Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932206Ab2JKNGW (ORCPT ); Thu, 11 Oct 2012 09:06:22 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:40735 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755968Ab2JKNGU (ORCPT ); Thu, 11 Oct 2012 09:06:20 -0400 Message-ID: <5076C444.8080309@gmail.com> Date: Thu, 11 Oct 2012 21:06:12 +0800 From: Xiao Guangrong User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120911 Thunderbird/15.0.1 MIME-Version: 1.0 To: Marcelo Tosatti CC: Xiao Guangrong , Avi Kivity , LKML , KVM Subject: Re: [PATCH v4 1/5] KVM: MMU: fix release noslot pfn References: <50716EE0.6010504@linux.vnet.ibm.com> <50716F1E.90308@linux.vnet.ibm.com> <20121010151125.GA28406@amt.cnet> In-Reply-To: <20121010151125.GA28406@amt.cnet> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7731 Lines: 222 On 10/10/2012 11:11 PM, Marcelo Tosatti wrote: > > Why does is_error_pfn() return true for mmio spte? Its not an "error", > after all. > > Please kill is_invalid_pfn and use > > -> is_error_pfn for checking for errors (mmio spte is not an error pfn, > its a special pfn) > > -> add explicit is_noslot_pfn checks where necessary in the code > (say to avoid interpreting a noslot_pfn's pfn "address" bits). > > (should have noticed this earlier, sorry). Never mind, your comments are always appreciated! ;) Marcelo, is it good to you? (will post it after your check and full test) diff --git a/arch/powerpc/kvm/book3s_32_mmu_host.c b/arch/powerpc/kvm/book3s_32_mmu_host.c index 837f13e..3a4d967 100644 --- a/arch/powerpc/kvm/book3s_32_mmu_host.c +++ b/arch/powerpc/kvm/book3s_32_mmu_host.c @@ -155,7 +155,7 @@ int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte) /* Get host physical address for gpa */ hpaddr = kvmppc_gfn_to_pfn(vcpu, orig_pte->raddr >> PAGE_SHIFT); - if (is_error_pfn(hpaddr)) { + if (is_error_noslot_pfn(hpaddr)) { printk(KERN_INFO "Couldn't get guest page for gfn %lx!\n", orig_pte->eaddr); r = -EINVAL; diff --git a/arch/powerpc/kvm/book3s_64_mmu_host.c b/arch/powerpc/kvm/book3s_64_mmu_host.c index 0688b6b..6c230a2 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_host.c +++ b/arch/powerpc/kvm/book3s_64_mmu_host.c @@ -92,7 +92,7 @@ int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte) /* Get host physical address for gpa */ hpaddr = kvmppc_gfn_to_pfn(vcpu, orig_pte->raddr >> PAGE_SHIFT); - if (is_error_pfn(hpaddr)) { + if (is_error_noslot_pfn(hpaddr)) { printk(KERN_INFO "Couldn't get guest page for gfn %lx!\n", orig_pte->eaddr); r = -EINVAL; goto out; diff --git a/arch/powerpc/kvm/e500_tlb.c b/arch/powerpc/kvm/e500_tlb.c index ff38b66..4b47eeb 100644 --- a/arch/powerpc/kvm/e500_tlb.c +++ b/arch/powerpc/kvm/e500_tlb.c @@ -521,7 +521,7 @@ static inline void kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500, if (likely(!pfnmap)) { unsigned long tsize_pages = 1 << (tsize + 10 - PAGE_SHIFT); pfn = gfn_to_pfn_memslot(slot, gfn); - if (is_error_pfn(pfn)) { + if (is_error_noslot_pfn(pfn)) { printk(KERN_ERR "Couldn't get real page for gfn %lx!\n", (long)gfn); return; diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 56c0e39..54c3557 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2699,7 +2699,7 @@ static void transparent_hugepage_adjust(struct kvm_vcpu *vcpu, * PT_PAGE_TABLE_LEVEL and there would be no adjustment done * here. */ - if (!is_error_pfn(pfn) && !kvm_is_mmio_pfn(pfn) && + if (!is_error_noslot_pfn(pfn) && !kvm_is_mmio_pfn(pfn) && level == PT_PAGE_TABLE_LEVEL && PageTransCompound(pfn_to_page(pfn)) && !has_wrprotected_page(vcpu->kvm, gfn, PT_DIRECTORY_LEVEL)) { @@ -2733,7 +2733,7 @@ static bool handle_abnormal_pfn(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn, bool ret = true; /* The pfn is invalid, report the error! */ - if (unlikely(is_invalid_pfn(pfn))) { + if (unlikely(is_error_pfn(pfn))) { *ret_val = kvm_handle_bad_page(vcpu, gfn, pfn); goto exit; } diff --git a/arch/x86/kvm/mmu_audit.c b/arch/x86/kvm/mmu_audit.c index daff69e..7709a75 100644 --- a/arch/x86/kvm/mmu_audit.c +++ b/arch/x86/kvm/mmu_audit.c @@ -116,7 +116,7 @@ static void audit_mappings(struct kvm_vcpu *vcpu, u64 *sptep, int level) gfn = kvm_mmu_page_get_gfn(sp, sptep - sp->spt); pfn = gfn_to_pfn_atomic(vcpu->kvm, gfn); - if (is_error_pfn(pfn)) + if (is_error_noslot_pfn(pfn)) return; hpa = pfn << PAGE_SHIFT; diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index f887e4c..89f3241 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -323,7 +323,7 @@ FNAME(prefetch_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, protect_clean_gpte(&pte_access, gpte); pfn = pte_prefetch_gfn_to_pfn(vcpu, gfn, no_dirty_log && (pte_access & ACC_WRITE_MASK)); - if (is_invalid_pfn(pfn)) + if (is_error_pfn(pfn)) return false; /* diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 1eefebe..91f8f71 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4502,7 +4502,7 @@ static bool reexecute_instruction(struct kvm_vcpu *vcpu, gva_t gva) * instruction -> ... */ pfn = gfn_to_pfn(vcpu->kvm, gpa_to_gfn(gpa)); - if (!is_error_pfn(pfn)) { + if (!is_error_noslot_pfn(pfn)) { kvm_release_pfn_clean(pfn); return true; } diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 93bfc9f..45ff7c6 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -58,28 +58,30 @@ /* * For the normal pfn, the highest 12 bits should be zero, - * so we can mask these bits to indicate the error. + * so we can mask bit 62 ~ bit 52 to indicate the error pfn, + * mask bit 63 to indicate the noslot pfn. */ -#define KVM_PFN_ERR_MASK (0xfffULL << 52) +#define KVM_PFN_ERR_MASK (0x7ffULL << 52) +#define KVM_PFN_ERR_NOSLOT_MASK (0xfffULL << 52) +#define KVM_PFN_NOSLOT (0x1ULL << 63) #define KVM_PFN_ERR_FAULT (KVM_PFN_ERR_MASK) #define KVM_PFN_ERR_HWPOISON (KVM_PFN_ERR_MASK + 1) -#define KVM_PFN_ERR_BAD (KVM_PFN_ERR_MASK + 2) -#define KVM_PFN_ERR_RO_FAULT (KVM_PFN_ERR_MASK + 3) +#define KVM_PFN_ERR_RO_FAULT (KVM_PFN_ERR_MASK + 2) static inline bool is_error_pfn(pfn_t pfn) { return !!(pfn & KVM_PFN_ERR_MASK); } -static inline bool is_noslot_pfn(pfn_t pfn) +static inline bool is_error_noslot_pfn(pfn_t pfn) { - return pfn == KVM_PFN_ERR_BAD; + return !!(pfn & KVM_PFN_ERR_NOSLOT_MASK); } -static inline bool is_invalid_pfn(pfn_t pfn) +static inline bool is_noslot_pfn(pfn_t pfn) { - return !is_noslot_pfn(pfn) && is_error_pfn(pfn); + return pfn == KVM_PFN_NOSLOT; } #define KVM_HVA_ERR_BAD (PAGE_OFFSET) diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c index 037cb67..5534f46 100644 --- a/virt/kvm/iommu.c +++ b/virt/kvm/iommu.c @@ -52,7 +52,7 @@ static pfn_t kvm_pin_pages(struct kvm_memory_slot *slot, gfn_t gfn, end_gfn = gfn + (size >> PAGE_SHIFT); gfn += 1; - if (is_error_pfn(pfn)) + if (is_error_noslot_pfn(pfn)) return pfn; while (gfn < end_gfn) @@ -106,7 +106,7 @@ int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot) * important because we unmap and unpin in 4kb steps later. */ pfn = kvm_pin_pages(slot, gfn, page_size); - if (is_error_pfn(pfn)) { + if (is_error_noslot_pfn(pfn)) { gfn += 1; continue; } diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index a65bc02..e26a55f 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1208,7 +1208,7 @@ __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, bool atomic, return KVM_PFN_ERR_RO_FAULT; if (kvm_is_error_hva(addr)) - return KVM_PFN_ERR_BAD; + return KVM_PFN_NOSLOT; /* Do not map writable pfn in the readonly memslot. */ if (writable && memslot_is_readonly(slot)) { @@ -1290,7 +1290,7 @@ EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic); static struct page *kvm_pfn_to_page(pfn_t pfn) { - if (is_error_pfn(pfn)) + if (is_error_noslot_pfn(pfn)) return KVM_ERR_PTR_BAD_PAGE; if (kvm_is_mmio_pfn(pfn)) { @@ -1322,7 +1322,7 @@ EXPORT_SYMBOL_GPL(kvm_release_page_clean); void kvm_release_pfn_clean(pfn_t pfn) { - if (!is_error_pfn(pfn) && !kvm_is_mmio_pfn(pfn)) + if (!is_error_noslot_pfn(pfn) && !kvm_is_mmio_pfn(pfn)) put_page(pfn_to_page(pfn)); } EXPORT_SYMBOL_GPL(kvm_release_pfn_clean); -- 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/