| Message ID | 20190918175305.23474.34783.stgit@localhost.localdomain (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm / virtio: Provide support for unused page reporting | expand |
On Wed, Sep 18, 2019 at 10:53:05AM -0700, Alexander Duyck wrote: > From: Alexander Duyck <alexander.h.duyck@linux.intel.com> > > Currently the page poisoning setting wasn't being enabled unless free page > hinting was enabled. However we will need the page poisoning tracking logic > as well for unused page reporting. As such pull it out and make it a > separate bit of config in the probe function. > > In addition we can actually wrap the code in a check for NO_SANITY. If we > don't care what is actually in the page we can just default to 0 and leave > it there. > > Reviewed-by: David Hildenbrand <david@redhat.com> > Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> I think this one can go in directly. Do you want me to merge it now? > --- > drivers/virtio/virtio_balloon.c | 22 +++++++++++++++------- > 1 file changed, 15 insertions(+), 7 deletions(-) > > diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c > index 226fbb995fb0..501a8d0ebf86 100644 > --- a/drivers/virtio/virtio_balloon.c > +++ b/drivers/virtio/virtio_balloon.c > @@ -842,7 +842,6 @@ static int virtio_balloon_register_shrinker(struct virtio_balloon *vb) > static int virtballoon_probe(struct virtio_device *vdev) > { > struct virtio_balloon *vb; > - __u32 poison_val; > int err; > > if (!vdev->config->get) { > @@ -909,11 +908,18 @@ static int virtballoon_probe(struct virtio_device *vdev) > VIRTIO_BALLOON_CMD_ID_STOP); > spin_lock_init(&vb->free_page_list_lock); > INIT_LIST_HEAD(&vb->free_page_list); > - if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON)) { > - memset(&poison_val, PAGE_POISON, sizeof(poison_val)); > - virtio_cwrite(vb->vdev, struct virtio_balloon_config, > - poison_val, &poison_val); > - } > + } > + if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON)) { > + __u32 poison_val; > + > + /* > + * Let the hypervisor know that we are expecting a > + * specific value to be written back in unused pages. > + */ > + memset(&poison_val, PAGE_POISON, sizeof(poison_val)); > + > + virtio_cwrite(vb->vdev, struct virtio_balloon_config, > + poison_val, &poison_val); > } > /* > * We continue to use VIRTIO_BALLOON_F_DEFLATE_ON_OOM to decide if a > @@ -1014,7 +1020,9 @@ static int virtballoon_restore(struct virtio_device *vdev) > > static int virtballoon_validate(struct virtio_device *vdev) > { > - if (!page_poisoning_enabled()) > + /* Tell the host whether we care about poisoned pages. */ > + if (IS_ENABLED(CONFIG_PAGE_POISONING_NO_SANITY) || > + !page_poisoning_enabled()) > __virtio_clear_bit(vdev, VIRTIO_BALLOON_F_PAGE_POISON); > > __virtio_clear_bit(vdev, VIRTIO_F_IOMMU_PLATFORM);
On Wed, 2019-09-18 at 13:58 -0400, Michael S. Tsirkin wrote: > On Wed, Sep 18, 2019 at 10:53:05AM -0700, Alexander Duyck wrote: > > From: Alexander Duyck <alexander.h.duyck@linux.intel.com> > > > > Currently the page poisoning setting wasn't being enabled unless free page > > hinting was enabled. However we will need the page poisoning tracking logic > > as well for unused page reporting. As such pull it out and make it a > > separate bit of config in the probe function. > > > > In addition we can actually wrap the code in a check for NO_SANITY. If we > > don't care what is actually in the page we can just default to 0 and leave > > it there. > > > > Reviewed-by: David Hildenbrand <david@redhat.com> > > Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> > > I think this one can go in directly. Do you want me to merge it now? That sounds good to me. Do you know if you can also pull in QEMU 1/3 into QEMU as well since the feature wasn't pulled into QEMU originally? https://lore.kernel.org/lkml/20190918175342.23606.12400.stgit@localhost.localdomain/ Thanks. - Alex
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 226fbb995fb0..501a8d0ebf86 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -842,7 +842,6 @@ static int virtio_balloon_register_shrinker(struct virtio_balloon *vb) static int virtballoon_probe(struct virtio_device *vdev) { struct virtio_balloon *vb; - __u32 poison_val; int err; if (!vdev->config->get) { @@ -909,11 +908,18 @@ static int virtballoon_probe(struct virtio_device *vdev) VIRTIO_BALLOON_CMD_ID_STOP); spin_lock_init(&vb->free_page_list_lock); INIT_LIST_HEAD(&vb->free_page_list); - if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON)) { - memset(&poison_val, PAGE_POISON, sizeof(poison_val)); - virtio_cwrite(vb->vdev, struct virtio_balloon_config, - poison_val, &poison_val); - } + } + if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON)) { + __u32 poison_val; + + /* + * Let the hypervisor know that we are expecting a + * specific value to be written back in unused pages. + */ + memset(&poison_val, PAGE_POISON, sizeof(poison_val)); + + virtio_cwrite(vb->vdev, struct virtio_balloon_config, + poison_val, &poison_val); } /* * We continue to use VIRTIO_BALLOON_F_DEFLATE_ON_OOM to decide if a @@ -1014,7 +1020,9 @@ static int virtballoon_restore(struct virtio_device *vdev) static int virtballoon_validate(struct virtio_device *vdev) { - if (!page_poisoning_enabled()) + /* Tell the host whether we care about poisoned pages. */ + if (IS_ENABLED(CONFIG_PAGE_POISONING_NO_SANITY) || + !page_poisoning_enabled()) __virtio_clear_bit(vdev, VIRTIO_BALLOON_F_PAGE_POISON); __virtio_clear_bit(vdev, VIRTIO_F_IOMMU_PLATFORM);