linux-kernel - [PATCH 03/11] KVM: SVM: Fix schedule-while-atomic on nested exception handling

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Date:	Fri, 19 Feb 2010 16:23:02 +0100
From:	Joerg Roedel <joerg.roedel@....com>
To:	Avi Kivity <avi@...hat.com>, Marcelo Tosatti <mtosatti@...hat.com>
CC:	kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
	Joerg Roedel <joerg.roedel@....com>, stable@...nel.org
Subject: [PATCH 03/11] KVM: SVM: Fix schedule-while-atomic on nested exception handling

Move the actual vmexit routine out of code that runs with
irqs and preemption disabled.

Cc: stable@...nel.org
Signed-off-by: Joerg Roedel <joerg.roedel@....com>
---
 arch/x86/kvm/svm.c |   23 +++++++++++++++++++----
 1 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index f87fc98..6dc7a41 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -128,6 +128,7 @@ static void svm_flush_tlb(struct kvm_vcpu *vcpu);
 static void svm_complete_interrupts(struct vcpu_svm *svm);
 
 static int nested_svm_exit_handled(struct vcpu_svm *svm);
+static int nested_svm_intercept(struct vcpu_svm *svm);
 static int nested_svm_vmexit(struct vcpu_svm *svm);
 static int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr,
 				      bool has_error_code, u32 error_code);
@@ -1378,6 +1379,8 @@ static int nested_svm_check_permissions(struct vcpu_svm *svm)
 static int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr,
 				      bool has_error_code, u32 error_code)
 {
+	int vmexit;
+
 	if (!is_nested(svm))
 		return 0;
 
@@ -1386,7 +1389,11 @@ static int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr,
 	svm->vmcb->control.exit_info_1 = error_code;
 	svm->vmcb->control.exit_info_2 = svm->vcpu.arch.cr2;
 
-	return nested_svm_exit_handled(svm);
+	vmexit = nested_svm_intercept(svm);
+	if (vmexit == NESTED_EXIT_DONE)
+		svm->nested.exit_required = true;
+
+	return vmexit;
 }
 
 /* This function returns true if it is save to enable the irq window */
@@ -1516,7 +1523,7 @@ static int nested_svm_exit_special(struct vcpu_svm *svm)
 /*
  * If this function returns true, this #vmexit was already handled
  */
-static int nested_svm_exit_handled(struct vcpu_svm *svm)
+static int nested_svm_intercept(struct vcpu_svm *svm)
 {
 	u32 exit_code = svm->vmcb->control.exit_code;
 	int vmexit = NESTED_EXIT_HOST;
@@ -1562,9 +1569,17 @@ static int nested_svm_exit_handled(struct vcpu_svm *svm)
 	}
 	}
 
-	if (vmexit == NESTED_EXIT_DONE) {
+	return vmexit;
+}
+
+static int nested_svm_exit_handled(struct vcpu_svm *svm)
+{
+	int vmexit;
+
+	vmexit = nested_svm_intercept(svm);
+
+	if (vmexit == NESTED_EXIT_DONE)
 		nested_svm_vmexit(svm);
-	}
 
 	return vmexit;
 }
-- 
1.6.6


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