On Thu, Oct 08, 2015 at 11:46:30AM +0300, Avi Kivity wrote: > > > On 10/08/2015 10:32 AM, Michael S. Tsirkin wrote: > >On Thu, Oct 08, 2015 at 08:33:45AM +0300, Avi Kivity wrote: > >>It is good practice to defend against root oopsing the kernel, but in some > >>cases it cannot be achieved. > >Absolutely. That's one of the issues with these patches. They don't even > >try where it's absolutely possible. > > > > Are you referring to blocking the maps of the msix BAR areas?
For example. There are more. I listed some of the issues on the mailing list, and I might have missed some. VFIO has code to address all this, people should share code to avoid duplication, or at least read it to understand the issues. > I think there is value in that. The value is small because a > corruption is more likely in the dynamic memory responsible for tens > of millions of DMA operations per second, rather than a static 4K > area, but it exists. There are other bugs which will hurt e.g. each time application does not exit gracefully. But well, heh :) That's precisely my feeling about the whole "running userspace drivers without an IOMMU" project. The value is small since modern hardware has fast IOMMUs, but it exists. -- MST -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
