| Message ID | 20200408225523.18764.86514.stgit@localhost.localdomain (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | virtio-balloon: add support for providing free page reporting | expand |
On 09.04.20 00:55, Alexander Duyck wrote: > From: Alexander Duyck <alexander.h.duyck@linux.intel.com> > > Add support for the page reporting feature provided by virtio-balloon. > Reporting differs from the regular balloon functionality in that is is > much less durable than a standard memory balloon. Instead of creating a > list of pages that cannot be accessed the pages are only inaccessible > while they are being indicated to the virtio interface. Once the > interface has acknowledged them they are placed back into their respective > free lists and are once again accessible by the guest system. > > Unlike a standard balloon we don't inflate and deflate the pages. Instead > we perform the reporting, and once the reporting is completed it is > assumed that the page has been dropped from the guest and will be faulted > back in the next time the page is accessed. > > This patch is a subset of the UAPI patch that was submitted for the Linux > kernel. The original patch can be found at: > https://lore.kernel.org/lkml/20200211224657.29318.68624.stgit@localhost.localdomain/ You don't need all these comments. Usually we do "linux-headers: update to contain virito-balloon free page reporting Let's sync the latest upstream changes for free page reporting. To be replaced by a full linux header sync. Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> " mst will replace this by a full header sync (if necessary) when sending it upstream
On Thu, Apr 9, 2020 at 12:36 AM David Hildenbrand <david@redhat.com> wrote: > > On 09.04.20 00:55, Alexander Duyck wrote: > > From: Alexander Duyck <alexander.h.duyck@linux.intel.com> > > > > Add support for the page reporting feature provided by virtio-balloon. > > Reporting differs from the regular balloon functionality in that is is > > much less durable than a standard memory balloon. Instead of creating a > > list of pages that cannot be accessed the pages are only inaccessible > > while they are being indicated to the virtio interface. Once the > > interface has acknowledged them they are placed back into their respective > > free lists and are once again accessible by the guest system. > > > > Unlike a standard balloon we don't inflate and deflate the pages. Instead > > we perform the reporting, and once the reporting is completed it is > > assumed that the page has been dropped from the guest and will be faulted > > back in the next time the page is accessed. > > > > This patch is a subset of the UAPI patch that was submitted for the Linux > > kernel. The original patch can be found at: > > https://lore.kernel.org/lkml/20200211224657.29318.68624.stgit@localhost.localdomain/ > > You don't need all these comments. Sorry about that. Those are basically the same comments from the original upstream patch. I just wasn't aware of the process so I just copied that over and added the comment/link to the original patch. > Usually we do > > "linux-headers: update to contain virito-balloon free page reporting > > Let's sync the latest upstream changes for free page reporting. To be > replaced by a full linux header sync. > > Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> > " > > mst will replace this by a full header sync (if necessary) when sending > it upstream I will update the patch description. Thanks. - Alex
On 09.04.20 16:41, Alexander Duyck wrote: > On Thu, Apr 9, 2020 at 12:36 AM David Hildenbrand <david@redhat.com> wrote: >> >> On 09.04.20 00:55, Alexander Duyck wrote: >>> From: Alexander Duyck <alexander.h.duyck@linux.intel.com> >>> >>> Add support for the page reporting feature provided by virtio-balloon. >>> Reporting differs from the regular balloon functionality in that is is >>> much less durable than a standard memory balloon. Instead of creating a >>> list of pages that cannot be accessed the pages are only inaccessible >>> while they are being indicated to the virtio interface. Once the >>> interface has acknowledged them they are placed back into their respective >>> free lists and are once again accessible by the guest system. >>> >>> Unlike a standard balloon we don't inflate and deflate the pages. Instead >>> we perform the reporting, and once the reporting is completed it is >>> assumed that the page has been dropped from the guest and will be faulted >>> back in the next time the page is accessed. >>> >>> This patch is a subset of the UAPI patch that was submitted for the Linux >>> kernel. The original patch can be found at: >>> https://lore.kernel.org/lkml/20200211224657.29318.68624.stgit@localhost.localdomain/ >> >> You don't need all these comments. > > Sorry about that. Those are basically the same comments from the > original upstream patch. I just wasn't aware of the process so I just > copied that over and added the comment/link to the original patch. No worries, it just felt like "oh, he spent a lot of time writing this, but after all it wasn't necessary" :)
diff --git a/include/standard-headers/linux/virtio_balloon.h b/include/standard-headers/linux/virtio_balloon.h index 9375ca2a70de..1c5f6d6f2de6 100644 --- a/include/standard-headers/linux/virtio_balloon.h +++ b/include/standard-headers/linux/virtio_balloon.h @@ -36,6 +36,7 @@ #define VIRTIO_BALLOON_F_DEFLATE_ON_OOM 2 /* Deflate balloon on OOM */ #define VIRTIO_BALLOON_F_FREE_PAGE_HINT 3 /* VQ to report free pages */ #define VIRTIO_BALLOON_F_PAGE_POISON 4 /* Guest is using page poisoning */ +#define VIRTIO_BALLOON_F_REPORTING 5 /* Page reporting virtqueue */ /* Size of a PFN in the balloon interface. */ #define VIRTIO_BALLOON_PFN_SHIFT 12