From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id B1FC2986561 for ; Fri, 8 Oct 2021 11:47:51 +0000 (UTC) From: Cornelia Huck In-Reply-To: <20211008071903-mutt-send-email-mst@kernel.org> References: <20211006141033.612283-1-parav@nvidia.com> <20211006111143-mutt-send-email-mst@kernel.org> <20211006163309-mutt-send-email-mst@kernel.org> <20211008063303-mutt-send-email-mst@kernel.org> <20211008071903-mutt-send-email-mst@kernel.org> Date: Fri, 08 Oct 2021 13:47:40 +0200 Message-ID: <87lf33ybz7.fsf@redhat.com> MIME-Version: 1.0 Subject: [virtio-dev] Re: [PATCH v2] Add device reset timeout field Content-Type: text/plain To: "Michael S. Tsirkin" , Parav Pandit Cc: "virtio-dev@lists.oasis-open.org" , Max Gurtovoy , Shahaf Shuler , Oren Duer List-ID: On Fri, Oct 08 2021, "Michael S. Tsirkin" wrote: > On Fri, Oct 08, 2021 at 10:59:02AM +0000, Parav Pandit wrote: >> It may be even a pre-boot environment where 100msec or 10msec may be too short interval as other extreme of VM boot time example. > > I don't really know what this means. We are talking about how long > it takes device to calm down and stop poking at the host > after it's told to reset. 10ms worst case not enough for this? To me, that sounded more like a physical device that needs to do something like boot its firmware before it can perform an actual virtio operation (and reset simply happens to be the first one.) So, I'm getting more confused about the scope of this timeout. If it's more a "device might not be ready yet" issue, I don't think we need a timeout for reset specifically. Same for races with hotplugging. If it's about "reset may take some time, because it will take some time before all operations have quiesced", I don't see how the device can come up with a value that isn't anything other than a wild guess, and the driver could do wild guessing equally well. I feel like I'm missing something. --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org