Re: [PATCH] virtio: skip guest index check on device load

2020-11-02 Thread Dr. David Alan Gilbert
* Stefan Hajnoczi (stefa...@redhat.com) wrote: > On Tue, Oct 27, 2020 at 09:04:46AM -0400, Michael S. Tsirkin wrote: > > It's not a waste of time, it's just a lot of work > > within guests. > > Luckily it does no harm to set the NEEDS_RESET bit even if the guest > doesn't handle it. > > If the gu

Re: [PATCH] virtio: skip guest index check on device load

2020-10-28 Thread Stefan Hajnoczi
On Wed, Oct 28, 2020 at 07:30:55AM -0400, Michael S. Tsirkin wrote: > On Wed, Oct 28, 2020 at 11:00:38AM +, Stefan Hajnoczi wrote: > > On Tue, Oct 27, 2020 at 09:04:46AM -0400, Michael S. Tsirkin wrote: > > > It's not a waste of time, it's just a lot of work > > > within guests. > > > > Luckil

Re: [PATCH] virtio: skip guest index check on device load

2020-10-28 Thread Michael S. Tsirkin
On Wed, Oct 28, 2020 at 11:00:38AM +, Stefan Hajnoczi wrote: > On Tue, Oct 27, 2020 at 09:04:46AM -0400, Michael S. Tsirkin wrote: > > It's not a waste of time, it's just a lot of work > > within guests. > > Luckily it does no harm to set the NEEDS_RESET bit even if the guest > doesn't handle

Re: [PATCH] virtio: skip guest index check on device load

2020-10-28 Thread Stefan Hajnoczi
On Tue, Oct 27, 2020 at 09:04:46AM -0400, Michael S. Tsirkin wrote: > It's not a waste of time, it's just a lot of work > within guests. Luckily it does no harm to set the NEEDS_RESET bit even if the guest doesn't handle it. If the guest driver is unaware it may continue to submit requests to the

Re: [PATCH] virtio: skip guest index check on device load

2020-10-27 Thread Michael S. Tsirkin
On Tue, Oct 27, 2020 at 01:02:59PM +, Felipe Franciosi wrote: > > > > On Oct 27, 2020, at 12:56 PM, Michael S. Tsirkin wrote: > > > > On Tue, Oct 27, 2020 at 12:53:29PM +, Felipe Franciosi wrote: > >> > >> > >>> On Oct 27, 2020, at 12:25 PM, Michael S. Tsirkin wrote: > >>> > >>> On

Re: [PATCH] virtio: skip guest index check on device load

2020-10-27 Thread Felipe Franciosi
> On Oct 27, 2020, at 12:25 PM, Michael S. Tsirkin wrote: > > On Tue, Oct 27, 2020 at 11:30:49AM +, Stefan Hajnoczi wrote: >> On Mon, Oct 26, 2020 at 03:13:32PM +, Felipe Franciosi wrote: >>> QEMU must be careful when loading device state off migration streams to >>> prevent a maliciou

Re: [PATCH] virtio: skip guest index check on device load

2020-10-27 Thread Felipe Franciosi
> On Oct 27, 2020, at 12:56 PM, Michael S. Tsirkin wrote: > > On Tue, Oct 27, 2020 at 12:53:29PM +, Felipe Franciosi wrote: >> >> >>> On Oct 27, 2020, at 12:25 PM, Michael S. Tsirkin wrote: >>> >>> On Tue, Oct 27, 2020 at 11:30:49AM +, Stefan Hajnoczi wrote: On Mon, Oct 26, 20

Re: [PATCH] virtio: skip guest index check on device load

2020-10-27 Thread Michael S. Tsirkin
On Tue, Oct 27, 2020 at 12:53:29PM +, Felipe Franciosi wrote: > > > > On Oct 27, 2020, at 12:25 PM, Michael S. Tsirkin wrote: > > > > On Tue, Oct 27, 2020 at 11:30:49AM +, Stefan Hajnoczi wrote: > >> On Mon, Oct 26, 2020 at 03:13:32PM +, Felipe Franciosi wrote: > >>> QEMU must be ca

Re: [PATCH] virtio: skip guest index check on device load

2020-10-27 Thread Michael S. Tsirkin
On Tue, Oct 27, 2020 at 11:30:49AM +, Stefan Hajnoczi wrote: > On Mon, Oct 26, 2020 at 03:13:32PM +, Felipe Franciosi wrote: > > QEMU must be careful when loading device state off migration streams to > > prevent a malicious source from exploiting the emulator. Overdoing these > > checks ha

Re: [PATCH] virtio: skip guest index check on device load

2020-10-27 Thread Stefan Hajnoczi
On Mon, Oct 26, 2020 at 03:13:32PM +, Felipe Franciosi wrote: > QEMU must be careful when loading device state off migration streams to > prevent a malicious source from exploiting the emulator. Overdoing these > checks has the side effect of allowing a guest to "pin itself" in cloud > environm

[PATCH] virtio: skip guest index check on device load

2020-10-26 Thread Felipe Franciosi
QEMU must be careful when loading device state off migration streams to prevent a malicious source from exploiting the emulator. Overdoing these checks has the side effect of allowing a guest to "pin itself" in cloud environments by messing with state which is entirely in its control. Similarly to