| Message ID | 20231221140239.4349-9-weijiang.yang@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Enable CET Virtualization | expand |
On Thu, 2023-12-21 at 09:02 -0500, Yang Weijiang wrote: > From: Sean Christopherson <seanjc@google.com> > > Rework and rename cpuid_get_supported_xcr0() to explicitly operate on > vCPU state, i.e. on a vCPU's CPUID state, now that the only usage of > the helper is to retrieve a vCPU's already-set CPUID. > > Prior to commit 275a87244ec8 ("KVM: x86: Don't adjust guest's CPUID.0x12.1 > (allowed SGX enclave XFRM)"), KVM incorrectly fudged guest CPUID at runtime, > which in turn necessitated massaging the incoming CPUID state for > KVM_SET_CPUID{2} so as not to run afoul of kvm_cpuid_check_equal(). > I.e. KVM also invoked cpuid_get_supported_xcr0() with the incoming CPUID > state, and thus without an explicit vCPU object. > > Opportunistically move the helper below kvm_update_cpuid_runtime() to make > it harder to repeat the mistake of querying supported XCR0 for runtime > updates. > > No functional change intended. > > Signed-off-by: Sean Christopherson <seanjc@google.com> > Signed-off-by: Yang Weijiang <weijiang.yang@intel.com> > --- > arch/x86/kvm/cpuid.c | 33 ++++++++++++++++----------------- > 1 file changed, 16 insertions(+), 17 deletions(-) > > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > index 294e5bd5f8a0..624954203b40 100644 > --- a/arch/x86/kvm/cpuid.c > +++ b/arch/x86/kvm/cpuid.c > @@ -247,21 +247,6 @@ void kvm_update_pv_runtime(struct kvm_vcpu *vcpu) > vcpu->arch.pv_cpuid.features = best->eax; > } > > -/* > - * Calculate guest's supported XCR0 taking into account guest CPUID data and > - * KVM's supported XCR0 (comprised of host's XCR0 and KVM_SUPPORTED_XCR0). > - */ > -static u64 cpuid_get_supported_xcr0(struct kvm_cpuid_entry2 *entries, int nent) > -{ > - struct kvm_cpuid_entry2 *best; > - > - best = cpuid_entry2_find(entries, nent, 0xd, 0); > - if (!best) > - return 0; > - > - return (best->eax | ((u64)best->edx << 32)) & kvm_caps.supported_xcr0; > -} > - > static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *entries, > int nent) > { > @@ -312,6 +297,21 @@ void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu) > } > EXPORT_SYMBOL_GPL(kvm_update_cpuid_runtime); > > +/* > + * Calculate guest's supported XCR0 taking into account guest CPUID data and > + * KVM's supported XCR0 (comprised of host's XCR0 and KVM_SUPPORTED_XCR0). > + */ > +static u64 vcpu_get_supported_xcr0(struct kvm_vcpu *vcpu) > +{ > + struct kvm_cpuid_entry2 *best; > + > + best = kvm_find_cpuid_entry_index(vcpu, 0xd, 0); > + if (!best) > + return 0; > + > + return (best->eax | ((u64)best->edx << 32)) & kvm_caps.supported_xcr0; > +} > + > static bool kvm_cpuid_has_hyperv(struct kvm_cpuid_entry2 *entries, int nent) > { > #ifdef CONFIG_KVM_HYPERV > @@ -361,8 +361,7 @@ static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) > kvm_apic_set_version(vcpu); > } > > - vcpu->arch.guest_supported_xcr0 = > - cpuid_get_supported_xcr0(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent); > + vcpu->arch.guest_supported_xcr0 = vcpu_get_supported_xcr0(vcpu); > > kvm_update_pv_runtime(vcpu); > Looks like I forgot to add my reviewed-by: Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Best regards, Maxim Levitsky
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 294e5bd5f8a0..624954203b40 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -247,21 +247,6 @@ void kvm_update_pv_runtime(struct kvm_vcpu *vcpu) vcpu->arch.pv_cpuid.features = best->eax; } -/* - * Calculate guest's supported XCR0 taking into account guest CPUID data and - * KVM's supported XCR0 (comprised of host's XCR0 and KVM_SUPPORTED_XCR0). - */ -static u64 cpuid_get_supported_xcr0(struct kvm_cpuid_entry2 *entries, int nent) -{ - struct kvm_cpuid_entry2 *best; - - best = cpuid_entry2_find(entries, nent, 0xd, 0); - if (!best) - return 0; - - return (best->eax | ((u64)best->edx << 32)) & kvm_caps.supported_xcr0; -} - static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *entries, int nent) { @@ -312,6 +297,21 @@ void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu) } EXPORT_SYMBOL_GPL(kvm_update_cpuid_runtime); +/* + * Calculate guest's supported XCR0 taking into account guest CPUID data and + * KVM's supported XCR0 (comprised of host's XCR0 and KVM_SUPPORTED_XCR0). + */ +static u64 vcpu_get_supported_xcr0(struct kvm_vcpu *vcpu) +{ + struct kvm_cpuid_entry2 *best; + + best = kvm_find_cpuid_entry_index(vcpu, 0xd, 0); + if (!best) + return 0; + + return (best->eax | ((u64)best->edx << 32)) & kvm_caps.supported_xcr0; +} + static bool kvm_cpuid_has_hyperv(struct kvm_cpuid_entry2 *entries, int nent) { #ifdef CONFIG_KVM_HYPERV @@ -361,8 +361,7 @@ static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) kvm_apic_set_version(vcpu); } - vcpu->arch.guest_supported_xcr0 = - cpuid_get_supported_xcr0(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent); + vcpu->arch.guest_supported_xcr0 = vcpu_get_supported_xcr0(vcpu); kvm_update_pv_runtime(vcpu);