diff options
| -rw-r--r-- | arch/x86/kvm/cpuid.c | 42 |
1 files changed, 29 insertions, 13 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index eb52dde5deec..a0fedf1514ab 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -84,9 +84,12 @@ static inline struct kvm_cpuid_entry2 *cpuid_entry2_find( return NULL; } -static int kvm_check_cpuid(struct kvm_cpuid_entry2 *entries, int nent) +static int kvm_check_cpuid(struct kvm_vcpu *vcpu, + struct kvm_cpuid_entry2 *entries, + int nent) { struct kvm_cpuid_entry2 *best; + u64 xfeatures; /* * The existing code assumes virtual address is 48-bit or 57-bit in the @@ -100,7 +103,20 @@ static int kvm_check_cpuid(struct kvm_cpuid_entry2 *entries, int nent) return -EINVAL; } - return 0; + /* + * Exposing dynamic xfeatures to the guest requires additional + * enabling in the FPU, e.g. to expand the guest XSAVE state size. + */ + best = cpuid_entry2_find(entries, nent, 0xd, 0); + if (!best) + return 0; + + xfeatures = best->eax | ((u64)best->edx << 32); + xfeatures &= XFEATURE_MASK_USER_DYNAMIC; + if (!xfeatures) + return 0; + + return fpu_enable_guest_xfd_features(&vcpu->arch.guest_fpu, xfeatures); } static void kvm_update_kvm_cpuid_base(struct kvm_vcpu *vcpu) @@ -280,21 +296,21 @@ u64 kvm_vcpu_reserved_gpa_bits_raw(struct kvm_vcpu *vcpu) static int kvm_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2, int nent) { - int r; + int r; - r = kvm_check_cpuid(e2, nent); - if (r) - return r; + r = kvm_check_cpuid(vcpu, e2, nent); + if (r) + return r; - kvfree(vcpu->arch.cpuid_entries); - vcpu->arch.cpuid_entries = e2; - vcpu->arch.cpuid_nent = nent; + kvfree(vcpu->arch.cpuid_entries); + vcpu->arch.cpuid_entries = e2; + vcpu->arch.cpuid_nent = nent; - kvm_update_kvm_cpuid_base(vcpu); - kvm_update_cpuid_runtime(vcpu); - kvm_vcpu_after_set_cpuid(vcpu); + kvm_update_kvm_cpuid_base(vcpu); + kvm_update_cpuid_runtime(vcpu); + kvm_vcpu_after_set_cpuid(vcpu); - return 0; + return 0; } /* when an old userspace process fills a new kernel module */ |