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 8DAA798674C for ; Fri, 17 Jun 2022 10:30:28 +0000 (UTC) Date: Fri, 17 Jun 2022 06:30:21 -0400 From: "Michael S. Tsirkin" Message-ID: <20220617062446-mutt-send-email-mst@kernel.org> References: <6355541D-E117-4E7F-B5D9-3CD0028ED7FF@apple.com> <20220605162839-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 In-Reply-To: Subject: Re: [virtio-dev] Clarification of VIRTIO_F_EVENT_IDX driver conditions. Content-Type: text/plain; charset=us-ascii Content-Disposition: inline To: Patrick Mosca Cc: Virtio-Dev , Cameron Esfahani List-ID: On Thu, Jun 16, 2022 at 01:53:38PM -0700, Patrick Mosca wrote: > The issue may trigger in the unlikely uint16_t overflow case of > computing the difference between two index positions. Are you sure this is not an implementation bug? I don't see anywhere in the spec where we suggest computing the difference between two index positions. > An > example would be a network driver where the host and guest are > producing and consuming steadily but at different rates. The > producer is producing faster than the consumer such that the > consumer never needed to be notified of new events, as it is > still playing catch up processing the queue. If the producer > finally catches up to the consumer and the catchup occurs just > past the overflow point, there exists a case where a > notification must be sent but is not sent according to the > current ruleset. > > -Patrick Mosca I don't see it sorry. Example? -- MST --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org