Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754729Ab3DXNfY (ORCPT ); Wed, 24 Apr 2013 09:35:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58533 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754034Ab3DXNfX (ORCPT ); Wed, 24 Apr 2013 09:35:23 -0400 Date: Wed, 24 Apr 2013 16:34:58 +0300 From: Gleb Natapov To: Xiao Guangrong Cc: mtosatti@redhat.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [PATCH v2 3/6] KVM: MMU: make return value of mmio page fault handler more readable Message-ID: <20130424133458.GR12401@redhat.com> References: <1364810209-25954-1-git-send-email-xiaoguangrong@linux.vnet.ibm.com> <1364810209-25954-4-git-send-email-xiaoguangrong@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1364810209-25954-4-git-send-email-xiaoguangrong@linux.vnet.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3856 Lines: 121 On Mon, Apr 01, 2013 at 05:56:46PM +0800, Xiao Guangrong wrote: > Define some meaningful names instead of raw code > > Signed-off-by: Xiao Guangrong > --- > arch/x86/kvm/mmu.c | 15 +++++---------- > arch/x86/kvm/mmu.h | 14 ++++++++++++++ > arch/x86/kvm/vmx.c | 4 ++-- > 3 files changed, 21 insertions(+), 12 deletions(-) > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index be4f733..31c5586 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -3182,17 +3182,12 @@ static u64 walk_shadow_page_get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr) > return spte; > } > > -/* > - * If it is a real mmio page fault, return 1 and emulat the instruction > - * directly, return 0 to let CPU fault again on the address, -1 is > - * returned if bug is detected. > - */ > int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct) > { > u64 spte; > > if (quickly_check_mmio_pf(vcpu, addr, direct)) > - return 1; > + return RET_MMIO_PF_EMU; > > spte = walk_shadow_page_get_mmio_spte(vcpu, addr); > > @@ -3205,7 +3200,7 @@ int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct) > > trace_handle_mmio_page_fault(addr, gfn, access); > vcpu_cache_mmio_info(vcpu, addr, gfn, access); > - return 1; > + return RET_MMIO_PF_EMU; > } > > /* > @@ -3213,13 +3208,13 @@ int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct) > * it's a BUG if the gfn is not a mmio page. > */ > if (direct && !check_direct_spte_mmio_pf(spte)) > - return -1; > + return RET_MMIO_PF_BUG; > > /* > * If the page table is zapped by other cpus, let CPU fault again on > * the address. > */ > - return 0; > + return RET_MMIO_PF_RETRY; > } > EXPORT_SYMBOL_GPL(handle_mmio_page_fault_common); > > @@ -3229,7 +3224,7 @@ static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, > int ret; > > ret = handle_mmio_page_fault_common(vcpu, addr, direct); > - WARN_ON(ret < 0); > + WARN_ON(ret == RET_MMIO_PF_BUG); > return ret; > } > > diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h > index 2adcbc2..6b4ba1e 100644 > --- a/arch/x86/kvm/mmu.h > +++ b/arch/x86/kvm/mmu.h > @@ -52,6 +52,20 @@ > > int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu *vcpu, u64 addr, u64 sptes[4]); > void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask); > + > +/* > + * Return values of handle_mmio_page_fault_common: > + * RET_MMIO_PF_EMU: it is a real mmio page fault, emulate the instruction > + * directly. > + * RET_MMIO_PF_RETRY: let CPU fault again on the address. > + * RET_MMIO_PF_BUG: bug is detected. > + */ > +enum { > + RET_MMIO_PF_EMU = 1, Make it RET_MMIO_PF_EMULATE please. > + RET_MMIO_PF_RETRY = 0, > + RET_MMIO_PF_BUG = -1 > +}; > + > int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct); > int kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, struct kvm_mmu *context); > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 915ef56..d0f2790 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -5135,10 +5135,10 @@ static int handle_ept_misconfig(struct kvm_vcpu *vcpu) > gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS); > > ret = handle_mmio_page_fault_common(vcpu, gpa, true); > - if (likely(ret == 1)) > + if (likely(ret == RET_MMIO_PF_EMU)) > return x86_emulate_instruction(vcpu, gpa, 0, NULL, 0) == > EMULATE_DONE; > - if (unlikely(!ret)) > + if (unlikely(ret == RET_MMIO_PF_RETRY)) > return 1; > > /* It is the real ept misconfig */ > -- > 1.7.7.6 -- Gleb. -- 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/