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| author | Nadav Amit <namit@cs.technion.ac.il> | 2014-09-16 15:10:03 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2014-09-24 14:07:48 +0200 |
| commit | dd598091de4aabbc8bd7290a04f364e443c03455 (patch) | |
| tree | 72123be86eb587d26b0bce0cca474aa05d3a2555 /arch/x86/kvm/cpuid.c | |
| parent | 3c3c29fd0d7cddc32862c350d0700ce69953e3bd (diff) | |
| download | linux-dd598091de4aabbc8bd7290a04f364e443c03455.tar.gz | |
KVM: x86: Warn if guest virtual address space is not 48-bits
The KVM emulator code assumes that the guest virtual address space (in 64-bit) is 48-bits wide. Fail the KVM_SET_CPUID and KVM_SET_CPUID2 ioctl if userspace tries to create a guest that does not obey this restriction. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/cpuid.c')
| -rw-r--r-- | arch/x86/kvm/cpuid.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index f4bad87ef256..e28d798f7277 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -53,14 +53,14 @@ u64 kvm_supported_xcr0(void) return xcr0; } -void kvm_update_cpuid(struct kvm_vcpu *vcpu) +int kvm_update_cpuid(struct kvm_vcpu *vcpu) { struct kvm_cpuid_entry2 *best; struct kvm_lapic *apic = vcpu->arch.apic; best = kvm_find_cpuid_entry(vcpu, 1, 0); if (!best) - return; + return 0; /* Update OSXSAVE bit */ if (cpu_has_xsave && best->function == 0x1) { @@ -88,7 +88,17 @@ void kvm_update_cpuid(struct kvm_vcpu *vcpu) xstate_required_size(vcpu->arch.xcr0); } + /* + * The existing code assumes virtual address is 48-bit in the canonical + * address checks; exit if it is ever changed. + */ + best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); + if (best && ((best->eax & 0xff00) >> 8) != 48 && + ((best->eax & 0xff00) >> 8) != 0) + return -EINVAL; + kvm_pmu_cpuid_update(vcpu); + return 0; } static int is_efer_nx(void) @@ -151,10 +161,9 @@ int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, } vcpu->arch.cpuid_nent = cpuid->nent; cpuid_fix_nx_cap(vcpu); - r = 0; kvm_apic_set_version(vcpu); kvm_x86_ops->cpuid_update(vcpu); - kvm_update_cpuid(vcpu); + r = kvm_update_cpuid(vcpu); out_free: vfree(cpuid_entries); @@ -178,9 +187,7 @@ int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, vcpu->arch.cpuid_nent = cpuid->nent; kvm_apic_set_version(vcpu); kvm_x86_ops->cpuid_update(vcpu); - kvm_update_cpuid(vcpu); - return 0; - + r = kvm_update_cpuid(vcpu); out: return r; } |