[v2,09/12] Retry fault before vmentry

Message ID	1258985167-29178-10-git-send-email-gleb@redhat.com (mailing list archive)
State	New, archived
Headers	show Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id nANEBoTQ018662 for <patchwork-kvm@patchwork.kernel.org>; Mon, 23 Nov 2009 14:11:51 GMT From: Gleb Natapov <gleb@redhat.com> To: kvm@vger.kernel.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, avi@redhat.com, mingo@elte.hu, a.p.zijlstra@chello.nl, tglx@linutronix.de, hpa@zytor.com, riel@redhat.com Subject: [PATCH v2 09/12] Retry fault before vmentry Date: Mon, 23 Nov 2009 16:06:04 +0200 Message-Id: <1258985167-29178-10-git-send-email-gleb@redhat.com> In-Reply-To: <1258985167-29178-1-git-send-email-gleb@redhat.com> References: <1258985167-29178-1-git-send-email-gleb@redhat.com> 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 ad177a4..39009a4 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -254,7 +254,7 @@ struct kvm_pio_request { */ struct kvm_mmu { void (*new_cr3)(struct kvm_vcpu *vcpu); - int (*page_fault)(struct kvm_vcpu *vcpu, gva_t gva, u32 err); + int (*page_fault)(struct kvm_vcpu *vcpu, gpa_t cr3, gva_t gva, u32 err); void (*free)(struct kvm_vcpu *vcpu); gpa_t (*gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t gva); void (*prefetch_page)(struct kvm_vcpu *vcpu, @@ -542,6 +542,8 @@ struct kvm_x86_ops { struct kvm_arch_async_pf { u32 token; + gpa_t cr3; + u32 error_code; }; extern struct kvm_x86_ops *kvm_x86_ops; @@ -828,6 +830,8 @@ void kvm_arch_inject_async_page_not_present(struct kvm_vcpu *vcpu, struct kvm_async_pf *work); void kvm_arch_inject_async_page_present(struct kvm_vcpu *vcpu, struct kvm_async_pf *work); +void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, + struct kvm_async_pf *work); bool kvm_arch_can_inject_async_page_present(struct kvm_vcpu *vcpu); #endif /* _ASM_X86_KVM_HOST_H */ diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 2cdf3e3..1225c31 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2172,7 +2172,7 @@ static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr) return vaddr; } -static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva, +static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gpa_t cr3, gva_t gva, u32 error_code) { gfn_t gfn; @@ -2192,10 +2192,13 @@ static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva, error_code & PFERR_WRITE_MASK, gfn); } -int kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn) +int kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr3, gva_t gva, + gfn_t gfn, u32 error_code) { struct kvm_arch_async_pf arch; arch.token = (vcpu->arch.async_pf_id++ << 12) | vcpu->vcpu_id; + arch.cr3 = cr3; + arch.error_code = error_code; return kvm_setup_async_pf(vcpu, gva, gfn, &arch); } @@ -2207,7 +2210,7 @@ static bool can_do_async_pf(struct kvm_vcpu *vcpu) return !!kvm_x86_ops->get_cpl(vcpu); } -static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, +static int tdp_page_fault(struct kvm_vcpu *vcpu, gpa_t cr3, gva_t gpa, u32 error_code) { pfn_t pfn; @@ -2230,7 +2233,7 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, mmu_seq = vcpu->kvm->mmu_notifier_seq; smp_rmb(); - if (can_do_async_pf(vcpu)) { + if (cr3 == vcpu->arch.cr3 && can_do_async_pf(vcpu)) { r = gfn_to_pfn_async(vcpu->kvm, gfn, &pfn); trace_kvm_try_async_get_page(r, pfn); } else { @@ -2240,7 +2243,7 @@ do_sync: } if (!r) { - if (!kvm_arch_setup_async_pf(vcpu, gpa, gfn)) + if (!kvm_arch_setup_async_pf(vcpu, cr3, gpa, gfn, error_code)) goto do_sync; return 0; } @@ -2810,7 +2813,7 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code) int r; enum emulation_result er; - r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code); + r = vcpu->arch.mmu.page_fault(vcpu, vcpu->arch.cr3, cr2, error_code); if (r < 0) goto out; diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 44d19dc..702893c 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -375,7 +375,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, * Returns: 1 if we need to emulate the instruction, 0 otherwise, or * a negative value on error. */ -static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, +static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t cr3, gva_t addr, u32 error_code) { int write_fault = error_code & PFERR_WRITE_MASK; @@ -388,6 +388,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, pfn_t pfn; int level = PT_PAGE_TABLE_LEVEL; unsigned long mmu_seq; + gpa_t curr_cr3 = vcpu->arch.cr3; pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code); kvm_mmu_audit(vcpu, "pre page fault"); @@ -396,6 +397,19 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, if (r) return r; + if (curr_cr3 != cr3) { + /* + * We do page fault on behaltf of a process that is sleeping + * because of async PF. PV guest shouldn't kill process while + * it waits for host to swap-in the page so cr3 has to be + * valid here. + */ + vcpu->arch.cr3 = cr3; + paging_new_cr3(vcpu); + if (kvm_mmu_reload(vcpu)) + goto switch_cr3; + } + /* * Look up the guest pte for the faulting address. */ @@ -406,6 +420,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, * The page is not mapped by the guest. Let the guest handle it. */ if (!r) { + if (curr_cr3 != vcpu->arch.cr3) + goto switch_cr3; pgprintk("%s: guest page fault\n", __func__); inject_page_fault(vcpu, addr, walker.error_code); vcpu->arch.last_pt_write_count = 0; /* reset fork detector */ @@ -420,7 +436,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, mmu_seq = vcpu->kvm->mmu_notifier_seq; smp_rmb(); - if (can_do_async_pf(vcpu)) { + if (curr_cr3 == vcpu->arch.cr3 && can_do_async_pf(vcpu)) { r = gfn_to_pfn_async(vcpu->kvm, walker.gfn, &pfn); trace_kvm_try_async_get_page(r, pfn); } else { @@ -430,13 +446,18 @@ do_sync: } if (!r) { - if (!kvm_arch_setup_async_pf(vcpu, addr, walker.gfn)) + if (!kvm_arch_setup_async_pf(vcpu, cr3, addr, walker.gfn, + error_code)) goto do_sync; + if (curr_cr3 != vcpu->arch.cr3) + goto switch_cr3; return 0; } /* mmio */ if (is_error_pfn(pfn)) { + if (curr_cr3 != vcpu->arch.cr3) + goto switch_cr3; pgprintk("gfn %lx is mmio\n", walker.gfn); kvm_release_pfn_clean(pfn); return 1; @@ -458,12 +479,23 @@ do_sync: kvm_mmu_audit(vcpu, "post page fault (fixed)"); spin_unlock(&vcpu->kvm->mmu_lock); + if (curr_cr3 != vcpu->arch.cr3) + goto switch_cr3; + return write_pt; out_unlock: spin_unlock(&vcpu->kvm->mmu_lock); kvm_release_pfn_clean(pfn); return 0; +switch_cr3: + if (curr_cr3 != vcpu->arch.cr3) { + vcpu->arch.cr3 = curr_cr3; + paging_new_cr3(vcpu); + kvm_mmu_reload(vcpu); + } + + return write_pt; } static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index cbbe5fd..c29af1d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5306,6 +5306,13 @@ void kvm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags) } EXPORT_SYMBOL_GPL(kvm_set_rflags); +void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, + struct kvm_async_pf *work) +{ + vcpu->arch.mmu.page_fault(vcpu, work->arch.cr3, work->gva, + work->arch.error_code); +} + void kvm_arch_inject_async_page_not_present(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) { diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 14ac02a..6e6769f 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1212,6 +1212,7 @@ void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu) spin_lock(&vcpu->async_pf_lock); list_del(&work->link); spin_unlock(&vcpu->async_pf_lock); + kvm_arch_async_page_ready(vcpu, work); put_page(work->page); async_pf_work_free(work); } @@ -1226,6 +1227,7 @@ void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu) list_del(&work->link); spin_unlock(&vcpu->async_pf_lock); + kvm_arch_async_page_ready(vcpu, work); kvm_arch_inject_async_page_present(vcpu, work); put_page(work->page);

[v2,09/12] Retry fault before vmentry

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Patch