similar to: [PATCH v2 1/3] virtio_net: Stop doing DMA from the stack

When sending control commands, virtio net sets up several buffers for DMA. The buffers are all part of the net device which means it's actually allocated by kvmalloc so it's in theory (on extreme memory pressure) possible to get a vmalloc'ed buffer which on some platforms means we can't DMA there. Fix up by moving the DMA buffers into a separate structure. Reported-by: Mikulas

When sending control commands, virtio net sets up several buffers for DMA. The buffers are all part of the net device which means it's actually allocated by kvmalloc so in theory (on extreme memory pressure) it's possible to get a vmalloc'ed buffer which on some platforms means we can't DMA there. Fix up by moving the DMA buffers out into a separate structure. Reported-by:

On Tue, Oct 27, 2015 at 10:30:19PM -0700, Andy Lutomirski wrote: > From: Andy Lutomirski <luto at amacapital.net> > > Once virtio starts using the DMA API, we won't be able to safely DMA > from the stack. virtio-net does a couple of config DMA requests > from small stack buffers -- switch to using dynamically-allocated > memory. > > This should have no effect

This switches virtio to use the DMA API unconditionally. I'm sure it breaks things, but it seems to work on x86 using virtio-pci, with and without Xen, and using both the modern 1.0 variant and the legacy variant. This appears to work on native and Xen x86_64 using both modern and legacy virtio-pci. It also appears to work on arm and arm64. It definitely won't work as-is on s390x, and

This switches virtio to use the DMA API unconditionally. I'm sure it breaks things, but it seems to work on x86 using virtio-pci, with and without Xen, and using both the modern 1.0 variant and the legacy variant. This appears to work on native and Xen x86_64 using both modern and legacy virtio-pci. It also appears to work on arm and arm64. It definitely won't work as-is on s390x, and

From: Andy Lutomirski <luto at amacapital.net> Once virtio starts using the DMA API, we won't be able to safely DMA from the stack. virtio-net does a couple of config DMA requests from small stack buffers -- switch to using dynamically-allocated memory. This should have no effect on any performance-critical code paths. Cc: "Michael S. Tsirkin" <mst at redhat.com> Cc:

On Tue, Oct 27, 2015 at 11:38:58PM -0700, Andy Lutomirski wrote: > From: Andy Lutomirski <luto at amacapital.net> > > Once virtio starts using the DMA API, we won't be able to safely DMA > from the stack. virtio-net does a couple of config DMA requests > from small stack buffers -- switch to using dynamically-allocated > memory. > > This should have no effect

This switches virtio to use the DMA API unconditionally. I'm sure it breaks things, but it seems to work on x86 using virtio-pci, with and without Xen, and using both the modern 1.0 variant and the legacy variant. Changes from v2: - Fix really embarrassing bug. This version actually works. Changes from v1: - Fix an endian conversion error causing a BUG to hit. - Fix a DMA ordering issue

This switches virtio to use the DMA API unconditionally. I'm sure it breaks things, but it seems to work on x86 using virtio-pci, with and without Xen, and using both the modern 1.0 variant and the legacy variant. Changes from v2: - Fix really embarrassing bug. This version actually works. Changes from v1: - Fix an endian conversion error causing a BUG to hit. - Fix a DMA ordering issue

From: "Michael S. Tsirkin" <mst at redhat.com> Once virtio starts using the DMA API, we won't be able to safely DMA from the stack. virtio-net does a couple of config DMA requests from small stack buffers -- switch to using dynamically-allocated memory. This should have no effect on any performance-critical code paths. [I wrote the subject and commit message. mst wrote the

Am 30.10.2015 um 02:09 schrieb Andy Lutomirski: > From: "Michael S. Tsirkin" <mst at redhat.com> > > Once virtio starts using the DMA API, we won't be able to safely DMA > from the stack. virtio-net does a couple of config DMA requests > from small stack buffers -- switch to using dynamically-allocated > memory. > > This should have no effect on any

This fixes virtio on Xen guests as well as on any other platform that uses virtio_pci on which physical addresses don't match bus addresses. This can be tested with: virtme-run --xen xen --kimg arch/x86/boot/bzImage --console using virtme from here: https://git.kernel.org/cgit/utils/kernel/virtme/virtme.git Without these patches, the guest hangs forever. With these patches,

This fixes virtio on Xen guests as well as on any other platform that uses virtio_pci on which physical addresses don't match bus addresses. This can be tested with: virtme-run --xen xen --kimg arch/x86/boot/bzImage --console using virtme from here: https://git.kernel.org/cgit/utils/kernel/virtme/virtme.git Without these patches, the guest hangs forever. With these patches,

This fixes virtio on Xen guests as well as on any other platform that uses virtio_pci on which physical addresses don't match bus addresses. This can be tested with: virtme-run --xen xen --kimg arch/x86/boot/bzImage --console using virtme from here: https://git.kernel.org/cgit/utils/kernel/virtme/virtme.git Without these patches, the guest hangs forever. With these patches,

This fixes virtio on Xen guests as well as on any other platform that uses virtio_pci on which physical addresses don't match bus addresses. This can be tested with: virtme-run --xen xen --kimg arch/x86/boot/bzImage --console using virtme from here: https://git.kernel.org/cgit/utils/kernel/virtme/virtme.git Without these patches, the guest hangs forever. With these patches,

This fixes virtio on Xen guests as well as on any other platform that uses virtio_pci on which physical addresses don't match bus addresses. This can be tested with: virtme-run --xen xen --kimg arch/x86/boot/bzImage --console using virtme from here: https://git.kernel.org/cgit/utils/kernel/virtme/virtme.git Without these patches, the guest hangs forever. With these patches,

This fixes virtio on Xen guests as well as on any other platform that uses virtio_pci on which physical addresses don't match bus addresses. This can be tested with: virtme-run --xen xen --kimg arch/x86/boot/bzImage --console using virtme from here: https://git.kernel.org/cgit/utils/kernel/virtme/virtme.git Without these patches, the guest hangs forever. With these patches,

This fixes virtio on Xen guests as well as on any other platform that uses virtio_pci on which physical addresses don't match bus addresses. This can be tested with: virtme-run --xen xen --kimg arch/x86/boot/bzImage --console using virtme from here: https://git.kernel.org/cgit/utils/kernel/virtme/virtme.git Without these patches, the guest hangs forever. With these patches,

This fixes virtio on Xen guests as well as on any other platform that uses virtio_pci on which physical addresses don't match bus addresses. This can be tested with: virtme-run --xen xen --kimg arch/x86/boot/bzImage --console using virtme from here: https://git.kernel.org/cgit/utils/kernel/virtme/virtme.git Without these patches, the guest hangs forever. With these patches,

The virtio_net driver never sends the multicast address list to the host. This is because send command takes a pointer to scatter list to send but only inserts that one entry into the outgoing scatter list. This bug has been there since: commit f565a7c259d71cc186753653d978c646d2354b36 Author: Alex Williamson <alex.williamson at hp.com> Date: Wed Feb 4 09:02:45 2009 +0000 virtio_net: