Messages in this thread | | | Date | Thu, 8 Oct 2015 12:16:19 +0300 | From | "Michael S. Tsirkin" <> | Subject | Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support |
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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
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