Re: [PATCH v3 5/6] KVM: PPC: mmio: Return to guest after emulation failure
From: Nicholas Piggin <npiggin@gmail.com>
Date: 2022-01-10 07:37:00
Excerpts from Fabiano Rosas's message of January 8, 2022 7:00 am:
quoted hunk ↗ jump to hunk
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> Reviewed-by: Alexey Kardashevskiy <redacted> --- 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 6daeea4a7de1..56b0faab7a5f 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;
So at this point can the pr_info just go away? I wonder if this shouldn't be a DSI rather than a program check. DSI with DSISR[37] looks a bit more expected. Not that Linux probably does much with it but at least it would give a SIGBUS rather than SIGILL. Thanks, Nick