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2d050ed07c
Let's compress the code a bit to improve readability. We can drop the vm_running check in virtio_balloon_free_page_start() as it's already properly checked in the single caller. Cc: Wei Wang <wei.w.wang@intel.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Philippe Mathieu-Daudé <philmd@redhat.com> Cc: Alexander Duyck <alexander.duyck@gmail.com> Cc: Juan Quintela <quintela@redhat.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> Message-Id: <20210708095339.20274-3-david@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
1084 lines
34 KiB
C
1084 lines
34 KiB
C
/*
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* Virtio Balloon Device
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*
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* Copyright IBM, Corp. 2008
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* Copyright (C) 2011 Red Hat, Inc.
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* Copyright (C) 2011 Amit Shah <amit.shah@redhat.com>
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*
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* Authors:
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* Anthony Liguori <aliguori@us.ibm.com>
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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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#include "qemu/osdep.h"
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#include "qemu/iov.h"
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#include "qemu/module.h"
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#include "qemu/timer.h"
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#include "hw/virtio/virtio.h"
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#include "hw/mem/pc-dimm.h"
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#include "hw/qdev-properties.h"
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#include "hw/boards.h"
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#include "sysemu/balloon.h"
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#include "hw/virtio/virtio-balloon.h"
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#include "exec/address-spaces.h"
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#include "qapi/error.h"
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#include "qapi/qapi-events-machine.h"
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#include "qapi/visitor.h"
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#include "trace.h"
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#include "qemu/error-report.h"
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#include "migration/misc.h"
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#include "migration/migration.h"
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#include "hw/virtio/virtio-bus.h"
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#include "hw/virtio/virtio-access.h"
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#define BALLOON_PAGE_SIZE (1 << VIRTIO_BALLOON_PFN_SHIFT)
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typedef struct PartiallyBalloonedPage {
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ram_addr_t base_gpa;
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unsigned long *bitmap;
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} PartiallyBalloonedPage;
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static void virtio_balloon_pbp_free(PartiallyBalloonedPage *pbp)
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{
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if (!pbp->bitmap) {
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return;
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}
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g_free(pbp->bitmap);
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pbp->bitmap = NULL;
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}
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static void virtio_balloon_pbp_alloc(PartiallyBalloonedPage *pbp,
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ram_addr_t base_gpa,
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long subpages)
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{
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pbp->base_gpa = base_gpa;
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pbp->bitmap = bitmap_new(subpages);
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}
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static bool virtio_balloon_pbp_matches(PartiallyBalloonedPage *pbp,
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ram_addr_t base_gpa)
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{
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return pbp->base_gpa == base_gpa;
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}
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static bool virtio_balloon_inhibited(void)
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{
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/*
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* Postcopy cannot deal with concurrent discards,
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* so it's special, as well as background snapshots.
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*/
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return ram_block_discard_is_disabled() || migration_in_incoming_postcopy() ||
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migration_in_bg_snapshot();
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}
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static void balloon_inflate_page(VirtIOBalloon *balloon,
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MemoryRegion *mr, hwaddr mr_offset,
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PartiallyBalloonedPage *pbp)
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{
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void *addr = memory_region_get_ram_ptr(mr) + mr_offset;
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ram_addr_t rb_offset, rb_aligned_offset, base_gpa;
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RAMBlock *rb;
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size_t rb_page_size;
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int subpages;
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/* XXX is there a better way to get to the RAMBlock than via a
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* host address? */
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rb = qemu_ram_block_from_host(addr, false, &rb_offset);
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rb_page_size = qemu_ram_pagesize(rb);
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if (rb_page_size == BALLOON_PAGE_SIZE) {
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/* Easy case */
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ram_block_discard_range(rb, rb_offset, rb_page_size);
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/* We ignore errors from ram_block_discard_range(), because it
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* has already reported them, and failing to discard a balloon
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* page is not fatal */
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return;
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}
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/* Hard case
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*
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* We've put a piece of a larger host page into the balloon - we
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* need to keep track until we have a whole host page to
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* discard
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*/
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warn_report_once(
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"Balloon used with backing page size > 4kiB, this may not be reliable");
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rb_aligned_offset = QEMU_ALIGN_DOWN(rb_offset, rb_page_size);
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subpages = rb_page_size / BALLOON_PAGE_SIZE;
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base_gpa = memory_region_get_ram_addr(mr) + mr_offset -
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(rb_offset - rb_aligned_offset);
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if (pbp->bitmap && !virtio_balloon_pbp_matches(pbp, base_gpa)) {
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/* We've partially ballooned part of a host page, but now
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* we're trying to balloon part of a different one. Too hard,
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* give up on the old partial page */
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virtio_balloon_pbp_free(pbp);
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}
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if (!pbp->bitmap) {
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virtio_balloon_pbp_alloc(pbp, base_gpa, subpages);
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}
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set_bit((rb_offset - rb_aligned_offset) / BALLOON_PAGE_SIZE,
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pbp->bitmap);
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if (bitmap_full(pbp->bitmap, subpages)) {
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/* We've accumulated a full host page, we can actually discard
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* it now */
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ram_block_discard_range(rb, rb_aligned_offset, rb_page_size);
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/* We ignore errors from ram_block_discard_range(), because it
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* has already reported them, and failing to discard a balloon
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* page is not fatal */
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virtio_balloon_pbp_free(pbp);
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}
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}
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static void balloon_deflate_page(VirtIOBalloon *balloon,
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MemoryRegion *mr, hwaddr mr_offset)
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{
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void *addr = memory_region_get_ram_ptr(mr) + mr_offset;
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ram_addr_t rb_offset;
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RAMBlock *rb;
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size_t rb_page_size;
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void *host_addr;
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int ret;
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/* XXX is there a better way to get to the RAMBlock than via a
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* host address? */
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rb = qemu_ram_block_from_host(addr, false, &rb_offset);
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rb_page_size = qemu_ram_pagesize(rb);
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host_addr = (void *)((uintptr_t)addr & ~(rb_page_size - 1));
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/* When a page is deflated, we hint the whole host page it lives
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* on, since we can't do anything smaller */
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ret = qemu_madvise(host_addr, rb_page_size, QEMU_MADV_WILLNEED);
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if (ret != 0) {
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warn_report("Couldn't MADV_WILLNEED on balloon deflate: %s",
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strerror(errno));
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/* Otherwise ignore, failing to page hint shouldn't be fatal */
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}
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}
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static const char *balloon_stat_names[] = {
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[VIRTIO_BALLOON_S_SWAP_IN] = "stat-swap-in",
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[VIRTIO_BALLOON_S_SWAP_OUT] = "stat-swap-out",
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[VIRTIO_BALLOON_S_MAJFLT] = "stat-major-faults",
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[VIRTIO_BALLOON_S_MINFLT] = "stat-minor-faults",
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[VIRTIO_BALLOON_S_MEMFREE] = "stat-free-memory",
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[VIRTIO_BALLOON_S_MEMTOT] = "stat-total-memory",
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[VIRTIO_BALLOON_S_AVAIL] = "stat-available-memory",
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[VIRTIO_BALLOON_S_CACHES] = "stat-disk-caches",
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[VIRTIO_BALLOON_S_HTLB_PGALLOC] = "stat-htlb-pgalloc",
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[VIRTIO_BALLOON_S_HTLB_PGFAIL] = "stat-htlb-pgfail",
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[VIRTIO_BALLOON_S_NR] = NULL
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};
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/*
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* reset_stats - Mark all items in the stats array as unset
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*
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* This function needs to be called at device initialization and before
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* updating to a set of newly-generated stats. This will ensure that no
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* stale values stick around in case the guest reports a subset of the supported
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* statistics.
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*/
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static inline void reset_stats(VirtIOBalloon *dev)
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{
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int i;
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for (i = 0; i < VIRTIO_BALLOON_S_NR; dev->stats[i++] = -1);
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}
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static bool balloon_stats_supported(const VirtIOBalloon *s)
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{
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VirtIODevice *vdev = VIRTIO_DEVICE(s);
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return virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_STATS_VQ);
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}
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static bool balloon_stats_enabled(const VirtIOBalloon *s)
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{
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return s->stats_poll_interval > 0;
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}
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static void balloon_stats_destroy_timer(VirtIOBalloon *s)
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{
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if (balloon_stats_enabled(s)) {
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timer_free(s->stats_timer);
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s->stats_timer = NULL;
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s->stats_poll_interval = 0;
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}
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}
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static void balloon_stats_change_timer(VirtIOBalloon *s, int64_t secs)
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{
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timer_mod(s->stats_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + secs * 1000);
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}
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static void balloon_stats_poll_cb(void *opaque)
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{
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VirtIOBalloon *s = opaque;
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VirtIODevice *vdev = VIRTIO_DEVICE(s);
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if (s->stats_vq_elem == NULL || !balloon_stats_supported(s)) {
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/* re-schedule */
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balloon_stats_change_timer(s, s->stats_poll_interval);
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return;
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}
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virtqueue_push(s->svq, s->stats_vq_elem, s->stats_vq_offset);
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virtio_notify(vdev, s->svq);
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g_free(s->stats_vq_elem);
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s->stats_vq_elem = NULL;
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}
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static void balloon_stats_get_all(Object *obj, Visitor *v, const char *name,
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void *opaque, Error **errp)
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{
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Error *err = NULL;
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VirtIOBalloon *s = opaque;
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int i;
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if (!visit_start_struct(v, name, NULL, 0, &err)) {
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goto out;
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}
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if (!visit_type_int(v, "last-update", &s->stats_last_update, &err)) {
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goto out_end;
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}
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if (!visit_start_struct(v, "stats", NULL, 0, &err)) {
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goto out_end;
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}
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for (i = 0; i < VIRTIO_BALLOON_S_NR; i++) {
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if (!visit_type_uint64(v, balloon_stat_names[i], &s->stats[i], &err)) {
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goto out_nested;
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}
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}
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visit_check_struct(v, &err);
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out_nested:
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visit_end_struct(v, NULL);
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if (!err) {
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visit_check_struct(v, &err);
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}
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out_end:
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visit_end_struct(v, NULL);
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out:
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error_propagate(errp, err);
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}
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static void balloon_stats_get_poll_interval(Object *obj, Visitor *v,
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const char *name, void *opaque,
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Error **errp)
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{
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VirtIOBalloon *s = opaque;
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visit_type_int(v, name, &s->stats_poll_interval, errp);
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}
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static void balloon_stats_set_poll_interval(Object *obj, Visitor *v,
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const char *name, void *opaque,
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Error **errp)
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{
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VirtIOBalloon *s = opaque;
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int64_t value;
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if (!visit_type_int(v, name, &value, errp)) {
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return;
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}
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if (value < 0) {
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error_setg(errp, "timer value must be greater than zero");
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return;
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}
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if (value > UINT32_MAX) {
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error_setg(errp, "timer value is too big");
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return;
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}
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if (value == s->stats_poll_interval) {
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return;
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}
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if (value == 0) {
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/* timer=0 disables the timer */
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balloon_stats_destroy_timer(s);
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return;
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}
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if (balloon_stats_enabled(s)) {
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/* timer interval change */
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s->stats_poll_interval = value;
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balloon_stats_change_timer(s, value);
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return;
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}
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/* create a new timer */
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g_assert(s->stats_timer == NULL);
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s->stats_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, balloon_stats_poll_cb, s);
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s->stats_poll_interval = value;
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balloon_stats_change_timer(s, 0);
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}
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static void virtio_balloon_handle_report(VirtIODevice *vdev, VirtQueue *vq)
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{
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VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
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VirtQueueElement *elem;
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while ((elem = virtqueue_pop(vq, sizeof(VirtQueueElement)))) {
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unsigned int i;
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/*
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* When we discard the page it has the effect of removing the page
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* from the hypervisor itself and causing it to be zeroed when it
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* is returned to us. So we must not discard the page if it is
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* accessible by another device or process, or if the guest is
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* expecting it to retain a non-zero value.
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*/
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if (virtio_balloon_inhibited() || dev->poison_val) {
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goto skip_element;
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}
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for (i = 0; i < elem->in_num; i++) {
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void *addr = elem->in_sg[i].iov_base;
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size_t size = elem->in_sg[i].iov_len;
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ram_addr_t ram_offset;
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RAMBlock *rb;
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/*
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* There is no need to check the memory section to see if
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* it is ram/readonly/romd like there is for handle_output
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* below. If the region is not meant to be written to then
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* address_space_map will have allocated a bounce buffer
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* and it will be freed in address_space_unmap and trigger
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* and unassigned_mem_write before failing to copy over the
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* buffer. If more than one bad descriptor is provided it
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* will return NULL after the first bounce buffer and fail
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* to map any resources.
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*/
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rb = qemu_ram_block_from_host(addr, false, &ram_offset);
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if (!rb) {
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trace_virtio_balloon_bad_addr(elem->in_addr[i]);
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continue;
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}
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/*
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* For now we will simply ignore unaligned memory regions, or
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* regions that overrun the end of the RAMBlock.
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*/
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if (!QEMU_IS_ALIGNED(ram_offset | size, qemu_ram_pagesize(rb)) ||
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(ram_offset + size) > qemu_ram_get_used_length(rb)) {
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continue;
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}
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ram_block_discard_range(rb, ram_offset, size);
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}
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skip_element:
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virtqueue_push(vq, elem, 0);
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virtio_notify(vdev, vq);
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g_free(elem);
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}
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}
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static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq)
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{
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VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
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VirtQueueElement *elem;
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MemoryRegionSection section;
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for (;;) {
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PartiallyBalloonedPage pbp = {};
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size_t offset = 0;
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uint32_t pfn;
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elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
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if (!elem) {
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break;
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}
|
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|
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while (iov_to_buf(elem->out_sg, elem->out_num, offset, &pfn, 4) == 4) {
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unsigned int p = virtio_ldl_p(vdev, &pfn);
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hwaddr pa;
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pa = (hwaddr) p << VIRTIO_BALLOON_PFN_SHIFT;
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offset += 4;
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section = memory_region_find(get_system_memory(), pa,
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BALLOON_PAGE_SIZE);
|
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if (!section.mr) {
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trace_virtio_balloon_bad_addr(pa);
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continue;
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}
|
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if (!memory_region_is_ram(section.mr) ||
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memory_region_is_rom(section.mr) ||
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memory_region_is_romd(section.mr)) {
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trace_virtio_balloon_bad_addr(pa);
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memory_region_unref(section.mr);
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continue;
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}
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|
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trace_virtio_balloon_handle_output(memory_region_name(section.mr),
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pa);
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if (!virtio_balloon_inhibited()) {
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if (vq == s->ivq) {
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balloon_inflate_page(s, section.mr,
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section.offset_within_region, &pbp);
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} else if (vq == s->dvq) {
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balloon_deflate_page(s, section.mr, section.offset_within_region);
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} else {
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g_assert_not_reached();
|
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}
|
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}
|
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memory_region_unref(section.mr);
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}
|
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|
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virtqueue_push(vq, elem, offset);
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virtio_notify(vdev, vq);
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g_free(elem);
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virtio_balloon_pbp_free(&pbp);
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}
|
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}
|
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|
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static void virtio_balloon_receive_stats(VirtIODevice *vdev, VirtQueue *vq)
|
|
{
|
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VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
|
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VirtQueueElement *elem;
|
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VirtIOBalloonStat stat;
|
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size_t offset = 0;
|
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qemu_timeval tv;
|
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|
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elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
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if (!elem) {
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goto out;
|
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}
|
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|
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if (s->stats_vq_elem != NULL) {
|
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/* This should never happen if the driver follows the spec. */
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virtqueue_push(vq, s->stats_vq_elem, 0);
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virtio_notify(vdev, vq);
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g_free(s->stats_vq_elem);
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}
|
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|
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s->stats_vq_elem = elem;
|
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|
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/* Initialize the stats to get rid of any stale values. This is only
|
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* needed to handle the case where a guest supports fewer stats than it
|
|
* used to (ie. it has booted into an old kernel).
|
|
*/
|
|
reset_stats(s);
|
|
|
|
while (iov_to_buf(elem->out_sg, elem->out_num, offset, &stat, sizeof(stat))
|
|
== sizeof(stat)) {
|
|
uint16_t tag = virtio_tswap16(vdev, stat.tag);
|
|
uint64_t val = virtio_tswap64(vdev, stat.val);
|
|
|
|
offset += sizeof(stat);
|
|
if (tag < VIRTIO_BALLOON_S_NR)
|
|
s->stats[tag] = val;
|
|
}
|
|
s->stats_vq_offset = offset;
|
|
|
|
if (qemu_gettimeofday(&tv) < 0) {
|
|
warn_report("%s: failed to get time of day", __func__);
|
|
goto out;
|
|
}
|
|
|
|
s->stats_last_update = tv.tv_sec;
|
|
|
|
out:
|
|
if (balloon_stats_enabled(s)) {
|
|
balloon_stats_change_timer(s, s->stats_poll_interval);
|
|
}
|
|
}
|
|
|
|
static void virtio_balloon_handle_free_page_vq(VirtIODevice *vdev,
|
|
VirtQueue *vq)
|
|
{
|
|
VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
|
|
qemu_bh_schedule(s->free_page_bh);
|
|
}
|
|
|
|
static bool get_free_page_hints(VirtIOBalloon *dev)
|
|
{
|
|
VirtQueueElement *elem;
|
|
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
|
|
VirtQueue *vq = dev->free_page_vq;
|
|
bool ret = true;
|
|
|
|
while (dev->block_iothread) {
|
|
qemu_cond_wait(&dev->free_page_cond, &dev->free_page_lock);
|
|
}
|
|
|
|
elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
|
|
if (!elem) {
|
|
return false;
|
|
}
|
|
|
|
if (elem->out_num) {
|
|
uint32_t id;
|
|
size_t size = iov_to_buf(elem->out_sg, elem->out_num, 0,
|
|
&id, sizeof(id));
|
|
|
|
virtio_tswap32s(vdev, &id);
|
|
if (unlikely(size != sizeof(id))) {
|
|
virtio_error(vdev, "received an incorrect cmd id");
|
|
ret = false;
|
|
goto out;
|
|
}
|
|
if (dev->free_page_hint_status == FREE_PAGE_HINT_S_REQUESTED &&
|
|
id == dev->free_page_hint_cmd_id) {
|
|
dev->free_page_hint_status = FREE_PAGE_HINT_S_START;
|
|
} else if (dev->free_page_hint_status == FREE_PAGE_HINT_S_START) {
|
|
/*
|
|
* Stop the optimization only when it has started. This
|
|
* avoids a stale stop sign for the previous command.
|
|
*/
|
|
dev->free_page_hint_status = FREE_PAGE_HINT_S_STOP;
|
|
}
|
|
}
|
|
|
|
if (elem->in_num && dev->free_page_hint_status == FREE_PAGE_HINT_S_START) {
|
|
qemu_guest_free_page_hint(elem->in_sg[0].iov_base,
|
|
elem->in_sg[0].iov_len);
|
|
}
|
|
|
|
out:
|
|
virtqueue_push(vq, elem, 1);
|
|
g_free(elem);
|
|
return ret;
|
|
}
|
|
|
|
static void virtio_ballloon_get_free_page_hints(void *opaque)
|
|
{
|
|
VirtIOBalloon *dev = opaque;
|
|
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
|
|
VirtQueue *vq = dev->free_page_vq;
|
|
bool continue_to_get_hints;
|
|
|
|
do {
|
|
qemu_mutex_lock(&dev->free_page_lock);
|
|
virtio_queue_set_notification(vq, 0);
|
|
continue_to_get_hints = get_free_page_hints(dev);
|
|
qemu_mutex_unlock(&dev->free_page_lock);
|
|
virtio_notify(vdev, vq);
|
|
/*
|
|
* Start to poll the vq once the hinting started. Otherwise, continue
|
|
* only when there are entries on the vq, which need to be given back.
|
|
*/
|
|
} while (continue_to_get_hints ||
|
|
dev->free_page_hint_status == FREE_PAGE_HINT_S_START);
|
|
virtio_queue_set_notification(vq, 1);
|
|
}
|
|
|
|
static bool virtio_balloon_free_page_support(void *opaque)
|
|
{
|
|
VirtIOBalloon *s = opaque;
|
|
VirtIODevice *vdev = VIRTIO_DEVICE(s);
|
|
|
|
return virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT);
|
|
}
|
|
|
|
static void virtio_balloon_free_page_start(VirtIOBalloon *s)
|
|
{
|
|
VirtIODevice *vdev = VIRTIO_DEVICE(s);
|
|
|
|
qemu_mutex_lock(&s->free_page_lock);
|
|
|
|
if (s->free_page_hint_cmd_id == UINT_MAX) {
|
|
s->free_page_hint_cmd_id = VIRTIO_BALLOON_FREE_PAGE_HINT_CMD_ID_MIN;
|
|
} else {
|
|
s->free_page_hint_cmd_id++;
|
|
}
|
|
|
|
s->free_page_hint_status = FREE_PAGE_HINT_S_REQUESTED;
|
|
qemu_mutex_unlock(&s->free_page_lock);
|
|
|
|
virtio_notify_config(vdev);
|
|
}
|
|
|
|
static void virtio_balloon_free_page_stop(VirtIOBalloon *s)
|
|
{
|
|
VirtIODevice *vdev = VIRTIO_DEVICE(s);
|
|
|
|
if (s->free_page_hint_status != FREE_PAGE_HINT_S_STOP) {
|
|
/*
|
|
* The lock also guarantees us that the
|
|
* virtio_ballloon_get_free_page_hints exits after the
|
|
* free_page_hint_status is set to S_STOP.
|
|
*/
|
|
qemu_mutex_lock(&s->free_page_lock);
|
|
/*
|
|
* The guest isn't done hinting, so send a notification
|
|
* to the guest to actively stop the hinting.
|
|
*/
|
|
s->free_page_hint_status = FREE_PAGE_HINT_S_STOP;
|
|
qemu_mutex_unlock(&s->free_page_lock);
|
|
virtio_notify_config(vdev);
|
|
}
|
|
}
|
|
|
|
static void virtio_balloon_free_page_done(VirtIOBalloon *s)
|
|
{
|
|
VirtIODevice *vdev = VIRTIO_DEVICE(s);
|
|
|
|
if (s->free_page_hint_status != FREE_PAGE_HINT_S_DONE) {
|
|
/* See virtio_balloon_free_page_stop() */
|
|
qemu_mutex_lock(&s->free_page_lock);
|
|
s->free_page_hint_status = FREE_PAGE_HINT_S_DONE;
|
|
qemu_mutex_unlock(&s->free_page_lock);
|
|
virtio_notify_config(vdev);
|
|
}
|
|
}
|
|
|
|
static int
|
|
virtio_balloon_free_page_hint_notify(NotifierWithReturn *n, void *data)
|
|
{
|
|
VirtIOBalloon *dev = container_of(n, VirtIOBalloon, free_page_hint_notify);
|
|
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
|
|
PrecopyNotifyData *pnd = data;
|
|
|
|
if (!virtio_balloon_free_page_support(dev)) {
|
|
/*
|
|
* This is an optimization provided to migration, so just return 0 to
|
|
* have the normal migration process not affected when this feature is
|
|
* not supported.
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Pages hinted via qemu_guest_free_page_hint() are cleared from the dirty
|
|
* bitmap and will not get migrated, especially also not when the postcopy
|
|
* destination starts using them and requests migration from the source; the
|
|
* faulting thread will stall until postcopy migration finishes and
|
|
* all threads are woken up. Let's not start free page hinting if postcopy
|
|
* is possible.
|
|
*/
|
|
if (migrate_postcopy_ram()) {
|
|
return 0;
|
|
}
|
|
|
|
switch (pnd->reason) {
|
|
case PRECOPY_NOTIFY_BEFORE_BITMAP_SYNC:
|
|
virtio_balloon_free_page_stop(dev);
|
|
break;
|
|
case PRECOPY_NOTIFY_AFTER_BITMAP_SYNC:
|
|
if (vdev->vm_running) {
|
|
virtio_balloon_free_page_start(dev);
|
|
break;
|
|
}
|
|
/*
|
|
* Set S_DONE before migrating the vmstate, so the guest will reuse
|
|
* all hinted pages once running on the destination. Fall through.
|
|
*/
|
|
case PRECOPY_NOTIFY_CLEANUP:
|
|
/*
|
|
* Especially, if something goes wrong during precopy or if migration
|
|
* is canceled, we have to properly communicate S_DONE to the VM.
|
|
*/
|
|
virtio_balloon_free_page_done(dev);
|
|
break;
|
|
case PRECOPY_NOTIFY_SETUP:
|
|
case PRECOPY_NOTIFY_COMPLETE:
|
|
break;
|
|
default:
|
|
virtio_error(vdev, "%s: %d reason unknown", __func__, pnd->reason);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static size_t virtio_balloon_config_size(VirtIOBalloon *s)
|
|
{
|
|
uint64_t features = s->host_features;
|
|
|
|
if (s->qemu_4_0_config_size) {
|
|
return sizeof(struct virtio_balloon_config);
|
|
}
|
|
if (virtio_has_feature(features, VIRTIO_BALLOON_F_PAGE_POISON)) {
|
|
return sizeof(struct virtio_balloon_config);
|
|
}
|
|
if (virtio_has_feature(features, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
|
|
return offsetof(struct virtio_balloon_config, poison_val);
|
|
}
|
|
return offsetof(struct virtio_balloon_config, free_page_hint_cmd_id);
|
|
}
|
|
|
|
static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data)
|
|
{
|
|
VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
|
|
struct virtio_balloon_config config = {};
|
|
|
|
config.num_pages = cpu_to_le32(dev->num_pages);
|
|
config.actual = cpu_to_le32(dev->actual);
|
|
config.poison_val = cpu_to_le32(dev->poison_val);
|
|
|
|
if (dev->free_page_hint_status == FREE_PAGE_HINT_S_REQUESTED) {
|
|
config.free_page_hint_cmd_id =
|
|
cpu_to_le32(dev->free_page_hint_cmd_id);
|
|
} else if (dev->free_page_hint_status == FREE_PAGE_HINT_S_STOP) {
|
|
config.free_page_hint_cmd_id =
|
|
cpu_to_le32(VIRTIO_BALLOON_CMD_ID_STOP);
|
|
} else if (dev->free_page_hint_status == FREE_PAGE_HINT_S_DONE) {
|
|
config.free_page_hint_cmd_id =
|
|
cpu_to_le32(VIRTIO_BALLOON_CMD_ID_DONE);
|
|
}
|
|
|
|
trace_virtio_balloon_get_config(config.num_pages, config.actual);
|
|
memcpy(config_data, &config, virtio_balloon_config_size(dev));
|
|
}
|
|
|
|
static int build_dimm_list(Object *obj, void *opaque)
|
|
{
|
|
GSList **list = opaque;
|
|
|
|
if (object_dynamic_cast(obj, TYPE_PC_DIMM)) {
|
|
DeviceState *dev = DEVICE(obj);
|
|
if (dev->realized) { /* only realized DIMMs matter */
|
|
*list = g_slist_prepend(*list, dev);
|
|
}
|
|
}
|
|
|
|
object_child_foreach(obj, build_dimm_list, opaque);
|
|
return 0;
|
|
}
|
|
|
|
static ram_addr_t get_current_ram_size(void)
|
|
{
|
|
GSList *list = NULL, *item;
|
|
ram_addr_t size = current_machine->ram_size;
|
|
|
|
build_dimm_list(qdev_get_machine(), &list);
|
|
for (item = list; item; item = g_slist_next(item)) {
|
|
Object *obj = OBJECT(item->data);
|
|
if (!strcmp(object_get_typename(obj), TYPE_PC_DIMM)) {
|
|
size += object_property_get_int(obj, PC_DIMM_SIZE_PROP,
|
|
&error_abort);
|
|
}
|
|
}
|
|
g_slist_free(list);
|
|
|
|
return size;
|
|
}
|
|
|
|
static bool virtio_balloon_page_poison_support(void *opaque)
|
|
{
|
|
VirtIOBalloon *s = opaque;
|
|
VirtIODevice *vdev = VIRTIO_DEVICE(s);
|
|
|
|
return virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON);
|
|
}
|
|
|
|
static void virtio_balloon_set_config(VirtIODevice *vdev,
|
|
const uint8_t *config_data)
|
|
{
|
|
VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
|
|
struct virtio_balloon_config config;
|
|
uint32_t oldactual = dev->actual;
|
|
ram_addr_t vm_ram_size = get_current_ram_size();
|
|
|
|
memcpy(&config, config_data, virtio_balloon_config_size(dev));
|
|
dev->actual = le32_to_cpu(config.actual);
|
|
if (dev->actual != oldactual) {
|
|
qapi_event_send_balloon_change(vm_ram_size -
|
|
((ram_addr_t) dev->actual << VIRTIO_BALLOON_PFN_SHIFT));
|
|
}
|
|
dev->poison_val = 0;
|
|
if (virtio_balloon_page_poison_support(dev)) {
|
|
dev->poison_val = le32_to_cpu(config.poison_val);
|
|
}
|
|
trace_virtio_balloon_set_config(dev->actual, oldactual);
|
|
}
|
|
|
|
static uint64_t virtio_balloon_get_features(VirtIODevice *vdev, uint64_t f,
|
|
Error **errp)
|
|
{
|
|
VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
|
|
f |= dev->host_features;
|
|
virtio_add_feature(&f, VIRTIO_BALLOON_F_STATS_VQ);
|
|
|
|
return f;
|
|
}
|
|
|
|
static void virtio_balloon_stat(void *opaque, BalloonInfo *info)
|
|
{
|
|
VirtIOBalloon *dev = opaque;
|
|
info->actual = get_current_ram_size() - ((uint64_t) dev->actual <<
|
|
VIRTIO_BALLOON_PFN_SHIFT);
|
|
}
|
|
|
|
static void virtio_balloon_to_target(void *opaque, ram_addr_t target)
|
|
{
|
|
VirtIOBalloon *dev = VIRTIO_BALLOON(opaque);
|
|
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
|
|
ram_addr_t vm_ram_size = get_current_ram_size();
|
|
|
|
if (target > vm_ram_size) {
|
|
target = vm_ram_size;
|
|
}
|
|
if (target) {
|
|
dev->num_pages = (vm_ram_size - target) >> VIRTIO_BALLOON_PFN_SHIFT;
|
|
virtio_notify_config(vdev);
|
|
}
|
|
trace_virtio_balloon_to_target(target, dev->num_pages);
|
|
}
|
|
|
|
static int virtio_balloon_post_load_device(void *opaque, int version_id)
|
|
{
|
|
VirtIOBalloon *s = VIRTIO_BALLOON(opaque);
|
|
|
|
if (balloon_stats_enabled(s)) {
|
|
balloon_stats_change_timer(s, s->stats_poll_interval);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static const VMStateDescription vmstate_virtio_balloon_free_page_hint = {
|
|
.name = "virtio-balloon-device/free-page-report",
|
|
.version_id = 1,
|
|
.minimum_version_id = 1,
|
|
.needed = virtio_balloon_free_page_support,
|
|
.fields = (VMStateField[]) {
|
|
VMSTATE_UINT32(free_page_hint_cmd_id, VirtIOBalloon),
|
|
VMSTATE_UINT32(free_page_hint_status, VirtIOBalloon),
|
|
VMSTATE_END_OF_LIST()
|
|
}
|
|
};
|
|
|
|
static const VMStateDescription vmstate_virtio_balloon_page_poison = {
|
|
.name = "vitio-balloon-device/page-poison",
|
|
.version_id = 1,
|
|
.minimum_version_id = 1,
|
|
.needed = virtio_balloon_page_poison_support,
|
|
.fields = (VMStateField[]) {
|
|
VMSTATE_UINT32(poison_val, VirtIOBalloon),
|
|
VMSTATE_END_OF_LIST()
|
|
}
|
|
};
|
|
|
|
static const VMStateDescription vmstate_virtio_balloon_device = {
|
|
.name = "virtio-balloon-device",
|
|
.version_id = 1,
|
|
.minimum_version_id = 1,
|
|
.post_load = virtio_balloon_post_load_device,
|
|
.fields = (VMStateField[]) {
|
|
VMSTATE_UINT32(num_pages, VirtIOBalloon),
|
|
VMSTATE_UINT32(actual, VirtIOBalloon),
|
|
VMSTATE_END_OF_LIST()
|
|
},
|
|
.subsections = (const VMStateDescription * []) {
|
|
&vmstate_virtio_balloon_free_page_hint,
|
|
&vmstate_virtio_balloon_page_poison,
|
|
NULL
|
|
}
|
|
};
|
|
|
|
static void virtio_balloon_device_realize(DeviceState *dev, Error **errp)
|
|
{
|
|
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
|
|
VirtIOBalloon *s = VIRTIO_BALLOON(dev);
|
|
int ret;
|
|
|
|
virtio_init(vdev, "virtio-balloon", VIRTIO_ID_BALLOON,
|
|
virtio_balloon_config_size(s));
|
|
|
|
ret = qemu_add_balloon_handler(virtio_balloon_to_target,
|
|
virtio_balloon_stat, s);
|
|
|
|
if (ret < 0) {
|
|
error_setg(errp, "Only one balloon device is supported");
|
|
virtio_cleanup(vdev);
|
|
return;
|
|
}
|
|
|
|
if (virtio_has_feature(s->host_features, VIRTIO_BALLOON_F_FREE_PAGE_HINT) &&
|
|
!s->iothread) {
|
|
error_setg(errp, "'free-page-hint' requires 'iothread' to be set");
|
|
virtio_cleanup(vdev);
|
|
return;
|
|
}
|
|
|
|
s->ivq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
|
|
s->dvq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
|
|
s->svq = virtio_add_queue(vdev, 128, virtio_balloon_receive_stats);
|
|
|
|
if (virtio_has_feature(s->host_features, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
|
|
s->free_page_vq = virtio_add_queue(vdev, VIRTQUEUE_MAX_SIZE,
|
|
virtio_balloon_handle_free_page_vq);
|
|
precopy_add_notifier(&s->free_page_hint_notify);
|
|
|
|
object_ref(OBJECT(s->iothread));
|
|
s->free_page_bh = aio_bh_new(iothread_get_aio_context(s->iothread),
|
|
virtio_ballloon_get_free_page_hints, s);
|
|
}
|
|
|
|
if (virtio_has_feature(s->host_features, VIRTIO_BALLOON_F_REPORTING)) {
|
|
s->reporting_vq = virtio_add_queue(vdev, 32,
|
|
virtio_balloon_handle_report);
|
|
}
|
|
|
|
reset_stats(s);
|
|
}
|
|
|
|
static void virtio_balloon_device_unrealize(DeviceState *dev)
|
|
{
|
|
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
|
|
VirtIOBalloon *s = VIRTIO_BALLOON(dev);
|
|
|
|
if (s->free_page_bh) {
|
|
qemu_bh_delete(s->free_page_bh);
|
|
object_unref(OBJECT(s->iothread));
|
|
virtio_balloon_free_page_stop(s);
|
|
precopy_remove_notifier(&s->free_page_hint_notify);
|
|
}
|
|
balloon_stats_destroy_timer(s);
|
|
qemu_remove_balloon_handler(s);
|
|
|
|
virtio_delete_queue(s->ivq);
|
|
virtio_delete_queue(s->dvq);
|
|
virtio_delete_queue(s->svq);
|
|
if (s->free_page_vq) {
|
|
virtio_delete_queue(s->free_page_vq);
|
|
}
|
|
if (s->reporting_vq) {
|
|
virtio_delete_queue(s->reporting_vq);
|
|
}
|
|
virtio_cleanup(vdev);
|
|
}
|
|
|
|
static void virtio_balloon_device_reset(VirtIODevice *vdev)
|
|
{
|
|
VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
|
|
|
|
if (virtio_balloon_free_page_support(s)) {
|
|
virtio_balloon_free_page_stop(s);
|
|
}
|
|
|
|
if (s->stats_vq_elem != NULL) {
|
|
virtqueue_unpop(s->svq, s->stats_vq_elem, 0);
|
|
g_free(s->stats_vq_elem);
|
|
s->stats_vq_elem = NULL;
|
|
}
|
|
|
|
s->poison_val = 0;
|
|
}
|
|
|
|
static void virtio_balloon_set_status(VirtIODevice *vdev, uint8_t status)
|
|
{
|
|
VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
|
|
|
|
if (!s->stats_vq_elem && vdev->vm_running &&
|
|
(status & VIRTIO_CONFIG_S_DRIVER_OK) && virtqueue_rewind(s->svq, 1)) {
|
|
/* poll stats queue for the element we have discarded when the VM
|
|
* was stopped */
|
|
virtio_balloon_receive_stats(vdev, s->svq);
|
|
}
|
|
|
|
if (virtio_balloon_free_page_support(s)) {
|
|
/*
|
|
* The VM is woken up and the iothread was blocked, so signal it to
|
|
* continue.
|
|
*/
|
|
if (vdev->vm_running && s->block_iothread) {
|
|
qemu_mutex_lock(&s->free_page_lock);
|
|
s->block_iothread = false;
|
|
qemu_cond_signal(&s->free_page_cond);
|
|
qemu_mutex_unlock(&s->free_page_lock);
|
|
}
|
|
|
|
/* The VM is stopped, block the iothread. */
|
|
if (!vdev->vm_running) {
|
|
qemu_mutex_lock(&s->free_page_lock);
|
|
s->block_iothread = true;
|
|
qemu_mutex_unlock(&s->free_page_lock);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void virtio_balloon_instance_init(Object *obj)
|
|
{
|
|
VirtIOBalloon *s = VIRTIO_BALLOON(obj);
|
|
|
|
qemu_mutex_init(&s->free_page_lock);
|
|
qemu_cond_init(&s->free_page_cond);
|
|
s->free_page_hint_cmd_id = VIRTIO_BALLOON_FREE_PAGE_HINT_CMD_ID_MIN;
|
|
s->free_page_hint_notify.notify = virtio_balloon_free_page_hint_notify;
|
|
|
|
object_property_add(obj, "guest-stats", "guest statistics",
|
|
balloon_stats_get_all, NULL, NULL, s);
|
|
|
|
object_property_add(obj, "guest-stats-polling-interval", "int",
|
|
balloon_stats_get_poll_interval,
|
|
balloon_stats_set_poll_interval,
|
|
NULL, s);
|
|
}
|
|
|
|
static const VMStateDescription vmstate_virtio_balloon = {
|
|
.name = "virtio-balloon",
|
|
.minimum_version_id = 1,
|
|
.version_id = 1,
|
|
.fields = (VMStateField[]) {
|
|
VMSTATE_VIRTIO_DEVICE,
|
|
VMSTATE_END_OF_LIST()
|
|
},
|
|
};
|
|
|
|
static Property virtio_balloon_properties[] = {
|
|
DEFINE_PROP_BIT("deflate-on-oom", VirtIOBalloon, host_features,
|
|
VIRTIO_BALLOON_F_DEFLATE_ON_OOM, false),
|
|
DEFINE_PROP_BIT("free-page-hint", VirtIOBalloon, host_features,
|
|
VIRTIO_BALLOON_F_FREE_PAGE_HINT, false),
|
|
DEFINE_PROP_BIT("page-poison", VirtIOBalloon, host_features,
|
|
VIRTIO_BALLOON_F_PAGE_POISON, true),
|
|
DEFINE_PROP_BIT("free-page-reporting", VirtIOBalloon, host_features,
|
|
VIRTIO_BALLOON_F_REPORTING, false),
|
|
/* QEMU 4.0 accidentally changed the config size even when free-page-hint
|
|
* is disabled, resulting in QEMU 3.1 migration incompatibility. This
|
|
* property retains this quirk for QEMU 4.1 machine types.
|
|
*/
|
|
DEFINE_PROP_BOOL("qemu-4-0-config-size", VirtIOBalloon,
|
|
qemu_4_0_config_size, false),
|
|
DEFINE_PROP_LINK("iothread", VirtIOBalloon, iothread, TYPE_IOTHREAD,
|
|
IOThread *),
|
|
DEFINE_PROP_END_OF_LIST(),
|
|
};
|
|
|
|
static void virtio_balloon_class_init(ObjectClass *klass, void *data)
|
|
{
|
|
DeviceClass *dc = DEVICE_CLASS(klass);
|
|
VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
|
|
|
|
device_class_set_props(dc, virtio_balloon_properties);
|
|
dc->vmsd = &vmstate_virtio_balloon;
|
|
set_bit(DEVICE_CATEGORY_MISC, dc->categories);
|
|
vdc->realize = virtio_balloon_device_realize;
|
|
vdc->unrealize = virtio_balloon_device_unrealize;
|
|
vdc->reset = virtio_balloon_device_reset;
|
|
vdc->get_config = virtio_balloon_get_config;
|
|
vdc->set_config = virtio_balloon_set_config;
|
|
vdc->get_features = virtio_balloon_get_features;
|
|
vdc->set_status = virtio_balloon_set_status;
|
|
vdc->vmsd = &vmstate_virtio_balloon_device;
|
|
}
|
|
|
|
static const TypeInfo virtio_balloon_info = {
|
|
.name = TYPE_VIRTIO_BALLOON,
|
|
.parent = TYPE_VIRTIO_DEVICE,
|
|
.instance_size = sizeof(VirtIOBalloon),
|
|
.instance_init = virtio_balloon_instance_init,
|
|
.class_init = virtio_balloon_class_init,
|
|
};
|
|
|
|
static void virtio_register_types(void)
|
|
{
|
|
type_register_static(&virtio_balloon_info);
|
|
}
|
|
|
|
type_init(virtio_register_types)
|