| Message ID | 1516165812-3995-4-git-send-email-wei.w.wang@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Jan 17, 2018 at 01:10:12PM +0800, Wei Wang wrote: > The guest free pages should not be discarded by the live migration thread > when page poisoning is enabled with PAGE_POISONING_NO_SANITY=n, because > skipping the transfer of such poisoned free pages will trigger false > positive when new pages are allocated and checked on the destination. > This patch adds a config field, poison_val. Guest writes to the config > field to tell the host about the poisoning value. The value will be 0 in > the following cases: > 1) PAGE_POISONING_NO_SANITY is enabled; > 2) page poisoning is disabled; or > 3) PAGE_POISONING_ZERO is enabled. > > Signed-off-by: Wei Wang <wei.w.wang@intel.com> > Suggested-by: Michael S. Tsirkin <mst@redhat.com> > Cc: Michal Hocko <mhocko@suse.com> Pls squash with the previous patch. It's not nice to break a config, then fix it up later. > --- > drivers/virtio/virtio_balloon.c | 8 ++++++++ > include/uapi/linux/virtio_balloon.h | 2 ++ > 2 files changed, 10 insertions(+) > > diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c > index b9561a5..5a42235 100644 > --- a/drivers/virtio/virtio_balloon.c > +++ b/drivers/virtio/virtio_balloon.c > @@ -706,6 +706,7 @@ static struct file_system_type balloon_fs = { > static int virtballoon_probe(struct virtio_device *vdev) > { > struct virtio_balloon *vb; > + __u32 poison_val; > int err; > > if (!vdev->config->get) { > @@ -740,6 +741,13 @@ static int virtballoon_probe(struct virtio_device *vdev) > WQ_FREEZABLE | WQ_CPU_INTENSIVE, 0); > INIT_WORK(&vb->report_free_page_work, report_free_page_func); > vb->stop_cmd_id = VIRTIO_BALLOON_FREE_PAGE_REPORT_STOP_ID; > + if (IS_ENABLED(CONFIG_PAGE_POISONING_NO_SANITY) || > + !page_poisoning_enabled()) > + poison_val = 0; > + else > + poison_val = PAGE_POISON; > + virtio_cwrite(vb->vdev, struct virtio_balloon_config, > + poison_val, &poison_val); > } > > vb->nb.notifier_call = virtballoon_oom_notify; > diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h > index 55e2456..5861876 100644 > --- a/include/uapi/linux/virtio_balloon.h > +++ b/include/uapi/linux/virtio_balloon.h > @@ -47,6 +47,8 @@ struct virtio_balloon_config { > __u32 actual; > /* Free page report command id, readonly by guest */ > __u32 free_page_report_cmd_id; > + /* Stores PAGE_POISON if page poisoning with sanity check is in use */ > + __u32 poison_val; > }; > > #define VIRTIO_BALLOON_S_SWAP_IN 0 /* Amount of memory swapped in */ > -- > 2.7.4
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index b9561a5..5a42235 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -706,6 +706,7 @@ static struct file_system_type balloon_fs = { static int virtballoon_probe(struct virtio_device *vdev) { struct virtio_balloon *vb; + __u32 poison_val; int err; if (!vdev->config->get) { @@ -740,6 +741,13 @@ static int virtballoon_probe(struct virtio_device *vdev) WQ_FREEZABLE | WQ_CPU_INTENSIVE, 0); INIT_WORK(&vb->report_free_page_work, report_free_page_func); vb->stop_cmd_id = VIRTIO_BALLOON_FREE_PAGE_REPORT_STOP_ID; + if (IS_ENABLED(CONFIG_PAGE_POISONING_NO_SANITY) || + !page_poisoning_enabled()) + poison_val = 0; + else + poison_val = PAGE_POISON; + virtio_cwrite(vb->vdev, struct virtio_balloon_config, + poison_val, &poison_val); } vb->nb.notifier_call = virtballoon_oom_notify; diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h index 55e2456..5861876 100644 --- a/include/uapi/linux/virtio_balloon.h +++ b/include/uapi/linux/virtio_balloon.h @@ -47,6 +47,8 @@ struct virtio_balloon_config { __u32 actual; /* Free page report command id, readonly by guest */ __u32 free_page_report_cmd_id; + /* Stores PAGE_POISON if page poisoning with sanity check is in use */ + __u32 poison_val; }; #define VIRTIO_BALLOON_S_SWAP_IN 0 /* Amount of memory swapped in */
The guest free pages should not be discarded by the live migration thread when page poisoning is enabled with PAGE_POISONING_NO_SANITY=n, because skipping the transfer of such poisoned free pages will trigger false positive when new pages are allocated and checked on the destination. This patch adds a config field, poison_val. Guest writes to the config field to tell the host about the poisoning value. The value will be 0 in the following cases: 1) PAGE_POISONING_NO_SANITY is enabled; 2) page poisoning is disabled; or 3) PAGE_POISONING_ZERO is enabled. Signed-off-by: Wei Wang <wei.w.wang@intel.com> Suggested-by: Michael S. Tsirkin <mst@redhat.com> Cc: Michal Hocko <mhocko@suse.com> --- drivers/virtio/virtio_balloon.c | 8 ++++++++ include/uapi/linux/virtio_balloon.h | 2 ++ 2 files changed, 10 insertions(+)