From: Yang Weijiang <weijiang.yang@intel.com>
To: pbonzini@redhat.com, jmattson@google.com, seanjc@google.com,
like.xu.linux@gmail.com, vkuznets@redhat.com,
kan.liang@linux.intel.com, wei.w.wang@intel.com,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Yang Weijiang <weijiang.yang@intel.com>,
Zhang Yi Z <yi.z.zhang@linux.intel.com>
Subject: [PATCH v12 04/16] KVM: x86: Refresh CPUID on writes to MSR_IA32_XSS
Date: Tue, 17 May 2022 11:40:48 -0400 [thread overview]
Message-ID: <20220517154100.29983-5-weijiang.yang@intel.com> (raw)
In-Reply-To: <20220517154100.29983-1-weijiang.yang@intel.com>
Updated CPUID.0xD.0x1, which reports the current required storage size
of all features enabled via XCR0 | XSS, when the guest's XSS is modified.
Note, KVM does not yet support any XSS based features, i.e. supported_xss
is guaranteed to be zero at this time.
Co-developed-by: Zhang Yi Z <yi.z.zhang@linux.intel.com>
Signed-off-by: Zhang Yi Z <yi.z.zhang@linux.intel.com>
Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
---
arch/x86/kvm/cpuid.c | 16 +++++++++++++---
arch/x86/kvm/x86.c | 6 ++++--
2 files changed, 17 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 8c1a3b2430a8..b88609847188 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -239,9 +239,19 @@ static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_e
best->ebx = xstate_required_size(vcpu->arch.xcr0, false);
best = cpuid_entry2_find(entries, nent, 0xD, 1);
- if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) ||
- cpuid_entry_has(best, X86_FEATURE_XSAVEC)))
- best->ebx = xstate_required_size(vcpu->arch.xcr0, true);
+ if (best) {
+ if (cpuid_entry_has(best, X86_FEATURE_XSAVES) ||
+ cpuid_entry_has(best, X86_FEATURE_XSAVEC)) {
+ u64 xstate = vcpu->arch.xcr0 | vcpu->arch.ia32_xss;
+
+ best->ebx = xstate_required_size(xstate, true);
+ }
+
+ if (!cpuid_entry_has(best, X86_FEATURE_XSAVES)) {
+ best->ecx = 0;
+ best->edx = 0;
+ }
+ }
best = __kvm_find_kvm_cpuid_features(vcpu, entries, nent);
if (kvm_hlt_in_guest(vcpu->kvm) && best &&
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6dcfedf10734..247c58f5c8af 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3613,8 +3613,10 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
*/
if (data & ~supported_xss)
return 1;
- vcpu->arch.ia32_xss = data;
- kvm_update_cpuid_runtime(vcpu);
+ if (vcpu->arch.ia32_xss != data) {
+ vcpu->arch.ia32_xss = data;
+ kvm_update_cpuid_runtime(vcpu);
+ }
break;
case MSR_SMI_COUNT:
if (!msr_info->host_initiated)
--
2.27.0
next prev parent reply other threads:[~2022-05-17 15:42 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-17 15:40 [PATCH v12 00/16] Introduce Architectural LBR for vPMU Yang Weijiang
2022-05-17 15:40 ` [PATCH v12 01/16] perf/x86/intel: Fix the comment about guest LBR support on KVM Yang Weijiang
2022-05-17 15:40 ` [PATCH v12 02/16] perf/x86/lbr: Simplify the exposure check for the LBR_INFO registers Yang Weijiang
2022-05-17 15:40 ` [PATCH v12 03/16] KVM: x86: Report XSS as an MSR to be saved if there are supported features Yang Weijiang
2022-05-17 15:40 ` Yang Weijiang [this message]
2022-05-17 15:40 ` [PATCH v12 05/16] KVM: x86: Add Arch LBR MSRs to msrs_to_save_all list Yang Weijiang
2022-05-17 15:40 ` [PATCH v12 06/16] KVM: vmx/pmu: Emulate MSR_ARCH_LBR_DEPTH for guest Arch LBR Yang Weijiang
2022-05-17 15:40 ` [PATCH v12 07/16] KVM: vmx/pmu: Emulate MSR_ARCH_LBR_CTL " Yang Weijiang
2022-05-17 15:40 ` [PATCH v12 08/16] KVM: x86/pmu: Refactor code to support " Yang Weijiang
2022-05-17 15:40 ` [PATCH v12 09/16] KVM: x86: Refine the matching and clearing logic for supported_xss Yang Weijiang
2022-05-17 15:40 ` [PATCH v12 10/16] KVM: x86/vmx: Check Arch LBR config when return perf capabilities Yang Weijiang
2022-05-17 15:40 ` [PATCH v12 11/16] KVM: x86: Add XSAVE Support for Architectural LBR Yang Weijiang
2022-05-17 15:40 ` [PATCH v12 12/16] KVM: nVMX: Add necessary Arch LBR settings for nested VM Yang Weijiang
2022-05-17 15:40 ` [PATCH v12 13/16] KVM: x86/vmx: Clear Arch LBREn bit before inject #DB to guest Yang Weijiang
2022-05-17 15:40 ` [PATCH v12 14/16] KVM: x86/vmx: Flip Arch LBREn bit on guest state change Yang Weijiang
2022-05-17 15:40 ` [PATCH v12 15/16] KVM: x86: Add Arch LBR data MSR access interface Yang Weijiang
2022-05-17 15:41 ` [PATCH v12 16/16] KVM: x86/cpuid: Advertise Arch LBR feature in CPUID Yang Weijiang
2022-05-20 12:28 ` [PATCH v12 00/16] Introduce Architectural LBR for vPMU Paolo Bonzini
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