similar to: [PATCH] vhost: fix performance on LE hosts

Hi, This patchset allows vhost to be used with legacy virtio when guest and host have a different endianness. It is compatible with modern virtio and can be fully compiled out through kernel config. FWIW, I could flawlessly kexec/reboot guests from ppc64 to ppc64le and back. I could also migrate from a ppc64 to a ppc64le host and back. No regressions on x86 as expected. My experimental QEMU tree

Hi, This patchset allows vhost to be used with legacy virtio when guest and host have a different endianness. It is compatible with modern virtio and can be fully compiled out through kernel config. FWIW, I could flawlessly kexec/reboot guests from ppc64 to ppc64le and back. I could also migrate from a ppc64 to a ppc64le host and back. No regressions on x86 as expected. My experimental QEMU tree

Only cosmetic and documentation changes since v5. --- Greg Kurz (8): virtio: introduce virtio_is_little_endian() helper tun: add tun_is_little_endian() helper macvtap: introduce macvtap_is_little_endian() helper vringh: introduce vringh_is_little_endian() helper vhost: introduce vhost_is_little_endian() helper virtio: add explicit big-endian support to memory

Only cosmetic and documentation changes since v5. --- Greg Kurz (8): virtio: introduce virtio_is_little_endian() helper tun: add tun_is_little_endian() helper macvtap: introduce macvtap_is_little_endian() helper vringh: introduce vringh_is_little_endian() helper vhost: introduce vhost_is_little_endian() helper virtio: add explicit big-endian support to memory

On Wed, Jan 13, 2016 at 06:09:41PM +0100, Greg Kurz wrote: > The default use case for vhost is when the host and the vring have the > same endianness (default native endianness). But there are cases where > they differ and vhost should byteswap when accessing the vring: > - the host is big endian and the vring comes from a virtio 1.0 device > which is always little endian > -

On Wed, Jan 13, 2016 at 06:09:41PM +0100, Greg Kurz wrote: > The default use case for vhost is when the host and the vring have the > same endianness (default native endianness). But there are cases where > they differ and vhost should byteswap when accessing the vring: > - the host is big endian and the vring comes from a virtio 1.0 device > which is always little endian > -

On Tue, Apr 07, 2015 at 02:19:31PM +0200, Greg Kurz wrote: > This patch brings cross-endian support to vhost when used to implement > legacy virtio devices. Since it is a relatively rare situation, the > feature availability is controlled by a kernel config option (not set > by default). > > The ioctls introduced by this patch are for legacy only: virtio 1.0 > devices are

On Tue, Apr 07, 2015 at 02:19:31PM +0200, Greg Kurz wrote: > This patch brings cross-endian support to vhost when used to implement > legacy virtio devices. Since it is a relatively rare situation, the > feature availability is controlled by a kernel config option (not set > by default). > > The ioctls introduced by this patch are for legacy only: virtio 1.0 > devices are

Hi, This patchset allows vhost to be used with legacy virtio when guest and host have a different endianness. Patch 7 got rewritten according to Cornelia's and Michael's comments. I have also introduced patch 8 that brings BE vnet headers support to tun/macvtap. This series is enough to have vhost_net working flawlessly. I could succesfully reboot guests from ppc64 to ppc64le and

Hi, This patchset allows vhost to be used with legacy virtio when guest and host have a different endianness. Patch 7 got rewritten according to Cornelia's and Michael's comments. I have also introduced patch 8 that brings BE vnet headers support to tun/macvtap. This series is enough to have vhost_net working flawlessly. I could succesfully reboot guests from ppc64 to ppc64le and

On Fri, Apr 10, 2015 at 12:19:16PM +0200, Greg Kurz wrote: > This patch brings cross-endian support to vhost when used to implement > legacy virtio devices. Since it is a relatively rare situation, the > feature availability is controlled by a kernel config option (not set > by default). > > The vq->is_le boolean field is added to cache the endianness to be > used for ring

On Fri, Apr 10, 2015 at 12:19:16PM +0200, Greg Kurz wrote: > This patch brings cross-endian support to vhost when used to implement > legacy virtio devices. Since it is a relatively rare situation, the > feature availability is controlled by a kernel config option (not set > by default). > > The vq->is_le boolean field is added to cache the endianness to be > used for ring

The vq->is_le field is used to fix endianness when accessing the vring via the cpu_to_vhost16() and vhost16_to_cpu() helpers in the following cases: 1) host is big endian and device is modern virtio 2) host has cross-endian support and device is legacy virtio with a different endianness than the host Both cases rely on the VHOST_SET_FEATURES ioctl, but 2) also needs the

The vq->is_le field is used to fix endianness when accessing the vring via the cpu_to_vhost16() and vhost16_to_cpu() helpers in the following cases: 1) host is big endian and device is modern virtio 2) host has cross-endian support and device is legacy virtio with a different endianness than the host Both cases rely on the VHOST_SET_FEATURES ioctl, but 2) also needs the

Hi, This patchset allows vhost to be used with legacy virtio when guest and host have a different endianness. Patches 1-6 remain the same as the previous post. Patch 7 was heavily changed according to MST's comments. --- Greg Kurz (7): virtio: introduce virtio_is_little_endian() helper tun: add tun_is_little_endian() helper macvtap: introduce macvtap_is_little_endian()

Hi, This patchset allows vhost to be used with legacy virtio when guest and host have a different endianness. Patches 1-6 remain the same as the previous post. Patch 7 was heavily changed according to MST's comments. --- Greg Kurz (7): virtio: introduce virtio_is_little_endian() helper tun: add tun_is_little_endian() helper macvtap: introduce macvtap_is_little_endian()

On Wed, Feb 10, 2016 at 01:11:34PM +0100, Greg Kurz wrote: > On Wed, 10 Feb 2016 13:21:22 +0200 > "Michael S. Tsirkin" <mst at redhat.com> wrote: > > > On Wed, Jan 13, 2016 at 06:09:41PM +0100, Greg Kurz wrote: > > > The default use case for vhost is when the host and the vring have the > > > same endianness (default native endianness). But there

On Wed, Feb 10, 2016 at 01:11:34PM +0100, Greg Kurz wrote: > On Wed, 10 Feb 2016 13:21:22 +0200 > "Michael S. Tsirkin" <mst at redhat.com> wrote: > > > On Wed, Jan 13, 2016 at 06:09:41PM +0100, Greg Kurz wrote: > > > The default use case for vhost is when the host and the vring have the > > > same endianness (default native endianness). But there

On Thu, 12 Nov 2015 15:46:30 +0200 "Michael S. Tsirkin" <mst at redhat.com> wrote: > On Fri, Oct 30, 2015 at 12:42:35PM +0100, Greg Kurz wrote: > > The vq->is_le field is used to fix endianness when accessing the vring via > > the cpu_to_vhost16() and vhost16_to_cpu() helpers in the following cases: > > > > 1) host is big endian and device is modern

On Thu, 12 Nov 2015 15:46:30 +0200 "Michael S. Tsirkin" <mst at redhat.com> wrote: > On Fri, Oct 30, 2015 at 12:42:35PM +0100, Greg Kurz wrote: > > The vq->is_le field is used to fix endianness when accessing the vring via > > the cpu_to_vhost16() and vhost16_to_cpu() helpers in the following cases: > > > > 1) host is big endian and device is modern