Reply-To: Sean Christopherson <seanjc@google.com>
Date:   Fri, 10 Mar 2023 13:42:31 -0800
In-Reply-To: <20230310214232.806108-1-seanjc@google.com>
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References: <20230310214232.806108-1-seanjc@google.com>
Message-ID: <20230310214232.806108-18-seanjc@google.com>
Subject: [PATCH v2 17/18] KVM: x86: Force kvm_rebooting=true during emergency reboot/crash
From:   Sean Christopherson <seanjc@google.com>
To:     Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        Sean Christopherson <seanjc@google.com>,
        Paolo Bonzini <pbonzini@redhat.com>
Cc:     linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        Andrew Cooper <Andrew.Cooper3@citrix.com>,
        Kai Huang <kai.huang@intel.com>, Chao Gao <chao.gao@intel.com>
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Precedence: bulk

Set kvm_rebooting when virtualization is disabled in an emergency so that
KVM eats faults on virtualization instructions even if kvm_reboot() isn't
reached.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/svm/svm.c | 2 ++
 arch/x86/kvm/vmx/vmx.c | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 2db03991dcdf..30f7840151be 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -608,6 +608,8 @@ static inline void kvm_cpu_svm_disable(void)
 
 static void svm_emergency_disable(void)
 {
+	kvm_rebooting = true;
+
 	kvm_cpu_svm_disable();
 }
 
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 374e3ddbd476..8626010f5d54 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -770,6 +770,8 @@ static void vmx_emergency_disable(void)
 	int cpu = raw_smp_processor_id();
 	struct loaded_vmcs *v;
 
+	kvm_rebooting = true;
+
 	list_for_each_entry(v, &per_cpu(loaded_vmcss_on_cpu, cpu),
 			    loaded_vmcss_on_cpu_link)
 		vmcs_clear(v->vmcs);
-- 
2.40.0.rc1.284.g88254d51c5-goog