Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760387AbcDEVje (ORCPT ); Tue, 5 Apr 2016 17:39:34 -0400 Received: from mail-pa0-f48.google.com ([209.85.220.48]:35781 "EHLO mail-pa0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760145AbcDEVjc (ORCPT ); Tue, 5 Apr 2016 17:39:32 -0400 Date: Tue, 5 Apr 2016 14:39:29 -0700 (PDT) From: Hugh Dickins X-X-Sender: hugh@eggly.anvils To: Andrew Morton cc: "Kirill A. Shutemov" , Andrea Arcangeli , Andres Lagar-Cavilla , Yang Shi , Ning Qu , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 16/31] kvm: plumb return of hva when resolving page fault. In-Reply-To: Message-ID: References: User-Agent: Alpine 2.11 (LSU 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6018 Lines: 176 From: Andres Lagar-Cavilla So we don't have to redo this work later. Note the hva is not racy, it is simple arithmetic based on the memslot. This will be used in the huge tmpfs commits. Signed-off-by: Andres Lagar-Cavilla Signed-off-by: Hugh Dickins --- Cc'ed to kvm@vger.kernel.org as an FYI: this patch is not expected to go into the tree in the next few weeks. The context is a huge tmpfs patchset which implements huge pagecache transparently on tmpfs, using a team of small pages rather than one compound page: please refer to linux-mm or linux-kernel for more context. arch/x86/kvm/mmu.c | 20 ++++++++++++++------ arch/x86/kvm/paging_tmpl.h | 3 ++- include/linux/kvm_host.h | 2 +- virt/kvm/kvm_main.c | 14 ++++++++------ 4 files changed, 25 insertions(+), 14 deletions(-) --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2992,7 +2992,8 @@ exit: } static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn, - gva_t gva, kvm_pfn_t *pfn, bool write, bool *writable); + gva_t gva, kvm_pfn_t *pfn, bool write, bool *writable, + unsigned long *hva); static void make_mmu_pages_available(struct kvm_vcpu *vcpu); static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, u32 error_code, @@ -3003,6 +3004,7 @@ static int nonpaging_map(struct kvm_vcpu bool force_pt_level = false; kvm_pfn_t pfn; unsigned long mmu_seq; + unsigned long hva; bool map_writable, write = error_code & PFERR_WRITE_MASK; level = mapping_level(vcpu, gfn, &force_pt_level); @@ -3024,7 +3026,8 @@ static int nonpaging_map(struct kvm_vcpu mmu_seq = vcpu->kvm->mmu_notifier_seq; smp_rmb(); - if (try_async_pf(vcpu, prefault, gfn, v, &pfn, write, &map_writable)) + if (try_async_pf(vcpu, prefault, gfn, v, &pfn, write, + &map_writable, &hva)) return 0; if (handle_abnormal_pfn(vcpu, v, gfn, pfn, ACC_ALL, &r)) @@ -3487,14 +3490,16 @@ static bool can_do_async_pf(struct kvm_v } static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn, - gva_t gva, kvm_pfn_t *pfn, bool write, bool *writable) + gva_t gva, kvm_pfn_t *pfn, bool write, bool *writable, + unsigned long *hva) { struct kvm_memory_slot *slot; bool async; slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); async = false; - *pfn = __gfn_to_pfn_memslot(slot, gfn, false, &async, write, writable); + *pfn = __gfn_to_pfn_memslot(slot, gfn, + false, &async, write, writable, hva); if (!async) return false; /* *pfn has correct page already */ @@ -3508,7 +3513,8 @@ static bool try_async_pf(struct kvm_vcpu return true; } - *pfn = __gfn_to_pfn_memslot(slot, gfn, false, NULL, write, writable); + *pfn = __gfn_to_pfn_memslot(slot, gfn, + false, NULL, write, writable, hva); return false; } @@ -3531,6 +3537,7 @@ static int tdp_page_fault(struct kvm_vcp bool force_pt_level; gfn_t gfn = gpa >> PAGE_SHIFT; unsigned long mmu_seq; + unsigned long hva; int write = error_code & PFERR_WRITE_MASK; bool map_writable; @@ -3559,7 +3566,8 @@ static int tdp_page_fault(struct kvm_vcp mmu_seq = vcpu->kvm->mmu_notifier_seq; smp_rmb(); - if (try_async_pf(vcpu, prefault, gfn, gpa, &pfn, write, &map_writable)) + if (try_async_pf(vcpu, prefault, gfn, gpa, &pfn, write, + &map_writable, &hva)) return 0; if (handle_abnormal_pfn(vcpu, 0, gfn, pfn, ACC_ALL, &r)) --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -712,6 +712,7 @@ static int FNAME(page_fault)(struct kvm_ int level = PT_PAGE_TABLE_LEVEL; bool force_pt_level = false; unsigned long mmu_seq; + unsigned long hva; bool map_writable, is_self_change_mapping; pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code); @@ -765,7 +766,7 @@ static int FNAME(page_fault)(struct kvm_ smp_rmb(); if (try_async_pf(vcpu, prefault, walker.gfn, addr, &pfn, write_fault, - &map_writable)) + &map_writable, &hva)) return 0; if (handle_abnormal_pfn(vcpu, mmu_is_nested(vcpu) ? 0 : addr, --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -600,7 +600,7 @@ kvm_pfn_t gfn_to_pfn_memslot(struct kvm_ kvm_pfn_t gfn_to_pfn_memslot_atomic(struct kvm_memory_slot *slot, gfn_t gfn); kvm_pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, bool atomic, bool *async, bool write_fault, - bool *writable); + bool *writable, unsigned long *hva); void kvm_release_pfn_clean(kvm_pfn_t pfn); void kvm_set_pfn_dirty(kvm_pfn_t pfn); --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1444,7 +1444,7 @@ exit: kvm_pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, bool atomic, bool *async, bool write_fault, - bool *writable) + bool *writable, unsigned long *hva) { unsigned long addr = __gfn_to_hva_many(slot, gfn, NULL, write_fault); @@ -1466,8 +1466,10 @@ kvm_pfn_t __gfn_to_pfn_memslot(struct kv writable = NULL; } - return hva_to_pfn(addr, atomic, async, write_fault, - writable); + if (hva) + *hva = addr; + + return hva_to_pfn(addr, atomic, async, write_fault, writable); } EXPORT_SYMBOL_GPL(__gfn_to_pfn_memslot); @@ -1475,19 +1477,19 @@ kvm_pfn_t gfn_to_pfn_prot(struct kvm *kv bool *writable) { return __gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn, false, NULL, - write_fault, writable); + write_fault, writable, NULL); } EXPORT_SYMBOL_GPL(gfn_to_pfn_prot); kvm_pfn_t gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn) { - return __gfn_to_pfn_memslot(slot, gfn, false, NULL, true, NULL); + return __gfn_to_pfn_memslot(slot, gfn, false, NULL, true, NULL, NULL); } EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot); kvm_pfn_t gfn_to_pfn_memslot_atomic(struct kvm_memory_slot *slot, gfn_t gfn) { - return __gfn_to_pfn_memslot(slot, gfn, true, NULL, true, NULL); + return __gfn_to_pfn_memslot(slot, gfn, true, NULL, true, NULL, NULL); } EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot_atomic);