From 9ec19493fb86d6d5fbf9286b94ff21e56ef66376 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 2 Apr 2019 08:03:11 -0700 Subject: [PATCH] KVM: x86: clear SMM flags before loading state while leaving SMM RSM emulation is currently broken on VMX when the interrupted guest has CR4.VMXE=1. Stop dancing around the issue of HF_SMM_MASK being set when loading SMSTATE into architectural state, e.g. by toggling it for problematic flows, and simply clear HF_SMM_MASK prior to loading architectural state (from SMRAM save state area). Reported-by: Jon Doron Cc: Jim Mattson Cc: Liran Alon Cc: Vitaly Kuznetsov Fixes: 5bea5123cbf0 ("KVM: VMX: check nested state and CR4.VMXE against SMM") Signed-off-by: Sean Christopherson Tested-by: Vitaly Kuznetsov Signed-off-by: Paolo Bonzini --- arch/x86/kvm/emulate.c | 12 ++++++------ arch/x86/kvm/svm.c | 12 ++++-------- arch/x86/kvm/vmx/vmx.c | 2 -- 3 files changed, 10 insertions(+), 16 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index a6b282853253..f526acee2eed 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2571,6 +2571,12 @@ static int em_rsm(struct x86_emulate_ctxt *ctxt) if (ret != X86EMUL_CONTINUE) return X86EMUL_UNHANDLEABLE; + if ((ctxt->ops->get_hflags(ctxt) & X86EMUL_SMM_INSIDE_NMI_MASK) == 0) + ctxt->ops->set_nmi_mask(ctxt, false); + + ctxt->ops->set_hflags(ctxt, ctxt->ops->get_hflags(ctxt) & + ~(X86EMUL_SMM_INSIDE_NMI_MASK | X86EMUL_SMM_MASK)); + /* * Get back to real mode, to prepare a safe state in which to load * CR0/CR3/CR4/EFER. It's all a bit more complicated if the vCPU @@ -2624,12 +2630,6 @@ static int em_rsm(struct x86_emulate_ctxt *ctxt) return X86EMUL_UNHANDLEABLE; } - if ((ctxt->ops->get_hflags(ctxt) & X86EMUL_SMM_INSIDE_NMI_MASK) == 0) - ctxt->ops->set_nmi_mask(ctxt, false); - - ctxt->ops->set_hflags(ctxt, ctxt->ops->get_hflags(ctxt) & - ~(X86EMUL_SMM_INSIDE_NMI_MASK | X86EMUL_SMM_MASK)); - ctxt->ops->post_leave_smm(ctxt); return X86EMUL_CONTINUE; diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 6b1cd73e4053..406b558abfef 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -6239,21 +6239,17 @@ static int svm_pre_leave_smm(struct kvm_vcpu *vcpu, const char *smstate) struct page *page; u64 guest; u64 vmcb; - int ret; guest = GET_SMSTATE(u64, smstate, 0x7ed8); vmcb = GET_SMSTATE(u64, smstate, 0x7ee0); if (guest) { - vcpu->arch.hflags &= ~HF_SMM_MASK; nested_vmcb = nested_svm_map(svm, vmcb, &page); - if (nested_vmcb) - enter_svm_guest_mode(svm, vmcb, nested_vmcb, page); - else - ret = 1; - vcpu->arch.hflags |= HF_SMM_MASK; + if (!nested_vmcb) + return 1; + enter_svm_guest_mode(svm, vmcb, nested_vmcb, page); } - return ret; + return 0; } static int enable_smi_window(struct kvm_vcpu *vcpu) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 14ea25eadde8..b4e7d645275a 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -7409,9 +7409,7 @@ static int vmx_pre_leave_smm(struct kvm_vcpu *vcpu, const char *smstate) } if (vmx->nested.smm.guest_mode) { - vcpu->arch.hflags &= ~HF_SMM_MASK; ret = nested_vmx_enter_non_root_mode(vcpu, false); - vcpu->arch.hflags |= HF_SMM_MASK; if (ret) return ret; -- 2.20.1