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[2003:cb:c70e:4f00:87ba:e9e9:3821:677b]) by smtp.gmail.com with ESMTPSA id w9-20020adfee49000000b002c7107ce17fsm15489511wro.3.2023.03.02.03.31.46 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 02 Mar 2023 03:31:47 -0800 (PST) Message-ID: <377c3521-ffe1-074b-48ac-71fd445b3bb4@redhat.com> Date: Thu, 2 Mar 2023 12:31:46 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.8.0 Subject: Re: [PATCH] hostmem: Add clear option to file backend Content-Language: en-US To: Fam Zheng , qemu-devel@nongnu.org Cc: Eduardo Habkost , Peter Xu , fam@euphon.net, Igor Mammedov , Markus Armbruster , =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= , Eric Blake , Paolo Bonzini , =?UTF-8?Q?Daniel_P=2e_Berrang=c3=a9?= , stefanha@redhat.com References: <20230302110925.4680-1-fam.zheng@bytedance.com> From: David Hildenbrand Organization: Red Hat In-Reply-To: <20230302110925.4680-1-fam.zheng@bytedance.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=david@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.09, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, 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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 02.03.23 12:09, Fam Zheng wrote: > This adds a memset to clear the backing memory. This is useful in the > case of PMEM DAX to drop dirty data, if the backing memory is handed > over from a previous application or firmware which didn't clean up > before exiting. > Why can't the VM manager do that instead? If you have a file that's certainly easily possible. -- Thanks, David / dhildenb