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Message-Id: <20221025124223.227577-16-mlevitsk@redhat.com>
Date: Tue, 25 Oct 2022 15:42:15 +0300
From: Maxim Levitsky <mlevitsk@...hat.com>
To: kvm@...r.kernel.org
Cc: Paolo Bonzini <pbonzini@...hat.com>,
Yang Zhong <yang.zhong@...el.com>,
linux-kselftest@...r.kernel.org, Kees Cook <keescook@...omium.org>,
Borislav Petkov <bp@...en8.de>,
Guang Zeng <guang.zeng@...el.com>,
Wanpeng Li <wanpengli@...cent.com>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>,
"H. Peter Anvin" <hpa@...or.com>,
Maxim Levitsky <mlevitsk@...hat.com>,
Joerg Roedel <joro@...tes.org>, linux-kernel@...r.kernel.org,
Wei Wang <wei.w.wang@...el.com>,
Jim Mattson <jmattson@...gle.com>,
Dave Hansen <dave.hansen@...ux.intel.com>,
Sean Christopherson <seanjc@...gle.com>,
Vitaly Kuznetsov <vkuznets@...hat.com>, x86@...nel.org,
Shuah Khan <shuah@...nel.org>
Subject: [PATCH v4 15/23] KVM: x86: smm: check for failures on smm entry
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@...gle.com>
Signed-off-by: Maxim Levitsky <mlevitsk@...hat.com>
---
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
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