2024-01-09 08:58:45

by Alexey Makhalov

[permalink] [raw]
Subject: [PATCH v6 0/7] VMware hypercalls enhancements

VMware hypercalls invocations were all spread out across the kernel
implementing same ABI as in-place asm-inline. With encrypted memory
and confidential computing it became harder to maintain every changes
in these hypercall implementations.

Intention of this patchset is to introduce arch independent VMware
hypercall API layer other subsystems such as device drivers can call
to, while hiding architecture specific implementation behind.

Second patch introduces the vmware_hypercall low and high bandwidth
families of functions, with little enhancements there.
Sixth patch adds tdx hypercall support

arm64 implementation of vmware_hypercalls is in drivers/gpu/drm/
vmwgfx/vmwgfx_msg_arm64.h and going to be moved to arch/arm64 with
a separate patchset with the introduction of VMware Linux guest
support for arm64.

No functional changes in drivers/input/mouse/vmmouse.c and
drivers/ptp/ptp_vmw.c

v5->v6 change:
- Added ack by Kirill A. Shutemov in patch 7.

v4->v5 changes:
[patch 2]:
- Fixed the problem reported by Simon Horman where build fails after
patch 2 application. Do not undefine VMWARE_HYPERCALL for now, and
update vmwgfx, vmmouse and ptp_vmw code for new VMWARE_HYPERCALL macro.
- Introduce new patch 6 to undefine VMWARE_HYPERCALL, which is safe to do
after patches 3 to 5.
- [patch 7 (former patch 6)]: Add missing r15 (CPL) initialization.

v3->v4 changes: (no functional changes in patches 1-5)
[patch 2]:
- Added the comment with VMware hypercall ABI description.
[patch 6]:
- vmware_tdx_hypercall_args remove in6/out6 arguments as excessive.
- vmware_tdx_hypercall return ULONG_MAX on error to mimic bad hypercall
command error from the hypervisor.
- Replaced pr_warn by pr_warn_once as pointed by Kirill Shutemov.
- Fixed the warning reported by Intel's kernel test robot.
- Added the comment describing VMware TDX hypercall ABI.

v2->v3 changes: (no functional changes in patches 1-5)
- Improved commit message in patches 1, 2 and 5 as was suggested by
Borislav Petkov.
- To address Dave Hansen's concern, patch 6 was reorganized to avoid
exporting bare __tdx_hypercall and to make exported vmware_tdx_hypercall
VMWare guest specific.

v1->v2 changes (no functional changes):
- Improved commit message in patches 2 and 5.
- Added Reviewed-by for all patches.
- Added Ack from Dmitry Torokhov in patch 4. No fixes regarding reported
by Simon Horman gcc error in this patch.

Alexey Makhalov (7):
x86/vmware: Move common macros to vmware.h
x86/vmware: Introduce VMware hypercall API
ptp/vmware: Use VMware hypercall API
input/vmmouse: Use VMware hypercall API
drm/vmwgfx: Use VMware hypercall API
x86/vmware: Undefine VMWARE_HYPERCALL
x86/vmware: Add TDX hypercall support

arch/x86/include/asm/vmware.h | 364 ++++++++++++++++++++--
arch/x86/kernel/cpu/vmware.c | 117 +++----
drivers/gpu/drm/vmwgfx/vmwgfx_msg.c | 173 ++++------
drivers/gpu/drm/vmwgfx/vmwgfx_msg_arm64.h | 197 ++++++++----
drivers/gpu/drm/vmwgfx/vmwgfx_msg_x86.h | 185 -----------
drivers/input/mouse/vmmouse.c | 76 ++---
drivers/ptp/ptp_vmw.c | 12 +-
7 files changed, 599 insertions(+), 525 deletions(-)

--
2.39.0



2024-01-09 08:59:00

by Alexey Makhalov

[permalink] [raw]
Subject: [PATCH v6 1/7] x86/vmware: Move common macros to vmware.h

Move VMware hypercall macros to vmware.h. This is a prerequisite for
the introduction of vmware_hypercall API. No functional changes besides
exporting vmware_hypercall_mode symbol.

Signed-off-by: Alexey Makhalov <[email protected]>
Reviewed-by: Nadav Amit <[email protected]>
---
arch/x86/include/asm/vmware.h | 72 +++++++++++++++++++++++++++++------
arch/x86/kernel/cpu/vmware.c | 57 +++------------------------
2 files changed, 66 insertions(+), 63 deletions(-)

diff --git a/arch/x86/include/asm/vmware.h b/arch/x86/include/asm/vmware.h
index ac9fc51e2b18..de2533337611 100644
--- a/arch/x86/include/asm/vmware.h
+++ b/arch/x86/include/asm/vmware.h
@@ -8,25 +8,34 @@

/*
* The hypercall definitions differ in the low word of the %edx argument
- * in the following way: the old port base interface uses the port
- * number to distinguish between high- and low bandwidth versions.
+ * in the following way: the old I/O port based interface uses the port
+ * number to distinguish between high- and low bandwidth versions, and
+ * uses IN/OUT instructions to define transfer direction.
*
* The new vmcall interface instead uses a set of flags to select
* bandwidth mode and transfer direction. The flags should be loaded
* into %dx by any user and are automatically replaced by the port
- * number if the VMWARE_HYPERVISOR_PORT method is used.
- *
- * In short, new driver code should strictly use the new definition of
- * %dx content.
+ * number if the I/O port method is used.
*/

-/* Old port-based version */
-#define VMWARE_HYPERVISOR_PORT 0x5658
-#define VMWARE_HYPERVISOR_PORT_HB 0x5659
+#define VMWARE_HYPERVISOR_HB BIT(0)
+#define VMWARE_HYPERVISOR_OUT BIT(1)
+
+#define VMWARE_HYPERVISOR_PORT 0x5658
+#define VMWARE_HYPERVISOR_PORT_HB (VMWARE_HYPERVISOR_PORT | \
+ VMWARE_HYPERVISOR_HB)
+
+#define VMWARE_HYPERVISOR_MAGIC 0x564d5868U
+
+#define VMWARE_CMD_GETVERSION 10
+#define VMWARE_CMD_GETHZ 45
+#define VMWARE_CMD_GETVCPU_INFO 68
+#define VMWARE_CMD_STEALCLOCK 91
+
+#define CPUID_VMWARE_FEATURES_ECX_VMMCALL BIT(0)
+#define CPUID_VMWARE_FEATURES_ECX_VMCALL BIT(1)

-/* Current vmcall / vmmcall version */
-#define VMWARE_HYPERVISOR_HB BIT(0)
-#define VMWARE_HYPERVISOR_OUT BIT(1)
+extern u8 vmware_hypercall_mode;

/* The low bandwidth call. The low word of edx is presumed clear. */
#define VMWARE_HYPERCALL \
@@ -54,4 +63,43 @@
"rep insb", \
"vmcall", X86_FEATURE_VMCALL, \
"vmmcall", X86_FEATURE_VMW_VMMCALL)
+
+#define VMWARE_PORT(cmd, eax, ebx, ecx, edx) \
+ __asm__("inl (%%dx), %%eax" : \
+ "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
+ "a"(VMWARE_HYPERVISOR_MAGIC), \
+ "c"(VMWARE_CMD_##cmd), \
+ "d"(VMWARE_HYPERVISOR_PORT), "b"(UINT_MAX) : \
+ "memory")
+
+#define VMWARE_VMCALL(cmd, eax, ebx, ecx, edx) \
+ __asm__("vmcall" : \
+ "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
+ "a"(VMWARE_HYPERVISOR_MAGIC), \
+ "c"(VMWARE_CMD_##cmd), \
+ "d"(0), "b"(UINT_MAX) : \
+ "memory")
+
+#define VMWARE_VMMCALL(cmd, eax, ebx, ecx, edx) \
+ __asm__("vmmcall" : \
+ "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
+ "a"(VMWARE_HYPERVISOR_MAGIC), \
+ "c"(VMWARE_CMD_##cmd), \
+ "d"(0), "b"(UINT_MAX) : \
+ "memory")
+
+#define VMWARE_CMD(cmd, eax, ebx, ecx, edx) do { \
+ switch (vmware_hypercall_mode) { \
+ case CPUID_VMWARE_FEATURES_ECX_VMCALL: \
+ VMWARE_VMCALL(cmd, eax, ebx, ecx, edx); \
+ break; \
+ case CPUID_VMWARE_FEATURES_ECX_VMMCALL: \
+ VMWARE_VMMCALL(cmd, eax, ebx, ecx, edx); \
+ break; \
+ default: \
+ VMWARE_PORT(cmd, eax, ebx, ecx, edx); \
+ break; \
+ } \
+ } while (0)
+
#endif
diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index 11f83d07925e..4db8e1daa4a1 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c
@@ -41,60 +41,14 @@

#define CPUID_VMWARE_INFO_LEAF 0x40000000
#define CPUID_VMWARE_FEATURES_LEAF 0x40000010
-#define CPUID_VMWARE_FEATURES_ECX_VMMCALL BIT(0)
-#define CPUID_VMWARE_FEATURES_ECX_VMCALL BIT(1)

-#define VMWARE_HYPERVISOR_MAGIC 0x564D5868
-
-#define VMWARE_CMD_GETVERSION 10
-#define VMWARE_CMD_GETHZ 45
-#define VMWARE_CMD_GETVCPU_INFO 68
-#define VMWARE_CMD_LEGACY_X2APIC 3
-#define VMWARE_CMD_VCPU_RESERVED 31
-#define VMWARE_CMD_STEALCLOCK 91
+#define VCPU_LEGACY_X2APIC 3
+#define VCPU_RESERVED 31

#define STEALCLOCK_NOT_AVAILABLE (-1)
#define STEALCLOCK_DISABLED 0
#define STEALCLOCK_ENABLED 1

-#define VMWARE_PORT(cmd, eax, ebx, ecx, edx) \
- __asm__("inl (%%dx), %%eax" : \
- "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
- "a"(VMWARE_HYPERVISOR_MAGIC), \
- "c"(VMWARE_CMD_##cmd), \
- "d"(VMWARE_HYPERVISOR_PORT), "b"(UINT_MAX) : \
- "memory")
-
-#define VMWARE_VMCALL(cmd, eax, ebx, ecx, edx) \
- __asm__("vmcall" : \
- "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
- "a"(VMWARE_HYPERVISOR_MAGIC), \
- "c"(VMWARE_CMD_##cmd), \
- "d"(0), "b"(UINT_MAX) : \
- "memory")
-
-#define VMWARE_VMMCALL(cmd, eax, ebx, ecx, edx) \
- __asm__("vmmcall" : \
- "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
- "a"(VMWARE_HYPERVISOR_MAGIC), \
- "c"(VMWARE_CMD_##cmd), \
- "d"(0), "b"(UINT_MAX) : \
- "memory")
-
-#define VMWARE_CMD(cmd, eax, ebx, ecx, edx) do { \
- switch (vmware_hypercall_mode) { \
- case CPUID_VMWARE_FEATURES_ECX_VMCALL: \
- VMWARE_VMCALL(cmd, eax, ebx, ecx, edx); \
- break; \
- case CPUID_VMWARE_FEATURES_ECX_VMMCALL: \
- VMWARE_VMMCALL(cmd, eax, ebx, ecx, edx); \
- break; \
- default: \
- VMWARE_PORT(cmd, eax, ebx, ecx, edx); \
- break; \
- } \
- } while (0)
-
struct vmware_steal_time {
union {
uint64_t clock; /* stolen time counter in units of vtsc */
@@ -108,7 +62,8 @@ struct vmware_steal_time {
};

static unsigned long vmware_tsc_khz __ro_after_init;
-static u8 vmware_hypercall_mode __ro_after_init;
+u8 vmware_hypercall_mode __ro_after_init;
+EXPORT_SYMBOL_GPL(vmware_hypercall_mode);

static inline int __vmware_platform(void)
{
@@ -476,8 +431,8 @@ static bool __init vmware_legacy_x2apic_available(void)
{
uint32_t eax, ebx, ecx, edx;
VMWARE_CMD(GETVCPU_INFO, eax, ebx, ecx, edx);
- return !(eax & BIT(VMWARE_CMD_VCPU_RESERVED)) &&
- (eax & BIT(VMWARE_CMD_LEGACY_X2APIC));
+ return !(eax & BIT(VCPU_RESERVED)) &&
+ (eax & BIT(VCPU_LEGACY_X2APIC));
}

#ifdef CONFIG_AMD_MEM_ENCRYPT
--
2.39.0


2024-01-09 09:02:21

by Alexey Makhalov

[permalink] [raw]
Subject: [PATCH v6 6/7] x86/vmware: Undefine VMWARE_HYPERCALL

No more direct use of VMWARE_HYPERCALL macro should be allowed.

Signed-off-by: Alexey Makhalov <[email protected]>
---
arch/x86/include/asm/vmware.h | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/x86/include/asm/vmware.h b/arch/x86/include/asm/vmware.h
index 2ac87068184a..84a31f579a30 100644
--- a/arch/x86/include/asm/vmware.h
+++ b/arch/x86/include/asm/vmware.h
@@ -273,5 +273,6 @@ unsigned long vmware_hypercall_hb_in(unsigned long cmd, unsigned long in2,
}
#undef VMW_BP_REG
#undef VMW_BP_CONSTRAINT
+#undef VMWARE_HYPERCALL

#endif
--
2.39.0


2024-01-09 10:22:15

by Borislav Petkov

[permalink] [raw]
Subject: Re: [PATCH v6 0/7] VMware hypercalls enhancements

On Tue, Jan 09, 2024 at 12:40:45AM -0800, Alexey Makhalov wrote:
> v5->v6 change:
> - Added ack by Kirill A. Shutemov in patch 7.

Please do not spam. Adding someone's Ack does not mean you have to
resend the whole thing immediately again.

While waiting, please read Documentation/process/submitting-patches.rst

and especially:

"Don't get discouraged - or impatient
------------------------------------

After you have submitted your change, be patient and wait. Reviewers are
busy people and may not get to your patch right away.

Once upon a time, patches used to disappear into the void without comment,
but the development process works more smoothly than that now. You should
receive comments within a few weeks (typically 2-3); if that does not
happen, make sure that you have sent your patches to the right place.
Wait for a minimum of one week before resubmitting or pinging reviewers
- possibly longer during busy times like merge windows."

--
Regards/Gruss,
Boris.

https://people.kernel.org/tglx/notes-about-netiquette