[179/200] KVM: SVM: Fix schedule-while-atomic on nested exception handling

Greg KH
2010-07-01T21:19:28Z

2.6.34-stable review patch. If anyone has any objections, please let me know.

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

From: Joerg Roedel <joerg.roedel@amd.com>

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>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

(Cherry-picked from commit b8e88bc8ffba5fe53fb8d8a0a4be3bbcffeebe56)
---
arch/x86/kvm/svm.c | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)

--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -129,6 +129,7 @@ static void svm_flush_tlb(struct kvm_vcp
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);
@@ -1384,6 +1385,8 @@ static int nested_svm_check_permissions(
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;

@@ -1392,7 +1395,11 @@ static int nested_svm_check_exception(st
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;
}

static inline int nested_svm_intr(struct vcpu_svm *svm)
@@ -1521,7 +1528,7 @@ static int nested_svm_exit_special(struc
/*
* 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;
@@ -1567,9 +1574,17 @@ static int nested_svm_exit_handled(struc
}
}

- 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;
}