search for: virtio_balloon_f_silent_deflate

...default without > breaking compatibility. You're right that for correctness the existing feature is enough: if it is not negotiated by the guest, the host ensures correctness by only giving the guest a fake balloon. However, the new feature is about optimization, not correctness. In fact, VIRTIO_BALLOON_F_SILENT_DEFLATE is the optimization feature that VIRTIO_BALLOON_F_MUST_TELL_HOST was meant to be. What I'm interested in, is drivers that can _optionally_ use silent deflation (as an optimization). These should not get a fake balloon! With the new feature bit, these drivers should propose both VIRTIO_BALLO...

...t; You're right that for correctness the existing feature is enough: >> if it is not negotiated by the guest, the host ensures correctness by >> only giving the guest a fake balloon. >> >> However, the new feature is about optimization, not correctness. >> In fact, VIRTIO_BALLOON_F_SILENT_DEFLATE is the optimization >> feature that VIRTIO_BALLOON_F_MUST_TELL_HOST was meant to be. >> >> What I'm interested in, is drivers that can _optionally_ use silent >> deflation (as an optimization). These should not get a fake balloon! >> >> With the new feature...

...atibility. > > You're right that for correctness the existing feature is enough: > if it is not negotiated by the guest, the host ensures correctness by > only giving the guest a fake balloon. > > However, the new feature is about optimization, not correctness. > In fact, VIRTIO_BALLOON_F_SILENT_DEFLATE is the optimization > feature that VIRTIO_BALLOON_F_MUST_TELL_HOST was meant to be. > > What I'm interested in, is drivers that can _optionally_ use silent > deflation (as an optimization). These should not get a fake balloon! > > With the new feature bit, these drivers sh...

...for correctness the existing feature is enough: > >> if it is not negotiated by the guest, the host ensures correctness by > >> only giving the guest a fake balloon. > >> > >> However, the new feature is about optimization, not correctness. > >> In fact, VIRTIO_BALLOON_F_SILENT_DEFLATE is the optimization > >> feature that VIRTIO_BALLOON_F_MUST_TELL_HOST was meant to be. > >> > >> What I'm interested in, is drivers that can _optionally_ use silent > >> deflation (as an optimization). These should not get a fake balloon! > >> >...

...the existing feature is enough: >>>> if it is not negotiated by the guest, the host ensures correctness by >>>> only giving the guest a fake balloon. >>>> >>>> However, the new feature is about optimization, not correctness. >>>> In fact, VIRTIO_BALLOON_F_SILENT_DEFLATE is the optimization >>>> feature that VIRTIO_BALLOON_F_MUST_TELL_HOST was meant to be. >>>> >>>> What I'm interested in, is drivers that can _optionally_ use silent >>>> deflation (as an optimization). These should not get a fake balloon! >&g...

...refuses migration if the target does not support all the features that were negotiated. But then: - a migration from non-MUST_TELL_HOST to MUST_TELL_HOST will succeed, which is wrong; - a migration from MUST_TELL_HOST to non-MUST_TELL_HOST will fail, which is useless. Add instead a new feature VIRTIO_BALLOON_F_SILENT_DEFLATE, and deprecate VIRTIO_BALLOON_F_MUST_TELL_HOST since it is never actually used. Signed-off-by: Paolo Bonzini <pbonzini at redhat.com> --- virtio-spec.lyx | 36 +++++++++++++++++++++++++++++++++--- 1 file modificato, 33 inserzioni(+), 3 rimozioni(-) diff --git a/virtio-spec.lyx b/virtio-spe...

...refuses migration if the target does not support all the features that were negotiated. But then: - a migration from non-MUST_TELL_HOST to MUST_TELL_HOST will succeed, which is wrong; - a migration from MUST_TELL_HOST to non-MUST_TELL_HOST will fail, which is useless. Add instead a new feature VIRTIO_BALLOON_F_SILENT_DEFLATE, and deprecate VIRTIO_BALLOON_F_MUST_TELL_HOST since it is never actually used. Signed-off-by: Paolo Bonzini <pbonzini at redhat.com> --- virtio-spec.lyx | 36 +++++++++++++++++++++++++++++++++--- 1 file modificato, 33 inserzioni(+), 3 rimozioni(-) diff --git a/virtio-spec.lyx b/virtio-spe...

...enough: > >>>> if it is not negotiated by the guest, the host ensures correctness by > >>>> only giving the guest a fake balloon. > >>>> > >>>> However, the new feature is about optimization, not correctness. > >>>> In fact, VIRTIO_BALLOON_F_SILENT_DEFLATE is the optimization > >>>> feature that VIRTIO_BALLOON_F_MUST_TELL_HOST was meant to be. > >>>> > >>>> What I'm interested in, is drivers that can _optionally_ use silent > >>>> deflation (as an optimization). These should not get a...

Il 28/05/2013 13:44, Michael S. Tsirkin ha scritto: > negotiated in spec means "present and acked by guest". > We can try and replace "negotiated" by "present and acked by guest" > everywhere - think it will be clearer? No, I understand what negotiated means. But in this case, "negotiated" is not the word that you want. >>>> Now

...\end_layout \begin_layout Description @@ -7192,6 +7230,20 @@ VIRTIO_BALLOON_F_STATS_VQ \end_inset (1) A virtqueue for reporting guest memory statistics is present. +\change_inserted 1531152142 1347020627 + +\end_layout + +\begin_layout Description + +\change_inserted 1531152142 1347020648 +VIRTIO_BALLOON_F_SILENT_DEFLATE +\begin_inset space ~ +\end_inset + +(2) Guest does not need to tell host before pages from the balloon are used. +\change_unchanged + \end_layout \end_deeper @@ -7342,9 +7394,27 @@ The driver constructs an array of addresses of memory pages it has previously \end_layout \begin_layout Enume...

...\end_layout \begin_layout Description @@ -7192,6 +7230,20 @@ VIRTIO_BALLOON_F_STATS_VQ \end_inset (1) A virtqueue for reporting guest memory statistics is present. +\change_inserted 1531152142 1347020627 + +\end_layout + +\begin_layout Description + +\change_inserted 1531152142 1347020648 +VIRTIO_BALLOON_F_SILENT_DEFLATE +\begin_inset space ~ +\end_inset + +(2) Guest does not need to tell host before pages from the balloon are used. +\change_unchanged + \end_layout \end_deeper @@ -7342,9 +7394,27 @@ The driver constructs an array of addresses of memory pages it has previously \end_layout \begin_layout Enume...

...-- a/virtio-spec.lyx +++ b/virtio-spec.lyx @@ -7267,6 +7267,20 @@ VIRTIO_BALLOON_F_STATS_VQ \end_inset (1) A virtqueue for reporting guest memory statistics is present. +\change_inserted 1531152142 1347020627 + +\end_layout + +\begin_layout Description + +\change_inserted 1531152142 1347020648 +VIRTIO_BALLOON_F_SILENT_DEFLATE +\begin_inset space ~ +\end_inset + +(2) Guest need not tell host before pages from the balloon are used. +\change_unchanged + \end_layout \end_deeper @@ -7627,6 +7641,168 @@ VIRTIO_BALLOON_S_MEMFREE The amount of memory not being used for any purpose VIRTIO_BALLOON_S_MEMTOT The total amount o...

Here is the series, split in two patches, with small edits and new commit messages. Paolo Bonzini (2): virtio-balloon spec: rewrite description of VIRTIO_BALLOON_F_MUST_TELL_HOST virtio-balloon spec: reintroduce "silent deflation" feature virtio-spec.lyx | 238 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 233 insertions(+), 5 deletions(-) --

...7267,20 @@ VIRTIO_BALLOON_F_STATS_VQ > \end_inset > > (1) A virtqueue for reporting guest memory statistics is present. > +\change_inserted 1531152142 1347020627 > + > +\end_layout > + > +\begin_layout Description > + > +\change_inserted 1531152142 1347020648 > +VIRTIO_BALLOON_F_SILENT_DEFLATE > +\begin_inset space ~ > +\end_inset > + > +(2) Guest need not tell host before pages from the balloon are used. > +\change_unchanged > + > \end_layout > > \end_deeper > @@ -7627,6 +7641,168 @@ VIRTIO_BALLOON_S_MEMFREE The amount of memory not being used for any p...