see my reply to Michael.
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
On Mon, Oct 25, 2021 at 08:27:39PM +0800, Tianyu Lan wrote:
> I just sent out v9 version and compile hv ghcb related functions
> when CONFIG_AMD_MEM_ENCRYPT is selected. The sev_es_ghcb_hv_call()
> stub is not necessary in the series and remove it. Please have a look
> and give your ack if it's ok. Then Wei can merge it through Hyper-V
> next branch.
I have merged it after running a bunch of randbuild tests and had to fix
one or two:
https://git.kernel.org/tip/007faec014cb5d26983c1f86fd08c6539b41392e
From my POV that branch is not going to change anymore so Wei can now
merge this tip branch - tip:x86/sev - and write a proper merge commit
message explaining why he's merging a tip branch and then apply the rest
of the HyperV stuff ontop.
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
On Mon, Oct 25, 2021 at 06:37:43PM +0200, Borislav Petkov wrote:
> On Mon, Oct 25, 2021 at 08:27:39PM +0800, Tianyu Lan wrote:
> > I just sent out v9 version and compile hv ghcb related functions
> > when CONFIG_AMD_MEM_ENCRYPT is selected. The sev_es_ghcb_hv_call()
> > stub is not necessary in the series and remove it. Please have a look
> > and give your ack if it's ok. Then Wei can merge it through Hyper-V
> > next branch.
>
> I have merged it after running a bunch of randbuild tests and had to fix
> one or two:
>
> https://git.kernel.org/tip/007faec014cb5d26983c1f86fd08c6539b41392e
>
> From my POV that branch is not going to change anymore so Wei can now
> merge this tip branch - tip:x86/sev - and write a proper merge commit
> message explaining why he's merging a tip branch and then apply the rest
> of the HyperV stuff ontop.
Thanks Borislav.
>
> Thx.
>
> --
> Regards/Gruss,
> Boris.
>
> https://people.kernel.org/tglx/notes-about-netiquette