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author | David Hildenbrand <david@redhat.com> | 2020-06-26 09:22:33 +0200 |
---|---|---|
committer | Michael S. Tsirkin <mst@redhat.com> | 2020-07-02 05:54:59 -0400 |
commit | 06df2e692a95509ee5f6e7d1663502adb74cb2a5 (patch) | |
tree | 417b17a874353240bc97efd49a9763c40ade45bd | |
parent | b030958c2b5c133e70d083ff8a612cb62254eabc (diff) | |
download | qemu-06df2e692a95509ee5f6e7d1663502adb74cb2a5.zip qemu-06df2e692a95509ee5f6e7d1663502adb74cb2a5.tar.gz qemu-06df2e692a95509ee5f6e7d1663502adb74cb2a5.tar.bz2 |
virtio-balloon: Rip out qemu_balloon_inhibit()
The only remaining special case is postcopy. It cannot handle
concurrent discards yet, which would result in requesting already sent
pages from the source. Special-case it in virtio-balloon instead.
Introduce migration_in_incoming_postcopy(), to find out if incoming
postcopy is active.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Juan Quintela <quintela@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200626072248.78761-7-david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
-rw-r--r-- | balloon.c | 18 | ||||
-rw-r--r-- | hw/virtio/virtio-balloon.c | 10 | ||||
-rw-r--r-- | include/migration/misc.h | 2 | ||||
-rw-r--r-- | include/sysemu/balloon.h | 2 | ||||
-rw-r--r-- | migration/migration.c | 7 | ||||
-rw-r--r-- | migration/postcopy-ram.c | 23 |
6 files changed, 17 insertions, 45 deletions
@@ -36,24 +36,6 @@ static QEMUBalloonEvent *balloon_event_fn; static QEMUBalloonStatus *balloon_stat_fn; static void *balloon_opaque; -static int balloon_inhibit_count; - -bool qemu_balloon_is_inhibited(void) -{ - return atomic_read(&balloon_inhibit_count) > 0 || - ram_block_discard_is_disabled(); -} - -void qemu_balloon_inhibit(bool state) -{ - if (state) { - atomic_inc(&balloon_inhibit_count); - } else { - atomic_dec(&balloon_inhibit_count); - } - - assert(atomic_read(&balloon_inhibit_count) >= 0); -} static bool have_balloon(Error **errp) { diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c index 8a84718..ae31f08 100644 --- a/hw/virtio/virtio-balloon.c +++ b/hw/virtio/virtio-balloon.c @@ -63,6 +63,12 @@ static bool virtio_balloon_pbp_matches(PartiallyBalloonedPage *pbp, return pbp->base_gpa == base_gpa; } +static bool virtio_balloon_inhibited(void) +{ + /* Postcopy cannot deal with concurrent discards, so it's special. */ + return ram_block_discard_is_disabled() || migration_in_incoming_postcopy(); +} + static void balloon_inflate_page(VirtIOBalloon *balloon, MemoryRegion *mr, hwaddr mr_offset, PartiallyBalloonedPage *pbp) @@ -336,7 +342,7 @@ static void virtio_balloon_handle_report(VirtIODevice *vdev, VirtQueue *vq) * accessible by another device or process, or if the guest is * expecting it to retain a non-zero value. */ - if (qemu_balloon_is_inhibited() || dev->poison_val) { + if (virtio_balloon_inhibited() || dev->poison_val) { goto skip_element; } @@ -421,7 +427,7 @@ static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq) trace_virtio_balloon_handle_output(memory_region_name(section.mr), pa); - if (!qemu_balloon_is_inhibited()) { + if (!virtio_balloon_inhibited()) { if (vq == s->ivq) { balloon_inflate_page(s, section.mr, section.offset_within_region, &pbp); diff --git a/include/migration/misc.h b/include/migration/misc.h index d276225..34e7d75 100644 --- a/include/migration/misc.h +++ b/include/migration/misc.h @@ -69,6 +69,8 @@ bool migration_has_failed(MigrationState *); /* ...and after the device transmission */ bool migration_in_postcopy_after_devices(MigrationState *); void migration_global_dump(Monitor *mon); +/* True if incomming migration entered POSTCOPY_INCOMING_DISCARD */ +bool migration_in_incoming_postcopy(void); /* migration/block-dirty-bitmap.c */ void dirty_bitmap_mig_init(void); diff --git a/include/sysemu/balloon.h b/include/sysemu/balloon.h index aea0c44..20a2def 100644 --- a/include/sysemu/balloon.h +++ b/include/sysemu/balloon.h @@ -23,7 +23,5 @@ typedef void (QEMUBalloonStatus)(void *opaque, BalloonInfo *info); int qemu_add_balloon_handler(QEMUBalloonEvent *event_func, QEMUBalloonStatus *stat_func, void *opaque); void qemu_remove_balloon_handler(void *opaque); -bool qemu_balloon_is_inhibited(void); -void qemu_balloon_inhibit(bool state); #endif diff --git a/migration/migration.c b/migration/migration.c index 481a590..d365d82 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -1772,6 +1772,13 @@ bool migration_in_postcopy_after_devices(MigrationState *s) return migration_in_postcopy() && s->postcopy_after_devices; } +bool migration_in_incoming_postcopy(void) +{ + PostcopyState ps = postcopy_state_get(); + + return ps >= POSTCOPY_INCOMING_DISCARD && ps < POSTCOPY_INCOMING_END; +} + bool migration_is_idle(void) { MigrationState *s = current_migration; diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index a364027..b41a9fe 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -27,7 +27,6 @@ #include "qemu/notify.h" #include "qemu/rcu.h" #include "sysemu/sysemu.h" -#include "sysemu/balloon.h" #include "qemu/error-report.h" #include "trace.h" #include "hw/boards.h" @@ -521,20 +520,6 @@ int postcopy_ram_incoming_init(MigrationIncomingState *mis) } /* - * Manage a single vote to the QEMU balloon inhibitor for all postcopy usage, - * last caller wins. - */ -static void postcopy_balloon_inhibit(bool state) -{ - static bool cur_state = false; - - if (state != cur_state) { - qemu_balloon_inhibit(state); - cur_state = state; - } -} - -/* * At the end of a migration where postcopy_ram_incoming_init was called. */ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis) @@ -565,8 +550,6 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis) mis->have_fault_thread = false; } - postcopy_balloon_inhibit(false); - if (enable_mlock) { if (os_mlock() < 0) { error_report("mlock: %s", strerror(errno)); @@ -1160,12 +1143,6 @@ int postcopy_ram_incoming_setup(MigrationIncomingState *mis) } memset(mis->postcopy_tmp_zero_page, '\0', mis->largest_page_size); - /* - * Ballooning can mark pages as absent while we're postcopying - * that would cause false userfaults. - */ - postcopy_balloon_inhibit(true); - trace_postcopy_ram_enable_notify(); return 0; |