From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1EC25C27C40 for ; Thu, 24 Aug 2023 08:13:07 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=chromium.org header.i=@chromium.org header.a=rsa-sha256 header.s=google header.b=PiabMMQh; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4RWbS15McLz3fHl for ; Thu, 24 Aug 2023 18:13:05 +1000 (AEST) Authentication-Results: lists.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=PiabMMQh; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=chromium.org (client-ip=2607:f8b0:4864:20::22d; helo=mail-oi1-x22d.google.com; envelope-from=stevensd@chromium.org; receiver=lists.ozlabs.org) Received: from mail-oi1-x22d.google.com (mail-oi1-x22d.google.com [IPv6:2607:f8b0:4864:20::22d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4RWbHk2Zdtz3dDQ for ; Thu, 24 Aug 2023 18:05:54 +1000 (AEST) Received: by mail-oi1-x22d.google.com with SMTP id 5614622812f47-3a7f4f7a8easo3008793b6e.2 for ; Thu, 24 Aug 2023 01:05:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1692864289; x=1693469089; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=5EE+UzoRngnjehf25g1txAUD7jFYvBFO8xVG5NUnepk=; b=PiabMMQhe9y2vUBAt7h+ntRdrItXl5XEmXNUAkQzHdz/5Usah2vUewJPe1DxJjyMoj MPwJ8vBC0PRuHBzkM99uP/8pDt3bKa4MMVAyZvrVMT5+kHkXevDD6Xbkw9rXNNage966 g+94vbQfs3rPzxqPbviDDzoC4v8GyCo9zgfVo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1692864289; x=1693469089; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=5EE+UzoRngnjehf25g1txAUD7jFYvBFO8xVG5NUnepk=; b=TzZ7EV6K8Z0ScObWG3SyG3KjKqmcbMCYytUO+tt9ELbmO9iDO5jlNmdRn/g9iZe8rO efRu6VBK7gNYgXUpSVU8aL4af10i89xbDiNDEHLGI2cU+ODJg9VZzj+Di4epK8Thizwv pPDjrsXutCldtoB1GXX4ZheXoJwPpQOE/LN3TTG9DADOR6jLnPzjn1uj/xu/UkvKIDOo xqA6OfZvQhzm4AxRmejrqBdKpxVtkJL2oS8QR8cvhpLhTQDTESC+thxCV0XkQirZnITq K6qtknuyoi7oU/ICclI22wBssHcX5LPoNeh4lTvLTD29oyFJB1DMlLErwB1Btk8uFOFB RY6Q== X-Gm-Message-State: AOJu0YyTIw8RcPLoMYOF/fXGGRWrWnhevQeT0UW8mySFBTEeSBwceMLe b8vX+W+5bsR9+RYAqU7pocleHA== X-Google-Smtp-Source: AGHT+IHkBcWKFj3+pW5fuuiWfLnbD3ta+ABypKF47WzCDkfdw67HWPAGK/Ns2WRoKXuxgQGkt6DXAw== X-Received: by 2002:a05:6358:720c:b0:13c:c84b:88bb with SMTP id h12-20020a056358720c00b0013cc84b88bbmr2497118rwa.27.1692864289233; Thu, 24 Aug 2023 01:04:49 -0700 (PDT) Received: from localhost ([2401:fa00:8f:203:515:8b2a:90c3:b79e]) by smtp.gmail.com with UTF8SMTPSA id a18-20020aa78652000000b00666e649ca46sm7014327pfo.101.2023.08.24.01.04.46 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 24 Aug 2023 01:04:48 -0700 (PDT) From: David Stevens X-Google-Original-From: David Stevens To: Sean Christopherson Subject: [PATCH v8 0/8] KVM: allow mapping non-refcounted pages Date: Thu, 24 Aug 2023 17:04:00 +0900 Message-ID: <20230824080408.2933205-1-stevensd@google.com> X-Mailer: git-send-email 2.42.0.rc1.204.g551eb34607-goog MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kvm@vger.kernel.org, Marc Zyngier , linux-kernel@vger.kernel.org, Peter Xu , Yu Zhang , Isaku Yamahata , kvmarm@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, David Stevens Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: David Stevens This patch series adds support for mapping VM_IO and VM_PFNMAP memory that is backed by struct pages that aren't currently being refcounted (e.g. tail pages of non-compound higher order allocations) into the guest. Our use case is virtio-gpu blob resources [1], which directly map host graphics buffers into the guest as "vram" for the virtio-gpu device. This feature currently does not work on systems using the amdgpu driver, as that driver allocates non-compound higher order pages via ttm_pool_alloc_page. First, this series replaces the __gfn_to_pfn_memslot API with a more extensible __kvm_faultin_pfn API. The updated API rearranges __gfn_to_pfn_memslot's args into a struct and where possible packs the bool arguments into a FOLL_ flags argument. The refactoring changes do not change any behavior, except as noted in the PPC change. When introduced in the refactoring, __kvm_faultin_pfn implies FOLL_GET to preserve existing behavior. From there, the API is made to support mapping non-refcounted pages by respecting the FOLL_GET flag. This series only adds support for non-refcounted pages to the x86 MMU. Other MMUs can likely be updated without too much difficulty, but it is not needed at this point. Updating other parts of KVM (e.g. pfncache) is not straightforward [2]. [1] https://patchwork.kernel.org/project/dri-devel/cover/20200814024000.2485-1-gurchetansingh@chromium.org/ [2] https://lore.kernel.org/all/ZBEEQtmtNPaEqU1i@google.com/ v7 -> v8: - Set access bits before releasing mmu_lock. - Pass FOLL_GET on 32-bit x86 or !tdp_enabled. - Refactor FOLL_GET handling, add kvm_follow_refcounted_pfn helper. - Set refcounted bit on >4k pages. - Add comments and apply formatting suggestions. - rebase on kvm next branch. v6 -> v7: - Replace __gfn_to_pfn_memslot with a more flexible __kvm_faultin_pfn, and extend that API to support non-refcounted pages. v5 -> v6: - rebase on kvm next branch - rename gfn_to_pfn_page to gfn_to_pfn_noref - fix uninitialized outparam in error case of __kvm_faultin_pfn - add kvm_release_pfn_noref_clean for releasing pfn/page pair v4 -> v5: - rebase on kvm next branch again v3 -> v4: - rebase on kvm next branch again - Add some more context to a comment in ensure_pfn_ref v2 -> v3: - rebase on kvm next branch v1 -> v2: - Introduce new gfn_to_pfn_page functions instead of modifying the behavior of existing gfn_to_pfn functions, to make the change less invasive. - Drop changes to mmu_audit.c - Include Nicholas Piggin's patch to avoid corrupting refcount in the follow_pte case, and use it in depreciated gfn_to_pfn functions. - Rebase on kvm/next David Stevens (7): KVM: mmu: Introduce __kvm_follow_pfn function KVM: mmu: Make __kvm_follow_pfn not imply FOLL_GET KVM: x86/mmu: Migrate to __kvm_follow_pfn KVM: x86/mmu: Don't pass FOLL_GET to __kvm_follow_pfn KVM: arm64: Migrate to __kvm_follow_pfn KVM: PPC: Migrate to __kvm_follow_pfn KVM: mmu: remove __gfn_to_pfn_memslot Sean Christopherson (1): KVM: Assert that a page's refcount is elevated when marking accessed/dirty arch/arm64/kvm/mmu.c | 25 +-- arch/powerpc/include/asm/kvm_book3s.h | 2 +- arch/powerpc/kvm/book3s_64_mmu_hv.c | 38 ++-- arch/powerpc/kvm/book3s_64_mmu_radix.c | 50 +++--- arch/powerpc/kvm/book3s_hv_nested.c | 4 +- arch/x86/kvm/mmu/mmu.c | 94 +++++++--- arch/x86/kvm/mmu/mmu_internal.h | 1 + arch/x86/kvm/mmu/paging_tmpl.h | 8 +- arch/x86/kvm/mmu/spte.c | 4 +- arch/x86/kvm/mmu/spte.h | 12 +- arch/x86/kvm/mmu/tdp_mmu.c | 22 ++- include/linux/kvm_host.h | 26 +++ virt/kvm/kvm_main.c | 231 ++++++++++++++----------- virt/kvm/kvm_mm.h | 3 +- virt/kvm/pfncache.c | 10 +- 15 files changed, 316 insertions(+), 214 deletions(-) -- 2.42.0.rc1.204.g551eb34607-goog