From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Huth Subject: Re: [PATCH] kvm-pr: manage illegal instructions Date: Thu, 21 Apr 2016 11:25:09 +0200 Message-ID: <57189C75.2060701@redhat.com> References: <1458073117-24652-1-git-send-email-lvivier@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: Gleb Natapov , Paolo Bonzini , Alexander Graf , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org To: Laurent Vivier , kvm-ppc@vger.kernel.org, kvm@vger.kernel.org Return-path: In-Reply-To: <1458073117-24652-1-git-send-email-lvivier@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 15.03.2016 21:18, Laurent Vivier wrote: > While writing some instruction tests for kvm-unit-tests for powerpc, > I've found that illegal instructions are not managed correctly with kvm-pr, > while it is fine with kvm-hv. > > When an illegal instruction (like ".long 0") is processed by kvm-pr, > the kernel logs are filled with: > > Couldn't emulate instruction 0x00000000 (op 0 xop 0) > kvmppc_handle_exit_pr: emulation at 700 failed (00000000) > > While the exception handler receives an interrupt for each instruction > executed after the illegal instruction. > > Signed-off-by: Laurent Vivier > --- > arch/powerpc/kvm/book3s_emulate.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/kvm/book3s_emulate.c b/arch/powerpc/kvm/book3s_emulate.c > index 2afdb9c..4ee969d 100644 > --- a/arch/powerpc/kvm/book3s_emulate.c > +++ b/arch/powerpc/kvm/book3s_emulate.c > @@ -99,7 +99,6 @@ int kvmppc_core_emulate_op_pr(struct kvm_run *run, struct kvm_vcpu *vcpu, > > switch (get_op(inst)) { > case 0: > - emulated = EMULATE_FAIL; > if ((kvmppc_get_msr(vcpu) & MSR_LE) && > (inst == swab32(inst_sc))) { > /* > @@ -112,6 +111,9 @@ int kvmppc_core_emulate_op_pr(struct kvm_run *run, struct kvm_vcpu *vcpu, > kvmppc_set_gpr(vcpu, 3, EV_UNIMPLEMENTED); > kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4); > emulated = EMULATE_DONE; > + } else { > + kvmppc_core_queue_program(vcpu, SRR1_PROGILL); > + emulated = EMULATE_AGAIN; > } > break; > case 19: > Tested-by: Thomas Huth