diff options
| author | Xiaoyao Li <xiaoyao.li@intel.com> | 2020-07-09 07:34:22 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-07-09 13:49:14 +0300 |
| commit | a76733a9875238e271a3fd5778d5596248904f07 (patch) | |
| tree | 348f26f3b9770899ef22847b3d77f47536b28c70 /arch/x86/kvm/cpuid.c | |
| parent | 36f37648ca982915918bea001a40172c5b0cb233 (diff) | |
| download | linux-a76733a9875238e271a3fd5778d5596248904f07.tar.xz | |
KVM: x86: Introduce kvm_check_cpuid()
Use kvm_check_cpuid() to validate if userspace provides legal cpuid
settings and call it before KVM take any action to update CPUID or
update vcpu states based on given CPUID settings.
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Message-Id: <20200709043426.92712-2-xiaoyao.li@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/cpuid.c')
| -rw-r--r-- | arch/x86/kvm/cpuid.c | 55 |
1 files changed, 35 insertions, 20 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index eebd66f86abe..1a053022a961 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -54,7 +54,26 @@ static u32 xstate_required_size(u64 xstate_bv, bool compacted) #define F feature_bit -int kvm_update_cpuid(struct kvm_vcpu *vcpu) +static int kvm_check_cpuid(struct kvm_vcpu *vcpu) +{ + struct kvm_cpuid_entry2 *best; + + /* + * The existing code assumes virtual address is 48-bit or 57-bit in the + * canonical address checks; exit if it is ever changed. + */ + best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); + if (best) { + int vaddr_bits = (best->eax & 0xff00) >> 8; + + if (vaddr_bits != 48 && vaddr_bits != 57 && vaddr_bits != 0) + return -EINVAL; + } + + return 0; +} + +void kvm_update_cpuid(struct kvm_vcpu *vcpu) { struct kvm_cpuid_entry2 *best; struct kvm_lapic *apic = vcpu->arch.apic; @@ -98,18 +117,6 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu) cpuid_entry_has(best, X86_FEATURE_XSAVEC))) best->ebx = xstate_required_size(vcpu->arch.xcr0, true); - /* - * The existing code assumes virtual address is 48-bit or 57-bit in the - * canonical address checks; exit if it is ever changed. - */ - best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); - if (best) { - int vaddr_bits = (best->eax & 0xff00) >> 8; - - if (vaddr_bits != 48 && vaddr_bits != 57 && vaddr_bits != 0) - return -EINVAL; - } - best = kvm_find_cpuid_entry(vcpu, KVM_CPUID_FEATURES, 0); if (kvm_hlt_in_guest(vcpu->kvm) && best && (best->eax & (1 << KVM_FEATURE_PV_UNHALT))) @@ -131,7 +138,6 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu) kvm_pmu_refresh(vcpu); vcpu->arch.cr4_guest_rsvd_bits = __cr4_reserved_bits(guest_cpuid_has, vcpu); - return 0; } static int is_efer_nx(void) @@ -206,11 +212,16 @@ int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, vcpu->arch.cpuid_entries[i].padding[2] = 0; } vcpu->arch.cpuid_nent = cpuid->nent; + r = kvm_check_cpuid(vcpu); + if (r) { + vcpu->arch.cpuid_nent = 0; + kvfree(cpuid_entries); + goto out; + } + cpuid_fix_nx_cap(vcpu); kvm_x86_ops.cpuid_update(vcpu); - r = kvm_update_cpuid(vcpu); - if (r) - vcpu->arch.cpuid_nent = 0; + kvm_update_cpuid(vcpu); kvfree(cpuid_entries); out: @@ -231,10 +242,14 @@ int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, cpuid->nent * sizeof(struct kvm_cpuid_entry2))) goto out; vcpu->arch.cpuid_nent = cpuid->nent; - kvm_x86_ops.cpuid_update(vcpu); - r = kvm_update_cpuid(vcpu); - if (r) + r = kvm_check_cpuid(vcpu); + if (r) { vcpu->arch.cpuid_nent = 0; + goto out; + } + + kvm_x86_ops.cpuid_update(vcpu); + kvm_update_cpuid(vcpu); out: return r; } |