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Groups > linux.kernel > #1242618
| From | Gleb Natapov <gleb@scylladb.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support |
| Date | 2015-10-08 19:10 +0200 |
| Message-ID | <qhmRA-1ld-15@gated-at.bofh.it> (permalink) |
| References | (5 earlier) <qhibg-30J-7@gated-at.bofh.it> <qhiuC-3nl-3@gated-at.bofh.it> <qhjqG-4LW-11@gated-at.bofh.it> <qhjqG-4LW-21@gated-at.bofh.it> <qhmyd-Jk-13@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Thu, Oct 08, 2015 at 07:43:04PM +0300, Michael S. Tsirkin wrote: > On Thu, Oct 08, 2015 at 04:28:34PM +0300, Gleb Natapov wrote: > > On Thu, Oct 08, 2015 at 04:20:04PM +0300, Michael S. Tsirkin wrote: > > > On Thu, Oct 08, 2015 at 03:27:37PM +0300, Gleb Natapov wrote: > > > > On Thu, Oct 08, 2015 at 03:06:07PM +0300, Michael S. Tsirkin wrote: > > > > > On Thu, Oct 08, 2015 at 12:44:09PM +0300, Avi Kivity wrote: > > > > > > > > > > > > > > > > > > On 10/08/2015 12:16 PM, Michael S. Tsirkin wrote: > > > > > > >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. > > > > > > > > > > > > All but one of those are unrelated to the patch that adds msix support. > > > > > > > > > > They are related because msix support enables bus mastering. Without it > > > > > device is passive and can't harm anyone. With it, suddently you need to > > > > > be very careful with the device to avoid corrupting kernel memory. > > > > > > > > > Most (if not all) uio_pci_generic users enable pci bus mastering. The > > > > fact that they do that without even tainting the kernel like the patch > > > > does make current situation much worse that with the patch. > > > > > > It isn't worse. It's a sane interface. Whoever enables bus mastering > > > must be careful. If userspace enables bus mastering then userspace > > > needs to be very careful with the device to avoid corrupting kernel > > > memory. If kernel does it, it's kernel's responsibility. > > > > > Although this definition of sanity sounds strange to me, but lets > > flow with it for the sake of this email: would it be OK if proposed > > interface refused to work if bus mastering is not already enabled by > > userspace? > > An interface could be acceptable if there's a fallback where it > works without BM but slower (e.g. poll pending bits). > OK. > But not the proposed one. > Why? Greg is against ioctl interface so it will be reworked, by besides that what is wrong with the concept of binding msi-x interrupt to eventfd? > Really, there's more to making msi-x work with > userspace drivers than this patch. As I keep telling people, you would > basically reimplement vfio/pci. Go over it, and see for yourself. > Almost everything it does is relevant for msi-x. It's just wrong to > duplicate so much code. > The patch is tested and works with msi-x. Restricting access to msi-x registers that vfio does is not relevant here. -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-06 16:40 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Vlad Zolotarov <vladz@cloudius-systems.com> - 2015-10-06 16:50 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-06 17:00 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Vlad Zolotarov <vladz@cloudius-systems.com> - 2015-10-06 17:30 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Avi Kivity <avi@scylladb.com> - 2015-10-06 17:30 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Alex Williamson <alex.williamson@redhat.com> - 2015-10-06 21:00 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Stephen Hemminger <stephen@networkplumber.org> - 2015-10-06 23:40 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Alex Williamson <alex.williamson@redhat.com> - 2015-10-06 23:50 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Vlad Zolotarov <vladz@cloudius-systems.com> - 2015-10-07 10:00 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Vlad Zolotarov <vladz@cloudius-systems.com> - 2015-10-07 10:10 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Vlad Zolotarov <vladz@cloudius-systems.com> - 2015-10-07 10:10 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Avi Kivity <avi@scylladb.com> - 2015-10-07 09:00 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Avi Kivity <avi@scylladb.com> - 2015-10-07 18:40 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-07 23:10 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Gleb Natapov <gleb@scylladb.com> - 2015-10-08 06:20 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-08 09:50 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Gleb Natapov <gleb@scylladb.com> - 2015-10-08 10:00 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-08 11:40 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Gleb Natapov <gleb@scylladb.com> - 2015-10-08 11:50 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-08 14:20 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Avi Kivity <avi@scylladb.com> - 2015-10-08 07:40 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-08 09:40 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Avi Kivity <avi@scylladb.com> - 2015-10-08 10:50 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-08 11:20 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Avi Kivity <avi@scylladb.com> - 2015-10-08 11:50 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-08 14:10 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Gleb Natapov <gleb@scylladb.com> - 2015-10-08 14:30 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-08 15:30 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Gleb Natapov <gleb@scylladb.com> - 2015-10-08 15:30 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-08 18:50 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Gleb Natapov <gleb@scylladb.com> - 2015-10-08 19:10 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-08 19:40 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Gleb Natapov <gleb@scylladb.com> - 2015-10-08 20:00 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Greg KH <gregkh@linuxfoundation.org> - 2015-10-08 20:40 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-08 10:40 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Gleb Natapov <gleb@scylladb.com> - 2015-10-08 11:00 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Avi Kivity <avi@scylladb.com> - 2015-10-08 11:20 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-08 12:30 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Avi Kivity <avi@scylladb.com> - 2015-10-08 15:30 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-08 16:20 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Alex Williamson <alex.williamson@redhat.com> - 2015-10-08 17:40 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Alex Williamson <alex.williamson@redhat.com> - 2015-10-07 18:40 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-07 22:10 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Vlad Zolotarov <vladz@cloudius-systems.com> - 2015-10-07 10:00 +0200
Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support "Michael S. Tsirkin" <mst@redhat.com> - 2015-10-08 10:50 +0200
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