search for: desc_driv

Get it now. Please correct me if I missing something. Flags status hints, - DESC_DRIVER only: driver owns the descriptor w/o available info ready for device to use - DESC_DRIVER | DESC_WRAP: driver has prepared an available descriptor, device hasn't used it yet - None: device has used the descriptor, and write descriptor out - DESC_WRAP only: shall not happen, device make sur...

Get it now. Please correct me if I missing something. Flags status hints, - DESC_DRIVER only: driver owns the descriptor w/o available info ready for device to use - DESC_DRIVER | DESC_WRAP: driver has prepared an available descriptor, device hasn't used it yet - None: device has used the descriptor, and write descriptor out - DESC_WRAP only: shall not happen, device make sur...

Michael, Would you please give an example or two how these two flags DESC_DRIVER and DESC_WRAP are used together? Like others, I am confused by the description and still don?t quite grok it. Steven On 9/25/17, 3:24 PM, "virtio-dev at lists.oasis-open.org on behalf of Michael S. Tsirkin" <virtio-dev at lists.oasis-open.org on behalf of mst at redhat.com> wrot...

On Thu, Sep 28, 2017 at 09:44:35AM +0000, Liang, Cunming wrote: > > Get it now. Please correct me if I missing something. > > > Flags status hints, > > - DESC_DRIVER only: driver owns the descriptor w/o available info ready for device to use > > - DESC_DRIVER | DESC_WRAP: driver has prepared an available descriptor, device hasn't used it yet > > - None: device has used the descriptor, and write descriptor out > > - DESC_WRAP only: sha...

On Sun, Oct 01, 2017 at 04:08:29AM +0000, Michael S. Tsirkin wrote: >On Thu, Sep 28, 2017 at 09:44:35AM +0000, Liang, Cunming wrote: >> >> Get it now. Please correct me if I missing something. >> >> >> Flags status hints, >> >> - DESC_DRIVER only: driver owns the descriptor w/o available info ready for device to use >> >> - DESC_DRIVER | DESC_WRAP: driver has prepared an available descriptor, device hasn't used it yet >> >> - None: device has used the descriptor, and write descriptor out >> >>...

On Sun, Oct 01, 2017 at 04:08:29AM +0000, Michael S. Tsirkin wrote: >On Thu, Sep 28, 2017 at 09:44:35AM +0000, Liang, Cunming wrote: >> >> Get it now. Please correct me if I missing something. >> >> >> Flags status hints, >> >> - DESC_DRIVER only: driver owns the descriptor w/o available info ready for device to use >> >> - DESC_DRIVER | DESC_WRAP: driver has prepared an available descriptor, device hasn't used it yet >> >> - None: device has used the descriptor, and write descriptor out >> >>...

...08:29AM +0000, Michael S. Tsirkin wrote: > > On Thu, Sep 28, 2017 at 09:44:35AM +0000, Liang, Cunming wrote: > > > > > > Get it now. Please correct me if I missing something. > > > > > > > > > Flags status hints, > > > > > > - DESC_DRIVER only: driver owns the descriptor w/o available info ready for device to use > > > > > > - DESC_DRIVER | DESC_WRAP: driver has prepared an available descriptor, device hasn't used it yet > > > > > > - None: device has used the descriptor, and write descrip...

...ote: > > > On Thu, Sep 28, 2017 at 09:44:35AM +0000, Liang, Cunming wrote: > > > > > > > > Get it now. Please correct me if I missing something. > > > > > > > > > > > > Flags status hints, > > > > > > > > - DESC_DRIVER only: driver owns the descriptor w/o available info > > > > ready for device to use > > > > > > > > - DESC_DRIVER | DESC_WRAP: driver has prepared an available > > > > descriptor, device hasn't used it yet > > > > > > > >...

...ote: > > > On Thu, Sep 28, 2017 at 09:44:35AM +0000, Liang, Cunming wrote: > > > > > > > > Get it now. Please correct me if I missing something. > > > > > > > > > > > > Flags status hints, > > > > > > > > - DESC_DRIVER only: driver owns the descriptor w/o available info > > > > ready for device to use > > > > > > > > - DESC_DRIVER | DESC_WRAP: driver has prepared an available > > > > descriptor, device hasn't used it yet > > > > > > > >...

On Tue, Sep 26, 2017 at 11:38:18PM +0000, Steven Luong (sluong) wrote: > Michael, > > Would you please give an example or two how these two flags DESC_DRIVER and DESC_WRAP are used together? Like others, I am confused by the description and still don?t quite grok it. > > Steven My bad, I will need to work on it. Here is an example: Let's assume device promised to consume packets in order ring size = 2 Ring is 0 initialized. Device init...

...Jason Wang <jasowang at redhat.com> wrote: > > > On 2017?09?10? 13:06, Michael S. Tsirkin wrote: >> >> This is an update from v2 version. >> Changes: >> - update event suppression mechanism >> - add wrap counter: DESC_WRAP flag in addition to >> DESC_DRIVER flag used for validity so device does not have to >> write out all used descriptors. > > > Do we have benchmark result to show the advantage of DESC_DRIVER over e.g > avail/used index? The KVM forum presentation has some numbers. I'm not sure that synthetic benchmarks w...

...Jason Wang <jasowang at redhat.com> wrote: > > > On 2017?09?10? 13:06, Michael S. Tsirkin wrote: >> >> This is an update from v2 version. >> Changes: >> - update event suppression mechanism >> - add wrap counter: DESC_WRAP flag in addition to >> DESC_DRIVER flag used for validity so device does not have to >> write out all used descriptors. > > > Do we have benchmark result to show the advantage of DESC_DRIVER over e.g > avail/used index? The KVM forum presentation has some numbers. I'm not sure that synthetic benchmarks w...

...M > > To: virtio-dev at lists.oasis-open.org > > Cc: virtualization at lists.linux-foundation.org > > Subject: [virtio-dev] packed ring layout proposal v3 > > > [...] > > * Descriptor ring: > > > > Driver writes descriptors with unique index values and DESC_DRIVER set in > > flags. > > Descriptors are written in a ring order: from start to end of ring, wrapping > > around to the beginning. > > Device writes used descriptors with correct len, index, and DESC_HW clear. > > Again descriptors are written in ring order. This might...

...M > > To: virtio-dev at lists.oasis-open.org > > Cc: virtualization at lists.linux-foundation.org > > Subject: [virtio-dev] packed ring layout proposal v3 > > > [...] > > * Descriptor ring: > > > > Driver writes descriptors with unique index values and DESC_DRIVER set in > > flags. > > Descriptors are written in a ring order: from start to end of ring, wrapping > > around to the beginning. > > Device writes used descriptors with correct len, index, and DESC_HW clear. > > Again descriptors are written in ring order. This might...

On 2017?09?10? 13:06, Michael S. Tsirkin wrote: > This is an update from v2 version. > Changes: > - update event suppression mechanism > - add wrap counter: DESC_WRAP flag in addition to > DESC_DRIVER flag used for validity so device does not have to > write out all used descriptors. Do we have benchmark result to show the advantage of DESC_DRIVER over e.g avail/used index? > - more options especially helpful for hardware implementations > - in-order processing option due to pop...

This is an update from v1 version. Changes: - update event suppression mechanism - separate options for indirect and direct s/g - lots of new features --- Performance analysis of this is in my kvm forum 2016 presentation. The idea is to have a r/w descriptor in a ring structure, replacing the used and available ring, index and descriptor buffer. * Descriptor ring: Guest adds descriptors with

This is an update from v1 version. Changes: - update event suppression mechanism - separate options for indirect and direct s/g - lots of new features --- Performance analysis of this is in my kvm forum 2016 presentation. The idea is to have a r/w descriptor in a ring structure, replacing the used and available ring, index and descriptor buffer. * Descriptor ring: Guest adds descriptors with

...Sent: Sunday, September 10, 2017 1:06 PM > To: virtio-dev at lists.oasis-open.org > Cc: virtualization at lists.linux-foundation.org > Subject: [virtio-dev] packed ring layout proposal v3 > [...] > * Descriptor ring: > > Driver writes descriptors with unique index values and DESC_DRIVER set in > flags. > Descriptors are written in a ring order: from start to end of ring, wrapping > around to the beginning. > Device writes used descriptors with correct len, index, and DESC_HW clear. > Again descriptors are written in ring order. This might not be the same order &gt...