search for: adjust_header

Add support for XDP adjust head by allocating a 256B header region that XDP programs can grow into. This is only enabled when a XDP program is loaded. In order to ensure that we do not have to unwind queue headroom push queue setup below bpf_prog_add. It reads better to do a prog ref unwind vs another queue setup call. TBD merge with Jason Wang's fixes, do a bit more testing, note

Add support for XDP adjust head by allocating a 256B header region that XDP programs can grow into. This is only enabled when a XDP program is loaded. In order to ensure that we do not have to unwind queue headroom push queue setup below bpf_prog_add. It reads better to do a prog ref unwind vs another queue setup call. TBD merge with Jason Wang's fixes, do a bit more testing, note

...200 > > > On Tue, Jan 24, 2017 at 03:09:59PM -0500, David Miller wrote: > >> From: "Michael S. Tsirkin" <mst at redhat.com> > >> Date: Tue, 24 Jan 2017 21:53:13 +0200 > >> > >> > I didn't realise. Why can't we? I thought that adjust_header is an > >> > optional feature that userspace can test for, so no rush. > >> > >> No, we want the base set of XDP features to be present in all drivers > >> supporting XDP. > > > > I see, I didn't realize this. In light of this, is there any &...

...200 > > > On Tue, Jan 24, 2017 at 03:09:59PM -0500, David Miller wrote: > >> From: "Michael S. Tsirkin" <mst at redhat.com> > >> Date: Tue, 24 Jan 2017 21:53:13 +0200 > >> > >> > I didn't realise. Why can't we? I thought that adjust_header is an > >> > optional feature that userspace can test for, so no rush. > >> > >> No, we want the base set of XDP features to be present in all drivers > >> supporting XDP. > > > > I see, I didn't realize this. In light of this, is there any &...

...in a week or two, but now we're > basically a month or so later. > > Please come to some kind of agreement about how to implement this > because we can't let v4.10 go out without this being resolved. > > Thank you. I didn't realise. Why can't we? I thought that adjust_header is an optional feature that userspace can test for, so no rush. -- MST

...in a week or two, but now we're > basically a month or so later. > > Please come to some kind of agreement about how to implement this > because we can't let v4.10 go out without this being resolved. > > Thank you. I didn't realise. Why can't we? I thought that adjust_header is an optional feature that userspace can test for, so no rush. -- MST

On Tue, Jan 24, 2017 at 03:09:59PM -0500, David Miller wrote: > From: "Michael S. Tsirkin" <mst at redhat.com> > Date: Tue, 24 Jan 2017 21:53:13 +0200 > > > I didn't realise. Why can't we? I thought that adjust_header is an > > optional feature that userspace can test for, so no rush. > > No, we want the base set of XDP features to be present in all drivers > supporting XDP. I see, I didn't realize this. In light of this, is there any guidance *how much* head room is required to be considere...

On Tue, Jan 24, 2017 at 03:09:59PM -0500, David Miller wrote: > From: "Michael S. Tsirkin" <mst at redhat.com> > Date: Tue, 24 Jan 2017 21:53:13 +0200 > > > I didn't realise. Why can't we? I thought that adjust_header is an > > optional feature that userspace can test for, so no rush. > > No, we want the base set of XDP features to be present in all drivers > supporting XDP. I see, I didn't realize this. In light of this, is there any guidance *how much* head room is required to be considere...

...gt; On Tue, Jan 24, 2017 at 03:09:59PM -0500, David Miller wrote: >> >> From: "Michael S. Tsirkin" <mst at redhat.com> >> >> Date: Tue, 24 Jan 2017 21:53:13 +0200 >> >> >> >> > I didn't realise. Why can't we? I thought that adjust_header is an >> >> > optional feature that userspace can test for, so no rush. >> >> >> >> No, we want the base set of XDP features to be present in all drivers >> >> supporting XDP. >> > >> > I see, I didn't realize this. In light...

On Tue, Jan 24, 2017 at 04:10:46PM -0500, David Miller wrote: > This works in the regimen that XDP packets always live in exactly one > page. That will be needed to mmap the RX ring into userspace, and it > helps make adjust_header trivial as well. I think the point was to avoid resets across xdp attach/detach. If we are doing resets now, we could do whatever buffering we want. We could also just disable mergeable buffers for that matter. > MTU 1500, PAGESIZE >= 4096, so a headroom of 256 is no problem, and > we s...

On Tue, Jan 24, 2017 at 04:10:46PM -0500, David Miller wrote: > This works in the regimen that XDP packets always live in exactly one > page. That will be needed to mmap the RX ring into userspace, and it > helps make adjust_header trivial as well. I think the point was to avoid resets across xdp attach/detach. If we are doing resets now, we could do whatever buffering we want. We could also just disable mergeable buffers for that matter. > MTU 1500, PAGESIZE >= 4096, so a headroom of 256 is no problem, and > we s...

We set queues before reset which will cause a crash[1]. This is because is_xdp_raw_buffer_queue() depends on the old xdp queue pairs number to do the correct detection. So fix this by: - set queues after reset, to keep the old vi->curr_queue_pairs. (in fact setting queues before reset does not works since after feature set, all queue pairs were enabled by default during reset). - change

We set queues before reset which will cause a crash[1]. This is because is_xdp_raw_buffer_queue() depends on the old xdp queue pairs number to do the correct detection. So fix this by: - set queues after reset, to keep the old vi->curr_queue_pairs. (in fact setting queues before reset does not works since after feature set, all queue pairs were enabled by default during reset). - change

From: Willem de Bruijn <willemb at google.com> Implement the reset communication request defined in the VIRTIO 1.0 specification and introduces in Linux in commit c00bbcf862896 ("virtio: add VIRTIO_CONFIG_S_NEEDS_RESET device status bit"). Use the virtnet_reset function introduced in commit 2de2f7f40ef9 ("virtio_net: XDP support for adjust_head"). That was removed in

From: Willem de Bruijn <willemb at google.com> Implement the reset communication request defined in the VIRTIO 1.0 specification and introduces in Linux in commit c00bbcf862896 ("virtio: add VIRTIO_CONFIG_S_NEEDS_RESET device status bit"). Use the virtnet_reset function introduced in commit 2de2f7f40ef9 ("virtio_net: XDP support for adjust_head"). That was removed in

On 16-12-23 06:37 AM, Jason Wang wrote: > Merry Xmas and a Happy New year to all: > > This series tries to fixes several issues for virtio-net XDP which > could be categorized into several parts: > > - fix several issues during XDP linearizing > - allow csumed packet to work for XDP_PASS > - make EWMA rxbuf size estimation works for XDP > - forbid XDP when GUEST_UFO is

From: "Michael S. Tsirkin" <mst at redhat.com> Date: Tue, 24 Jan 2017 21:53:13 +0200 > I didn't realise. Why can't we? I thought that adjust_header is an > optional feature that userspace can test for, so no rush. No, we want the base set of XDP features to be present in all drivers supporting XDP.

...: Tue, 24 Jan 2017 22:45:37 +0200 > On Tue, Jan 24, 2017 at 03:09:59PM -0500, David Miller wrote: >> From: "Michael S. Tsirkin" <mst at redhat.com> >> Date: Tue, 24 Jan 2017 21:53:13 +0200 >> >> > I didn't realise. Why can't we? I thought that adjust_header is an >> > optional feature that userspace can test for, so no rush. >> >> No, we want the base set of XDP features to be present in all drivers >> supporting XDP. > > I see, I didn't realize this. In light of this, is there any > guidance *how much* head r...

On Mon, Jul 17, 2017 at 08:43:56PM +0800, Jason Wang wrote: > Hi: > > This series brings two optimizations for virtio-net XDP: > > - avoid reset during XDP set > - turn off offloads on demand I'm glad to see this take shape - this can be extended to optimize virtnet_get_headroom so we don't waste room if adjust_head is enabled. I see a couple of issues, responded to

I don't have any guests with PAGE_SIZE > 64k but the code seems to be clearly broken in that case as PAGE_SIZE / MERGEABLE_BUFFER_ALIGN will need more than 8 bit and so the code in mergeable_ctx_to_buf_address does not give us the actual true size. Cc: John Fastabend <john.fastabend at gmail.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- changes from v1: fix