68 lines
2.1 KiB
Diff
68 lines
2.1 KiB
Diff
From a01916088ebb15b357d5c110270b797295d02f78 Mon Sep 17 00:00:00 2001
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From: Maxim Levitsky <mlevitsk@redhat.com>
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Date: Tue, 25 Oct 2022 15:47:33 +0300
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Subject: [PATCH] KVM: x86: smm: check for failures on smm entry
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In the rare case of the failure on SMM entry, the KVM should at
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least terminate the VM instead of going south.
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Suggested-by: Sean Christopherson <seanjc@google.com>
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Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
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---
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arch/x86/kvm/smm.c | 19 +++++++++++++++----
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1 file changed, 15 insertions(+), 4 deletions(-)
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diff --git a/arch/x86/kvm/smm.c b/arch/x86/kvm/smm.c
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index b290ad14070f..1191a79cf027 100644
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--- a/arch/x86/kvm/smm.c
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+++ b/arch/x86/kvm/smm.c
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@@ -211,11 +211,17 @@ void enter_smm(struct kvm_vcpu *vcpu)
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* Give enter_smm() a chance to make ISA-specific changes to the vCPU
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* state (e.g. leave guest mode) after we've saved the state into the
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* SMM state-save area.
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+ *
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+ * Kill the VM in the unlikely case of failure, because the VM
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+ * can be in undefined state in this case.
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*/
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- static_call(kvm_x86_enter_smm)(vcpu, buf);
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+ if (static_call(kvm_x86_enter_smm)(vcpu, buf))
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+ goto error;
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kvm_smm_changed(vcpu, true);
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- kvm_vcpu_write_guest(vcpu, vcpu->arch.smbase + 0xfe00, buf, sizeof(buf));
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+
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+ if (kvm_vcpu_write_guest(vcpu, vcpu->arch.smbase + 0xfe00, buf, sizeof(buf)))
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+ goto error;
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if (static_call(kvm_x86_get_nmi_mask)(vcpu))
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vcpu->arch.hflags |= HF_SMM_INSIDE_NMI_MASK;
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@@ -235,7 +241,8 @@ void enter_smm(struct kvm_vcpu *vcpu)
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dt.address = dt.size = 0;
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static_call(kvm_x86_set_idt)(vcpu, &dt);
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- kvm_set_dr(vcpu, 7, DR7_FIXED_1);
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+ if (WARN_ON_ONCE(kvm_set_dr(vcpu, 7, DR7_FIXED_1)))
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+ goto error;
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cs.selector = (vcpu->arch.smbase >> 4) & 0xffff;
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cs.base = vcpu->arch.smbase;
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@@ -264,11 +271,15 @@ void enter_smm(struct kvm_vcpu *vcpu)
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#ifdef CONFIG_X86_64
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if (guest_cpuid_has(vcpu, X86_FEATURE_LM))
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- static_call(kvm_x86_set_efer)(vcpu, 0);
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+ if (static_call(kvm_x86_set_efer)(vcpu, 0))
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+ goto error;
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#endif
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kvm_update_cpuid_runtime(vcpu);
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kvm_mmu_reset_context(vcpu);
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+ return;
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+error:
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+ kvm_vm_dead(vcpu->kvm);
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}
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static void rsm_set_desc_flags(struct kvm_segment *desc, u32 flags)
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--
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2.38.1
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