Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752170AbbEGM7i (ORCPT ); Thu, 7 May 2015 08:59:38 -0400 Received: from www.osadl.org ([62.245.132.105]:36135 "EHLO www.osadl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751050AbbEGM7f (ORCPT ); Thu, 7 May 2015 08:59:35 -0400 From: Nicholas Mc Guire To: Gleb Natapov Cc: Paolo Bonzini , Ralf Baechle , kvm@vger.kernel.org, linux-mips@linux-mips.org, linux-kernel@vger.kernel.org, Nicholas Mc Guire Subject: [PATCH RFC] MIPS: KVM: role back pc in case of EMULATE_FAIL Date: Thu, 7 May 2015 14:51:31 +0200 Message-Id: <1431003091-30161-1-git-send-email-hofrat@osadl.org> X-Mailer: git-send-email 1.7.10.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1832 Lines: 52 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 --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/