Messages in this thread Patch in this message | | | Date | Sun, 23 Jan 2022 12:37:44 +0800 | Subject | [PATCH v3] KVM: x86: Sync the states size with the XCR0/IA32_XSS at, any time | From | Like Xu <> |
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From: Like Xu <likexu@tencent.com>
XCR0 is reset to 1 by RESET but not INIT and IA32_XSS is zeroed by both RESET and INIT. The kvm_set_msr_common()'s handling of MSR_IA32_XSS also needs to update kvm_update_cpuid_runtime(). In the above cases, the size in bytes of the XSAVE area containing all states enabled by XCR0 or (XCRO | IA32_XSS) needs to be updated.
For simplicity and consistency, existing helpers are used to write values and call kvm_update_cpuid_runtime(), and it's not exactly a fast path.
Fixes: a554d207dc46 ("KVM: X86: Processor States following Reset or INIT") Signed-off-by: Like Xu <likexu@tencent.com> --- v2 -> v3 Changelog: - Apply s/legacy/existing in the commit message; (Sean) - Invoke kvm_update_cpuid_runtime() for MSR_IA32_XSS; (Sean)
arch/x86/kvm/x86.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 55518b7d3b96..4b509b26d9ab 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3535,6 +3535,7 @@ 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); break; case MSR_SMI_COUNT: if (!msr_info->host_initiated) @@ -11256,7 +11257,7 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
vcpu->arch.msr_misc_features_enables = 0;
- vcpu->arch.xcr0 = XFEATURE_MASK_FP; + __kvm_set_xcr(vcpu, 0, XFEATURE_MASK_FP); }
/* All GPRs except RDX (handled below) are zeroed on RESET/INIT. */ @@ -11273,7 +11274,7 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) cpuid_0x1 = kvm_find_cpuid_entry(vcpu, 1, 0); kvm_rdx_write(vcpu, cpuid_0x1 ? cpuid_0x1->eax : 0x600);
- vcpu->arch.ia32_xss = 0; + __kvm_set_msr(vcpu, MSR_IA32_XSS, 0, true);
static_call(kvm_x86_vcpu_reset)(vcpu, init_event);
-- 2.33.1
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