From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 8 Feb 2022 10:37:45 -0500 From: "Michael S. Tsirkin" Subject: Re: [PATCH v3 1/4] Add virtio Admin virtqueue Message-ID: <20220208103637-mutt-send-email-mst@kernel.org> References: <20220207052843-mutt-send-email-mst@kernel.org> <20220208014039-mutt-send-email-mst@kernel.org> <878rulv6kq.fsf@redhat.com> <20220208084022-mutt-send-email-mst@kernel.org> <875yppv1z2.fsf@redhat.com> <20220208102341-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=us-ascii Content-Disposition: inline To: Parav Pandit Cc: Cornelia Huck , Max Gurtovoy , "virtio-comment@lists.oasis-open.org" , "virtio-dev@lists.oasis-open.org" , "jasowang@redhat.com" , Shahaf Shuler , Oren Duer , "stefanha@redhat.com" List-ID: On Tue, Feb 08, 2022 at 03:35:58PM +0000, Parav Pandit wrote: > > > From: Michael S. Tsirkin > > Sent: Tuesday, February 8, 2022 8:56 PM > > > > I might have been a bit too vague about what I had been thinking > > > about. Let's do a sketch (intentionally without concrete sizes): > > > > > > +-------------------------------------------------------+ > > > | command | > > > +-------------------------------------------------------+ > > > | target type (0 - self, 1 - dev id, 2 - group id, ... | > > > +-------------------------------------------------------+ > > > | dev id | > > > +-------------------------------------------------------+ > > > | group id | > > > +-------------------------------------------------------+ > > > | command-specific data | > > > +-------------------------------------------------------+ > > > | response part | > > > +-------------------------------------------------------+ > > > > > > 'dev id' would be valid for 'target type' == 1, 'group id' would be > > > valid for 'target type' == 2. Alternatively, 'dev id' and 'group id' > > > could be a single 'target id' field; if there's nothing better to use, > > > it can simply contain a uuid. > > > > I am not sure why do we have both dev id and group id. > > They are never used together right? > > Maybe just have an id length field if we can't agree on how much space to > > reserve. > This is what I propose in a previous email. > A device id can be duplicate in different groups. > So to build hierarchy group id will be desired. > > So id[] array can contain nested one or multiple fields. I guess nesting is for when there's like an SF within a VF? -- MST