[v4,04/18] KVM: MMU: cache mmio info on page fault path

Message ID	4E1B4DA8.7080903@cn.fujitsu.com (mailing list archive)
State	New, archived
Headers	show Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p6BJVUYN016732 for <patchwork-kvm@patchwork.kernel.org>; Mon, 11 Jul 2011 19:31:32 GMT Message-ID: <4E1B4DA8.7080903@cn.fujitsu.com> Date: Tue, 12 Jul 2011 03:23:20 +0800 From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.17) Gecko/20110428 Fedora/3.1.10-1.fc15 Thunderbird/3.1.10 MIME-Version: 1.0 To: Avi Kivity <avi@redhat.com> CC: Marcelo Tosatti <mtosatti@redhat.com>, LKML <linux-kernel@vger.kernel.org>, KVM <kvm@vger.kernel.org> Subject: [PATCH v4 04/18] KVM: MMU: cache mmio info on page fault path References: <4E1B4CF8.605@cn.fujitsu.com> In-Reply-To: <4E1B4CF8.605@cn.fujitsu.com> Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=UTF-8 Sender: kvm-owner@vger.kernel.org Precedence: bulk

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index da6bbee..7b0834a 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -415,6 +415,11 @@ struct kvm_vcpu_arch { u64 mcg_ctl; u64 *mce_banks; + /* Cache MMIO info */ + u64 mmio_gva; + unsigned access; + gfn_t mmio_gfn; + /* used for guest single stepping over the given code position */ unsigned long singlestep_rip; diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 02c839f..d1986b7 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -217,11 +217,6 @@ void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask, } EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes); -static bool is_write_protection(struct kvm_vcpu *vcpu) -{ - return kvm_read_cr0_bits(vcpu, X86_CR0_WP); -} - static int is_cpuid_PSE36(void) { return 1; @@ -243,11 +238,6 @@ static int is_large_pte(u64 pte) return pte & PT_PAGE_SIZE_MASK; } -static int is_writable_pte(unsigned long pte) -{ - return pte & PT_WRITABLE_MASK; -} - static int is_dirty_gpte(unsigned long pte) { return pte & PT_DIRTY_MASK; @@ -2247,15 +2237,17 @@ static void kvm_send_hwpoison_signal(unsigned long address, struct task_struct * send_sig_info(SIGBUS, &info, tsk); } -static int kvm_handle_bad_page(struct kvm *kvm, gfn_t gfn, pfn_t pfn) +static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gva_t gva, + unsigned access, gfn_t gfn, pfn_t pfn) { kvm_release_pfn_clean(pfn); if (is_hwpoison_pfn(pfn)) { - kvm_send_hwpoison_signal(gfn_to_hva(kvm, gfn), current); + kvm_send_hwpoison_signal(gfn_to_hva(vcpu->kvm, gfn), current); return 0; } else if (is_fault_pfn(pfn)) return -EFAULT; + vcpu_cache_mmio_info(vcpu, gva, gfn, access); return 1; } @@ -2337,7 +2329,7 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn, /* mmio */ if (is_error_pfn(pfn)) - return kvm_handle_bad_page(vcpu->kvm, gfn, pfn); + return kvm_handle_bad_page(vcpu, v, ACC_ALL, gfn, pfn); spin_lock(&vcpu->kvm->mmu_lock); if (mmu_notifier_retry(vcpu, mmu_seq)) @@ -2564,6 +2556,7 @@ static void mmu_sync_roots(struct kvm_vcpu *vcpu) if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) return; + vcpu_clear_mmio_info(vcpu, ~0ul); trace_kvm_mmu_audit(vcpu, AUDIT_PRE_SYNC); if (vcpu->arch.mmu.root_level == PT64_ROOT_LEVEL) { hpa_t root = vcpu->arch.mmu.root_hpa; @@ -2710,7 +2703,7 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, u32 error_code, /* mmio */ if (is_error_pfn(pfn)) - return kvm_handle_bad_page(vcpu->kvm, gfn, pfn); + return kvm_handle_bad_page(vcpu, 0, 0, gfn, pfn); spin_lock(&vcpu->kvm->mmu_lock); if (mmu_notifier_retry(vcpu, mmu_seq)) goto out_unlock; diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h index 7086ca8..05310b1 100644 --- a/arch/x86/kvm/mmu.h +++ b/arch/x86/kvm/mmu.h @@ -76,4 +76,27 @@ static inline int is_present_gpte(unsigned long pte) return pte & PT_PRESENT_MASK; } +static inline int is_writable_pte(unsigned long pte) +{ + return pte & PT_WRITABLE_MASK; +} + +static inline bool is_write_protection(struct kvm_vcpu *vcpu) +{ + return kvm_read_cr0_bits(vcpu, X86_CR0_WP); +} + +static inline bool check_write_user_access(struct kvm_vcpu *vcpu, + bool write_fault, bool user_fault, + unsigned long pte) +{ + if (unlikely(write_fault && !is_writable_pte(pte) + && (user_fault || is_write_protection(vcpu)))) + return false; + + if (unlikely(user_fault && !(pte & PT_USER_MASK))) + return false; + + return true; +} #endif diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 1e1c244..f0fb1a4 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -208,11 +208,8 @@ retry_walk: goto error; } - if (unlikely(write_fault && !is_writable_pte(pte) - && (user_fault || is_write_protection(vcpu)))) - eperm = true; - - if (unlikely(user_fault && !(pte & PT_USER_MASK))) + if (!check_write_user_access(vcpu, write_fault, user_fault, + pte)) eperm = true; #if PTTYPE == 64 @@ -625,8 +622,16 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code, return 0; /* mmio */ - if (is_error_pfn(pfn)) - return kvm_handle_bad_page(vcpu->kvm, walker.gfn, pfn); + if (is_error_pfn(pfn)) { + unsigned access = walker.pte_access; + bool dirty = is_dirty_gpte(walker.ptes[walker.level - 1]); + + if (!dirty) + access &= ~ACC_WRITE_MASK; + + return kvm_handle_bad_page(vcpu, mmu_is_nested(vcpu) ? 0 : + addr, access, walker.gfn, pfn); + } spin_lock(&vcpu->kvm->mmu_lock); if (mmu_notifier_retry(vcpu, mmu_seq)) @@ -666,6 +671,8 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva) u64 *sptep; int need_flush = 0; + vcpu_clear_mmio_info(vcpu, gva); + spin_lock(&vcpu->kvm->mmu_lock); for_each_shadow_entry(vcpu, gva, iterator) { diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d77ac44..b3716f1 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3950,6 +3950,14 @@ static int vcpu_mmio_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva, { u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0; + if (vcpu_match_mmio_gva(vcpu, gva) && + check_write_user_access(vcpu, write, access, + vcpu->arch.access)) { + *gpa = vcpu->arch.mmio_gfn << PAGE_SHIFT | + (gva & (PAGE_SIZE - 1)); + return 1; + } + if (write) access |= PFERR_WRITE_MASK; @@ -3962,6 +3970,9 @@ static int vcpu_mmio_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva, if ((*gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE) return 1; + if (vcpu_match_mmio_gpa(vcpu, *gpa)) + return 1; + return 0; } diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index 256da82..d36fe23 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -75,6 +75,42 @@ static inline u32 bit(int bitno) return 1 << (bitno & 31); } +static inline void vcpu_cache_mmio_info(struct kvm_vcpu *vcpu, + gva_t gva, gfn_t gfn, unsigned access) +{ + vcpu->arch.mmio_gva = gva & PAGE_MASK; + vcpu->arch.access = access; + vcpu->arch.mmio_gfn = gfn; +} + +/* + * Clear the mmio cache info for the given gva, + * specially, if gva is ~0ul, we clear all mmio cache info. + */ +static inline void vcpu_clear_mmio_info(struct kvm_vcpu *vcpu, gva_t gva) +{ + if (gva != (~0ul) && vcpu->arch.mmio_gva != (gva & PAGE_MASK)) + return; + + vcpu->arch.mmio_gva = 0; +} + +static inline bool vcpu_match_mmio_gva(struct kvm_vcpu *vcpu, unsigned long gva) +{ + if (vcpu->arch.mmio_gva && vcpu->arch.mmio_gva == (gva & PAGE_MASK)) + return true; + + return false; +} + +static inline bool vcpu_match_mmio_gpa(struct kvm_vcpu *vcpu, gpa_t gpa) +{ + if (vcpu->arch.mmio_gfn && vcpu->arch.mmio_gfn == gpa >> PAGE_SHIFT) + return true; + + return false; +} + void kvm_before_handle_nmi(struct kvm_vcpu *vcpu); void kvm_after_handle_nmi(struct kvm_vcpu *vcpu); int kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip);

[v4,04/18] KVM: MMU: cache mmio info on page fault path

Commit Message

Patch