On Thu, Friday, August 05, 2016 3:56 AM, Michael S. Tsirkin wrote: > -----Original Message----- > From: Michael S. Tsirkin [mailto:m...@redhat.com] > Sent: Friday, August 05, 2016 3:56 AM > To: Gonglei (Arei) > Cc: Zeng, Xin; qemu-devel@nongnu.org; virtio-...@lists.oasis-open.org; > Huangpeng (Peter); Luonengjun; cornelia.h...@de.ibm.com; > stefa...@redhat.com; denglin...@chinamobile.com; Jani Kokkonen; > ola.liljed...@arm.com; varun.se...@freescale.com; Keating, Brian A; Ma, > Liang J; Griffin, John; Hanweidong (Randy); Huangweidong (C) > Subject: Re: [PATCH v6 1/2] virtio-crypto: Add virtio crypto device > specification > > On Thu, Aug 04, 2016 at 11:24:26AM +0000, Gonglei (Arei) wrote: > > > > +The first driver-read-only field, \field{version} specifies the > > > > +virtio crypto's version, which is reserved for back-compatibility > > > > +in future.It's currently defined for the version field: > > > > + > > > > +\begin{lstlisting} > > > > +#define VIRTIO_CRYPTO_VERSION_1 (1) > > > > > > Suggest to remove this macro, > > > Do you think a version which is composed of major version and minor > > > version is better? > > > > > > > I think we should tell the developer how to set the value of version > > field, but I have no idea about which value or form is better, so I > > used 1 as the first version. What's your opinion? > > My opinion is that you should drop this completely. We do feature bits, not > version numbers in virtio. We do not want each device doing its own thing for > compatibility. >
But as I mentioned before, considering the bug fix case, if each backend device release need a feature bit meaning "some bugs are fixed", are the feature bits enough? Physical devices usually have a revision ID to mark its version, could we have a revision Id field for each virtio device to distinguish the the virtio devices which have the same feature sets but have different version? > -- > MST
