From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Christie Date: Mon, 02 Nov 2020 16:19:43 +0000 Subject: Re: [PATCH 07/17] vhost scsi: support delayed IO vq creation Message-Id: <4add5334-e345-f7f1-4fe7-2fb66d86ae34@oracle.com> List-Id: References: <1603326903-27052-1-git-send-email-michael.christie@oracle.com> <1603326903-27052-8-git-send-email-michael.christie@oracle.com> <9e97ea2a-bc57-d4aa-4711-35dba20b3b9e@redhat.com> <49c2fc29-348c-06db-4823-392f7476d318@oracle.com> <20201030044402-mutt-send-email-mst@kernel.org> <688e46b6-77f1-1629-0c93-e3a27d582da5@redhat.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: Jason Wang , "Michael S. Tsirkin" Cc: martin.petersen@oracle.com, linux-scsi@vger.kernel.org, virtualization@lists.linux-foundation.org, target-devel@vger.kernel.org, stefanha@redhat.com, pbonzini@redhat.com Archived-At: List-Archive: List-Post: On 11/2/20 12:49 AM, Jason Wang wrote: > > On 2020/11/2 下午2:36, Jason Wang wrote: >>> >>> The need to share event/control vqs between devices is a problem though, >>> and sending lots of ioctls on things like reset is also not that >>> elegant. >>> Jason, did you have a good solution in mind? >> >> >> Nope, I'm not familiar with SCSI so I don't even know sharing evt/cvq >> is possible. Consider VHOST_SCSI_MAX_VQ is already 128 per device. >> Mike's proposal seems to be better. Hey, which proposal are you saying was best? 1. Add on to the current scsi mq design where we are doing a single device and multiple vqs already. So basically just fix what we have and add in patches 12 - 16 to do a thread per VQ? 2. The proposal I stated to hack up over the weekend to try and support the current design and then add in support for your multiple device single vq design: http://archive.lwn.net:8080/linux-scsi/292879d9-915d-8587-0678-8677a800c613@oracle.com/ >> >> Thanks > > > Btw, it looks to me vhost_scsi_do_evt_work() has the assumption of iovec > layout which needs to be fixed. I wanted to be clear, because I thought you meant #1, but this comment seems like it would only be for #2.