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[81.2.115.148]) by smtp.gmail.com with ESMTPSA id k16sm7410907wrl.65.2020.11.12.06.40.47 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 12 Nov 2020 06:40:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=xpY+qBYQS+fcNHN03IyJvcvU2rXnoyuOeph6fIF4tkE=; b=oYLG76D8TuYx8P5ql94dGcvhjIjB+EttMYdJaUPPWg6MCjVMs92U5B8sJDwG24A8Ib OVvmoKnPFnK5SeWa3vFaxY9t11o2RYWyACOsRiipWZW9SOt0IHDqPKaxzhSPibS66zmR Oar+sjZjNciJRp1oFc4hYgpCOnBVA00arvYqXJhehLt5c+GahQbk6zFWqbYIVrpMuaV5 EvSmmFmVkGeQ+AA5Tm+qeJOGFxkQWr//eBDIiA0p3ii0DbomtoKUendMEuW1t5xX0w+t Qpl8aPRut80upgQuF2z8adbCIuwBG4qddVBhbZp6djrJboocdJyat6T1EgWaSKTwCdFG DMnQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=xpY+qBYQS+fcNHN03IyJvcvU2rXnoyuOeph6fIF4tkE=; b=SLvTt9lPcyJRi52/1YWQvhEpfRjwo70UrqG2OK2RMoLCxkTLc2LKUBykR7Pl+bVSEt uYlTF25zNL+GusEVK+bW3lynC7rTLdKC8zw5Ct2fmawS75x5BjKAMG4CiJ2ALvt2PFl3 s+XZRHXtnAt9fHETRZKd84eorFrVXiZi19S2xMoUY9/mFgUDFkd+2NTZMo1XKRSnKPyj dBlt6E2PZsu35nx0JiBlMIu9iRgy83lmbuRZaBG1EKN2jtyPSq7p80g8e56RCURkgl0K 9W+1o1M3GbsOorTGJ23dTnVN14xQuKr1J/7Le0Hv2+FOXQwzKBQAln8q5gtBq+WCEffo IPrw== X-Gm-Message-State: AOAM532l+SeFclcuD63TlfAGpTkcxrbu6q1dAvj87E1E3YOEh2aVEz0S IAIYuKYFEr7ABWuGEQwu6JgzOZMjFTShPA== X-Google-Smtp-Source: ABdhPJzw72F9P56oVIjJLkaLAibI9hSYm7oB/NsFZ2ITZe55GLv3+a0epvdPjxfReNgROpLFcEw/nA== X-Received: by 2002:adf:ee12:: with SMTP id y18mr29041126wrn.231.1605192048552; Thu, 12 Nov 2020 06:40:48 -0800 (PST) From: Peter Maydell To: qemu-devel@nongnu.org Subject: [for-5.2 4/9] docs/system/virtio-pmem.rst: Fix minor style issues Date: Thu, 12 Nov 2020 14:40:36 +0000 Message-Id: <20201112144041.32278-5-peter.maydell@linaro.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20201112144041.32278-1-peter.maydell@linaro.org> References: <20201112144041.32278-1-peter.maydell@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2a00:1450:4864:20::436; envelope-from=peter.maydell@linaro.org; helo=mail-wr1-x436.google.com X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: pass (identity @linaro.org) Content-Type: text/plain; charset="utf-8" The virtio-pmem documentation has some minor style issues we hadn't noticed since we weren't rendering it in our docs: * Sphinx doesn't complain about overlong title-underlining the way it complains about too-short underlining, but it looks odd; make the underlines of the top level title the right length * Indent of paragraphs makes them render as blockquotes; remove the indent so they just render as normal text * Leading 'o' isn't rst markup, so it just renders as a literal "o"; reformat as a subsection heading instead * "QEMU" in the document title and section headings are a bit odd and unnecessary since this is the QEMU manual; delete or rephrase them * There's no need to specify what QEMU version the device first appeared in. Signed-off-by: Peter Maydell Reviewed-by: Alex Benn=C3=A9e Reviewed-by: Pankaj Gupta --- docs/system/virtio-pmem.rst | 55 ++++++++++++++++++------------------- 1 file changed, 27 insertions(+), 28 deletions(-) diff --git a/docs/system/virtio-pmem.rst b/docs/system/virtio-pmem.rst index 4bf5d004432..e5f91eff1c2 100644 --- a/docs/system/virtio-pmem.rst +++ b/docs/system/virtio-pmem.rst @@ -1,38 +1,37 @@ =20 -=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D -QEMU virtio pmem -=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D +virtio pmem +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =20 - This document explains the setup and usage of the virtio pmem device - which is available since QEMU v4.1.0. - - The virtio pmem device is a paravirtualized persistent memory device - on regular (i.e non-NVDIMM) storage. +This document explains the setup and usage of the virtio pmem device. +The virtio pmem device is a paravirtualized persistent memory device +on regular (i.e non-NVDIMM) storage. =20 Usecase -------- =20 - Virtio pmem allows to bypass the guest page cache and directly use - host page cache. This reduces guest memory footprint as the host can - make efficient memory reclaim decisions under memory pressure. +Virtio pmem allows to bypass the guest page cache and directly use +host page cache. This reduces guest memory footprint as the host can +make efficient memory reclaim decisions under memory pressure. =20 -o How does virtio-pmem compare to the nvdimm emulation supported by QEMU? +How does virtio-pmem compare to the nvdimm emulation? +----------------------------------------------------- =20 - NVDIMM emulation on regular (i.e. non-NVDIMM) host storage does not - persist the guest writes as there are no defined semantics in the device - specification. The virtio pmem device provides guest write persistence - on non-NVDIMM host storage. +NVDIMM emulation on regular (i.e. non-NVDIMM) host storage does not +persist the guest writes as there are no defined semantics in the device +specification. The virtio pmem device provides guest write persistence +on non-NVDIMM host storage. =20 virtio pmem usage ----------------- =20 - A virtio pmem device backed by a memory-backend-file can be created on - the QEMU command line as in the following example:: +A virtio pmem device backed by a memory-backend-file can be created on +the QEMU command line as in the following example:: =20 -object memory-backend-file,id=3Dmem1,share,mem-path=3D./virtio_pmem.i= mg,size=3D4G -device virtio-pmem-pci,memdev=3Dmem1,id=3Dnv1 =20 - where: +where: =20 - "object memory-backend-file,id=3Dmem1,share,mem-path=3D, size= =3D" creates a backend file with the specified size. @@ -40,8 +39,8 @@ virtio pmem usage - "device virtio-pmem-pci,id=3Dnvdimm1,memdev=3Dmem1" creates a virtio p= mem pci device whose storage is provided by above memory backend device. =20 - Multiple virtio pmem devices can be created if multiple pairs of "-objec= t" - and "-device" are provided. +Multiple virtio pmem devices can be created if multiple pairs of "-object" +and "-device" are provided. =20 Hotplug ------- @@ -59,14 +58,14 @@ the guest:: Guest Data Persistence ---------------------- =20 - Guest data persistence on non-NVDIMM requires guest userspace applications - to perform fsync/msync. This is different from a real nvdimm backend where - no additional fsync/msync is required. This is to persist guest writes in - host backing file which otherwise remains in host page cache and there is - risk of losing the data in case of power failure. +Guest data persistence on non-NVDIMM requires guest userspace applications +to perform fsync/msync. This is different from a real nvdimm backend where +no additional fsync/msync is required. This is to persist guest writes in +host backing file which otherwise remains in host page cache and there is +risk of losing the data in case of power failure. =20 - With virtio pmem device, MAP_SYNC mmap flag is not supported. This provid= es - a hint to application to perform fsync for write persistence. +With virtio pmem device, MAP_SYNC mmap flag is not supported. This provides +a hint to application to perform fsync for write persistence. =20 Limitations ------------ --=20 2.20.1