3.12-stable review patch. If anyone has any objections, please let me know.
------------------ From: Jan Kiszka <[email protected]> commit 29bf08f12b2fd72b882da0d85b7385e4a438a297 upstream. 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. Signed-off-by: Jan Kiszka <[email protected]> Signed-off-by: Marcelo Tosatti <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/x86/kvm/vmx.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -8218,8 +8218,7 @@ static void load_vmcs12_host_state(struc 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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
