a8cd64d488
We still have multiple issues in the current code
- The PBP is not freed during unrealize()
- The PBP is not reset on device resets: After a reset, the PBP is stale.
- We are not indicating VIRTIO_BALLOON_F_MUST_TELL_HOST, therefore
guests (esp. legacy guests) will reuse pages without deflating,
turning the PBP stale. Adding that would require compat handling.
Instead, let's use the PBP only temporarily, when processing one bulk of
inflation requests. This will keep guest_page_size > 4k working (with
Linux guests). There is nothing to do for deflation requests anymore.
The pbp is only used for a limited amount of time.
Fixes: ed48c59875 ("virtio-balloon: Safely handle BALLOON_PAGE_SIZE < host page size")
Cc: qemu-stable@nongnu.org #v4.0.0
Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20190722134108.22151-7-david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
76 lines
2.0 KiB
C
76 lines
2.0 KiB
C
/*
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* Virtio Support
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*
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* Copyright IBM, Corp. 2007-2008
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*
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* Authors:
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* Anthony Liguori <aliguori@us.ibm.com>
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* Rusty Russell <rusty@rustcorp.com.au>
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*
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*/
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#ifndef QEMU_VIRTIO_BALLOON_H
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#define QEMU_VIRTIO_BALLOON_H
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#include "standard-headers/linux/virtio_balloon.h"
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#include "hw/virtio/virtio.h"
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#include "sysemu/iothread.h"
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#define TYPE_VIRTIO_BALLOON "virtio-balloon-device"
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#define VIRTIO_BALLOON(obj) \
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OBJECT_CHECK(VirtIOBalloon, (obj), TYPE_VIRTIO_BALLOON)
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#define VIRTIO_BALLOON_FREE_PAGE_REPORT_CMD_ID_MIN 0x80000000
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typedef struct virtio_balloon_stat VirtIOBalloonStat;
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typedef struct virtio_balloon_stat_modern {
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uint16_t tag;
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uint8_t reserved[6];
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uint64_t val;
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} VirtIOBalloonStatModern;
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enum virtio_balloon_free_page_report_status {
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FREE_PAGE_REPORT_S_STOP = 0,
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FREE_PAGE_REPORT_S_REQUESTED = 1,
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FREE_PAGE_REPORT_S_START = 2,
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FREE_PAGE_REPORT_S_DONE = 3,
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};
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typedef struct VirtIOBalloon {
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VirtIODevice parent_obj;
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VirtQueue *ivq, *dvq, *svq, *free_page_vq;
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uint32_t free_page_report_status;
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uint32_t num_pages;
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uint32_t actual;
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uint32_t free_page_report_cmd_id;
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uint64_t stats[VIRTIO_BALLOON_S_NR];
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VirtQueueElement *stats_vq_elem;
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size_t stats_vq_offset;
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QEMUTimer *stats_timer;
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IOThread *iothread;
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QEMUBH *free_page_bh;
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/*
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* Lock to synchronize threads to access the free page reporting related
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* fields (e.g. free_page_report_status).
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*/
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QemuMutex free_page_lock;
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QemuCond free_page_cond;
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/*
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* Set to block iothread to continue reading free page hints as the VM is
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* stopped.
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*/
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bool block_iothread;
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NotifierWithReturn free_page_report_notify;
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int64_t stats_last_update;
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int64_t stats_poll_interval;
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uint32_t host_features;
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bool qemu_4_0_config_size;
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} VirtIOBalloon;
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#endif
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