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| author | Jan Kiszka <jan.kiszka@web.de> | 2013-12-28 16:31:52 +0100 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2014-01-02 11:22:14 -0200 |
| commit | 29bf08f12b2fd72b882da0d85b7385e4a438a297 (patch) | |
| tree | 28885189e817ce710ec013f05911c1babeeab462 | |
| parent | e66d2ae7c67bd9ac982a3d1890564de7f7eabf4b (diff) | |
| download | lwn-29bf08f12b2fd72b882da0d85b7385e4a438a297.tar.gz lwn-29bf08f12b2fd72b882da0d85b7385e4a438a297.zip | |
KVM: nVMX: Unconditionally uninit the MMU on nested vmexit
Three reasons for doing this: 1. arch.walk_mmu points to arch.mmu anyway
in case nested EPT wasn't in use. 2. this aligns VMX with SVM. But 3. is
most important: nested_cpu_has_ept(vmcs12) queries the VMCS page, and if
one guest VCPU manipulates the page of another VCPU in L2, we may be
fooled to skip over the nested_ept_uninit_mmu_context, leaving mmu in
nested state. That can crash the host later on if nested_ept_get_cr3 is
invoked while L1 already left vmxon and nested.current_vmcs12 became
NULL therefore.
Cc: stable@kernel.org
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
| -rw-r--r-- | arch/x86/kvm/vmx.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index b2fe1c252f35..da7837e1349d 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -8283,8 +8283,7 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu, vcpu->arch.cr4_guest_owned_bits = ~vmcs_readl(CR4_GUEST_HOST_MASK); kvm_set_cr4(vcpu, vmcs12->host_cr4); - if (nested_cpu_has_ept(vmcs12)) - nested_ept_uninit_mmu_context(vcpu); + nested_ept_uninit_mmu_context(vcpu); kvm_set_cr3(vcpu, vmcs12->host_cr3); kvm_mmu_reset_context(vcpu); |