linux-kernel - [PATCH 03/10] KVM: SVM: Fix schedule-while-atomic on nested exception handling

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Date:	Thu, 18 Feb 2010 12:38:28 +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 03/10] 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 |   20 +++++++++++++++++---
 1 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 7c96b8b..25d26ec 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_exit_handled_atomic(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);
@@ -1386,7 +1387,7 @@ 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);
+	return nested_svm_exit_handled_atomic(svm);
 }
 
 /* This function returns true if it is save to enable the irq window */
@@ -1520,7 +1521,7 @@ 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_exit_handled(struct vcpu_svm *svm, bool atomic)
 {
 	u32 exit_code = svm->vmcb->control.exit_code;
 	int vmexit = NESTED_EXIT_HOST;
@@ -1567,12 +1568,25 @@ static int nested_svm_exit_handled(struct vcpu_svm *svm)
 	}
 
 	if (vmexit == NESTED_EXIT_DONE) {
-		nested_svm_vmexit(svm);
+		if (!atomic)
+			nested_svm_vmexit(svm);
+		else
+			svm->nested.exit_required = true;
 	}
 
 	return vmexit;
 }
 
+static int nested_svm_exit_handled(struct vcpu_svm *svm)
+{
+	return __nested_svm_exit_handled(svm, false);
+}
+
+static int nested_svm_exit_handled_atomic(struct vcpu_svm *svm)
+{
+	return __nested_svm_exit_handled(svm, true);
+}
+
 static inline void copy_vmcb_control_area(struct vmcb *dst_vmcb, struct vmcb *from_vmcb)
 {
 	struct vmcb_control_area *dst  = &dst_vmcb->control;
-- 
1.6.6


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