qemu-kvm/kvm-migration-always-initialise-ram_counters-for-a-new-m.patch
Danilo C. L. de Paula 200e3560ab * Tue Sep 10 2019 Danilo Cesar Lemes de Paula <ddepaula@redhat.com> - 4.1.0-9.el8
- kvm-migration-always-initialise-ram_counters-for-a-new-m.patch [bz#1734316]
- kvm-migration-add-qemu_file_update_transfer-interface.patch [bz#1734316]
- kvm-migration-add-speed-limit-for-multifd-migration.patch [bz#1734316]
- kvm-migration-update-ram_counters-for-multifd-sync-packe.patch [bz#1734316]
- kvm-spapr-pci-Consolidate-de-allocation-of-MSIs.patch [bz#1750200]
- kvm-spapr-pci-Free-MSIs-during-reset.patch [bz#1750200]
- Resolves: bz#1734316
  (multifd migration does not honour speed limits, consumes entire bandwidth of NIC)
- Resolves: bz#1750200
  ([RHEL8.1][QEMU4.1]boot up guest with vf device,then system_reset guest,error prompt(qemu-kvm: Can't allocate MSIs for device 2800: IRQ 4904 is not free))
2019-09-10 19:56:34 +01:00

140 lines
5.2 KiB
Diff

From 7ec124b3de4e7c7ef093955813a213d7a976d395 Mon Sep 17 00:00:00 2001
From: Juan Quintela <quintela@redhat.com>
Date: Wed, 4 Sep 2019 11:23:29 +0100
Subject: [PATCH 1/6] migration: always initialise ram_counters for a new
migration
RH-Author: Juan Quintela <quintela@redhat.com>
Message-id: <20190904112332.16160-2-quintela@redhat.com>
Patchwork-id: 90278
O-Subject: [RHEL-AV-8.1 qemu-kvm PATCH v2 1/4] migration: always initialise ram_counters for a new migration
Bugzilla: 1734316
RH-Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
RH-Acked-by: Peter Xu <peterx@redhat.com>
RH-Acked-by: Danilo de Paula <ddepaula@redhat.com>
From: Ivan Ren <ivanren@tencent.com>
This patch fix a multifd migration bug in migration speed calculation, this
problem can be reproduced as follows:
1. start a vm and give a heavy memory write stress to prevent the vm be
successfully migrated to destination
2. begin a migration with multifd
3. migrate for a long time [actually, this can be measured by transferred bytes]
4. migrate cancel
5. begin a new migration with multifd, the migration will directly run into
migration_completion phase
Reason as follows:
Migration update bandwidth and s->threshold_size in function
migration_update_counters after BUFFER_DELAY time:
current_bytes = migration_total_bytes(s);
transferred = current_bytes - s->iteration_initial_bytes;
time_spent = current_time - s->iteration_start_time;
bandwidth = (double)transferred / time_spent;
s->threshold_size = bandwidth * s->parameters.downtime_limit;
In multifd migration, migration_total_bytes function return
qemu_ftell(s->to_dst_file) + ram_counters.multifd_bytes.
s->iteration_initial_bytes will be initialized to 0 at every new migration,
but ram_counters is a global variable, and history migration data will be
accumulated. So if the ram_counters.multifd_bytes is big enough, it may lead
pending_size >= s->threshold_size become false in migration_iteration_run
after the first migration_update_counters.
Signed-off-by: Ivan Ren <ivanren@tencent.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Wei Yang <richardw.yang@linux.intel.com>
Suggested-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <1564741121-1840-1-git-send-email-ivanren@tencent.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
(cherry picked from commit 87f3bd8717cd88932de302e215f1da51bfb8051a)
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
---
migration/migration.c | 25 +++++++++++++++++++------
migration/savevm.c | 1 +
2 files changed, 20 insertions(+), 6 deletions(-)
diff --git a/migration/migration.c b/migration/migration.c
index beffbfd..5299597 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1910,6 +1910,11 @@ static bool migrate_prepare(MigrationState *s, bool blk, bool blk_inc,
}
migrate_init(s);
+ /*
+ * set ram_counters memory to zero for a
+ * new migration
+ */
+ memset(&ram_counters, 0, sizeof(ram_counters));
return true;
}
@@ -3027,6 +3032,17 @@ static void migration_calculate_complete(MigrationState *s)
}
}
+static void update_iteration_initial_status(MigrationState *s)
+{
+ /*
+ * Update these three fields at the same time to avoid mismatch info lead
+ * wrong speed calculation.
+ */
+ s->iteration_start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
+ s->iteration_initial_bytes = migration_total_bytes(s);
+ s->iteration_initial_pages = ram_get_total_transferred_pages();
+}
+
static void migration_update_counters(MigrationState *s,
int64_t current_time)
{
@@ -3062,9 +3078,7 @@ static void migration_update_counters(MigrationState *s,
qemu_file_reset_rate_limit(s->to_dst_file);
- s->iteration_start_time = current_time;
- s->iteration_initial_bytes = current_bytes;
- s->iteration_initial_pages = ram_get_total_transferred_pages();
+ update_iteration_initial_status(s);
trace_migrate_transferred(transferred, time_spent,
bandwidth, s->threshold_size);
@@ -3188,7 +3202,7 @@ static void *migration_thread(void *opaque)
rcu_register_thread();
object_ref(OBJECT(s));
- s->iteration_start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
+ update_iteration_initial_status(s);
qemu_savevm_state_header(s->to_dst_file);
@@ -3253,8 +3267,7 @@ static void *migration_thread(void *opaque)
* the local variables. This is important to avoid
* breaking transferred_bytes and bandwidth calculation
*/
- s->iteration_start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
- s->iteration_initial_bytes = 0;
+ update_iteration_initial_status(s);
}
current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
diff --git a/migration/savevm.c b/migration/savevm.c
index 79ed44d..480c511 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1424,6 +1424,7 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
}
migrate_init(ms);
+ memset(&ram_counters, 0, sizeof(ram_counters));
ms->to_dst_file = f;
qemu_mutex_unlock_iothread();
--
1.8.3.1