In the rare case of the failure on SMM entry, the KVM should at least terminate the VM instead of going south. Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx> Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx> --- arch/x86/kvm/smm.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/smm.c b/arch/x86/kvm/smm.c index b290ad14070f72..1191a79cf027e5 100644 --- a/arch/x86/kvm/smm.c +++ b/arch/x86/kvm/smm.c @@ -211,11 +211,17 @@ void enter_smm(struct kvm_vcpu *vcpu) * Give enter_smm() a chance to make ISA-specific changes to the vCPU * state (e.g. leave guest mode) after we've saved the state into the * SMM state-save area. + * + * Kill the VM in the unlikely case of failure, because the VM + * can be in undefined state in this case. */ - static_call(kvm_x86_enter_smm)(vcpu, buf); + if (static_call(kvm_x86_enter_smm)(vcpu, buf)) + goto error; kvm_smm_changed(vcpu, true); - kvm_vcpu_write_guest(vcpu, vcpu->arch.smbase + 0xfe00, buf, sizeof(buf)); + + if (kvm_vcpu_write_guest(vcpu, vcpu->arch.smbase + 0xfe00, buf, sizeof(buf))) + goto error; if (static_call(kvm_x86_get_nmi_mask)(vcpu)) vcpu->arch.hflags |= HF_SMM_INSIDE_NMI_MASK; @@ -235,7 +241,8 @@ void enter_smm(struct kvm_vcpu *vcpu) dt.address = dt.size = 0; static_call(kvm_x86_set_idt)(vcpu, &dt); - kvm_set_dr(vcpu, 7, DR7_FIXED_1); + if (WARN_ON_ONCE(kvm_set_dr(vcpu, 7, DR7_FIXED_1))) + goto error; cs.selector = (vcpu->arch.smbase >> 4) & 0xffff; cs.base = vcpu->arch.smbase; @@ -264,11 +271,15 @@ void enter_smm(struct kvm_vcpu *vcpu) #ifdef CONFIG_X86_64 if (guest_cpuid_has(vcpu, X86_FEATURE_LM)) - static_call(kvm_x86_set_efer)(vcpu, 0); + if (static_call(kvm_x86_set_efer)(vcpu, 0)) + goto error; #endif kvm_update_cpuid_runtime(vcpu); kvm_mmu_reset_context(vcpu); + return; +error: + kvm_vm_dead(vcpu->kvm); } static void rsm_set_desc_flags(struct kvm_segment *desc, u32 flags) -- 2.34.3
