[PATCH] KVM: MMU: Detect oom conditions and propagate error to userspace

Signed-off-by: Avi Kivity <avi@qumranet.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 12 insertions, 3 deletions

diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 59178ad4d344..ed3956739771 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -1289,6 +1289,7 @@ static int handle_exception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
         unsigned long cr2, rip;
         u32 vect_info;
         enum emulation_result er;
+        int r;
 
         vect_info = vmcs_read32(IDT_VECTORING_INFO_FIELD);
         intr_info = vmcs_read32(VM_EXIT_INTR_INFO);
@@ -1317,7 +1318,12 @@ static int handle_exception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
                 cr2 = vmcs_readl(EXIT_QUALIFICATION);
 
                 spin_lock(&vcpu->kvm->lock);
-                if (!kvm_mmu_page_fault(vcpu, cr2, error_code)) {
+                r = kvm_mmu_page_fault(vcpu, cr2, error_code);
+                if (r < 0) {
+                        spin_unlock(&vcpu->kvm->lock);
+                        return r;
+                }
+                if (!r) {
                         spin_unlock(&vcpu->kvm->lock);
                         return 1;
                 }
@@ -1680,6 +1686,7 @@ static int vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
         u8 fail;
         u16 fs_sel, gs_sel, ldt_sel;
         int fs_gs_ldt_reload_needed;
+        int r;
 
 again:
         /*
@@ -1853,6 +1860,7 @@ again:
         if (fail) {
                 kvm_run->exit_type = KVM_EXIT_TYPE_FAIL_ENTRY;
                 kvm_run->exit_reason = vmcs_read32(VM_INSTRUCTION_ERROR);
+                r = 0;
         } else {
                 if (fs_gs_ldt_reload_needed) {
                         load_ldt(ldt_sel);
@@ -1872,7 +1880,8 @@ again:
                 }
                 vcpu->launched = 1;
                 kvm_run->exit_type = KVM_EXIT_TYPE_VM_EXIT;
-                if (kvm_handle_exit(kvm_run, vcpu)) {
+                r = kvm_handle_exit(kvm_run, vcpu);
+                if (r > 0) {
                         /* Give scheduler a change to reschedule. */
                         if (signal_pending(current)) {
                                 ++kvm_stat.signal_exits;
@@ -1892,7 +1901,7 @@ again:
         }
 
         post_kvm_run_save(vcpu, kvm_run);
-        return 0;
+        return r;
 }
 
 static void vmx_flush_tlb(struct kvm_vcpu *vcpu)