Hyper-V supports the use of XMM registers to perform fast hypercalls.
This allows guests to take advantage of the improved performance of the
fast hypercall interface even though a hypercall may require more than
(the current maximum of) two general purpose registers.
The XMM fast hypercall interface uses an additional six XMM registers
(XMM0 to XMM5) to allow the caller to pass an input parameter block of
up to 112 bytes. Hyper-V can also return data back to the guest in the
remaining XMM registers that are not used by the current hypercall.
Although the Hyper-v TLFS mentions that a guest cannot use this feature
unless the hypervisor advertises support for it, some hypercalls which
we plan on upstreaming in future uses them anyway. This patchset adds
necessary infrastructure for handling input/output via XMM registers and
patches kvm_hv_flush_tlb() to use xmm input arguments.
~ Sid.
v3:
- Remove inline for kvm_hv_hypercall_{read,write}_xmm()
- Fix typo: s/ouput/output/
- Remove sse128_t from kvm_emulate.h
- Reword comment to match TLFS wording
- Move num XMM registers macro to hyperv-tlfs.h
- Stop advertising HV_X64_HYPERCALL_XMM_OUTPUT_AVAILABLE
v2:
- Remove inline for kvm_hv_hypercall_{read,write}_xmm()
- Fix typo: s/ouput/output/
- Remove sse128_t from kvm_emulate.h
- Reword comment to match TLFS wording
- Move num XMM registers macro to hyperv-tlfs.h
- Stop advertising HV_X64_HYPERCALL_XMM_OUTPUT_AVAILABLE
Siddharth Chandrasekaran (4):
KVM: x86: Move FPU register accessors into fpu.h
KVM: hyper-v: Collect hypercall params into struct
KVM: x86: kvm_hv_flush_tlb use inputs from XMM registers
KVM: hyper-v: Advertise support for fast XMM hypercalls
arch/x86/include/asm/hyperv-tlfs.h | 9 +-
arch/x86/kvm/emulate.c | 137 +++---------------
arch/x86/kvm/fpu.h | 140 ++++++++++++++++++
arch/x86/kvm/hyperv.c | 222 +++++++++++++++++++----------
arch/x86/kvm/kvm_emulate.h | 3 +-
5 files changed, 309 insertions(+), 202 deletions(-)
create mode 100644 arch/x86/kvm/fpu.h
--
2.17.1
Amazon Development Center Germany GmbH
Krausenstr. 38
10117 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B
Sitz: Berlin
Ust-ID: DE 289 237 879
As of now there are 7 parameters (and flags) that are used in various
hyper-v hypercall handlers. There are 6 more input/output parameters
passed from XMM registers which are to be added in an upcoming patch.
To make passing arguments to the handlers more readable, capture all
these parameters into a single structure.
Cc: Alexander Graf <[email protected]>
Cc: Evgeny Iakovlev <[email protected]>
Signed-off-by: Siddharth Chandrasekaran <[email protected]>
---
arch/x86/kvm/hyperv.c | 147 +++++++++++++++++++++++-------------------
1 file changed, 79 insertions(+), 68 deletions(-)
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index f98370a39936..8a542243e1cd 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1623,7 +1623,18 @@ static __always_inline unsigned long *sparse_set_to_vcpu_mask(
return vcpu_bitmap;
}
-static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, u64 ingpa, u16 rep_cnt, bool ex)
+struct kvm_hv_hcall {
+ u64 param;
+ u64 ingpa;
+ u64 outgpa;
+ u16 code;
+ u16 rep_cnt;
+ u16 rep_idx;
+ bool fast;
+ bool rep;
+};
+
+static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc, bool ex)
{
struct kvm *kvm = vcpu->kvm;
struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
@@ -1638,7 +1649,7 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, u64 ingpa, u16 rep_cnt, bool
bool all_cpus;
if (!ex) {
- if (unlikely(kvm_read_guest(kvm, ingpa, &flush, sizeof(flush))))
+ if (unlikely(kvm_read_guest(kvm, hc->ingpa, &flush, sizeof(flush))))
return HV_STATUS_INVALID_HYPERCALL_INPUT;
trace_kvm_hv_flush_tlb(flush.processor_mask,
@@ -1657,7 +1668,7 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, u64 ingpa, u16 rep_cnt, bool
all_cpus = (flush.flags & HV_FLUSH_ALL_PROCESSORS) ||
flush.processor_mask == 0;
} else {
- if (unlikely(kvm_read_guest(kvm, ingpa, &flush_ex,
+ if (unlikely(kvm_read_guest(kvm, hc->ingpa, &flush_ex,
sizeof(flush_ex))))
return HV_STATUS_INVALID_HYPERCALL_INPUT;
@@ -1679,8 +1690,8 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, u64 ingpa, u16 rep_cnt, bool
if (!all_cpus &&
kvm_read_guest(kvm,
- ingpa + offsetof(struct hv_tlb_flush_ex,
- hv_vp_set.bank_contents),
+ hc->ingpa + offsetof(struct hv_tlb_flush_ex,
+ hv_vp_set.bank_contents),
sparse_banks,
sparse_banks_len))
return HV_STATUS_INVALID_HYPERCALL_INPUT;
@@ -1700,9 +1711,9 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, u64 ingpa, u16 rep_cnt, bool
NULL, vcpu_mask, &hv_vcpu->tlb_flush);
ret_success:
- /* We always do full TLB flush, set rep_done = rep_cnt. */
+ /* We always do full TLB flush, set 'Reps completed' = 'Rep Count' */
return (u64)HV_STATUS_SUCCESS |
- ((u64)rep_cnt << HV_HYPERCALL_REP_COMP_OFFSET);
+ ((u64)hc->rep_cnt << HV_HYPERCALL_REP_COMP_OFFSET);
}
static void kvm_send_ipi_to_many(struct kvm *kvm, u32 vector,
@@ -1724,8 +1735,7 @@ static void kvm_send_ipi_to_many(struct kvm *kvm, u32 vector,
}
}
-static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, u64 ingpa, u64 outgpa,
- bool ex, bool fast)
+static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc, bool ex)
{
struct kvm *kvm = vcpu->kvm;
struct hv_send_ipi_ex send_ipi_ex;
@@ -1740,25 +1750,25 @@ static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, u64 ingpa, u64 outgpa,
bool all_cpus;
if (!ex) {
- if (!fast) {
- if (unlikely(kvm_read_guest(kvm, ingpa, &send_ipi,
+ if (!hc->fast) {
+ if (unlikely(kvm_read_guest(kvm, hc->ingpa, &send_ipi,
sizeof(send_ipi))))
return HV_STATUS_INVALID_HYPERCALL_INPUT;
sparse_banks[0] = send_ipi.cpu_mask;
vector = send_ipi.vector;
} else {
/* 'reserved' part of hv_send_ipi should be 0 */
- if (unlikely(ingpa >> 32 != 0))
+ if (unlikely(hc->ingpa >> 32 != 0))
return HV_STATUS_INVALID_HYPERCALL_INPUT;
- sparse_banks[0] = outgpa;
- vector = (u32)ingpa;
+ sparse_banks[0] = hc->outgpa;
+ vector = (u32)hc->ingpa;
}
all_cpus = false;
valid_bank_mask = BIT_ULL(0);
trace_kvm_hv_send_ipi(vector, sparse_banks[0]);
} else {
- if (unlikely(kvm_read_guest(kvm, ingpa, &send_ipi_ex,
+ if (unlikely(kvm_read_guest(kvm, hc->ingpa, &send_ipi_ex,
sizeof(send_ipi_ex))))
return HV_STATUS_INVALID_HYPERCALL_INPUT;
@@ -1778,8 +1788,8 @@ static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, u64 ingpa, u64 outgpa,
if (!all_cpus &&
kvm_read_guest(kvm,
- ingpa + offsetof(struct hv_send_ipi_ex,
- vp_set.bank_contents),
+ hc->ingpa + offsetof(struct hv_send_ipi_ex,
+ vp_set.bank_contents),
sparse_banks,
sparse_banks_len))
return HV_STATUS_INVALID_HYPERCALL_INPUT;
@@ -1839,20 +1849,21 @@ static int kvm_hv_hypercall_complete_userspace(struct kvm_vcpu *vcpu)
return kvm_hv_hypercall_complete(vcpu, vcpu->run->hyperv.u.hcall.result);
}
-static u16 kvm_hvcall_signal_event(struct kvm_vcpu *vcpu, bool fast, u64 param)
+static u16 kvm_hvcall_signal_event(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
{
struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
struct eventfd_ctx *eventfd;
- if (unlikely(!fast)) {
+ if (unlikely(!hc->fast)) {
int ret;
- gpa_t gpa = param;
+ gpa_t gpa = hc->ingpa;
- if ((gpa & (__alignof__(param) - 1)) ||
- offset_in_page(gpa) + sizeof(param) > PAGE_SIZE)
+ if ((gpa & (__alignof__(hc->ingpa) - 1)) ||
+ offset_in_page(gpa) + sizeof(hc->ingpa) > PAGE_SIZE)
return HV_STATUS_INVALID_ALIGNMENT;
- ret = kvm_vcpu_read_guest(vcpu, gpa, ¶m, sizeof(param));
+ ret = kvm_vcpu_read_guest(vcpu, gpa,
+ &hc->ingpa, sizeof(hc->ingpa));
if (ret < 0)
return HV_STATUS_INVALID_ALIGNMENT;
}
@@ -1862,15 +1873,15 @@ static u16 kvm_hvcall_signal_event(struct kvm_vcpu *vcpu, bool fast, u64 param)
* have no use for it, and in all known usecases it is zero, so just
* report lookup failure if it isn't.
*/
- if (param & 0xffff00000000ULL)
+ if (hc->ingpa & 0xffff00000000ULL)
return HV_STATUS_INVALID_PORT_ID;
/* remaining bits are reserved-zero */
- if (param & ~KVM_HYPERV_CONN_ID_MASK)
+ if (hc->ingpa & ~KVM_HYPERV_CONN_ID_MASK)
return HV_STATUS_INVALID_HYPERCALL_INPUT;
/* the eventfd is protected by vcpu->kvm->srcu, but conn_to_evt isn't */
rcu_read_lock();
- eventfd = idr_find(&hv->conn_to_evt, param);
+ eventfd = idr_find(&hv->conn_to_evt, hc->ingpa);
rcu_read_unlock();
if (!eventfd)
return HV_STATUS_INVALID_PORT_ID;
@@ -1881,9 +1892,8 @@ static u16 kvm_hvcall_signal_event(struct kvm_vcpu *vcpu, bool fast, u64 param)
int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
{
- u64 param, ingpa, outgpa, ret = HV_STATUS_SUCCESS;
- uint16_t code, rep_idx, rep_cnt;
- bool fast, rep;
+ struct kvm_hv_hcall hc;
+ u64 ret = HV_STATUS_SUCCESS;
/*
* hypercall generates UD from non zero cpl and real mode
@@ -1896,104 +1906,105 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
#ifdef CONFIG_X86_64
if (is_64_bit_mode(vcpu)) {
- param = kvm_rcx_read(vcpu);
- ingpa = kvm_rdx_read(vcpu);
- outgpa = kvm_r8_read(vcpu);
+ hc.param = kvm_rcx_read(vcpu);
+ hc.ingpa = kvm_rdx_read(vcpu);
+ hc.outgpa = kvm_r8_read(vcpu);
} else
#endif
{
- param = ((u64)kvm_rdx_read(vcpu) << 32) |
- (kvm_rax_read(vcpu) & 0xffffffff);
- ingpa = ((u64)kvm_rbx_read(vcpu) << 32) |
- (kvm_rcx_read(vcpu) & 0xffffffff);
- outgpa = ((u64)kvm_rdi_read(vcpu) << 32) |
- (kvm_rsi_read(vcpu) & 0xffffffff);
+ hc.param = ((u64)kvm_rdx_read(vcpu) << 32) |
+ (kvm_rax_read(vcpu) & 0xffffffff);
+ hc.ingpa = ((u64)kvm_rbx_read(vcpu) << 32) |
+ (kvm_rcx_read(vcpu) & 0xffffffff);
+ hc.outgpa = ((u64)kvm_rdi_read(vcpu) << 32) |
+ (kvm_rsi_read(vcpu) & 0xffffffff);
}
- code = param & 0xffff;
- fast = !!(param & HV_HYPERCALL_FAST_BIT);
- rep_cnt = (param >> HV_HYPERCALL_REP_COMP_OFFSET) & 0xfff;
- rep_idx = (param >> HV_HYPERCALL_REP_START_OFFSET) & 0xfff;
- rep = !!(rep_cnt || rep_idx);
+ hc.code = hc.param & 0xffff;
+ hc.fast = !!(hc.param & HV_HYPERCALL_FAST_BIT);
+ hc.rep_cnt = (hc.param >> HV_HYPERCALL_REP_COMP_OFFSET) & 0xfff;
+ hc.rep_idx = (hc.param >> HV_HYPERCALL_REP_START_OFFSET) & 0xfff;
+ hc.rep = !!(hc.rep_cnt || hc.rep_idx);
- trace_kvm_hv_hypercall(code, fast, rep_cnt, rep_idx, ingpa, outgpa);
+ trace_kvm_hv_hypercall(hc.code, hc.fast, hc.rep_cnt, hc.rep_idx,
+ hc.ingpa, hc.outgpa);
- switch (code) {
+ switch (hc.code) {
case HVCALL_NOTIFY_LONG_SPIN_WAIT:
- if (unlikely(rep)) {
+ if (unlikely(hc.rep)) {
ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
break;
}
kvm_vcpu_on_spin(vcpu, true);
break;
case HVCALL_SIGNAL_EVENT:
- if (unlikely(rep)) {
+ if (unlikely(hc.rep)) {
ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
break;
}
- ret = kvm_hvcall_signal_event(vcpu, fast, ingpa);
+ ret = kvm_hvcall_signal_event(vcpu, &hc);
if (ret != HV_STATUS_INVALID_PORT_ID)
break;
fallthrough; /* maybe userspace knows this conn_id */
case HVCALL_POST_MESSAGE:
/* don't bother userspace if it has no way to handle it */
- if (unlikely(rep || !to_hv_synic(vcpu)->active)) {
+ if (unlikely(hc.rep || !to_hv_synic(vcpu)->active)) {
ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
break;
}
vcpu->run->exit_reason = KVM_EXIT_HYPERV;
vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
- vcpu->run->hyperv.u.hcall.input = param;
- vcpu->run->hyperv.u.hcall.params[0] = ingpa;
- vcpu->run->hyperv.u.hcall.params[1] = outgpa;
+ vcpu->run->hyperv.u.hcall.input = hc.param;
+ vcpu->run->hyperv.u.hcall.params[0] = hc.ingpa;
+ vcpu->run->hyperv.u.hcall.params[1] = hc.outgpa;
vcpu->arch.complete_userspace_io =
kvm_hv_hypercall_complete_userspace;
return 0;
case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
- if (unlikely(fast || !rep_cnt || rep_idx)) {
+ if (unlikely(hc.fast || !hc.rep_cnt || hc.rep_idx)) {
ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
break;
}
- ret = kvm_hv_flush_tlb(vcpu, ingpa, rep_cnt, false);
+ ret = kvm_hv_flush_tlb(vcpu, &hc, false);
break;
case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
- if (unlikely(fast || rep)) {
+ if (unlikely(hc.fast || hc.rep)) {
ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
break;
}
- ret = kvm_hv_flush_tlb(vcpu, ingpa, rep_cnt, false);
+ ret = kvm_hv_flush_tlb(vcpu, &hc, false);
break;
case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
- if (unlikely(fast || !rep_cnt || rep_idx)) {
+ if (unlikely(hc.fast || !hc.rep_cnt || hc.rep_idx)) {
ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
break;
}
- ret = kvm_hv_flush_tlb(vcpu, ingpa, rep_cnt, true);
+ ret = kvm_hv_flush_tlb(vcpu, &hc, true);
break;
case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
- if (unlikely(fast || rep)) {
+ if (unlikely(hc.fast || hc.rep)) {
ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
break;
}
- ret = kvm_hv_flush_tlb(vcpu, ingpa, rep_cnt, true);
+ ret = kvm_hv_flush_tlb(vcpu, &hc, true);
break;
case HVCALL_SEND_IPI:
- if (unlikely(rep)) {
+ if (unlikely(hc.rep)) {
ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
break;
}
- ret = kvm_hv_send_ipi(vcpu, ingpa, outgpa, false, fast);
+ ret = kvm_hv_send_ipi(vcpu, &hc, false);
break;
case HVCALL_SEND_IPI_EX:
- if (unlikely(fast || rep)) {
+ if (unlikely(hc.fast || hc.rep)) {
ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
break;
}
- ret = kvm_hv_send_ipi(vcpu, ingpa, outgpa, true, false);
+ ret = kvm_hv_send_ipi(vcpu, &hc, true);
break;
case HVCALL_POST_DEBUG_DATA:
case HVCALL_RETRIEVE_DEBUG_DATA:
- if (unlikely(fast)) {
+ if (unlikely(hc.fast)) {
ret = HV_STATUS_INVALID_PARAMETER;
break;
}
@@ -2012,9 +2023,9 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
}
vcpu->run->exit_reason = KVM_EXIT_HYPERV;
vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
- vcpu->run->hyperv.u.hcall.input = param;
- vcpu->run->hyperv.u.hcall.params[0] = ingpa;
- vcpu->run->hyperv.u.hcall.params[1] = outgpa;
+ vcpu->run->hyperv.u.hcall.input = hc.param;
+ vcpu->run->hyperv.u.hcall.params[0] = hc.ingpa;
+ vcpu->run->hyperv.u.hcall.params[1] = hc.outgpa;
vcpu->arch.complete_userspace_io =
kvm_hv_hypercall_complete_userspace;
return 0;
--
2.17.1
Amazon Development Center Germany GmbH
Krausenstr. 38
10117 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B
Sitz: Berlin
Ust-ID: DE 289 237 879