linux-kernel - Re: [PATCH v3 10/25] virtio: add API to enable VQs early

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <8738asea14.fsf@rustcorp.com.au>
Date:	Mon, 13 Oct 2014 17:22:39 +1030
From:	Rusty Russell <rusty@...tcorp.com.au>
To:	"Michael S. Tsirkin" <mst@...hat.com>, linux-kernel@...r.kernel.org
Cc:	virtualization@...ts.linux-foundation.org,
	linux-scsi@...r.kernel.org, linux-s390@...r.kernel.org,
	v9fs-developer@...ts.sourceforge.net, netdev@...r.kernel.org,
	kvm@...r.kernel.org, Amit Shah <amit.shah@...hat.com>,
	Cornelia Huck <cornelia.huck@...ibm.com>,
	Christian Borntraeger <borntraeger@...ibm.com>,
	"David S. Miller" <davem@...emloft.net>,
	Paolo Bonzini <pbonzini@...hat.com>
Subject: Re: [PATCH v3 10/25] virtio: add API to enable VQs early

"Michael S. Tsirkin" <mst@...hat.com> writes:
> virtio spec 0.9.X requires DRIVER_OK to be set before
> VQs are used, but some drivers use VQs before probe
> function returns.
> Since DRIVER_OK is set after probe, this violates the spec.
>
> Even though under virtio 1.0 transitional devices support this
> behaviour, we want to make it possible for those early callers to become
> spec compliant and eventually support non-transitional devices.
>
> Add API for drivers to call before using VQs.
>
> Sets DRIVER_OK internally.
>
> Signed-off-by: Michael S. Tsirkin <mst@...hat.com>
> Reviewed-by: Cornelia Huck <cornelia.huck@...ibm.com>

OK, this all looks good, but I think we should do two things:

1) rename virtio_enable_vqs_early() to virtio_device_ready().
2) Add a BUG_ON in the virtio_ring code to make sure device is ready
   before any ops are called.

Cheers,
Rusty.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/