similar to: [PATCH 0/3] virtio: simplify virtio_ring.

This fixes virtio on Xen guests as well as on any other platform 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, everything works. There

This fixes virtio on Xen guests as well as on any other platform 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, everything works. There

OK, so I've spent a few days benchmarking. Turns out 80% of virtio_add_buf cases are uni-directional (including the always-performance-sensitive networking code), and that gets no performance penalty (though tests with real networking would be appreciated!). I'm not reposting all the "convert driver to virtio_add_outbuf()" patches: just the scsi one which I didn't have

OK, so I've spent a few days benchmarking. Turns out 80% of virtio_add_buf cases are uni-directional (including the always-performance-sensitive networking code), and that gets no performance penalty (though tests with real networking would be appreciated!). I'm not reposting all the "convert driver to virtio_add_outbuf()" patches: just the scsi one which I didn't have

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,

Add virtqueue_add_sgs which is more general than virtqueue_add_buf, which makes virtio-scsi and virtio-blk nicer, then add virtqueue_add_inbuf and virtqueue_add_outbuf which handle the more general case, and finally delete virtqueue_add_buf(). I'm hoping this will be the final post of the whole series, and it can move from my pending-rebases tree into virtio-next. Thanks! Rusty. Paolo

Add virtqueue_add_sgs which is more general than virtqueue_add_buf, which makes virtio-scsi and virtio-blk nicer, then add virtqueue_add_inbuf and virtqueue_add_outbuf which handle the more general case, and finally delete virtqueue_add_buf(). I'm hoping this will be the final post of the whole series, and it can move from my pending-rebases tree into virtio-next. Thanks! Rusty. Paolo

Hello all: We free old transmitted packets in ndo_start_xmit() currently, so any packet must be orphaned also there. This was used to reduce the overhead of tx interrupt to achieve better performance. But this may not work for some protocols such as TCP stream. TCP depends on the value of sk_wmem_alloc to implement various optimization for small packets stream such as TCP small queue and auto

Hello all: We free old transmitted packets in ndo_start_xmit() currently, so any packet must be orphaned also there. This was used to reduce the overhead of tx interrupt to achieve better performance. But this may not work for some protocols such as TCP stream. TCP depends on the value of sk_wmem_alloc to implement various optimization for small packets stream such as TCP small queue and auto

On Thu, Aug 28, 2014 at 11:29 AM, Christian Borntraeger <borntraeger at de.ibm.com> wrote: > On 28/08/14 20:06, Andy Lutomirski wrote: > [...] >>> block seems to work, with net a simple ping works, iperf causes this: >> >> I neither see the bug, nor can I reproduce it on x86_64 on KVM. I >> doubt that dma vs. non-dma is relevant. I tried -net user a -net

On Thu, Aug 28, 2014 at 11:29 AM, Christian Borntraeger <borntraeger at de.ibm.com> wrote: > On 28/08/14 20:06, Andy Lutomirski wrote: > [...] >>> block seems to work, with net a simple ping works, iperf causes this: >> >> I neither see the bug, nor can I reproduce it on x86_64 on KVM. I >> doubt that dma vs. non-dma is relevant. I tried -net user a -net

On Thu, Aug 28, 2014 at 12:44 AM, Christian Borntraeger <borntraeger at de.ibm.com> wrote: > On 27/08/14 23:50, Andy Lutomirski wrote: >> 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

On Thu, Aug 28, 2014 at 12:44 AM, Christian Borntraeger <borntraeger at de.ibm.com> wrote: > On 27/08/14 23:50, Andy Lutomirski wrote: >> 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

Andy Lutomirski <luto at amacapital.net> writes: > The only unusual thing about virtio's use of scatterlists is that > two of the APIs accept scatterlists that might not be terminated. > Using function pointers to handle this case is overkill; for_each_sg > can do it. > > There's a small subtlely here: for_each_sg assumes that the provided > count is correct,

Andy Lutomirski <luto at amacapital.net> writes: > The only unusual thing about virtio's use of scatterlists is that > two of the APIs accept scatterlists that might not be terminated. > Using function pointers to handle this case is overkill; for_each_sg > can do it. > > There's a small subtlely here: for_each_sg assumes that the provided > count is correct,

We used to have several callers which just used arrays. They're gone, so we can use sg_next() everywhere, simplifying the code. On my laptop, this slowed down vring_bench by 15%: vring_bench before: 936153354-967745359(9.44739e+08+/-6.1e+06)ns vring_bench after: 1061485790-1104800648(1.08254e+09+/-6.6e+06)ns However, a more realistic test using pktgen on a AMD FX(tm)-8320 saw a few

On Wed, 22 Oct 2014 17:02:26 +0300 "Michael S. Tsirkin" <mst at redhat.com> wrote: > On Tue, Oct 07, 2014 at 04:39:45PM +0200, Cornelia Huck wrote: > > From: Rusty Russell <rusty at rustcorp.com.au> > > > > [Cornelia Huck: we don't need the vq->vring.num -> vq->ring_mask change] > > Signed-off-by: Rusty Russell <rusty at