xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

KVM: PPC: Allow kvmppc_get_last_inst() to fail

Browse Source 
On book3e, guest last instruction is read on the exit path using load
external pid (lwepx) dedicated instruction. This load operation may fail
due to TLB eviction and execute-but-not-read entries.

This patch lay down the path for an alternative solution to read the guest
last instruction, by allowing kvmppc_get_lat_inst() function to fail.
Architecture specific implmentations of kvmppc_load_last_inst() may read
last guest instruction and instruct the emulation layer to re-execute the
guest in case of failure.

Make kvmppc_get_last_inst() definition common between architectures.

Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
Mihai Caraman
2014-07-23 19:06:21 +03:00
committed by Alexander Graf
parent 9a26af64d6
commit 51f047261e
11 changed files with 140 additions and 77 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
arch/powerpc/kvm/powerpc.c
View File

@@ -280,6 +280,9 @@ int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu)
* actually modified. */
r = RESUME_GUEST_NV;
break;
case EMULATE_AGAIN:
r = RESUME_GUEST;
break;
case EMULATE_DO_MMIO:
run->exit_reason = KVM_EXIT_MMIO;
/* We must reload nonvolatiles because "update" load/store
@@ -289,11 +292,15 @@ int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu)
r = RESUME_HOST_NV;
break;
case EMULATE_FAIL:
{
u32 last_inst;
kvmppc_get_last_inst(vcpu, false, &last_inst);
/* XXX Deliver Program interrupt to guest. */
printk(KERN_EMERG "%s: emulation failed (%08x)\n", __func__,
kvmppc_get_last_inst(vcpu));
pr_emerg("%s: emulation failed (%08x)\n", __func__, last_inst);
r = RESUME_HOST;
break;
}
default:
WARN_ON(1);
r = RESUME_GUEST;