From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 14681606A31A for ; Wed, 21 Oct 2026 11:31:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=wr2rCBP6; dkim=fail reason="signature verification failed" (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=peV2frh8 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Zv1Y4e1jGjrVZfkirUL7wsSHDB1rVpoMvujPNRNpZAE=; b=wr2rCBP6rIjwSj c/u9o+uERqjBKxH6FulxDUEpK9IhaadFuDq5TlTEZU1Yxj7qCt/b9RvVRlzPvvcwZdX71A5BrMBby BJck4qZcONl2Dqm1tWlHiKEkQaRszgz5shiucEZCSXohvVV9ZAKywyfH5KVLZhPq0jkxb02wNNyAP o+VUs78HJgX+1Kq6G6gRJeTdLojANLHwN3ujV+dCJS1oMjx7Dx61C/bmAOt3awwQefYTyeXESfiOl MHVM4i977s5gfBxJxwwYr0IDkuZTUGyivhN6aw+163zumK1tZ5F68mY0A4o0nIgNeb0HGIMmElIOu WBpXYQpy91QMI5lJXi/g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xJUWo-0000000BiuR-2rZA; Wed, 21 Oct 2026 11:30:42 +0000 Received: from out-37.mta0.migadu.com ([2001:41d0:1004:224b::25] helo=mta0.migadu.com) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xJUWm-0000000Bita-0F7W for linux-riscv@lists.infradead.org; Wed, 21 Oct 2026 11:30:41 +0000 X-Envelope-To: linux-riscv@lists.infradead.org DKIM-Signature: a=rsa-sha256; bh=ajoLYE5AD2heyAC44s3QWW8/SJdTozUgA/AhWcBRkvo=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1792582235; v=1; x=1793187035; b=peV2frh87rolLVSFnvECmmtCIKSTBix8AHi94IGRwH2+Zplz/8TmlcfbFbtgWK++PPc/FcIX LF4vX1JfVq8eQAPn3Km9B4spHNUfS/5G43hyqiZ3M2xqyrStXmaDXJ780crtyJQOZLG9IS6I3x8 kHbmK8qsFXefL7HyACclAzCE= X-Envelope-To: linux-riscv@lists.infradead.org Received: by smtp.migadu.com with ESMTPS id 591aea82344d2dfa; Wed, 21 Oct 2026 11:30:20 +0000 X-Mizu-Trace-ID: 591aea82344d2dfa X-Migadu-Flow: FLOW_OUT From: Jinyu Tang To: SeungJu Cheon Cc: Jinyu Tang , anup@brainfault.org, atish.patra@linux.dev, tjytimi@163.com, inochiama@gmail.com, pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, alex@ghiti.fr, andrew.jones@linux.dev, pbonzini@redhat.com, seanjc@google.com, kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] KVM: riscv: Set Accessed bit in dirty-log write fault fast path Date: Wed, 21 Oct 2026 19:30:10 +0800 Message-ID: <20261021113010.2476783-1-jinyu.tang@linux.dev> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20261016101458.221648-1-suunj1331@gmail.com> References: <20261016101458.221648-1-suunj1331@gmail.com> X-Archived-By: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261021_043040_238484_61C87D84 X-CRM114-Status: UNSURE ( 7.14 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -2.1 (--) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" X-Spam-Status: No, score=-17.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_EF,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Fri, Oct 16, 2026 at 07:14:58PM +0900, SeungJu Cheon wrote: > @@ -591,14 +591,15 @@ static bool kvm_riscv_mmu_dirty_log_write_fault_fast(struct kvm *kvm, > dirty_marked = true; > } > > - if ((pte_val(old_pte) & (_PAGE_WRITE | _PAGE_DIRTY)) == > - (_PAGE_WRITE | _PAGE_DIRTY)) { > + if ((pte_val(old_pte) & > + (_PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED)) == > + (_PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED)) { > new_pte = old_pte; > ret = true; > break; > } > > - new_pte = pte_mkdirty(pte_mkwrite_novma(old_pte)); > + new_pte = pte_mkyoung(pte_mkdirty(pte_mkwrite_novma(old_pte))); I tested this on QEMU 10.2.1 with Svade enabled and Svadu disabled. With dirty logging enabled, the test clears A through page-idle tracking, write-protects the page with KVM_GET_DIRTY_LOG, and resumes the guest write. The unpatched kernel times out after 10 seconds, while the same test completes with this patch applied. Reviewed-by: Jinyu Tang Thanks, Jinyu _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 23E7D606A31A for ; Wed, 21 Oct 2026 11:30:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=T8adJ0zO; dkim=fail reason="signature verification failed" (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=peV2frh8 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=thx8d5mNS6Bds7+SEYIrDmrvUJJPrJJ4HARsWSnO4Ss=; b=T8adJ0zOaMLaih 13XSQUxvrbMfQlYU3EW9Y0LNqP+fzJx7DPC+s7bOdnvyCyCzZxOKleej+osUj74M0C2beUMQ5IZoe KIBPzidY1mKwKjX8gGSy1SoQzQ3o6w5C6ZgObUj/JJlYJuvzskJiEDecTvgTns2DHAbiY3VOsHL3b uk2OQKZK3NXDmCahLthOoc1o8z26lfxPcRSmxVRmftDcb+NxxB3YnXmsPIILnYUIHJTKMbaZmFi4g OnAJy6rkxEk7kT3LZRGXDYM31DvK+770L6hkeXPbLp2PKEuiUtv7opB4t02m5aT0ze7mNaikTJtcV s/0inOBoUB38+sreUZAQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xJUWo-0000000BiuV-39sL; Wed, 21 Oct 2026 11:30:42 +0000 Received: from out-34.mta0.migadu.com ([2001:41d0:1004:224b::22] helo=mta0.migadu.com) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xJUWl-0000000BitO-3PFc for kvm-riscv@lists.infradead.org; Wed, 21 Oct 2026 11:30:41 +0000 X-Envelope-To: kvm-riscv@lists.infradead.org DKIM-Signature: a=rsa-sha256; bh=ajoLYE5AD2heyAC44s3QWW8/SJdTozUgA/AhWcBRkvo=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1792582235; v=1; x=1793187035; b=peV2frh87rolLVSFnvECmmtCIKSTBix8AHi94IGRwH2+Zplz/8TmlcfbFbtgWK++PPc/FcIX LF4vX1JfVq8eQAPn3Km9B4spHNUfS/5G43hyqiZ3M2xqyrStXmaDXJ780crtyJQOZLG9IS6I3x8 kHbmK8qsFXefL7HyACclAzCE= X-Envelope-To: kvm-riscv@lists.infradead.org Received: by smtp.migadu.com with ESMTPS id 591aea82344d2dfa; Wed, 21 Oct 2026 11:30:20 +0000 X-Mizu-Trace-ID: 591aea82344d2dfa X-Migadu-Flow: FLOW_OUT From: Jinyu Tang To: SeungJu Cheon Cc: Jinyu Tang , anup@brainfault.org, atish.patra@linux.dev, tjytimi@163.com, inochiama@gmail.com, pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, alex@ghiti.fr, andrew.jones@linux.dev, pbonzini@redhat.com, seanjc@google.com, kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] KVM: riscv: Set Accessed bit in dirty-log write fault fast path Date: Wed, 21 Oct 2026 19:30:10 +0800 Message-ID: <20261021113010.2476783-1-jinyu.tang@linux.dev> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20261016101458.221648-1-suunj1331@gmail.com> References: <20261016101458.221648-1-suunj1331@gmail.com> X-Archived-By: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261021_043040_125781_AD13EF85 X-CRM114-Status: UNSURE ( 7.14 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -2.1 (--) X-BeenThere: kvm-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kvm-riscv" X-Spam-Status: No, score=-17.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_EF,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Fri, Oct 16, 2026 at 07:14:58PM +0900, SeungJu Cheon wrote: > @@ -591,14 +591,15 @@ static bool kvm_riscv_mmu_dirty_log_write_fault_fast(struct kvm *kvm, > dirty_marked = true; > } > > - if ((pte_val(old_pte) & (_PAGE_WRITE | _PAGE_DIRTY)) == > - (_PAGE_WRITE | _PAGE_DIRTY)) { > + if ((pte_val(old_pte) & > + (_PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED)) == > + (_PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED)) { > new_pte = old_pte; > ret = true; > break; > } > > - new_pte = pte_mkdirty(pte_mkwrite_novma(old_pte)); > + new_pte = pte_mkyoung(pte_mkdirty(pte_mkwrite_novma(old_pte))); I tested this on QEMU 10.2.1 with Svade enabled and Svadu disabled. With dirty logging enabled, the test clears A through page-idle tracking, write-protects the page with KVM_GET_DIRTY_LOG, and resumes the guest write. The unpatched kernel times out after 10 seconds, while the same test completes with this patch applied. Reviewed-by: Jinyu Tang Thanks, Jinyu -- kvm-riscv mailing list kvm-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kvm-riscv From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.92 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792582239; b=PiehPUjLSL+n6gpW+UKZuatJqmHSdwFK+nJPcJuYPzSOXVeNKvGXCKiKLujccW9scWgM OMV7+fxJreXC3q+k41GxN1h2MJ25Xv1yHObeaL5H2bYafIp13kuq8omt/SiBEFqCqi8PQ HvBHUVseYYtKUOFAnDYh1l2xrt3QE2wWTUA8ldMLl/xwuO/xrHw4pfej5/xUNoh1di/mQ cpQW3T/OoVUZYObw3yz120drni2fYWUviyBMLB7WBrBBGmhutgXYBY+CWUIOyCjPx+nCz f36cALE7vcPcaPiVs8w7d2MjzrPRsF7XC92DmkamuHYM5udfrYMnxCXPjxhHjs+73FQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792582239; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:From:To:Cc:Subject:Date:Message-ID: X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding; bh=U+xSPnvmF/tO+Fgf3pJ9qhNAxgNa/gXXKtkwmbQs8oM=; b=aO7g1lYxsij4MGUtzCldl9OUl3uyLvx9fTJ1bYGHtiZPX/Lzq7ws1YXmlPxwHDLgqo7w qF9WOaSkUCT5YgWph3cnFPl3zpsbPBuM/C/10TIo/VME+GUC84DG5+kF6mx+KuDuUMIYA 32J+TWEXGqMRRMlHQHtLpAO0R17ko1QBBw8K/G3ns9R7jGtfl+bO6v5NjEDb1eJr7XBJ4 z9Pm9mlZkvJ0RIssN9viwziFPpuhopQ8DdwvMd5096l5LV1ayC+/sbH+cTMDbQUYEfdea NrCeqxOAjjmYC+0ysZTu8TYcGen0wZH+IIWWi1FCKcc2W0GVHtL4ZTPoiUUQ0P+LPfA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=peV2frh8; arc=none smtp.remote-ip=91.218.175.92 Received: from mta0.migadu.com (out-92.mta0.migadu.com [91.218.175.92]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E7E64606A31B for ; Wed, 21 Oct 2026 11:30:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org E7E64606A31B Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=peV2frh8 X-Envelope-To: kvm@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=ajoLYE5AD2heyAC44s3QWW8/SJdTozUgA/AhWcBRkvo=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1792582235; v=1; x=1793187035; b=peV2frh87rolLVSFnvECmmtCIKSTBix8AHi94IGRwH2+Zplz/8TmlcfbFbtgWK++PPc/FcIX LF4vX1JfVq8eQAPn3Km9B4spHNUfS/5G43hyqiZ3M2xqyrStXmaDXJ780crtyJQOZLG9IS6I3x8 kHbmK8qsFXefL7HyACclAzCE= X-Envelope-To: kvm@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 591aea82344d2dfa; Wed, 21 Oct 2026 11:30:20 +0000 X-Mizu-Trace-ID: 591aea82344d2dfa X-Migadu-Flow: FLOW_OUT From: Jinyu Tang To: SeungJu Cheon Cc: Jinyu Tang , anup@brainfault.org, atish.patra@linux.dev, tjytimi@163.com, inochiama@gmail.com, pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, alex@ghiti.fr, andrew.jones@linux.dev, pbonzini@redhat.com, seanjc@google.com, kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] KVM: riscv: Set Accessed bit in dirty-log write fault fast path Date: Wed, 21 Oct 2026 19:30:10 +0800 Message-ID: <20261021113010.2476783-1-jinyu.tang@linux.dev> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20261016101458.221648-1-suunj1331@gmail.com> References: <20261016101458.221648-1-suunj1331@gmail.com> X-Mailing-List: kvm@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Fri, Oct 16, 2026 at 07:14:58PM +0900, SeungJu Cheon wrote: > @@ -591,14 +591,15 @@ static bool kvm_riscv_mmu_dirty_log_write_fault_fast(struct kvm *kvm, > dirty_marked = true; > } > > - if ((pte_val(old_pte) & (_PAGE_WRITE | _PAGE_DIRTY)) == > - (_PAGE_WRITE | _PAGE_DIRTY)) { > + if ((pte_val(old_pte) & > + (_PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED)) == > + (_PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED)) { > new_pte = old_pte; > ret = true; > break; > } > > - new_pte = pte_mkdirty(pte_mkwrite_novma(old_pte)); > + new_pte = pte_mkyoung(pte_mkdirty(pte_mkwrite_novma(old_pte))); I tested this on QEMU 10.2.1 with Svade enabled and Svadu disabled. With dirty logging enabled, the test clears A through page-idle tracking, write-protects the page with KVM_GET_DIRTY_LOG, and resumes the guest write. The unpatched kernel times out after 10 seconds, while the same test completes with this patch applied. Reviewed-by: Jinyu Tang Thanks, Jinyu