similar to: [PATCH] virtio_balloon: don't push uninitialized buffers to stats virtqueue

On Wed, Mar 22, 2017 at 5:14 PM, Michael S. Tsirkin <mst at redhat.com> wrote: > On Wed, Mar 22, 2017 at 04:10:27PM +0100, Ladi Prosek wrote: >> When init_vqs runs, virtio_balloon.stats is either uninitialized or >> contains stale values. The host updates its state with garbage data >> because it has no way of knowing that this is just a marker buffer >> used for

On Wed, Mar 22, 2017 at 5:14 PM, Michael S. Tsirkin <mst at redhat.com> wrote: > On Wed, Mar 22, 2017 at 04:10:27PM +0100, Ladi Prosek wrote: >> When init_vqs runs, virtio_balloon.stats is either uninitialized or >> contains stale values. The host updates its state with garbage data >> because it has no way of knowing that this is just a marker buffer >> used for

This series fixes issues with variable initialization in the virtio balloon driver which manifest as the driver sending invalid memory stats to the host. v1->v2: * Call update_balloon_stats instead of filling the buffer with invalid tags. * Add BUG_ON to update_balloon_stats to formalize the invariant that all slots in the buffer must be initialized. v2->v3: * Remove BUG_ON and

This series fixes issues with variable initialization in the virtio balloon driver which manifest as the driver sending invalid memory stats to the host. v1->v2: * Call update_balloon_stats instead of filling the buffer with invalid tags. * Add BUG_ON to update_balloon_stats to formalize the invariant that all slots in the buffer must be initialized. v2->v3: * Remove BUG_ON and

When init_vqs runs, virtio_balloon.stats is either uninitialized or contains stale values. The host updates its state with garbage data because it has no way of knowing that this is just a marker buffer used for signaling. This patch updates the stats before pushing the initial buffer. An assertion is also added to update_balloon_stats to make sure that all stats fields are initialized.

When init_vqs runs, virtio_balloon.stats is either uninitialized or contains stale values. The host updates its state with garbage data because it has no way of knowing that this is just a marker buffer used for signaling. This patch updates the stats before pushing the initial buffer. An assertion is also added to update_balloon_stats to make sure that all stats fields are initialized.

On Wed, Mar 22, 2017 at 06:05:39PM +0100, Ladi Prosek wrote: > On Wed, Mar 22, 2017 at 5:14 PM, Michael S. Tsirkin <mst at redhat.com> wrote: > > On Wed, Mar 22, 2017 at 04:10:27PM +0100, Ladi Prosek wrote: > >> When init_vqs runs, virtio_balloon.stats is either uninitialized or > >> contains stale values. The host updates its state with garbage data > >>

On Wed, Mar 22, 2017 at 04:10:27PM +0100, Ladi Prosek wrote: > When init_vqs runs, virtio_balloon.stats is either uninitialized or > contains stale values. The host updates its state with garbage data > because it has no way of knowing that this is just a marker buffer > used for signaling. > > This patch initializes all tags with U16_MAX which is guaranteed to > be ignored

On Fri, Mar 24, 2017 at 09:40:07PM +0100, Arnd Bergmann wrote: > On Fri, Mar 24, 2017 at 9:11 PM, Ladi Prosek <lprosek at redhat.com> wrote: > > On Fri, Mar 24, 2017 at 7:38 PM, David Hildenbrand <david at redhat.com> wrote: > >> On 23.03.2017 16:17, Arnd Bergmann wrote: > >>> The latest gcc-7.0.1 snapshot reports a new warning: > >>> >

On Fri, Mar 24, 2017 at 09:40:07PM +0100, Arnd Bergmann wrote: > On Fri, Mar 24, 2017 at 9:11 PM, Ladi Prosek <lprosek at redhat.com> wrote: > > On Fri, Mar 24, 2017 at 7:38 PM, David Hildenbrand <david at redhat.com> wrote: > >> On 23.03.2017 16:17, Arnd Bergmann wrote: > >>> The latest gcc-7.0.1 snapshot reports a new warning: > >>> >

On Fri, Mar 24, 2017 at 7:38 PM, David Hildenbrand <david at redhat.com> wrote: > On 23.03.2017 16:17, Arnd Bergmann wrote: >> The latest gcc-7.0.1 snapshot reports a new warning: >> >> virtio/virtio_balloon.c: In function 'update_balloon_stats': >> virtio/virtio_balloon.c:258:26: error: 'events[2]' is used uninitialized in this function

On Fri, Mar 24, 2017 at 7:38 PM, David Hildenbrand <david at redhat.com> wrote: > On 23.03.2017 16:17, Arnd Bergmann wrote: >> The latest gcc-7.0.1 snapshot reports a new warning: >> >> virtio/virtio_balloon.c: In function 'update_balloon_stats': >> virtio/virtio_balloon.c:258:26: error: 'events[2]' is used uninitialized in this function

On Mon, Mar 27, 2017 at 12:02:33PM +0200, Ladi Prosek wrote: > On Fri, Mar 24, 2017 at 9:59 PM, Michael S. Tsirkin <mst at redhat.com> wrote: > > On Fri, Mar 24, 2017 at 09:40:07PM +0100, Arnd Bergmann wrote: > >> On Fri, Mar 24, 2017 at 9:11 PM, Ladi Prosek <lprosek at redhat.com> wrote: > >> > On Fri, Mar 24, 2017 at 7:38 PM, David Hildenbrand <david

On Mon, Mar 27, 2017 at 12:02:33PM +0200, Ladi Prosek wrote: > On Fri, Mar 24, 2017 at 9:59 PM, Michael S. Tsirkin <mst at redhat.com> wrote: > > On Fri, Mar 24, 2017 at 09:40:07PM +0100, Arnd Bergmann wrote: > >> On Fri, Mar 24, 2017 at 9:11 PM, Ladi Prosek <lprosek at redhat.com> wrote: > >> > On Fri, Mar 24, 2017 at 7:38 PM, David Hildenbrand <david

The virtio balloon driver contained a not-so-obvious invariant that update_balloon_stats has to update exactly VIRTIO_BALLOON_S_NR counters in order to send valid stats to the host. This commit fixes it by having update_balloon_stats return the actual number of counters, and its callers use it when pushing buffers to the stats virtqueue. Note that it is still out of spec to change the number of

This series is split from the "Virtio-balloon: support free page reporting" series to make some improvements. v1->v2 ChangeLog: - register the shrinker when VIRTIO_BALLOON_F_DEFLATE_ON_OOM is negotiated. Wei Wang (2): virtio-balloon: remove BUG() in init_vqs virtio_balloon: replace oom notifier with shrinker drivers/virtio/virtio_balloon.c | 125

This series is split from the "Virtio-balloon: support free page reporting" series to make some improvements. v1->v2 ChangeLog: - register the shrinker when VIRTIO_BALLOON_F_DEFLATE_ON_OOM is negotiated. Wei Wang (2): virtio-balloon: remove BUG() in init_vqs virtio_balloon: replace oom notifier with shrinker drivers/virtio/virtio_balloon.c | 125

Changes since V3: - Do not do endian conversions as they will be done in the host - Report stats that reference a quantity of memory in bytes - Minor coding style updates Changes since V2: - Increase stat field size to 64 bits - Report all sizes in kb (not pages) - Drop anon_pages stat and fix endianness conversion Changes since V1: - Use a virtqueue instead of the device config space

Changes since V3: - Do not do endian conversions as they will be done in the host - Report stats that reference a quantity of memory in bytes - Minor coding style updates Changes since V2: - Increase stat field size to 64 bits - Report all sizes in kb (not pages) - Drop anon_pages stat and fix endianness conversion Changes since V1: - Use a virtqueue instead of the device config space

Rusty and Anthony, If I've addressed all outstanding issues, please consider this patch for inclusion. Thanks. Changes since V2: - Increase stat field size to 64 bits - Report all sizes in kb (not pages) - Drop anon_pages stat and fix endianness conversion Changes since V1: - Use a virtqueue instead of the device config space When using ballooning to manage overcommitted memory on a