On Wed, Mar 11, 2015 at 02:47:47PM +0800, Fam Zheng wrote: > On Wed, 03/11 07:19, Michael S. Tsirkin wrote: > > On Wed, Mar 11, 2015 at 04:29:30PM +1030, Rusty Russell wrote: > > > The virtio 'used' ring describes descriptors which have been used. It > > > also says how many bytes have been written to the ring. For some cases, > > > this value is ignored by Linux guests, thus errors have not been noticed. > > > I was working on increasing the checking in Linux when I noticed this > > > behaviour. > > > > > > The first patch changes the 'len' formal parameter name to 'len_written' > > > to > > > make the API clearer, and adds an assert(). The second fixes block writes. > > > > > > Cheers, > > > Rusty. > > > PS. It's based on MST's virtio-1.0 tree, but should be easily ported. > > > > Thanks, this applies to current master without issues. > > However, I think it's best to apply patch 2, then patch 1, > > to avoid triggering errors when bisecting. > > I'm seeing a make check failure. If this is a false alarm, the test should be > fixed too.
Yea, I'm also now thinking we need a spec clarification on this one, and some testing with non linux drivers before jumping to changing hosts and guests. > --- > > qemu-system-x86_64: /var/tmp/patchew-test/git/hw/virtio/virtio.c:254: > virtqueue_fill: Assertion `len_written <= tot_wlen' failed. > Broken pipe > GTester: last random seed: R02Se642bf29179ebe0c4a92eb02cc488dd8 > [vmxnet3][WR][vmxnet3_peer_has_vnet_hdr]: Peer has no virtio extension. Task > offloads will be emulated. > make: *** [check-qtest-x86_64] Error 1
