Re: [PATCH v2 6/7] KVM: PPC: mmio: Return to guest after emulation failure
From: Alexey Kardashevskiy <hidden>
Date: 2022-01-07 01:09:33
On 07/01/2022 07:03, Fabiano Rosas wrote:
If MMIO emulation fails we don't want to crash the whole guest by
returning to userspace.
The original commit bbf45ba57eae ("KVM: ppc: PowerPC 440 KVM
implementation") added a todo:
/* XXX Deliver Program interrupt to guest. */
and later the commit d69614a295ae ("KVM: PPC: Separate loadstore
emulation from priv emulation") added the Program interrupt injection
but in another file, so I'm assuming it was missed that this block
needed to be altered.
Signed-off-by: Fabiano Rosas <redacted>Looks right. Reviewed-by: Alexey Kardashevskiy <redacted> but this means if I want to keep debugging those kvm selftests in comfort, I'll have to have some exception handlers in the vm as otherwise the failing $pc is lost after this change :)
quoted hunk ↗ jump to hunk
--- arch/powerpc/kvm/powerpc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index a2e78229d645..50e08635e18a 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c@@ -309,7 +309,7 @@ int kvmppc_emulate_mmio(struct kvm_vcpu *vcpu) kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst); kvmppc_core_queue_program(vcpu, 0); pr_info("%s: emulation failed (%08x)\n", __func__, last_inst); - r = RESUME_HOST; + r = RESUME_GUEST; break; } default:
-- Alexey