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

Joerg Roedel
2010-02-18T11:38:58Z

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

Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.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