linux-kernel - [109/140] KVM: SVM: Handle MCEs early in the vmexit process

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Date:	Fri, 30 Jul 2010 10:31:14 -0700
From:	Greg KH <gregkh@...e.de>
To:	linux-kernel@...r.kernel.org, stable@...nel.org
Cc:	stable-review@...nel.org, torvalds@...ux-foundation.org,
	akpm@...ux-foundation.org, alan@...rguk.ukuu.org.uk,
	Joerg Roedel <joerg.roedel@....com>,
	Avi Kivity <avi@...hat.com>
Subject: [109/140] KVM: SVM: Handle MCEs early in the vmexit process

2.6.33-stable review patch.  If anyone has any objections, please let us know.

------------------

This patch moves handling of the MC vmexits to an earlier
point in the vmexit. The handle_exit function is too late
because the vcpu might alreadry have changed its physical
cpu.

Cc: stable@...nel.org
Signed-off-by: Joerg Roedel <joerg.roedel@....com>
Signed-off-by: Avi Kivity <avi@...hat.com>
(cherry picked from commit fe5913e4e1700cbfc337f4b1da9ddb26f6a55586)
---
 arch/x86/kvm/svm.c |   15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1255,7 +1255,7 @@ static int nm_interception(struct vcpu_s
 	return 1;
 }
 
-static int mc_interception(struct vcpu_svm *svm)
+static void svm_handle_mce(struct vcpu_svm *svm)
 {
 	/*
 	 * On an #MC intercept the MCE handler is not called automatically in
@@ -1265,6 +1265,11 @@ static int mc_interception(struct vcpu_s
 		"int $0x12\n");
 	/* not sure if we ever come back to this point */
 
+	return;
+}
+
+static int mc_interception(struct vcpu_svm *svm)
+{
 	return 1;
 }
 
@@ -2820,6 +2825,14 @@ static void svm_vcpu_run(struct kvm_vcpu
 		vcpu->arch.regs_avail &= ~(1 << VCPU_EXREG_PDPTR);
 		vcpu->arch.regs_dirty &= ~(1 << VCPU_EXREG_PDPTR);
 	}
+
+	/*
+	 * We need to handle MC intercepts here before the vcpu has a chance to
+	 * change the physical cpu
+	 */
+	if (unlikely(svm->vmcb->control.exit_code ==
+		     SVM_EXIT_EXCP_BASE + MC_VECTOR))
+		svm_handle_mce(svm);
 }
 
 #undef R


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