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authorJim Mattson <jmattson@google.com>2017-08-10 10:14:13 -0700
committerPaolo Bonzini <pbonzini@redhat.com>2017-08-11 18:59:30 +0200
commitd3802286fa0f9886700f2e47c05876ddb86dcb77 (patch)
treefe99f4eea10114a46f113b3affb555d934b23b13 /arch
parent26eeb53cf0f9a0557be09b7efdeb2392c92b1a4f (diff)
downloadlinux-d3802286fa0f9886700f2e47c05876ddb86dcb77.tar.bz2
kvm: x86: Disallow illegal IA32_APIC_BASE MSR values
Host-initiated writes to the IA32_APIC_BASE MSR do not have to follow local APIC state transition constraints, but the value written must be valid. Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/x86.c14
1 files changed, 8 insertions, 6 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index e40a779711a9..e10eda86bc7b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -313,10 +313,10 @@ int kvm_set_apic_base(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
u64 reserved_bits = ((~0ULL) << cpuid_maxphyaddr(vcpu)) | 0x2ff |
(guest_cpuid_has(vcpu, X86_FEATURE_X2APIC) ? 0 : X2APIC_ENABLE);
+ if ((msr_info->data & reserved_bits) || new_state == X2APIC_ENABLE)
+ return 1;
if (!msr_info->host_initiated &&
- ((msr_info->data & reserved_bits) != 0 ||
- new_state == X2APIC_ENABLE ||
- (new_state == MSR_IA32_APICBASE_ENABLE &&
+ ((new_state == MSR_IA32_APICBASE_ENABLE &&
old_state == (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE)) ||
(new_state == (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE) &&
old_state == 0)))
@@ -7424,6 +7424,11 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
(sregs->cr4 & X86_CR4_OSXSAVE))
return -EINVAL;
+ apic_base_msr.data = sregs->apic_base;
+ apic_base_msr.host_initiated = true;
+ if (kvm_set_apic_base(vcpu, &apic_base_msr))
+ return -EINVAL;
+
dt.size = sregs->idt.limit;
dt.address = sregs->idt.base;
kvm_x86_ops->set_idt(vcpu, &dt);
@@ -7440,9 +7445,6 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
mmu_reset_needed |= vcpu->arch.efer != sregs->efer;
kvm_x86_ops->set_efer(vcpu, sregs->efer);
- apic_base_msr.data = sregs->apic_base;
- apic_base_msr.host_initiated = true;
- kvm_set_apic_base(vcpu, &apic_base_msr);
mmu_reset_needed |= kvm_read_cr0(vcpu) != sregs->cr0;
kvm_x86_ops->set_cr0(vcpu, sregs->cr0);