From patchwork Fri Jun 25 07:36:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Stevens X-Patchwork-Id: 1496975 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=kvm-ppc-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=chromium.org header.i=@chromium.org header.a=rsa-sha256 header.s=google header.b=LXB8g40v; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4GB83W4XMjz9sjD for ; Fri, 25 Jun 2021 17:37:27 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230002AbhFYHjq (ORCPT ); Fri, 25 Jun 2021 03:39:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48704 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230013AbhFYHjp (ORCPT ); Fri, 25 Jun 2021 03:39:45 -0400 Received: from mail-pj1-x1033.google.com (mail-pj1-x1033.google.com [IPv6:2607:f8b0:4864:20::1033]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5B785C061574 for ; Fri, 25 Jun 2021 00:37:24 -0700 (PDT) Received: by mail-pj1-x1033.google.com with SMTP id z3-20020a17090a3983b029016bc232e40bso5019945pjb.4 for ; Fri, 25 Jun 2021 00:37:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=LzgP6h2D/QFeac1VzX61noEzAJ/USmwi4gQaHInAahw=; b=LXB8g40vStNBwD+4feBv7G1sswWg7tKXE2UuAUSDoyq52hfi4irDQ/yiXu8Ug+ZDws xIzft/b25MjWvtHFPnJ6SklO93ihyo0nBxWHm/9AZX/s3potEvqVSuo/FGmincAfc25Y X1yk5o0729qjIfPuIaA+V96KO60J3W+vXFDLY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=LzgP6h2D/QFeac1VzX61noEzAJ/USmwi4gQaHInAahw=; b=YO0fserDKoEQIH5KM/kit5YLAgjQpeEYvFIxqnHrxYR8Lsod87Qlk2kJYTeLUPcqq+ 53HEq6ki9wH46piVmFebTIFlK4xo0n6GOkx9eHzgDrFxFy7ecso/hSupYQQ16ljI20TI 3ZUxOkhI8qX3f1+TKsQ5al/4Vf+GxRsDfKoxAA0alSBSXVCM3g+ErXXbnVOfEyPt9X2R bLFzAVuZCs/qZUn6zQHCTXBUv8E5jIEdOqdIR7LHBqZJtAqbRcpNt4a867w0m2PWY7MY jGnHwn2E7JZPLIhw3L+rP3MAOPuU8ufN7bInCJ1duCn6kb9h6UbjOkQYzH3CmahzuEoV c3QA== X-Gm-Message-State: AOAM532BRhKlNGVR1Om6Fw/cQ/t0azUIdHhWTsOtF7lAgjIRr7I7G6ik ZCHTMmdmb0erfzYqA2hnTMoEVQ== X-Google-Smtp-Source: ABdhPJzquQUc1a7oAEf0YGdzW5/tdcjfbVYUNDDWR+jVqhrRl2C1S/KaYW68U6E8tZbflFTo+iOEfA== X-Received: by 2002:a17:902:e843:b029:109:4dbc:d4ed with SMTP id t3-20020a170902e843b02901094dbcd4edmr7948926plg.74.1624606643957; Fri, 25 Jun 2021 00:37:23 -0700 (PDT) Received: from localhost ([2401:fa00:8f:203:1492:9d4f:19fa:df61]) by smtp.gmail.com with UTF8SMTPSA id r4sm4766830pja.41.2021.06.25.00.37.19 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 25 Jun 2021 00:37:23 -0700 (PDT) From: David Stevens X-Google-Original-From: David Stevens To: Marc Zyngier , Huacai Chen , Aleksandar Markovic , Paul Mackerras , Paolo Bonzini , Nick Piggin Cc: James Morse , Alexandru Elisei , Suzuki K Poulose , Will Deacon , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Zhenyu Wang , Zhi Wang , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: [PATCH v2 1/5] KVM: do not allow mapping valid but non-refcounted pages Date: Fri, 25 Jun 2021 16:36:12 +0900 Message-Id: <20210625073616.2184426-2-stevensd@google.com> X-Mailer: git-send-email 2.32.0.93.g670b81a890-goog In-Reply-To: <20210625073616.2184426-1-stevensd@google.com> References: <20210625073616.2184426-1-stevensd@google.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org From: Nicholas Piggin It's possible to create a region which maps valid but non-refcounted pages (e.g., tail pages of non-compound higher order allocations). These host pages can then be returned by gfn_to_page, gfn_to_pfn, etc., family of APIs, which take a reference to the page, which takes it from 0 to 1. When the reference is dropped, this will free the page incorrectly. Fix this by only taking a reference on the page if it was non-zero, which indicates it is participating in normal refcounting (and can be released with put_page). Signed-off-by: Nicholas Piggin Reviewed-by: Christian Borntraeger --- virt/kvm/kvm_main.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 3dcc2abbfc60..f7445c3bcd90 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2175,6 +2175,13 @@ static bool vma_is_valid(struct vm_area_struct *vma, bool write_fault) return true; } +static int kvm_try_get_pfn(kvm_pfn_t pfn) +{ + if (kvm_is_reserved_pfn(pfn)) + return 1; + return get_page_unless_zero(pfn_to_page(pfn)); +} + static int hva_to_pfn_remapped(struct vm_area_struct *vma, unsigned long addr, bool *async, bool write_fault, bool *writable, @@ -2224,13 +2231,21 @@ static int hva_to_pfn_remapped(struct vm_area_struct *vma, * Whoever called remap_pfn_range is also going to call e.g. * unmap_mapping_range before the underlying pages are freed, * causing a call to our MMU notifier. + * + * Certain IO or PFNMAP mappings can be backed with valid + * struct pages, but be allocated without refcounting e.g., + * tail pages of non-compound higher order allocations, which + * would then underflow the refcount when the caller does the + * required put_page. Don't allow those pages here. */ - kvm_get_pfn(pfn); + if (!kvm_try_get_pfn(pfn)) + r = -EFAULT; out: pte_unmap_unlock(ptep, ptl); *p_pfn = pfn; - return 0; + + return r; } /* From patchwork Fri Jun 25 07:36:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Stevens X-Patchwork-Id: 1496976 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=kvm-ppc-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=chromium.org header.i=@chromium.org header.a=rsa-sha256 header.s=google header.b=jsVWx4zR; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4GB83l4JlNz9sjD for ; Fri, 25 Jun 2021 17:37:39 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229772AbhFYHj5 (ORCPT ); Fri, 25 Jun 2021 03:39:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48766 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229764AbhFYHjz (ORCPT ); Fri, 25 Jun 2021 03:39:55 -0400 Received: from mail-pf1-x42d.google.com (mail-pf1-x42d.google.com [IPv6:2607:f8b0:4864:20::42d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3D431C061768 for ; Fri, 25 Jun 2021 00:37:31 -0700 (PDT) Received: by mail-pf1-x42d.google.com with SMTP id g192so7357141pfb.6 for ; Fri, 25 Jun 2021 00:37:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=u4Msfi+S3PkAmckIb45Y4YhfvK0zrfK1v0GQOeKxL8U=; b=jsVWx4zRHi5LgbBDABZxQBMVf0I5Pehki/bLP1YEDTCFU+7oqcawuLdQyOF/WTHvrm GkAZKMD5IiMtCqrbGlu910q/CyOs+isCAewjZKOhwg59+E7AXomrJ6A2uZ9RqaGcXirk lV0SFGaAyCFC4T82D6h/FrcpvKiIknqhpH6yk= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=u4Msfi+S3PkAmckIb45Y4YhfvK0zrfK1v0GQOeKxL8U=; b=J1Vo9LKIGBM8M45JLlETiBVqimAolr4p6VmM1pB3sD855twz0TRJkpx8xw6P77Jwsd bEWT7LO2p85G/DOCFUhvj8SDhwiijf3VSTf+eLPH0dNc2SP5FICMEgOpwfp+Ao5HSSjg GSeJborsyOawSkZBsxDPGVvLxp76QcmJdIcyy1sF5A/sh9HARy+6pbvuZI6cwpKykFGR s4ycnLdB3+QdS1iOPEGtbuIUBQG4cet/snnvcCPikJYQDI09qqChk4Gqm3PAlqiZo9Ga SHeV/LIalm6AqkGyVVQw/05iOz1gXLY0aQhoITcPTqWUrM5945KNn7UHmGJdusohJFyz yMUw== X-Gm-Message-State: AOAM530qtoVZmU8wJJRIWPReP7+KGEI+ecbLxbQu1OEbrt8yUEoaL+2Q T9JOtMRX/YjtSJqoQbR4Ek35BA== X-Google-Smtp-Source: ABdhPJyyESM737HvNDRLo7wsjj7srNzMihvC96O4J3ijX1Pbthrr46lvLTHJ0sjdv2LUYHCcdC3mGQ== X-Received: by 2002:a05:6a00:238e:b029:2ef:839b:adc7 with SMTP id f14-20020a056a00238eb02902ef839badc7mr9115989pfc.54.1624606650766; Fri, 25 Jun 2021 00:37:30 -0700 (PDT) Received: from localhost ([2401:fa00:8f:203:1492:9d4f:19fa:df61]) by smtp.gmail.com with UTF8SMTPSA id j22sm4516344pgb.62.2021.06.25.00.37.25 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 25 Jun 2021 00:37:30 -0700 (PDT) From: David Stevens X-Google-Original-From: David Stevens To: Marc Zyngier , Huacai Chen , Aleksandar Markovic , Paul Mackerras , Paolo Bonzini , Nick Piggin Cc: James Morse , Alexandru Elisei , Suzuki K Poulose , Will Deacon , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Zhenyu Wang , Zhi Wang , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, David Stevens Subject: [PATCH v2 2/5] KVM: mmu: introduce new gfn_to_pfn_page functions Date: Fri, 25 Jun 2021 16:36:13 +0900 Message-Id: <20210625073616.2184426-3-stevensd@google.com> X-Mailer: git-send-email 2.32.0.93.g670b81a890-goog In-Reply-To: <20210625073616.2184426-1-stevensd@google.com> References: <20210625073616.2184426-1-stevensd@google.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org From: David Stevens Introduce new gfn_to_pfn_page functions that parallel existing gfn_to_pfn functions. The new functions are identical except they take an additional out parameter that is used to return the struct page if the hva was resolved by gup. This allows callers to differentiate the gup and follow_pte cases, which in turn allows callers to only touch the page refcount when necessitated by gup. The old gfn_to_pfn functions are depreciated, and all callers should be migrated to the new gfn_to_pfn_page functions. In the interim, the gfn_to_pfn functions are reimplemented as wrappers of the corresponding gfn_to_pfn_page functions. The wrappers take a reference to the pfn's page that had previously been taken in hva_to_pfn_remapped. Signed-off-by: David Stevens --- include/linux/kvm_host.h | 17 ++++ virt/kvm/kvm_main.c | 186 ++++++++++++++++++++++++++++----------- 2 files changed, 152 insertions(+), 51 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index ae7735b490b4..2f828edd7278 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -820,6 +820,19 @@ kvm_pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, bool atomic, bool *async, bool write_fault, bool *writable, hva_t *hva); +kvm_pfn_t gfn_to_pfn_page(struct kvm *kvm, gfn_t gfn, struct page **page); +kvm_pfn_t gfn_to_pfn_page_prot(struct kvm *kvm, gfn_t gfn, + bool write_fault, bool *writable, + struct page **page); +kvm_pfn_t gfn_to_pfn_page_memslot(struct kvm_memory_slot *slot, + gfn_t gfn, struct page **page); +kvm_pfn_t gfn_to_pfn_page_memslot_atomic(struct kvm_memory_slot *slot, + gfn_t gfn, struct page **page); +kvm_pfn_t __gfn_to_pfn_page_memslot(struct kvm_memory_slot *slot, + gfn_t gfn, bool atomic, bool *async, + bool write_fault, bool *writable, + hva_t *hva, struct page **page); + void kvm_release_pfn_clean(kvm_pfn_t pfn); void kvm_release_pfn_dirty(kvm_pfn_t pfn); void kvm_set_pfn_dirty(kvm_pfn_t pfn); @@ -901,6 +914,10 @@ struct kvm_memslots *kvm_vcpu_memslots(struct kvm_vcpu *vcpu); struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn); kvm_pfn_t kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu *vcpu, gfn_t gfn); kvm_pfn_t kvm_vcpu_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn); +kvm_pfn_t kvm_vcpu_gfn_to_pfn_page_atomic(struct kvm_vcpu *vcpu, gfn_t gfn, + struct page **page); +kvm_pfn_t kvm_vcpu_gfn_to_pfn_page(struct kvm_vcpu *vcpu, gfn_t gfn, + struct page **page); int kvm_vcpu_map(struct kvm_vcpu *vcpu, gpa_t gpa, struct kvm_host_map *map); int kvm_map_gfn(struct kvm_vcpu *vcpu, gfn_t gfn, struct kvm_host_map *map, struct gfn_to_pfn_cache *cache, bool atomic); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index f7445c3bcd90..1de8702845ac 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2102,9 +2102,9 @@ static inline int check_user_page_hwpoison(unsigned long addr) * only part that runs if we can in atomic context. */ static bool hva_to_pfn_fast(unsigned long addr, bool write_fault, - bool *writable, kvm_pfn_t *pfn) + bool *writable, kvm_pfn_t *pfn, + struct page **page) { - struct page *page[1]; /* * Fast pin a writable pfn only if it is a write fault request @@ -2115,7 +2115,7 @@ static bool hva_to_pfn_fast(unsigned long addr, bool write_fault, return false; if (get_user_page_fast_only(addr, FOLL_WRITE, page)) { - *pfn = page_to_pfn(page[0]); + *pfn = page_to_pfn(*page); if (writable) *writable = true; @@ -2130,10 +2130,9 @@ static bool hva_to_pfn_fast(unsigned long addr, bool write_fault, * 1 indicates success, -errno is returned if error is detected. */ static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault, - bool *writable, kvm_pfn_t *pfn) + bool *writable, kvm_pfn_t *pfn, struct page **page) { unsigned int flags = FOLL_HWPOISON; - struct page *page; int npages = 0; might_sleep(); @@ -2146,7 +2145,7 @@ static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault, if (async) flags |= FOLL_NOWAIT; - npages = get_user_pages_unlocked(addr, 1, &page, flags); + npages = get_user_pages_unlocked(addr, 1, page, flags); if (npages != 1) return npages; @@ -2156,11 +2155,11 @@ static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault, if (get_user_page_fast_only(addr, FOLL_WRITE, &wpage)) { *writable = true; - put_page(page); - page = wpage; + put_page(*page); + *page = wpage; } } - *pfn = page_to_pfn(page); + *pfn = page_to_pfn(*page); return npages; } @@ -2175,13 +2174,6 @@ static bool vma_is_valid(struct vm_area_struct *vma, bool write_fault) return true; } -static int kvm_try_get_pfn(kvm_pfn_t pfn) -{ - if (kvm_is_reserved_pfn(pfn)) - return 1; - return get_page_unless_zero(pfn_to_page(pfn)); -} - static int hva_to_pfn_remapped(struct vm_area_struct *vma, unsigned long addr, bool *async, bool write_fault, bool *writable, @@ -2221,26 +2213,6 @@ static int hva_to_pfn_remapped(struct vm_area_struct *vma, *writable = pte_write(*ptep); pfn = pte_pfn(*ptep); - /* - * Get a reference here because callers of *hva_to_pfn* and - * *gfn_to_pfn* ultimately call kvm_release_pfn_clean on the - * returned pfn. This is only needed if the VMA has VM_MIXEDMAP - * set, but the kvm_get_pfn/kvm_release_pfn_clean pair will - * simply do nothing for reserved pfns. - * - * Whoever called remap_pfn_range is also going to call e.g. - * unmap_mapping_range before the underlying pages are freed, - * causing a call to our MMU notifier. - * - * Certain IO or PFNMAP mappings can be backed with valid - * struct pages, but be allocated without refcounting e.g., - * tail pages of non-compound higher order allocations, which - * would then underflow the refcount when the caller does the - * required put_page. Don't allow those pages here. - */ - if (!kvm_try_get_pfn(pfn)) - r = -EFAULT; - out: pte_unmap_unlock(ptep, ptl); *p_pfn = pfn; @@ -2262,8 +2234,9 @@ static int hva_to_pfn_remapped(struct vm_area_struct *vma, * 2): @write_fault = false && @writable, @writable will tell the caller * whether the mapping is writable. */ -static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, - bool write_fault, bool *writable) +static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, + bool *async, bool write_fault, bool *writable, + struct page **page) { struct vm_area_struct *vma; kvm_pfn_t pfn = 0; @@ -2272,13 +2245,14 @@ static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, /* we can do it either atomically or asynchronously, not both */ BUG_ON(atomic && async); - if (hva_to_pfn_fast(addr, write_fault, writable, &pfn)) + if (hva_to_pfn_fast(addr, write_fault, writable, &pfn, page)) return pfn; if (atomic) return KVM_PFN_ERR_FAULT; - npages = hva_to_pfn_slow(addr, async, write_fault, writable, &pfn); + npages = hva_to_pfn_slow(addr, async, write_fault, writable, + &pfn, page); if (npages == 1) return pfn; @@ -2310,12 +2284,14 @@ static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, return pfn; } -kvm_pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, - bool atomic, bool *async, bool write_fault, - bool *writable, hva_t *hva) +kvm_pfn_t __gfn_to_pfn_page_memslot(struct kvm_memory_slot *slot, + gfn_t gfn, bool atomic, bool *async, + bool write_fault, bool *writable, + hva_t *hva, struct page **page) { unsigned long addr = __gfn_to_hva_many(slot, gfn, NULL, write_fault); + *page = NULL; if (hva) *hva = addr; @@ -2338,45 +2314,153 @@ kvm_pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, } return hva_to_pfn(addr, atomic, async, write_fault, - writable); + writable, page); +} +EXPORT_SYMBOL_GPL(__gfn_to_pfn_page_memslot); + +kvm_pfn_t gfn_to_pfn_page_prot(struct kvm *kvm, gfn_t gfn, bool write_fault, + bool *writable, struct page **page) +{ + return __gfn_to_pfn_page_memslot(gfn_to_memslot(kvm, gfn), gfn, false, + NULL, write_fault, writable, NULL, + page); +} +EXPORT_SYMBOL_GPL(gfn_to_pfn_page_prot); + +kvm_pfn_t gfn_to_pfn_page_memslot(struct kvm_memory_slot *slot, gfn_t gfn, + struct page **page) +{ + return __gfn_to_pfn_page_memslot(slot, gfn, false, NULL, true, + NULL, NULL, page); +} +EXPORT_SYMBOL_GPL(gfn_to_pfn_page_memslot); + +kvm_pfn_t gfn_to_pfn_page_memslot_atomic(struct kvm_memory_slot *slot, + gfn_t gfn, struct page **page) +{ + return __gfn_to_pfn_page_memslot(slot, gfn, true, NULL, true, NULL, + NULL, page); +} +EXPORT_SYMBOL_GPL(gfn_to_pfn_page_memslot_atomic); + +kvm_pfn_t kvm_vcpu_gfn_to_pfn_page_atomic(struct kvm_vcpu *vcpu, gfn_t gfn, + struct page **page) +{ + return gfn_to_pfn_page_memslot_atomic( + kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn, page); +} +EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn_page_atomic); + +kvm_pfn_t gfn_to_pfn_page(struct kvm *kvm, gfn_t gfn, struct page **page) +{ + return gfn_to_pfn_page_memslot(gfn_to_memslot(kvm, gfn), gfn, page); +} +EXPORT_SYMBOL_GPL(gfn_to_pfn_page); + +kvm_pfn_t kvm_vcpu_gfn_to_pfn_page(struct kvm_vcpu *vcpu, gfn_t gfn, + struct page **page) +{ + return gfn_to_pfn_page_memslot(kvm_vcpu_gfn_to_memslot(vcpu, gfn), + gfn, page); +} +EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn_page); + +static kvm_pfn_t ensure_pfn_ref(struct page *page, kvm_pfn_t pfn) +{ + if (page || is_error_pfn(pfn) || kvm_is_reserved_pfn(pfn)) + return pfn; + + /* + * Certain IO or PFNMAP mappings can be backed with valid + * struct pages, but be allocated without refcounting e.g., + * tail pages of non-compound higher order allocations, which + * would then underflow the refcount when the caller does the + * required put_page. Don't allow those pages here. + */ + if (get_page_unless_zero(pfn_to_page(pfn))) + return pfn; + + return KVM_PFN_ERR_FAULT; +} + +kvm_pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, + bool atomic, bool *async, bool write_fault, + bool *writable, hva_t *hva) +{ + struct page *page; + kvm_pfn_t pfn; + + pfn = __gfn_to_pfn_page_memslot(slot, gfn, atomic, async, + write_fault, writable, hva, &page); + + return ensure_pfn_ref(page, pfn); } EXPORT_SYMBOL_GPL(__gfn_to_pfn_memslot); kvm_pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault, bool *writable) { - return __gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn, false, NULL, - write_fault, writable, NULL); + struct page *page; + kvm_pfn_t pfn; + + pfn = gfn_to_pfn_page_prot(kvm, gfn, write_fault, writable, &page); + + return ensure_pfn_ref(page, pfn); } 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, NULL); + struct page *page; + kvm_pfn_t pfn; + + pfn = gfn_to_pfn_page_memslot(slot, gfn, &page); + + return ensure_pfn_ref(page, pfn); } 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, NULL); + struct page *page; + kvm_pfn_t pfn; + + pfn = gfn_to_pfn_page_memslot_atomic(slot, gfn, &page); + + return ensure_pfn_ref(page, pfn); } EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot_atomic); kvm_pfn_t kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu *vcpu, gfn_t gfn) { - return gfn_to_pfn_memslot_atomic(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn); + struct page *page; + kvm_pfn_t pfn; + + pfn = kvm_vcpu_gfn_to_pfn_page_atomic(vcpu, gfn, &page); + + return ensure_pfn_ref(page, pfn); } EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn_atomic); kvm_pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn) { - return gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn); + struct page *page; + kvm_pfn_t pfn; + + pfn = gfn_to_pfn_page(kvm, gfn, &page); + + return ensure_pfn_ref(page, pfn); } EXPORT_SYMBOL_GPL(gfn_to_pfn); kvm_pfn_t kvm_vcpu_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn) { - return gfn_to_pfn_memslot(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn); + struct page *page; + kvm_pfn_t pfn; + + pfn = kvm_vcpu_gfn_to_pfn_page(vcpu, gfn, &page); + + return ensure_pfn_ref(page, pfn); } EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn); From patchwork Fri Jun 25 07:36:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Stevens X-Patchwork-Id: 1496977 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=kvm-ppc-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=chromium.org header.i=@chromium.org header.a=rsa-sha256 header.s=google header.b=V3TR8715; 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Fri, 25 Jun 2021 00:37:37 -0700 (PDT) Received: from localhost ([2401:fa00:8f:203:1492:9d4f:19fa:df61]) by smtp.gmail.com with UTF8SMTPSA id c20sm4941588pfp.203.2021.06.25.00.37.32 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 25 Jun 2021 00:37:37 -0700 (PDT) From: David Stevens X-Google-Original-From: David Stevens To: Marc Zyngier , Huacai Chen , Aleksandar Markovic , Paul Mackerras , Paolo Bonzini , Nick Piggin Cc: James Morse , Alexandru Elisei , Suzuki K Poulose , Will Deacon , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Zhenyu Wang , Zhi Wang , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, David Stevens Subject: [PATCH v2 3/5] KVM: x86/mmu: use gfn_to_pfn_page Date: Fri, 25 Jun 2021 16:36:14 +0900 Message-Id: <20210625073616.2184426-4-stevensd@google.com> X-Mailer: git-send-email 2.32.0.93.g670b81a890-goog In-Reply-To: <20210625073616.2184426-1-stevensd@google.com> References: <20210625073616.2184426-1-stevensd@google.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org From: David Stevens Covert usages of the deprecated gfn_to_pfn functions to the new gfn_to_pfn_page functions. Signed-off-by: David Stevens --- arch/x86/kvm/mmu/mmu.c | 43 ++++++++++++++++++++------------- arch/x86/kvm/mmu/mmu_internal.h | 3 ++- arch/x86/kvm/mmu/paging_tmpl.h | 23 +++++++++++------- arch/x86/kvm/mmu/tdp_mmu.c | 6 ++--- arch/x86/kvm/mmu/tdp_mmu.h | 4 +-- arch/x86/kvm/x86.c | 6 +++-- 6 files changed, 51 insertions(+), 34 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 00732757cc60..dd5cb6e33591 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -2702,8 +2702,9 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, return ret; } -static kvm_pfn_t pte_prefetch_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn, - bool no_dirty_log) +static kvm_pfn_t pte_prefetch_gfn_to_pfn_page(struct kvm_vcpu *vcpu, + gfn_t gfn, bool no_dirty_log, + struct page **page) { struct kvm_memory_slot *slot; @@ -2711,7 +2712,7 @@ static kvm_pfn_t pte_prefetch_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn, if (!slot) return KVM_PFN_ERR_FAULT; - return gfn_to_pfn_memslot_atomic(slot, gfn); + return gfn_to_pfn_page_memslot_atomic(slot, gfn, page); } static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, @@ -2840,7 +2841,8 @@ int kvm_mmu_max_mapping_level(struct kvm *kvm, int kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, gfn_t gfn, int max_level, kvm_pfn_t *pfnp, - bool huge_page_disallowed, int *req_level) + struct page *page, bool huge_page_disallowed, + int *req_level) { struct kvm_memory_slot *slot; kvm_pfn_t pfn = *pfnp; @@ -2852,6 +2854,9 @@ int kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, gfn_t gfn, if (unlikely(max_level == PG_LEVEL_4K)) return PG_LEVEL_4K; + if (!page) + return PG_LEVEL_4K; + if (is_error_noslot_pfn(pfn) || kvm_is_reserved_pfn(pfn)) return PG_LEVEL_4K; @@ -2906,7 +2911,8 @@ void disallowed_hugepage_adjust(u64 spte, gfn_t gfn, int cur_level, } static int __direct_map(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, - int map_writable, int max_level, kvm_pfn_t pfn, + int map_writable, int max_level, + kvm_pfn_t pfn, struct page *page, bool prefault, bool is_tdp) { bool nx_huge_page_workaround_enabled = is_nx_huge_page_enabled(); @@ -2919,7 +2925,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, gfn_t gfn = gpa >> PAGE_SHIFT; gfn_t base_gfn = gfn; - level = kvm_mmu_hugepage_adjust(vcpu, gfn, max_level, &pfn, + level = kvm_mmu_hugepage_adjust(vcpu, gfn, max_level, &pfn, page, huge_page_disallowed, &req_level); trace_kvm_mmu_spte_requested(gpa, level, pfn); @@ -3768,8 +3774,9 @@ static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, } static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn, - gpa_t cr2_or_gpa, kvm_pfn_t *pfn, hva_t *hva, - bool write, bool *writable) + gpa_t cr2_or_gpa, kvm_pfn_t *pfn, + hva_t *hva, bool write, bool *writable, + struct page **page) { struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); bool async; @@ -3790,8 +3797,8 @@ static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn, } async = false; - *pfn = __gfn_to_pfn_memslot(slot, gfn, false, &async, - write, writable, hva); + *pfn = __gfn_to_pfn_page_memslot(slot, gfn, false, &async, + write, writable, hva, page); if (!async) return false; /* *pfn has correct page already */ @@ -3805,8 +3812,8 @@ static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn, return true; } - *pfn = __gfn_to_pfn_memslot(slot, gfn, false, NULL, - write, writable, hva); + *pfn = __gfn_to_pfn_page_memslot(slot, gfn, false, NULL, + write, writable, hva, page); return false; } @@ -3820,6 +3827,7 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, gfn_t gfn = gpa >> PAGE_SHIFT; unsigned long mmu_seq; kvm_pfn_t pfn; + struct page *page; hva_t hva; int r; @@ -3840,7 +3848,7 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, smp_rmb(); if (try_async_pf(vcpu, prefault, gfn, gpa, &pfn, &hva, - write, &map_writable)) + write, &map_writable, &page)) return RET_PF_RETRY; if (handle_abnormal_pfn(vcpu, is_tdp ? 0 : gpa, gfn, pfn, ACC_ALL, &r)) @@ -3861,17 +3869,18 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, if (is_tdp_mmu_fault) r = kvm_tdp_mmu_map(vcpu, gpa, error_code, map_writable, max_level, - pfn, prefault); + pfn, page, prefault); else - r = __direct_map(vcpu, gpa, error_code, map_writable, max_level, pfn, - prefault, is_tdp); + r = __direct_map(vcpu, gpa, error_code, map_writable, max_level, + pfn, page, prefault, is_tdp); out_unlock: if (is_tdp_mmu_fault) read_unlock(&vcpu->kvm->mmu_lock); else write_unlock(&vcpu->kvm->mmu_lock); - kvm_release_pfn_clean(pfn); + if (page) + put_page(page); return r; } diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h index 35567293c1fd..cc02fe22b450 100644 --- a/arch/x86/kvm/mmu/mmu_internal.h +++ b/arch/x86/kvm/mmu/mmu_internal.h @@ -159,7 +159,8 @@ int kvm_mmu_max_mapping_level(struct kvm *kvm, kvm_pfn_t pfn, int max_level); int kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, gfn_t gfn, int max_level, kvm_pfn_t *pfnp, - bool huge_page_disallowed, int *req_level); + struct page *page, bool huge_page_disallowed, + int *req_level); void disallowed_hugepage_adjust(u64 spte, gfn_t gfn, int cur_level, kvm_pfn_t *pfnp, int *goal_levelp); diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h index 490a028ddabe..f1ebb1ee7f0f 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h @@ -564,6 +564,7 @@ FNAME(prefetch_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, unsigned pte_access; gfn_t gfn; kvm_pfn_t pfn; + struct page *page; if (FNAME(prefetch_invalid_gpte)(vcpu, sp, spte, gpte)) return false; @@ -573,8 +574,8 @@ FNAME(prefetch_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, gfn = gpte_to_gfn(gpte); pte_access = sp->role.access & FNAME(gpte_access)(gpte); FNAME(protect_clean_gpte)(vcpu->arch.mmu, &pte_access, gpte); - pfn = pte_prefetch_gfn_to_pfn(vcpu, gfn, - no_dirty_log && (pte_access & ACC_WRITE_MASK)); + pfn = pte_prefetch_gfn_to_pfn_page(vcpu, gfn, + no_dirty_log && (pte_access & ACC_WRITE_MASK), &page); if (is_error_pfn(pfn)) return false; @@ -585,7 +586,8 @@ FNAME(prefetch_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, mmu_set_spte(vcpu, spte, pte_access, false, PG_LEVEL_4K, gfn, pfn, true, true); - kvm_release_pfn_clean(pfn); + if (page) + put_page(page); return true; } @@ -665,8 +667,8 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw, */ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gpa_t addr, struct guest_walker *gw, u32 error_code, - int max_level, kvm_pfn_t pfn, bool map_writable, - bool prefault) + int max_level, kvm_pfn_t pfn, struct page *page, + bool map_writable, bool prefault) { bool nx_huge_page_workaround_enabled = is_nx_huge_page_enabled(); bool write_fault = error_code & PFERR_WRITE_MASK; @@ -723,7 +725,8 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gpa_t addr, } level = kvm_mmu_hugepage_adjust(vcpu, gw->gfn, max_level, &pfn, - huge_page_disallowed, &req_level); + page, huge_page_disallowed, + &req_level); trace_kvm_mmu_spte_requested(addr, gw->level, pfn); @@ -830,6 +833,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code, struct guest_walker walker; int r; kvm_pfn_t pfn; + struct page *page; hva_t hva; unsigned long mmu_seq; bool map_writable, is_self_change_mapping; @@ -882,7 +886,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code, smp_rmb(); if (try_async_pf(vcpu, prefault, walker.gfn, addr, &pfn, &hva, - write_fault, &map_writable)) + write_fault, &map_writable, &page)) return RET_PF_RETRY; if (handle_abnormal_pfn(vcpu, addr, walker.gfn, pfn, walker.pte_access, &r)) @@ -916,13 +920,14 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code, r = make_mmu_pages_available(vcpu); if (r) goto out_unlock; - r = FNAME(fetch)(vcpu, addr, &walker, error_code, max_level, pfn, + r = FNAME(fetch)(vcpu, addr, &walker, error_code, max_level, pfn, page, map_writable, prefault); kvm_mmu_audit(vcpu, AUDIT_POST_PAGE_FAULT); out_unlock: write_unlock(&vcpu->kvm->mmu_lock); - kvm_release_pfn_clean(pfn); + if (page) + put_page(page); return r; } diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index caac4ddb46df..10572af6fe91 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -966,8 +966,8 @@ static int tdp_mmu_map_handle_target_level(struct kvm_vcpu *vcpu, int write, * page tables and SPTEs to translate the faulting guest physical address. */ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, - int map_writable, int max_level, kvm_pfn_t pfn, - bool prefault) + int map_writable, int max_level, + kvm_pfn_t pfn, struct page *page, bool prefault) { bool nx_huge_page_workaround_enabled = is_nx_huge_page_enabled(); bool write = error_code & PFERR_WRITE_MASK; @@ -983,7 +983,7 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, int level; int req_level; - level = kvm_mmu_hugepage_adjust(vcpu, gfn, max_level, &pfn, + level = kvm_mmu_hugepage_adjust(vcpu, gfn, max_level, &pfn, page, huge_page_disallowed, &req_level); trace_kvm_mmu_spte_requested(gpa, level, pfn); diff --git a/arch/x86/kvm/mmu/tdp_mmu.h b/arch/x86/kvm/mmu/tdp_mmu.h index 1cae4485b3bc..3afaf73adfe7 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.h +++ b/arch/x86/kvm/mmu/tdp_mmu.h @@ -52,8 +52,8 @@ void kvm_tdp_mmu_invalidate_all_roots(struct kvm *kvm); void kvm_tdp_mmu_zap_invalidated_roots(struct kvm *kvm); int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, - int map_writable, int max_level, kvm_pfn_t pfn, - bool prefault); + int map_writable, int max_level, + kvm_pfn_t pfn, struct page *page, bool prefault); bool kvm_tdp_mmu_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range, bool flush); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 17468d983fbd..1a21b6702de5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7511,6 +7511,7 @@ static bool reexecute_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, { gpa_t gpa = cr2_or_gpa; kvm_pfn_t pfn; + struct page *page; if (!(emulation_type & EMULTYPE_ALLOW_RETRY_PF)) return false; @@ -7540,7 +7541,7 @@ static bool reexecute_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, * retry instruction -> write #PF -> emulation fail -> retry * instruction -> ... */ - pfn = gfn_to_pfn(vcpu->kvm, gpa_to_gfn(gpa)); + pfn = gfn_to_pfn_page(vcpu->kvm, gpa_to_gfn(gpa), &page); /* * If the instruction failed on the error pfn, it can not be fixed, @@ -7549,7 +7550,8 @@ static bool reexecute_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, if (is_error_noslot_pfn(pfn)) return false; - kvm_release_pfn_clean(pfn); + if (page) + put_page(page); /* The instructions are well-emulated on direct mmu. */ if (vcpu->arch.mmu->direct_map) { From patchwork Fri Jun 25 07:36:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Stevens X-Patchwork-Id: 1496979 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; 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Fri, 25 Jun 2021 00:37:43 -0700 (PDT) Received: from localhost ([2401:fa00:8f:203:1492:9d4f:19fa:df61]) by smtp.gmail.com with UTF8SMTPSA id m18sm5284072pff.88.2021.06.25.00.37.38 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 25 Jun 2021 00:37:43 -0700 (PDT) From: David Stevens X-Google-Original-From: David Stevens To: Marc Zyngier , Huacai Chen , Aleksandar Markovic , Paul Mackerras , Paolo Bonzini , Nick Piggin Cc: James Morse , Alexandru Elisei , Suzuki K Poulose , Will Deacon , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Zhenyu Wang , Zhi Wang , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, David Stevens Subject: [PATCH v2 4/5] KVM: arm64/mmu: use gfn_to_pfn_page Date: Fri, 25 Jun 2021 16:36:15 +0900 Message-Id: <20210625073616.2184426-5-stevensd@google.com> X-Mailer: git-send-email 2.32.0.93.g670b81a890-goog In-Reply-To: <20210625073616.2184426-1-stevensd@google.com> References: <20210625073616.2184426-1-stevensd@google.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org From: David Stevens Covert usages of the deprecated gfn_to_pfn functions to the new gfn_to_pfn_page functions. Signed-off-by: David Stevens --- arch/arm64/kvm/mmu.c | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index c10207fed2f3..c29da690ed74 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -780,7 +780,7 @@ static bool fault_supports_stage2_huge_mapping(struct kvm_memory_slot *memslot, static unsigned long transparent_hugepage_adjust(struct kvm_memory_slot *memslot, unsigned long hva, kvm_pfn_t *pfnp, - phys_addr_t *ipap) + struct page **page, phys_addr_t *ipap) { kvm_pfn_t pfn = *pfnp; @@ -789,7 +789,7 @@ transparent_hugepage_adjust(struct kvm_memory_slot *memslot, * sure that the HVA and IPA are sufficiently aligned and that the * block map is contained within the memslot. */ - if (kvm_is_transparent_hugepage(pfn) && + if (*page && kvm_is_transparent_hugepage(pfn) && fault_supports_stage2_huge_mapping(memslot, hva, PMD_SIZE)) { /* * The address we faulted on is backed by a transparent huge @@ -810,10 +810,11 @@ transparent_hugepage_adjust(struct kvm_memory_slot *memslot, * page accordingly. */ *ipap &= PMD_MASK; - kvm_release_pfn_clean(pfn); + put_page(*page); pfn &= ~(PTRS_PER_PMD - 1); - kvm_get_pfn(pfn); *pfnp = pfn; + *page = pfn_to_page(pfn); + get_page(*page); return PMD_SIZE; } @@ -837,6 +838,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, short vma_shift; gfn_t gfn; kvm_pfn_t pfn; + struct page *page; bool logging_active = memslot_is_logging(memslot); unsigned long fault_level = kvm_vcpu_trap_get_fault_level(vcpu); unsigned long vma_pagesize, fault_granule; @@ -933,8 +935,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, */ smp_rmb(); - pfn = __gfn_to_pfn_memslot(memslot, gfn, false, NULL, - write_fault, &writable, NULL); + pfn = __gfn_to_pfn_page_memslot(memslot, gfn, false, NULL, + write_fault, &writable, NULL, &page); if (pfn == KVM_PFN_ERR_HWPOISON) { kvm_send_hwpoison_signal(hva, vma_shift); return 0; @@ -967,7 +969,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, */ if (vma_pagesize == PAGE_SIZE && !force_pte) vma_pagesize = transparent_hugepage_adjust(memslot, hva, - &pfn, &fault_ipa); + &pfn, &page, + &fault_ipa); if (writable) prot |= KVM_PGTABLE_PROT_W; @@ -999,14 +1002,17 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, /* Mark the page dirty only if the fault is handled successfully */ if (writable && !ret) { - kvm_set_pfn_dirty(pfn); + if (page) + kvm_set_pfn_dirty(pfn); mark_page_dirty_in_slot(kvm, memslot, gfn); } out_unlock: spin_unlock(&kvm->mmu_lock); - kvm_set_pfn_accessed(pfn); - kvm_release_pfn_clean(pfn); + if (page) { + kvm_set_pfn_accessed(pfn); + put_page(page); + } return ret != -EAGAIN ? ret : 0; } From patchwork Fri Jun 25 07:36:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Stevens X-Patchwork-Id: 1496980 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=kvm-ppc-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=chromium.org header.i=@chromium.org header.a=rsa-sha256 header.s=google header.b=j1IBKqLi; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4GB8466gbwz9sjD for ; Fri, 25 Jun 2021 17:37:58 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230249AbhFYHkR (ORCPT ); Fri, 25 Jun 2021 03:40:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48876 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230112AbhFYHkL (ORCPT ); Fri, 25 Jun 2021 03:40:11 -0400 Received: from mail-pj1-x1032.google.com (mail-pj1-x1032.google.com [IPv6:2607:f8b0:4864:20::1032]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CD3A5C061760 for ; Fri, 25 Jun 2021 00:37:50 -0700 (PDT) Received: by mail-pj1-x1032.google.com with SMTP id h23so4978951pjv.2 for ; Fri, 25 Jun 2021 00:37:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=16WTMv4TM6XRqCXu1WqfhwXLGUuF1I5eSAZgF8nuzNU=; b=j1IBKqLi1jF1pVyyqujoaaEyDD956vhQFsW4IqQOy9pFHxew6pDCRuHqUYQPzXhgIV rZzKBOewFTMPizmmlwFMEzkUu3wwxGe2e89oLtXslKb8oDVXALVjACeulmB5NJhacKR6 l2tBxaC35ppPnNjz4UkRwFuKRG263fy/OfW/I= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=16WTMv4TM6XRqCXu1WqfhwXLGUuF1I5eSAZgF8nuzNU=; b=kDQXxd4EBChsBusbgrotlQTdooJlISf5K+mgo2qRzTPPMgQCgW1NYb4/NFv3DiX0xD 3nIbO3780YW9HePm7IQuDU+LPNHgv1jrBJ1NA3dny6W4ZOAnEk00fiSYvHmx6iDwrcGe WF2GITOlabccjL3COkMP8RpDwVnZWbAYa9zOvYZxI/hzZQ0ZUBwg4QgJ9GsVWE6PB9B8 2i8LFrozR/tKDs1z7D5Hc/RnbkCAVwI1aU8//92Oaz5mGFbhaLdEF+6jvxcML/shIwCQ K7xlTVuCEiOoUEOZ5P6decF7mDRnZEQeWr9yP2YzJXuxszkbT+5WZcWPVtcS8Iovk41J 6X3Q== X-Gm-Message-State: AOAM532M96Iw91yv3O6vvP9JPuhlkjCs1TYElNQSk/RUrMlL/P6xTqoA QBcpbvToFcXIBIAonOUya9Y/ig== X-Google-Smtp-Source: ABdhPJyNGzGIGPRke+4sy9vknoJlahbCbtDrQ1Pof1+x3qW6lrR+9qBg5laf4ZCLScq2FNWqiUDGlQ== X-Received: by 2002:a17:90b:b18:: with SMTP id bf24mr9795691pjb.220.1624606670432; Fri, 25 Jun 2021 00:37:50 -0700 (PDT) Received: from localhost ([2401:fa00:8f:203:1492:9d4f:19fa:df61]) by smtp.gmail.com with UTF8SMTPSA id j10sm4395324pjb.36.2021.06.25.00.37.45 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 25 Jun 2021 00:37:50 -0700 (PDT) From: David Stevens X-Google-Original-From: David Stevens To: Marc Zyngier , Huacai Chen , Aleksandar Markovic , Paul Mackerras , Paolo Bonzini , Nick Piggin Cc: James Morse , Alexandru Elisei , Suzuki K Poulose , Will Deacon , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Zhenyu Wang , Zhi Wang , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, David Stevens Subject: [PATCH v2 5/5] KVM: mmu: remove over-aggressive warnings Date: Fri, 25 Jun 2021 16:36:16 +0900 Message-Id: <20210625073616.2184426-6-stevensd@google.com> X-Mailer: git-send-email 2.32.0.93.g670b81a890-goog In-Reply-To: <20210625073616.2184426-1-stevensd@google.com> References: <20210625073616.2184426-1-stevensd@google.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org From: David Stevens Remove two warnings that require ref counts for pages to be non-zero, as mapped pfns from follow_pfn may not have an initialized ref count. Signed-off-by: David Stevens --- arch/x86/kvm/mmu/mmu.c | 7 ------- virt/kvm/kvm_main.c | 2 +- 2 files changed, 1 insertion(+), 8 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index dd5cb6e33591..0c47245594c6 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -607,13 +607,6 @@ static int mmu_spte_clear_track_bits(u64 *sptep) pfn = spte_to_pfn(old_spte); - /* - * KVM does not hold the refcount of the page used by - * kvm mmu, before reclaiming the page, we should - * unmap it from mmu first. - */ - WARN_ON(!kvm_is_reserved_pfn(pfn) && !page_count(pfn_to_page(pfn))); - if (is_accessed_spte(old_spte)) kvm_set_pfn_accessed(pfn); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 1de8702845ac..ce7126bab4b0 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -168,7 +168,7 @@ bool kvm_is_zone_device_pfn(kvm_pfn_t pfn) * the device has been pinned, e.g. by get_user_pages(). WARN if the * page_count() is zero to help detect bad usage of this helper. */ - if (!pfn_valid(pfn) || WARN_ON_ONCE(!page_count(pfn_to_page(pfn)))) + if (!pfn_valid(pfn) || !page_count(pfn_to_page(pfn))) return false; return is_zone_device_page(pfn_to_page(pfn));