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

From: Joerg Roedel
Date: Fri Feb 19 2010 - 10:24:40 EST


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

Cc: stable@xxxxxxxxxx
Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
---
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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