kernel/linux.git/include/uapi/linux/virtio_balloon.h, branch v6.6.132

virtio_balloon: correct tags for config space fields

2020-08-05T13:30:20+00:00

Tag config space fields as having little endian-ness. Note that balloon is special: LE even when using the legacy interface. Signed-off-by: Michael S. Tsirkin Acked-by: David Hildenbrand Reviewed-by: Cornelia Huck

virtio-balloon: Avoid using the word 'report' when referring to free page hinting

2020-04-17T10:05:30+00:00

It can be confusing to have multiple features within the same driver that are using the same verbage. As such this patch is creating a union of free_page_report_cmd_id with free_page_hint_cmd_id so that we can clean-up the userspace code a bit in terms of readability while maintaining the functionality of legacy code. Signed-off-by: Alexander Duyck Link: https://lore.kernel.org/r/20200415174318.13597.99753.stgit@localhost.localdomain Signed-off-by: Michael S. Tsirkin

virtio-balloon: add support for providing free page reports to host

2020-04-07T17:43:39+00:00

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. Signed-off-by: Alexander Duyck Signed-off-by: Andrew Morton Reviewed-by: David Hildenbrand Acked-by: Michael S. Tsirkin Cc: Andrea Arcangeli Cc: Dan Williams Cc: Dave Hansen Cc: Konrad Rzeszutek Wilk Cc: Luiz Capitulino Cc: Matthew Wilcox Cc: Mel Gorman Cc: Michal Hocko Cc: Nitesh Narayan Lal Cc: Oscar Salvador Cc: Pankaj Gupta Cc: Paolo Bonzini Cc: Rik van Riel Cc: Vlastimil Babka Cc: Wei Wang Cc: Yang Zhang Cc: wei qi Link: http://lkml.kernel.org/r/20200211224657.29318.68624.stgit@localhost.localdomain Signed-off-by: Linus Torvalds

virtio-balloon: VIRTIO_BALLOON_F_PAGE_POISON

2018-10-25T00:57:55+00:00

The VIRTIO_BALLOON_F_PAGE_POISON feature bit is used to indicate if the guest is using page poisoning. Guest writes to the poison_val config field to tell host about the page poisoning value that is in use. Suggested-by: Michael S. Tsirkin Signed-off-by: Wei Wang Cc: Michael S. Tsirkin Cc: Michal Hocko Cc: Andrew Morton Signed-off-by: Michael S. Tsirkin

virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT

2018-10-25T00:57:55+00:00

Negotiation of the VIRTIO_BALLOON_F_FREE_PAGE_HINT feature indicates the support of reporting hints of guest free pages to host via virtio-balloon. Currenlty, only free page blocks of MAX_ORDER - 1 are reported. They are obtained one by one from the mm free list via the regular allocation function. Host requests the guest to report free page hints by sending a new cmd id to the guest via the free_page_report_cmd_id configuration register. When the guest starts to report, it first sends a start cmd to host via the free page vq, which acks to host the cmd id received. When the guest finishes reporting free pages, a stop cmd is sent to host via the vq. Host may also send a stop cmd id to the guest to stop the reporting. VIRTIO_BALLOON_CMD_ID_STOP: Host sends this cmd to stop the guest reporting. VIRTIO_BALLOON_CMD_ID_DONE: Host sends this cmd to tell the guest that the reported pages are ready to be freed. Why does the guest free the reported pages when host tells it is ready to free? This is because freeing pages appears to be expensive for live migration. free_pages() dirties memory very quickly and makes the live migraion not converge in some cases. So it is good to delay the free_page operation when the migration is done, and host sends a command to guest about that. Why do we need the new VIRTIO_BALLOON_CMD_ID_DONE, instead of reusing VIRTIO_BALLOON_CMD_ID_STOP? This is because live migration is usually done in several rounds. At the end of each round, host needs to send a VIRTIO_BALLOON_CMD_ID_STOP cmd to the guest to stop (or say pause) the reporting. The guest resumes the reporting when it receives a new command id at the beginning of the next round. So we need a new cmd id to distinguish between "stop reporting" and "ready to free the reported pages". TODO: - Add a batch page allocation API to amortize the allocation overhead. Signed-off-by: Wei Wang Signed-off-by: Liang Li Cc: Michael S. Tsirkin Cc: Michal Hocko Cc: Andrew Morton Cc: Linus Torvalds Signed-off-by: Michael S. Tsirkin

virtio_balloon: add array of stat names

2018-04-24T18:44:01+00:00

Jason Wang points out that it's very hard for users to build an array of stat names. The naive thing is to use VIRTIO_BALLOON_S_NR but that breaks if we add more stats - as done e.g. recently by commit 6c64fe7f2 ("virtio_balloon: export hugetlb page allocation counts"). Let's add an array of reasonably readable names. Fixes: 6c64fe7f2 ("virtio_balloon: export hugetlb page allocation counts") Cc: Jason Wang Signed-off-by: Michael S. Tsirkin Reviewed-by: Jonathan Helman

virtio_balloon: export hugetlb page allocation counts

2018-04-10T18:23:55+00:00

Export the number of successful and failed hugetlb page allocations via the virtio balloon driver. These 2 counts come directly from the vm_events HTLB_BUDDY_PGALLOC and HTLB_BUDDY_PGALLOC_FAIL. Signed-off-by: Jonathan Helman Signed-off-by: Michael S. Tsirkin Reviewed-by: Jason Wang

virtio_balloon: include disk/file caches memory statistics

2018-01-30T23:47:33+00:00

Add a new field VIRTIO_BALLOON_S_CACHES to virtio_balloon memory statistics protocol. The value represents all disk/file caches. In this case it corresponds to the sum of values Buffers+Cached+SwapCached from /proc/meminfo. Signed-off-by: Tomáš Golembiovský Signed-off-by: Michael S. Tsirkin

virtio_balloon: export 'available' memory to balloon statistics

2016-03-17T22:09:34+00:00

Add a new field, VIRTIO_BALLOON_S_AVAIL, to virtio_balloon memory statistics protocol, corresponding to 'Available' in /proc/meminfo. It indicates to the hypervisor how big the balloon can be inflated without pushing the guest system to swap. Signed-off-by: Igor Redko Signed-off-by: Denis V. Lunev Reviewed-by: Roman Kagan Cc: Michael S. Tsirkin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

include/uapi/linux/virtio_balloon.h: include linux/virtio_types.h

2015-06-01T13:46:54+00:00

Fixes userspace compilation error: error: unknown type name ‘__virtio16’ __virtio16 tag; Signed-off-by: Mikko Rapeli Signed-off-by: Michael S. Tsirkin