* [PATCH 0/9] KVM: x86: Add a quirk for feature MSR initialization
@ 2024-08-02 18:55 Sean Christopherson
2024-08-02 18:55 ` [PATCH 1/9] KVM: x86: Co-locate initialization of feature MSRs in kvm_arch_vcpu_create() Sean Christopherson
` (9 more replies)
0 siblings, 10 replies; 12+ messages in thread
From: Sean Christopherson @ 2024-08-02 18:55 UTC (permalink / raw)
To: Paolo Bonzini, Sean Christopherson; +Cc: kvm, linux-kernel
The primary goal of this series to fix an issue where KVM's initialization
of feature MSRs during vCPU creation results in a failed save/restore of
PERF_CAPABILITIES. If userspace configures the VM to _not_ have a PMU,
because KVM initializes the vCPU's PERF_CAPABILTIIES, trying to save/restore
the non-zero value will be rejected by the destination.
The secondary goal is to try and avoid such goofs in the future, by making
it explicitly clear that userspace owns the vCPU model.
To achieve both goals, quirk KVM's initialization of feature MSRs and give
userspace full control of feature MSRs, mostly. I left VMX_CR{0,4}_FIXED1
as-is, partly because there was pushback on quirking those in the past[1],
partly because I (somewhat begrudgingly) actually think that it makes sense
for KVM to take control of the allowed-1 CR4 bits, as there is no known use
case for having the post-VMXON CR4 bits diverge from pre-VMXON (guest CPUID),
and trying to sort out what should happen if there was a divergence would be
a mess.
I did apply the quirk to VMX secondary execution controls, because unlike
the CR{0,4} bits, KVM doesn't take _full_ control, and more importantly, I
want to stem the bleeding and avoid KVM fiddling with more VMX MSRs, e.g.
tertiary controls.
Note, this applies on top of the MSR userspace access series [2], and the
tests will fail without those underlying changes.
[1] https://lore.kernel.org/all/20220607213604.3346000-13-seanjc@google.com
[2] https://lore.kernel.org/all/20240802181935.292540-1-seanjc@google.com
Sean Christopherson (9):
KVM: x86: Co-locate initialization of feature MSRs in
kvm_arch_vcpu_create()
KVM: x86: Disallow changing MSR_PLATFORM_INFO after vCPU has run
KVM: x86: Quirk initialization of feature MSRs to KVM's max
configuration
KVM: x86: Reject userspace attempts to access PERF_CAPABILITIES w/o
PDCM
KVM: VMX: Remove restriction that PMU version > 0 for
PERF_CAPABILITIES
KVM: x86: Reject userspace attempts to access ARCH_CAPABILITIES w/o
support
KVM: x86: Remove ordering check b/w MSR_PLATFORM_INFO and
MISC_FEATURES_ENABLES
KVM: selftests: Verify get/set PERF_CAPABILITIES w/o guest PDMC
behavior
KVM: selftests: Add a testcase for disabling feature MSRs init quirk
Documentation/virt/kvm/api.rst | 22 ++++
arch/x86/include/asm/kvm_host.h | 3 +-
arch/x86/include/uapi/asm/kvm.h | 1 +
arch/x86/kvm/svm/svm.c | 4 +-
arch/x86/kvm/vmx/vmx.c | 11 +-
arch/x86/kvm/x86.c | 34 +++---
tools/testing/selftests/kvm/Makefile | 2 +-
.../selftests/kvm/x86_64/feature_msrs_test.c | 113 ++++++++++++++++++
.../kvm/x86_64/get_msr_index_features.c | 35 ------
.../selftests/kvm/x86_64/platform_info_test.c | 2 -
.../selftests/kvm/x86_64/vmx_pmu_caps_test.c | 23 ++++
11 files changed, 189 insertions(+), 61 deletions(-)
create mode 100644 tools/testing/selftests/kvm/x86_64/feature_msrs_test.c
delete mode 100644 tools/testing/selftests/kvm/x86_64/get_msr_index_features.c
base-commit: 540fa2dc3c53613817bd7b345e1466d4a6f0ab5d
--
2.46.0.rc2.264.g509ed76dc8-goog
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH 1/9] KVM: x86: Co-locate initialization of feature MSRs in kvm_arch_vcpu_create()
2024-08-02 18:55 [PATCH 0/9] KVM: x86: Add a quirk for feature MSR initialization Sean Christopherson
@ 2024-08-02 18:55 ` Sean Christopherson
2024-08-02 18:55 ` [PATCH 2/9] KVM: x86: Disallow changing MSR_PLATFORM_INFO after vCPU has run Sean Christopherson
` (8 subsequent siblings)
9 siblings, 0 replies; 12+ messages in thread
From: Sean Christopherson @ 2024-08-02 18:55 UTC (permalink / raw)
To: Paolo Bonzini, Sean Christopherson; +Cc: kvm, linux-kernel
Bunch all of the feature MSR initialization in kvm_arch_vcpu_create() so
that it can be easily quirked in a future patch.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/x86.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 08c3480f1606..9d667c5ab1a9 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -12259,6 +12259,8 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
kvm_async_pf_hash_reset(vcpu);
+ vcpu->arch.arch_capabilities = kvm_get_arch_capabilities();
+ vcpu->arch.msr_platform_info = MSR_PLATFORM_INFO_CPUID_FAULT;
vcpu->arch.perf_capabilities = kvm_caps.supported_perf_cap;
kvm_pmu_init(vcpu);
@@ -12273,8 +12275,6 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
if (r)
goto free_guest_fpu;
- vcpu->arch.arch_capabilities = kvm_get_arch_capabilities();
- vcpu->arch.msr_platform_info = MSR_PLATFORM_INFO_CPUID_FAULT;
kvm_xen_init_vcpu(vcpu);
vcpu_load(vcpu);
kvm_set_tsc_khz(vcpu, vcpu->kvm->arch.default_tsc_khz);
--
2.46.0.rc2.264.g509ed76dc8-goog
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH 2/9] KVM: x86: Disallow changing MSR_PLATFORM_INFO after vCPU has run
2024-08-02 18:55 [PATCH 0/9] KVM: x86: Add a quirk for feature MSR initialization Sean Christopherson
2024-08-02 18:55 ` [PATCH 1/9] KVM: x86: Co-locate initialization of feature MSRs in kvm_arch_vcpu_create() Sean Christopherson
@ 2024-08-02 18:55 ` Sean Christopherson
2024-08-02 18:55 ` [PATCH 3/9] KVM: x86: Quirk initialization of feature MSRs to KVM's max configuration Sean Christopherson
` (7 subsequent siblings)
9 siblings, 0 replies; 12+ messages in thread
From: Sean Christopherson @ 2024-08-02 18:55 UTC (permalink / raw)
To: Paolo Bonzini, Sean Christopherson; +Cc: kvm, linux-kernel
Tag MSR_PLATFORM_INFO as a feature MSR (because it is), i.e. disallow it
from being modified after the vCPU has run.
To make KVM's selftest compliant, simply delete the userspace MSR write
that restores KVM's original value at the end of the test. Verifying that
userspace can write back what it originally read is uninteresting in this
particular case, because KVM doesn't enforce _any_ bits in the MSR, i.e.
userspace should be able to write any arbitrary value.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/x86.c | 1 +
tools/testing/selftests/kvm/x86_64/platform_info_test.c | 2 --
2 files changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9d667c5ab1a9..a9566c035857 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -451,6 +451,7 @@ static const u32 msr_based_features_all_except_vmx[] = {
MSR_IA32_UCODE_REV,
MSR_IA32_ARCH_CAPABILITIES,
MSR_IA32_PERF_CAPABILITIES,
+ MSR_PLATFORM_INFO,
};
static u32 msr_based_features[ARRAY_SIZE(msr_based_features_all_except_vmx) +
diff --git a/tools/testing/selftests/kvm/x86_64/platform_info_test.c b/tools/testing/selftests/kvm/x86_64/platform_info_test.c
index eda88080c186..9cbf283ebc55 100644
--- a/tools/testing/selftests/kvm/x86_64/platform_info_test.c
+++ b/tools/testing/selftests/kvm/x86_64/platform_info_test.c
@@ -72,8 +72,6 @@ int main(int argc, char *argv[])
}
done:
- vcpu_set_msr(vcpu, MSR_PLATFORM_INFO, msr_platform_info);
-
kvm_vm_free(vm);
return 0;
--
2.46.0.rc2.264.g509ed76dc8-goog
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH 3/9] KVM: x86: Quirk initialization of feature MSRs to KVM's max configuration
2024-08-02 18:55 [PATCH 0/9] KVM: x86: Add a quirk for feature MSR initialization Sean Christopherson
2024-08-02 18:55 ` [PATCH 1/9] KVM: x86: Co-locate initialization of feature MSRs in kvm_arch_vcpu_create() Sean Christopherson
2024-08-02 18:55 ` [PATCH 2/9] KVM: x86: Disallow changing MSR_PLATFORM_INFO after vCPU has run Sean Christopherson
@ 2024-08-02 18:55 ` Sean Christopherson
2024-08-02 18:55 ` [PATCH 4/9] KVM: x86: Reject userspace attempts to access PERF_CAPABILITIES w/o PDCM Sean Christopherson
` (6 subsequent siblings)
9 siblings, 0 replies; 12+ messages in thread
From: Sean Christopherson @ 2024-08-02 18:55 UTC (permalink / raw)
To: Paolo Bonzini, Sean Christopherson; +Cc: kvm, linux-kernel
Add a quirk to control KVM's misguided initialization of select feature
MSRs to KVM's max configuration, as enabling features by default violates
KVM's approach of letting userspace own the vCPU model, and is actively
problematic for MSRs that are conditionally supported, as the vCPU will
end up with an MSR value that userspace can't restore. E.g. if the vCPU
is configured with PDCM=0, userspace will save and attempt to restore a
non-zero PERF_CAPABILITIES, thanks to KVM's meddling.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
Documentation/virt/kvm/api.rst | 22 ++++++++++++++++++++++
arch/x86/include/asm/kvm_host.h | 3 ++-
arch/x86/include/uapi/asm/kvm.h | 1 +
arch/x86/kvm/svm/svm.c | 4 +++-
arch/x86/kvm/vmx/vmx.c | 9 ++++++---
arch/x86/kvm/x86.c | 8 +++++---
6 files changed, 39 insertions(+), 8 deletions(-)
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 8e5dad80b337..d85480848e4e 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -8073,6 +8073,28 @@ KVM_X86_QUIRK_MWAIT_NEVER_UD_FAULTS By default, KVM emulates MONITOR/MWAIT (if
guest CPUID on writes to MISC_ENABLE if
KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT is
disabled.
+
+KVM_X86_QUIRK_STUFF_FEATURE_MSRS By default, at vCPU creation, KVM sets the
+ vCPU's MSR_IA32_PERF_CAPABILITIES (0x345),
+ MSR_IA32_ARCH_CAPABILITIES (0x10a),
+ MSR_PLATFORM_INFO (0xce), and all VMX MSRs
+ (0x480..0x492) to the maximal capabilities
+ supported by KVM. KVM also sets
+ MSR_IA32_UCODE_REV (0x8b) to an arbitrary
+ value (which is different for Intel vs.
+ AMD). Lastly, when guest CPUID is set (by
+ userspace), KVM modifies select VMX MSR
+ fields to force consistency between guest
+ CPUID and L2's effective ISA. When this
+ quirk is disabled, KVM zeroes the vCPU's MSR
+ values (with two exceptions, see below),
+ i.e. treats the feature MSRs like CPUID
+ leaves and gives userspace full control of
+ the vCPU model definition. This quirk does
+ not affect VMX MSRs CR0/CR4_FIXED1 (0x487
+ and 0x489), as KVM does now allow them to
+ be set by userspace (KVM sets them based on
+ guest CPUID, for safety purposes).
=================================== ============================================
7.32 KVM_CAP_MAX_VCPU_ID
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index b9d784abafdf..2fee988a6a44 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -2342,7 +2342,8 @@ int memslot_rmap_alloc(struct kvm_memory_slot *slot, unsigned long npages);
KVM_X86_QUIRK_OUT_7E_INC_RIP | \
KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT | \
KVM_X86_QUIRK_FIX_HYPERCALL_INSN | \
- KVM_X86_QUIRK_MWAIT_NEVER_UD_FAULTS)
+ KVM_X86_QUIRK_MWAIT_NEVER_UD_FAULTS | \
+ KVM_X86_QUIRK_STUFF_FEATURE_MSRS)
/*
* KVM previously used a u32 field in kvm_run to indicate the hypercall was
diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index bf57a824f722..f768902a73d4 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -439,6 +439,7 @@ struct kvm_sync_regs {
#define KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT (1 << 4)
#define KVM_X86_QUIRK_FIX_HYPERCALL_INSN (1 << 5)
#define KVM_X86_QUIRK_MWAIT_NEVER_UD_FAULTS (1 << 6)
+#define KVM_X86_QUIRK_STUFF_FEATURE_MSRS (1 << 7)
#define KVM_STATE_NESTED_FORMAT_VMX 0
#define KVM_STATE_NESTED_FORMAT_SVM 1
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index f6980e0d2941..e21c3a622764 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1390,7 +1390,9 @@ static void __svm_vcpu_reset(struct kvm_vcpu *vcpu)
svm_vcpu_init_msrpm(vcpu, svm->msrpm);
svm_init_osvw(vcpu);
- vcpu->arch.microcode_version = 0x01000065;
+
+ if (kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_STUFF_FEATURE_MSRS))
+ vcpu->arch.microcode_version = 0x01000065;
svm->tsc_ratio_msr = kvm_caps.default_tsc_scaling_ratio;
svm->nmi_masked = false;
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index cf85f8d50ccb..c1d06f800b8e 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4556,7 +4556,8 @@ vmx_adjust_secondary_exec_control(struct vcpu_vmx *vmx, u32 *exec_control,
* Update the nested MSR settings so that a nested VMM can/can't set
* controls for features that are/aren't exposed to the guest.
*/
- if (nested) {
+ if (nested &&
+ kvm_check_has_quirk(vmx->vcpu.kvm, KVM_X86_QUIRK_STUFF_FEATURE_MSRS)) {
/*
* All features that can be added or removed to VMX MSRs must
* be supported in the first place for nested virtualization.
@@ -4846,7 +4847,8 @@ static void __vmx_vcpu_reset(struct kvm_vcpu *vcpu)
init_vmcs(vmx);
- if (nested)
+ if (nested &&
+ kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_STUFF_FEATURE_MSRS))
memcpy(&vmx->nested.msrs, &vmcs_config.nested, sizeof(vmx->nested.msrs));
vcpu_setup_sgx_lepubkeyhash(vcpu);
@@ -4859,7 +4861,8 @@ static void __vmx_vcpu_reset(struct kvm_vcpu *vcpu)
vmx->nested.hv_evmcs_vmptr = EVMPTR_INVALID;
#endif
- vcpu->arch.microcode_version = 0x100000000ULL;
+ if (kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_STUFF_FEATURE_MSRS))
+ vcpu->arch.microcode_version = 0x100000000ULL;
vmx->msr_ia32_feature_control_valid_bits = FEAT_CTL_LOCKED;
/*
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a9566c035857..9b52d8f3304f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -12260,9 +12260,11 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
kvm_async_pf_hash_reset(vcpu);
- vcpu->arch.arch_capabilities = kvm_get_arch_capabilities();
- vcpu->arch.msr_platform_info = MSR_PLATFORM_INFO_CPUID_FAULT;
- vcpu->arch.perf_capabilities = kvm_caps.supported_perf_cap;
+ if (kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_STUFF_FEATURE_MSRS)) {
+ vcpu->arch.arch_capabilities = kvm_get_arch_capabilities();
+ vcpu->arch.msr_platform_info = MSR_PLATFORM_INFO_CPUID_FAULT;
+ vcpu->arch.perf_capabilities = kvm_caps.supported_perf_cap;
+ }
kvm_pmu_init(vcpu);
vcpu->arch.pending_external_vector = -1;
--
2.46.0.rc2.264.g509ed76dc8-goog
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH 4/9] KVM: x86: Reject userspace attempts to access PERF_CAPABILITIES w/o PDCM
2024-08-02 18:55 [PATCH 0/9] KVM: x86: Add a quirk for feature MSR initialization Sean Christopherson
` (2 preceding siblings ...)
2024-08-02 18:55 ` [PATCH 3/9] KVM: x86: Quirk initialization of feature MSRs to KVM's max configuration Sean Christopherson
@ 2024-08-02 18:55 ` Sean Christopherson
2024-08-02 18:55 ` [PATCH 5/9] KVM: VMX: Remove restriction that PMU version > 0 for PERF_CAPABILITIES Sean Christopherson
` (5 subsequent siblings)
9 siblings, 0 replies; 12+ messages in thread
From: Sean Christopherson @ 2024-08-02 18:55 UTC (permalink / raw)
To: Paolo Bonzini, Sean Christopherson; +Cc: kvm, linux-kernel
Reject userspace accesses to PERF_CAPABILITIES if PDCM isn't set in guest
CPUID, i.e. if the vCPU doesn't actually have PERF_CAPABILITIES. But! Do
so via KVM_MSR_RET_UNSUPPORTED, so that reads get '0' and writes of '0'
are ignored if KVM advertised support PERF_CAPABILITIES.
KVM's ABI is that userspace must set guest CPUID prior to setting MSRs,
and that setting MSRs that aren't supposed exist is disallowed (modulo the
'0' exemption).
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/x86.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9b52d8f3304f..dbb5e06ef264 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3803,8 +3803,10 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
vcpu->arch.arch_capabilities = data;
break;
case MSR_IA32_PERF_CAPABILITIES:
- if (!msr_info->host_initiated)
- return 1;
+ if (!msr_info->host_initiated ||
+ !guest_cpuid_has(vcpu, X86_FEATURE_PDCM))
+ return KVM_MSR_RET_UNSUPPORTED;
+
if (data & ~kvm_caps.supported_perf_cap)
return 1;
@@ -4263,9 +4265,8 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
msr_info->data = vcpu->arch.arch_capabilities;
break;
case MSR_IA32_PERF_CAPABILITIES:
- if (!msr_info->host_initiated &&
- !guest_cpuid_has(vcpu, X86_FEATURE_PDCM))
- return 1;
+ if (!guest_cpuid_has(vcpu, X86_FEATURE_PDCM))
+ return KVM_MSR_RET_UNSUPPORTED;
msr_info->data = vcpu->arch.perf_capabilities;
break;
case MSR_IA32_POWER_CTL:
--
2.46.0.rc2.264.g509ed76dc8-goog
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH 5/9] KVM: VMX: Remove restriction that PMU version > 0 for PERF_CAPABILITIES
2024-08-02 18:55 [PATCH 0/9] KVM: x86: Add a quirk for feature MSR initialization Sean Christopherson
` (3 preceding siblings ...)
2024-08-02 18:55 ` [PATCH 4/9] KVM: x86: Reject userspace attempts to access PERF_CAPABILITIES w/o PDCM Sean Christopherson
@ 2024-08-02 18:55 ` Sean Christopherson
2024-08-02 18:55 ` [PATCH 6/9] KVM: x86: Reject userspace attempts to access ARCH_CAPABILITIES w/o support Sean Christopherson
` (4 subsequent siblings)
9 siblings, 0 replies; 12+ messages in thread
From: Sean Christopherson @ 2024-08-02 18:55 UTC (permalink / raw)
To: Paolo Bonzini, Sean Christopherson; +Cc: kvm, linux-kernel
Drop the restriction that the PMU version is non-zero when handling writes
to PERF_CAPABILITIES now that KVM unconditionally checks for PDCM support.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/vmx/vmx.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index c1d06f800b8e..f636d811bdc1 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2460,8 +2460,6 @@ int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
vmx->pt_desc.guest.addr_a[index / 2] = data;
break;
case MSR_IA32_PERF_CAPABILITIES:
- if (data && !vcpu_to_pmu(vcpu)->version)
- return 1;
if (data & PMU_CAP_LBR_FMT) {
if ((data & PMU_CAP_LBR_FMT) !=
(kvm_caps.supported_perf_cap & PMU_CAP_LBR_FMT))
--
2.46.0.rc2.264.g509ed76dc8-goog
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH 6/9] KVM: x86: Reject userspace attempts to access ARCH_CAPABILITIES w/o support
2024-08-02 18:55 [PATCH 0/9] KVM: x86: Add a quirk for feature MSR initialization Sean Christopherson
` (4 preceding siblings ...)
2024-08-02 18:55 ` [PATCH 5/9] KVM: VMX: Remove restriction that PMU version > 0 for PERF_CAPABILITIES Sean Christopherson
@ 2024-08-02 18:55 ` Sean Christopherson
2024-08-02 18:55 ` [PATCH 7/9] KVM: x86: Remove ordering check b/w MSR_PLATFORM_INFO and MISC_FEATURES_ENABLES Sean Christopherson
` (3 subsequent siblings)
9 siblings, 0 replies; 12+ messages in thread
From: Sean Christopherson @ 2024-08-02 18:55 UTC (permalink / raw)
To: Paolo Bonzini, Sean Christopherson; +Cc: kvm, linux-kernel
Reject userspace accesses to ARCH_CAPABILITIES if the MSR isn't supposed
to exist, according to guest CPUID. However, "reject" accesses with
KVM_MSR_RET_UNSUPPORTED, so that reads get '0' and writes of '0' are
ignored if KVM advertised support ARCH_CAPABILITIES.
KVM's ABI is that userspace must set guest CPUID prior to setting MSRs,
and that setting MSRs that aren't supposed exist is disallowed (modulo the
'0' exemption).
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/x86.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index dbb5e06ef264..8bce40c649b4 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3798,8 +3798,9 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
vcpu->arch.microcode_version = data;
break;
case MSR_IA32_ARCH_CAPABILITIES:
- if (!msr_info->host_initiated)
- return 1;
+ if (!msr_info->host_initiated ||
+ !guest_cpuid_has(vcpu, X86_FEATURE_ARCH_CAPABILITIES))
+ return KVM_MSR_RET_UNSUPPORTED;
vcpu->arch.arch_capabilities = data;
break;
case MSR_IA32_PERF_CAPABILITIES:
@@ -4259,9 +4260,8 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
msr_info->data = vcpu->arch.microcode_version;
break;
case MSR_IA32_ARCH_CAPABILITIES:
- if (!msr_info->host_initiated &&
- !guest_cpuid_has(vcpu, X86_FEATURE_ARCH_CAPABILITIES))
- return 1;
+ if (!guest_cpuid_has(vcpu, X86_FEATURE_ARCH_CAPABILITIES))
+ return KVM_MSR_RET_UNSUPPORTED;
msr_info->data = vcpu->arch.arch_capabilities;
break;
case MSR_IA32_PERF_CAPABILITIES:
--
2.46.0.rc2.264.g509ed76dc8-goog
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH 7/9] KVM: x86: Remove ordering check b/w MSR_PLATFORM_INFO and MISC_FEATURES_ENABLES
2024-08-02 18:55 [PATCH 0/9] KVM: x86: Add a quirk for feature MSR initialization Sean Christopherson
` (5 preceding siblings ...)
2024-08-02 18:55 ` [PATCH 6/9] KVM: x86: Reject userspace attempts to access ARCH_CAPABILITIES w/o support Sean Christopherson
@ 2024-08-02 18:55 ` Sean Christopherson
2024-08-02 18:55 ` [PATCH 8/9] KVM: selftests: Verify get/set PERF_CAPABILITIES w/o guest PDMC behavior Sean Christopherson
` (2 subsequent siblings)
9 siblings, 0 replies; 12+ messages in thread
From: Sean Christopherson @ 2024-08-02 18:55 UTC (permalink / raw)
To: Paolo Bonzini, Sean Christopherson; +Cc: kvm, linux-kernel
Drop KVM's odd restriction that disallows clearing CPUID_FAULT in
MSR_PLATFORM_INFO if CPL>0 CPUID faulting is enabled in
MSR_MISC_FEATURES_ENABLES. KVM generally doesn't require specific
ordering when userspace sets MSRs, and the completely arbitrary order of
MSRs in emulated_msrs_all means that a userspace that uses KVM's list
verbatim could run afoul of the check.
Dropping the restriction obviously means that userspace could stuff a
nonsensical vCPU model, but that's the case all over KVM. KVM typically
restricts userspace MSR writes only when it makes things easier for KVM
and/or userspace.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/x86.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 8bce40c649b4..32483cc16d6a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4119,9 +4119,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
vcpu->arch.osvw.status = data;
break;
case MSR_PLATFORM_INFO:
- if (!msr_info->host_initiated ||
- (!(data & MSR_PLATFORM_INFO_CPUID_FAULT) &&
- cpuid_fault_enabled(vcpu)))
+ if (!msr_info->host_initiated)
return 1;
vcpu->arch.msr_platform_info = data;
break;
--
2.46.0.rc2.264.g509ed76dc8-goog
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH 8/9] KVM: selftests: Verify get/set PERF_CAPABILITIES w/o guest PDMC behavior
2024-08-02 18:55 [PATCH 0/9] KVM: x86: Add a quirk for feature MSR initialization Sean Christopherson
` (6 preceding siblings ...)
2024-08-02 18:55 ` [PATCH 7/9] KVM: x86: Remove ordering check b/w MSR_PLATFORM_INFO and MISC_FEATURES_ENABLES Sean Christopherson
@ 2024-08-02 18:55 ` Sean Christopherson
2024-08-02 18:55 ` [PATCH 9/9] KVM: selftests: Add a testcase for disabling feature MSRs init quirk Sean Christopherson
2024-10-31 19:51 ` [PATCH 0/9] KVM: x86: Add a quirk for feature MSR initialization Sean Christopherson
9 siblings, 0 replies; 12+ messages in thread
From: Sean Christopherson @ 2024-08-02 18:55 UTC (permalink / raw)
To: Paolo Bonzini, Sean Christopherson; +Cc: kvm, linux-kernel
Add another testcase to x86's PMU capabilities test to verify that KVM's
handling of userspace accesses to PERF_CAPABILITIES when the vCPU doesn't
support the MSR (per the vCPU's CPUID). KVM's (newly established) ABI is
that userspace MSR accesses are subject to architectural existence checks,
but that if the MSR is advertised as supported _by KVM_, "bad" reads get
'0' and writes of '0' are always allowed.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
.../selftests/kvm/x86_64/vmx_pmu_caps_test.c | 23 +++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/tools/testing/selftests/kvm/x86_64/vmx_pmu_caps_test.c b/tools/testing/selftests/kvm/x86_64/vmx_pmu_caps_test.c
index 7c92536551cc..a1f5ff45d518 100644
--- a/tools/testing/selftests/kvm/x86_64/vmx_pmu_caps_test.c
+++ b/tools/testing/selftests/kvm/x86_64/vmx_pmu_caps_test.c
@@ -207,6 +207,29 @@ KVM_ONE_VCPU_TEST(vmx_pmu_caps, lbr_perf_capabilities, guest_code)
TEST_ASSERT(!r, "Writing LBR_TOS should fail after disabling vPMU");
}
+KVM_ONE_VCPU_TEST(vmx_pmu_caps, perf_capabilities_unsupported, guest_code)
+{
+ uint64_t val;
+ int i, r;
+
+ vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, host_cap.capabilities);
+ val = vcpu_get_msr(vcpu, MSR_IA32_PERF_CAPABILITIES);
+ TEST_ASSERT_EQ(val, host_cap.capabilities);
+
+ vcpu_clear_cpuid_feature(vcpu, X86_FEATURE_PDCM);
+
+ val = vcpu_get_msr(vcpu, MSR_IA32_PERF_CAPABILITIES);
+ TEST_ASSERT_EQ(val, 0);
+
+ vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, 0);
+
+ for (i = 0; i < 64; i++) {
+ r = _vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, BIT_ULL(i));
+ TEST_ASSERT(!r, "Setting PERF_CAPABILITIES bit %d (= 0x%llx) should fail without PDCM",
+ i, BIT_ULL(i));
+ }
+}
+
int main(int argc, char *argv[])
{
TEST_REQUIRE(kvm_is_pmu_enabled());
--
2.46.0.rc2.264.g509ed76dc8-goog
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH 9/9] KVM: selftests: Add a testcase for disabling feature MSRs init quirk
2024-08-02 18:55 [PATCH 0/9] KVM: x86: Add a quirk for feature MSR initialization Sean Christopherson
` (7 preceding siblings ...)
2024-08-02 18:55 ` [PATCH 8/9] KVM: selftests: Verify get/set PERF_CAPABILITIES w/o guest PDMC behavior Sean Christopherson
@ 2024-08-02 18:55 ` Sean Christopherson
2024-10-31 19:51 ` [PATCH 0/9] KVM: x86: Add a quirk for feature MSR initialization Sean Christopherson
9 siblings, 0 replies; 12+ messages in thread
From: Sean Christopherson @ 2024-08-02 18:55 UTC (permalink / raw)
To: Paolo Bonzini, Sean Christopherson; +Cc: kvm, linux-kernel
Expand and rename the feature MSRs test to verify KVM's ABI and quirk
for initializing feature MSRs.
Exempt VM_CR{0,4}_FIXED1 from most tests as KVM intentionally takes full
control of the MSRs, e.g. to prevent L1 from running L2 with bogus CR0
and/or CR4 values.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
tools/testing/selftests/kvm/Makefile | 2 +-
.../selftests/kvm/x86_64/feature_msrs_test.c | 113 ++++++++++++++++++
.../kvm/x86_64/get_msr_index_features.c | 35 ------
3 files changed, 114 insertions(+), 36 deletions(-)
create mode 100644 tools/testing/selftests/kvm/x86_64/feature_msrs_test.c
delete mode 100644 tools/testing/selftests/kvm/x86_64/get_msr_index_features.c
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index b084ba2262a0..827b523a18fa 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -67,7 +67,7 @@ TEST_PROGS_x86_64 += x86_64/nx_huge_pages_test.sh
TEST_GEN_PROGS_x86_64 = x86_64/cpuid_test
TEST_GEN_PROGS_x86_64 += x86_64/cr4_cpuid_sync_test
TEST_GEN_PROGS_x86_64 += x86_64/dirty_log_page_splitting_test
-TEST_GEN_PROGS_x86_64 += x86_64/get_msr_index_features
+TEST_GEN_PROGS_x86_64 += x86_64/feature_msrs_test
TEST_GEN_PROGS_x86_64 += x86_64/exit_on_emulation_failure_test
TEST_GEN_PROGS_x86_64 += x86_64/fix_hypercall_test
TEST_GEN_PROGS_x86_64 += x86_64/hwcr_msr_test
diff --git a/tools/testing/selftests/kvm/x86_64/feature_msrs_test.c b/tools/testing/selftests/kvm/x86_64/feature_msrs_test.c
new file mode 100644
index 000000000000..a72f13ae2edb
--- /dev/null
+++ b/tools/testing/selftests/kvm/x86_64/feature_msrs_test.c
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020, Red Hat, Inc.
+ */
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "processor.h"
+
+static bool is_kvm_controlled_msr(uint32_t msr)
+{
+ return msr == MSR_IA32_VMX_CR0_FIXED1 || msr == MSR_IA32_VMX_CR4_FIXED1;
+}
+
+/*
+ * For VMX MSRs with a "true" variant, KVM requires userspace to set the "true"
+ * MSR, and doesn't allow setting the hidden version.
+ */
+static bool is_hidden_vmx_msr(uint32_t msr)
+{
+ switch (msr) {
+ case MSR_IA32_VMX_PINBASED_CTLS:
+ case MSR_IA32_VMX_PROCBASED_CTLS:
+ case MSR_IA32_VMX_EXIT_CTLS:
+ case MSR_IA32_VMX_ENTRY_CTLS:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static bool is_quirked_msr(uint32_t msr)
+{
+ return msr != MSR_AMD64_DE_CFG;
+}
+
+static void test_feature_msr(uint32_t msr)
+{
+ const uint64_t supported_mask = kvm_get_feature_msr(msr);
+ uint64_t reset_value = is_quirked_msr(msr) ? supported_mask : 0;
+ struct kvm_vcpu *vcpu;
+ struct kvm_vm *vm;
+
+ /*
+ * Don't bother testing KVM-controlled MSRs beyond verifying that the
+ * MSR can be read from userspace. Any value is effectively legal, as
+ * KVM is bound by x86 architecture, not by ABI.
+ */
+ if (is_kvm_controlled_msr(msr))
+ return;
+
+ /*
+ * More goofy behavior. KVM reports the host CPU's actual revision ID,
+ * but initializes the vCPU's revision ID to an arbitrary value.
+ */
+ if (msr == MSR_IA32_UCODE_REV)
+ reset_value = host_cpu_is_intel ? 0x100000000ULL : 0x01000065;
+
+ /*
+ * For quirked MSRs, KVM's ABI is to initialize the vCPU's value to the
+ * full set of features supported by KVM. For non-quirked MSRs, and
+ * when the quirk is disabled, KVM must zero-initialize the MSR and let
+ * userspace do the configuration.
+ */
+ vm = vm_create_with_one_vcpu(&vcpu, NULL);
+ TEST_ASSERT(vcpu_get_msr(vcpu, msr) == reset_value,
+ "Wanted 0x%lx for %squirked MSR 0x%x, got 0x%lx",
+ reset_value, is_quirked_msr(msr) ? "" : "non-", msr,
+ vcpu_get_msr(vcpu, msr));
+ if (!is_hidden_vmx_msr(msr))
+ vcpu_set_msr(vcpu, msr, supported_mask);
+ kvm_vm_free(vm);
+
+ if (is_hidden_vmx_msr(msr))
+ return;
+
+ if (!kvm_has_cap(KVM_CAP_DISABLE_QUIRKS2) ||
+ !(kvm_check_cap(KVM_CAP_DISABLE_QUIRKS2) & KVM_X86_QUIRK_STUFF_FEATURE_MSRS))
+ return;
+
+ vm = vm_create(1);
+ vm_enable_cap(vm, KVM_CAP_DISABLE_QUIRKS2, KVM_X86_QUIRK_STUFF_FEATURE_MSRS);
+
+ vcpu = vm_vcpu_add(vm, 0, NULL);
+ TEST_ASSERT(!vcpu_get_msr(vcpu, msr),
+ "Quirk disabled, wanted '0' for MSR 0x%x, got 0x%lx",
+ msr, vcpu_get_msr(vcpu, msr));
+ kvm_vm_free(vm);
+}
+
+int main(int argc, char *argv[])
+{
+ const struct kvm_msr_list *feature_list;
+ int i;
+
+ /*
+ * Skip the entire test if MSR_FEATURES isn't supported, other tests
+ * will cover the "regular" list of MSRs, the coverage here is purely
+ * opportunistic and not interesting on its own.
+ */
+ TEST_REQUIRE(kvm_has_cap(KVM_CAP_GET_MSR_FEATURES));
+
+ (void)kvm_get_msr_index_list();
+
+ feature_list = kvm_get_feature_msr_index_list();
+ for (i = 0; i < feature_list->nmsrs; i++)
+ test_feature_msr(feature_list->indices[i]);
+}
diff --git a/tools/testing/selftests/kvm/x86_64/get_msr_index_features.c b/tools/testing/selftests/kvm/x86_64/get_msr_index_features.c
deleted file mode 100644
index d09b3cbcadc6..000000000000
--- a/tools/testing/selftests/kvm/x86_64/get_msr_index_features.c
+++ /dev/null
@@ -1,35 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Test that KVM_GET_MSR_INDEX_LIST and
- * KVM_GET_MSR_FEATURE_INDEX_LIST work as intended
- *
- * Copyright (C) 2020, Red Hat, Inc.
- */
-#include <fcntl.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/ioctl.h>
-
-#include "test_util.h"
-#include "kvm_util.h"
-#include "processor.h"
-
-int main(int argc, char *argv[])
-{
- const struct kvm_msr_list *feature_list;
- int i;
-
- /*
- * Skip the entire test if MSR_FEATURES isn't supported, other tests
- * will cover the "regular" list of MSRs, the coverage here is purely
- * opportunistic and not interesting on its own.
- */
- TEST_REQUIRE(kvm_has_cap(KVM_CAP_GET_MSR_FEATURES));
-
- (void)kvm_get_msr_index_list();
-
- feature_list = kvm_get_feature_msr_index_list();
- for (i = 0; i < feature_list->nmsrs; i++)
- kvm_get_feature_msr(feature_list->indices[i]);
-}
--
2.46.0.rc2.264.g509ed76dc8-goog
^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH 0/9] KVM: x86: Add a quirk for feature MSR initialization
2024-08-02 18:55 [PATCH 0/9] KVM: x86: Add a quirk for feature MSR initialization Sean Christopherson
` (8 preceding siblings ...)
2024-08-02 18:55 ` [PATCH 9/9] KVM: selftests: Add a testcase for disabling feature MSRs init quirk Sean Christopherson
@ 2024-10-31 19:51 ` Sean Christopherson
2024-11-01 19:23 ` Sean Christopherson
9 siblings, 1 reply; 12+ messages in thread
From: Sean Christopherson @ 2024-10-31 19:51 UTC (permalink / raw)
To: Sean Christopherson, Paolo Bonzini; +Cc: kvm, linux-kernel
On Fri, 02 Aug 2024 11:55:02 -0700, Sean Christopherson wrote:
> The primary goal of this series to fix an issue where KVM's initialization
> of feature MSRs during vCPU creation results in a failed save/restore of
> PERF_CAPABILITIES. If userspace configures the VM to _not_ have a PMU,
> because KVM initializes the vCPU's PERF_CAPABILTIIES, trying to save/restore
> the non-zero value will be rejected by the destination.
>
> The secondary goal is to try and avoid such goofs in the future, by making
> it explicitly clear that userspace owns the vCPU model.
>
> [...]
Applied to kvm-x86 misc, thanks!
[1/9] KVM: x86: Co-locate initialization of feature MSRs in kvm_arch_vcpu_create()
https://github.com/kvm-x86/linux/commit/383383cfd202
[2/9] KVM: x86: Disallow changing MSR_PLATFORM_INFO after vCPU has run
https://github.com/kvm-x86/linux/commit/d76a5e78f16d
[3/9] KVM: x86: Quirk initialization of feature MSRs to KVM's max configuration
https://github.com/kvm-x86/linux/commit/088b8eeb25ec
[4/9] KVM: x86: Reject userspace attempts to access PERF_CAPABILITIES w/o PDCM
https://github.com/kvm-x86/linux/commit/c2eb2d0318c0
[5/9] KVM: VMX: Remove restriction that PMU version > 0 for PERF_CAPABILITIES
https://github.com/kvm-x86/linux/commit/bae593b20e92
[6/9] KVM: x86: Reject userspace attempts to access ARCH_CAPABILITIES w/o support
https://github.com/kvm-x86/linux/commit/83a5fe6cf1eb
[7/9] KVM: x86: Remove ordering check b/w MSR_PLATFORM_INFO and MISC_FEATURES_ENABLES
https://github.com/kvm-x86/linux/commit/9d2dcfb82db1
[8/9] KVM: selftests: Verify get/set PERF_CAPABILITIES w/o guest PDMC behavior
https://github.com/kvm-x86/linux/commit/6a4511f8602f
[9/9] KVM: selftests: Add a testcase for disabling feature MSRs init quirk
https://github.com/kvm-x86/linux/commit/58a7368f104d
--
https://github.com/kvm-x86/linux/tree/next
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 0/9] KVM: x86: Add a quirk for feature MSR initialization
2024-10-31 19:51 ` [PATCH 0/9] KVM: x86: Add a quirk for feature MSR initialization Sean Christopherson
@ 2024-11-01 19:23 ` Sean Christopherson
0 siblings, 0 replies; 12+ messages in thread
From: Sean Christopherson @ 2024-11-01 19:23 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: kvm, linux-kernel
On Thu, Oct 31, 2024, Sean Christopherson wrote:
> On Fri, 02 Aug 2024 11:55:02 -0700, Sean Christopherson wrote:
> > The primary goal of this series to fix an issue where KVM's initialization
> > of feature MSRs during vCPU creation results in a failed save/restore of
> > PERF_CAPABILITIES. If userspace configures the VM to _not_ have a PMU,
> > because KVM initializes the vCPU's PERF_CAPABILTIIES, trying to save/restore
> > the non-zero value will be rejected by the destination.
> >
> > The secondary goal is to try and avoid such goofs in the future, by making
> > it explicitly clear that userspace owns the vCPU model.
> >
> > [...]
>
> Applied to kvm-x86 misc, thanks!
>
> [1/9] KVM: x86: Co-locate initialization of feature MSRs in kvm_arch_vcpu_create()
> https://github.com/kvm-x86/linux/commit/383383cfd202
> [2/9] KVM: x86: Disallow changing MSR_PLATFORM_INFO after vCPU has run
> https://github.com/kvm-x86/linux/commit/d76a5e78f16d
> [3/9] KVM: x86: Quirk initialization of feature MSRs to KVM's max configuration
> https://github.com/kvm-x86/linux/commit/088b8eeb25ec
> [4/9] KVM: x86: Reject userspace attempts to access PERF_CAPABILITIES w/o PDCM
> https://github.com/kvm-x86/linux/commit/c2eb2d0318c0
> [5/9] KVM: VMX: Remove restriction that PMU version > 0 for PERF_CAPABILITIES
> https://github.com/kvm-x86/linux/commit/bae593b20e92
> [6/9] KVM: x86: Reject userspace attempts to access ARCH_CAPABILITIES w/o support
> https://github.com/kvm-x86/linux/commit/83a5fe6cf1eb
> [7/9] KVM: x86: Remove ordering check b/w MSR_PLATFORM_INFO and MISC_FEATURES_ENABLES
> https://github.com/kvm-x86/linux/commit/9d2dcfb82db1
> [8/9] KVM: selftests: Verify get/set PERF_CAPABILITIES w/o guest PDMC behavior
> https://github.com/kvm-x86/linux/commit/6a4511f8602f
> [9/9] KVM: selftests: Add a testcase for disabling feature MSRs init quirk
> https://github.com/kvm-x86/linux/commit/58a7368f104d
FYI, I rebased misc to v6.12-rc5, as patches in another series had already been
taken through the tip tree. New hashes:
[1/9] KVM: x86: Co-locate initialization of feature MSRs in kvm_arch_vcpu_create()
https://github.com/kvm-x86/linux/commit/2142ac663a6a
[2/9] KVM: x86: Disallow changing MSR_PLATFORM_INFO after vCPU has run
https://github.com/kvm-x86/linux/commit/bc2ca3680b30
[3/9] KVM: x86: Quirk initialization of feature MSRs to KVM's max configuration
https://github.com/kvm-x86/linux/commit/dcb988cdac85
[4/9] KVM: x86: Reject userspace attempts to access PERF_CAPABILITIES w/o PDCM
https://github.com/kvm-x86/linux/commit/d75cac366f44
[5/9] KVM: VMX: Remove restriction that PMU version > 0 for PERF_CAPABILITIES
https://github.com/kvm-x86/linux/commit/a1039111192b
[6/9] KVM: x86: Reject userspace attempts to access ARCH_CAPABILITIES w/o support
https://github.com/kvm-x86/linux/commit/a5d563890b8f
[7/9] KVM: x86: Remove ordering check b/w MSR_PLATFORM_INFO and MISC_FEATURES_ENABLES
https://github.com/kvm-x86/linux/commit/1ded7a57b805
[8/9] KVM: selftests: Verify get/set PERF_CAPABILITIES w/o guest PDMC behavior
https://github.com/kvm-x86/linux/commit/b799e3e7da2c
[9/9] KVM: selftests: Add a testcase for disabling feature MSRs init quirk
https://github.com/kvm-x86/linux/commit/0581dfbad954
^ permalink raw reply [flat|nested] 12+ messages in thread
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Thread overview: 12+ messages (download: mbox.gz follow: Atom feed
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2024-08-02 18:55 [PATCH 0/9] KVM: x86: Add a quirk for feature MSR initialization Sean Christopherson
2024-08-02 18:55 ` [PATCH 1/9] KVM: x86: Co-locate initialization of feature MSRs in kvm_arch_vcpu_create() Sean Christopherson
2024-08-02 18:55 ` [PATCH 2/9] KVM: x86: Disallow changing MSR_PLATFORM_INFO after vCPU has run Sean Christopherson
2024-08-02 18:55 ` [PATCH 3/9] KVM: x86: Quirk initialization of feature MSRs to KVM's max configuration Sean Christopherson
2024-08-02 18:55 ` [PATCH 4/9] KVM: x86: Reject userspace attempts to access PERF_CAPABILITIES w/o PDCM Sean Christopherson
2024-08-02 18:55 ` [PATCH 5/9] KVM: VMX: Remove restriction that PMU version > 0 for PERF_CAPABILITIES Sean Christopherson
2024-08-02 18:55 ` [PATCH 6/9] KVM: x86: Reject userspace attempts to access ARCH_CAPABILITIES w/o support Sean Christopherson
2024-08-02 18:55 ` [PATCH 7/9] KVM: x86: Remove ordering check b/w MSR_PLATFORM_INFO and MISC_FEATURES_ENABLES Sean Christopherson
2024-08-02 18:55 ` [PATCH 8/9] KVM: selftests: Verify get/set PERF_CAPABILITIES w/o guest PDMC behavior Sean Christopherson
2024-08-02 18:55 ` [PATCH 9/9] KVM: selftests: Add a testcase for disabling feature MSRs init quirk Sean Christopherson
2024-10-31 19:51 ` [PATCH 0/9] KVM: x86: Add a quirk for feature MSR initialization Sean Christopherson
2024-11-01 19:23 ` Sean Christopherson
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