Currently if kvm_mips_complete_mmio_load() fails with EMULATE_FAIL it will
not role back the pc nor will the caller handle this failure.
Signed-off-by: Nicholas Mc Guire <hofrat@xxxxxxxxx>
---
arch/mips/kvm/emulate.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
kvm_mips_complete_mmio_load is called only in arch/mips/kvm/mips.c without
checking the return value to signal EMULATE_FAIL:
383 if (vcpu->mmio_needed) {
384 if (!vcpu->mmio_is_write)
385 kvm_mips_complete_mmio_load(vcpu, run);
386 vcpu->mmio_needed = 0;
387 }
so maybe kvm_mips_complete_mmio_load should role back in case of failure
at arch/mips/kvm/emuilate.c:kvm_mips_complete_mmio_load()
2406 if (er == EMULATE_FAIL) {
2408 return er;
something like the below patch - only based no looking at how EMULATE_FAIL
is handled at other locations - not sure if this is appropriate here.
Patch was only compile tested msp71xx_defconfig + CONFIG_KVM=m
Patch is against 4.1-rc2 (localversion-next is -next-20150506)
diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c
index 2f0fc60..b58596b 100644
--- a/arch/mips/kvm/emulate.c
+++ b/arch/mips/kvm/emulate.c
@@ -2403,8 +2403,10 @@ enum emulation_result kvm_mips_complete_mmio_load(struct kvm_vcpu *vcpu,
*/
curr_pc = vcpu->arch.pc;
er = update_pc(vcpu, vcpu->arch.pending_load_cause);
- if (er == EMULATE_FAIL)
+ if (er == EMULATE_FAIL) {
+ vcpu->arch.pc = curr_pc;
return er;
+ }
switch (run->mmio.len) {
case 4:
--
1.7.10.4
