From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rusty Russell Subject: Re: [PATCH 0/3] virtio-net: inline header support Date: Fri, 05 Oct 2012 15:13:01 +0930 Message-ID: <87391t1nkq.fsf@rustcorp.com.au> References: <87vces2gxq.fsf__45058.6618776017$1349247807$gmane$org@rustcorp.com.au> <506C192E.5060700@redhat.com> <87bogj2j1b.fsf@rustcorp.com.au> <506D3610.7000103@redhat.com> <87ipaq1jtt.fsf@rustcorp.com.au> <506D8DD5.20904@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "Michael S. Tsirkin" , Thomas Lendacky , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, avi@redhat.com, Sasha Levin To: Paolo Bonzini Return-path: In-Reply-To: <506D8DD5.20904@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org Paolo Bonzini writes: > Il 04/10/2012 14:51, Rusty Russell ha scritto: >> Paolo Bonzini writes: >> >>> Il 04/10/2012 02:11, Rusty Russell ha scritto: >>>>>> There's a reason I haven't done this. I really, really dislike "my >>>>>> implemention isn't broken" feature bits. We could have an infinite >>>>>> number of them, for each bug in each device. >>>>> >>>>> However, this bug affects (almost) all implementations and (almost) all >>>>> devices. It even makes sense to reserve a transport feature bit for it >>>>> instead of a device feature bit. >>>> >>>> Perhaps, but we have to fix the bugs first! >>> >>> Yes. :) Isn't that what mst's patch does? >>> >>>> As I said, my torture patch broke qemu immediately. Since noone has >>>> leapt onto fixing that, I'll take a look now... >>> >>> I can look at virtio-scsi. >> >> Actually, you can't, see my reply to Anthony... >> >> Message-ID: <87lifm1y1n.fsf@rustcorp.com.au> > > struct virtio_scsi_req_cmd { > // Read-only > u8 lun[8]; > u64 id; > u8 task_attr; > u8 prio; > u8 crn; > char cdb[cdb_size]; > char dataout[]; > // Write-only part > u32 sense_len; > u32 residual; > u16 status_qualifier; > u8 status; > u8 response; > u8 sense[sense_size]; > char datain[]; > }; > > where cdb_size and sense_size come from configuration space. The device > right now expects everything before dataout/datain to be in a single > descriptor, but that's in no way part of the spec. Am I missing > something egregious? Since you wrote it, I hope not :) That's good. But virtio_blk's scsi command is insoluble AFAICT. As I said to Anthony, the best rules are "always" and "never", so I'd really rather not have to grandfather that in. Cheers, Rusty.