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From: Juan Quintela <quintela@redhat.com>
To: qemu-devel@nongnu.org
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>,
	Juan Quintela <quintela@redhat.com>,
	Laurent Vivier <lvivier@redhat.com>,
	kvm@vger.kernel.org, Thomas Huth <thuth@redhat.com>,
	Richard Henderson <rth@twiddle.net>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Peng Tao <tao.peng@linux.alibaba.com>,
	Yury Kotov <yury-kotov@yandex-team.ru>,
	Jiangshan Lai <laijs@hyper.sh>, Xu Wang <xu@hyper.sh>
Subject: [PULL 19/19] migration: allow private destination ram with x-ignore-shared
Date: Thu, 11 Jul 2019 12:44:12 +0200
Message-ID: <20190711104412.31233-20-quintela@redhat.com> (raw)
In-Reply-To: <20190711104412.31233-1-quintela@redhat.com>

From: Peng Tao <tao.peng@linux.alibaba.com>

By removing the share ram check, qemu is able to migrate
to private destination ram when x-ignore-shared capability
is on. Then we can create multiple destination VMs based
on the same source VM.

This changes the x-ignore-shared migration capability to
work similar to Lai's original bypass-shared-memory
work(https://lists.gnu.org/archive/html/qemu-devel/2018-04/msg00003.html)
which enables kata containers (https://katacontainers.io)
to implement the VM templating feature.

An example usage in kata containers(https://katacontainers.io):
1. Start the source VM:
   qemu-system-x86 -m 2G \
     -object memory-backend-file,id=mem0,size=2G,share=on,mem-path=/tmpfs/template-memory \
     -numa node,memdev=mem0
2. Stop the template VM, set migration x-ignore-shared capability,
   migrate "exec:cat>/tmpfs/state", quit it
3. Start target VM:
   qemu-system-x86 -m 2G \
     -object memory-backend-file,id=mem0,size=2G,share=off,mem-path=/tmpfs/template-memory \
     -numa node,memdev=mem0 \
     -incoming defer
4. connect to target VM qmp, set migration x-ignore-shared capability,
migrate_incoming "exec:cat /tmpfs/state"
5. create more target VMs repeating 3 and 4

Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Yury Kotov <yury-kotov@yandex-team.ru>
Cc: Jiangshan Lai <laijs@hyper.sh>
Cc: Xu Wang <xu@hyper.sh>
Signed-off-by: Peng Tao <tao.peng@linux.alibaba.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1560494113-1141-1-git-send-email-tao.peng@linux.alibaba.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 migration/ram.c | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index 8a6ad61d3d..8622b4dc49 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -3426,7 +3426,6 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
         }
         if (migrate_ignore_shared()) {
             qemu_put_be64(f, block->mr->addr);
-            qemu_put_byte(f, ramblock_is_ignored(block) ? 1 : 0);
         }
     }
 
@@ -4393,12 +4392,6 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
                     }
                     if (migrate_ignore_shared()) {
                         hwaddr addr = qemu_get_be64(f);
-                        bool ignored = qemu_get_byte(f);
-                        if (ignored != ramblock_is_ignored(block)) {
-                            error_report("RAM block %s should %s be migrated",
-                                         id, ignored ? "" : "not");
-                            ret = -EINVAL;
-                        }
                         if (ramblock_is_ignored(block) &&
                             block->mr->addr != addr) {
                             error_report("Mismatched GPAs for block %s "
-- 
2.21.0


  parent reply index

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-11 10:43 [PULL 00/19] Migration patches Juan Quintela
2019-07-11 10:43 ` [PULL 01/19] migration: fix multifd_recv event typo Juan Quintela
2019-07-11 10:43 ` [PULL 02/19] migration-test: rename parameter to parameter_int Juan Quintela
2019-07-11 10:43 ` [PULL 03/19] migration-test: Add migration multifd test Juan Quintela
2019-07-11 10:43 ` [PULL 04/19] migration/multifd: call multifd_send_sync_main when sending RAM_SAVE_FLAG_EOS Juan Quintela
2019-07-11 10:43 ` [PULL 05/19] migration/xbzrle: update cache and current_data in one place Juan Quintela
2019-07-11 10:43 ` [PULL 06/19] cutils: remove one unnecessary pointer operation Juan Quintela
2019-07-11 10:44 ` [PULL 07/19] migration/multifd: sync packet_num after all thread are done Juan Quintela
2019-07-11 10:44 ` [PULL 08/19] migratioin/ram.c: reset complete_round when we gets a queued page Juan Quintela
2019-07-11 10:44 ` [PULL 09/19] migration: No need to take rcu during sync_dirty_bitmap Juan Quintela
2019-07-11 10:44 ` [PULL 10/19] memory: Don't set migration bitmap when without migration Juan Quintela
2019-07-11 10:44 ` [PULL 11/19] bitmap: Add bitmap_copy_with_{src|dst}_offset() Juan Quintela
2019-07-11 10:44 ` [PULL 12/19] memory: Pass mr into snapshot_and_clear_dirty Juan Quintela
2019-07-11 10:44 ` [PULL 13/19] memory: Introduce memory listener hook log_clear() Juan Quintela
2019-07-11 10:44 ` [PULL 14/19] kvm: Update comments for sync_dirty_bitmap Juan Quintela
2019-07-11 10:44 ` [PULL 15/19] kvm: Persistent per kvmslot dirty bitmap Juan Quintela
2019-07-11 10:44 ` [PULL 16/19] kvm: Introduce slots lock for memory listener Juan Quintela
2019-07-11 10:44 ` [PULL 17/19] kvm: Support KVM_CLEAR_DIRTY_LOG Juan Quintela
2019-07-11 10:44 ` Juan Quintela [this message]
2019-07-11 11:19 ` [PULL 00/19] Migration patches Paolo Bonzini
2019-07-11 11:32   ` Juan Quintela
2019-07-11 11:34   ` Dr. David Alan Gilbert
2019-07-11 11:40     ` [Qemu-devel] " Peter Maydell
2019-07-11 12:39 ` Peter Maydell
2019-07-12 14:06   ` Juan Quintela
2019-07-11 12:55 ` Christian Borntraeger
2019-07-11 13:01   ` [Qemu-devel] " Peter Maydell
2019-07-11 13:00 ` no-reply
2019-07-12 14:33 ` no-reply
2019-07-12 14:31 Juan Quintela
2019-07-12 14:32 ` [PULL 19/19] migration: allow private destination ram with x-ignore-shared Juan Quintela

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