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X-Received-From: 2a00:1450:4864:20::32b 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: , Cc: qemu-block@nongnu.org, "qemu-devel@nongnu.org" , Jon Maloy , "hare@suse.de" , "pbonzini@redhat.com" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --n8g4imXOkfNTN/H1 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Mar 10, 2020 at 06:18:00AM +0000, Lin Ma wrote: > First of all, Thanks for your reply, Stefan. >=20 > We know that the GET LBA STATUS works well under scsi lun passthrough due= to the vm directly talks to the scsi target. > I'm curious that if I use file backend image(say qcow2) + qemu scsi emula= tion, Does it make sense if I issue sg_get_lba_status in vm to get the lba = status? > If it doesn't make sense, That could explain why qemu scsi emulation laye= r lack of this support for a long time and no user complains. It does make sense to implement GET LBA STATUS because QEMU emulates the UNMAP command. Be careful though because there is no asynchronous bdrv_block_status() API yet. Internally the BlockDriver->bdrv_co_block_status() function is already asynchronous because it runs in a coroutine. It will be necessary to expose a new bdrv_aio_get_block_status() or similar API so the device models (i.e. SCSI emulation code) can take advantage of that. 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