From 52ad7eb3d668867f9ee2e34d715cfb4860d36a93 Mon Sep 17 00:00:00 2001 From: Liran Alon Date: Tue, 13 Nov 2018 17:44:46 +0200 Subject: [PATCH] KVM: nVMX: vmcs12 revision_id is always VMCS12_REVISION even when copied from eVMCS vmcs12 represents the per-CPU cache of L1 active vmcs12. This cache can be loaded by one of the following: 1) Guest making a vmcs12 active by exeucting VMPTRLD 2) Guest specifying eVMCS in VP assist page and executing VMLAUNCH/VMRESUME. Either way, vmcs12 should have revision_id of VMCS12_REVISION. Which is not equal to eVMCS revision_id which specifies used VersionNumber of eVMCS struct (e.g. KVM_EVMCS_VERSION). Specifically, this causes an issue in restoring a nested VM state because vmx_set_nested_state() verifies that vmcs12->revision_id is equal to VMCS12_REVISION which was not true in case vmcs12 was populated from an eVMCS by vmx_get_nested_state() which calls copy_enlightened_to_vmcs12(). Reviewed-by: Darren Kenny Signed-off-by: Liran Alon Reviewed-by: Vitaly Kuznetsov Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 0ffd8b2..02edd99 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -8673,8 +8673,6 @@ static int copy_enlightened_to_vmcs12(struct vcpu_vmx *vmx) struct vmcs12 *vmcs12 = vmx->nested.cached_vmcs12; struct hv_enlightened_vmcs *evmcs = vmx->nested.hv_evmcs; - vmcs12->hdr.revision_id = evmcs->revision_id; - /* HV_VMX_ENLIGHTENED_CLEAN_FIELD_NONE */ vmcs12->tpr_threshold = evmcs->tpr_threshold; vmcs12->guest_rip = evmcs->guest_rip; @@ -9422,9 +9420,11 @@ static int nested_vmx_handle_enlightened_vmptrld(struct kvm_vcpu *vcpu, * present in struct hv_enlightened_vmcs, ...). Make sure there * are no leftovers. */ - if (from_launch) - memset(vmx->nested.cached_vmcs12, 0, - sizeof(*vmx->nested.cached_vmcs12)); + if (from_launch) { + struct vmcs12 *vmcs12 = get_vmcs12(vcpu); + memset(vmcs12, 0, sizeof(*vmcs12)); + vmcs12->hdr.revision_id = VMCS12_REVISION; + } } return 1; -- 2.7.4