[libvirt] [PATCH] qemu: Reject migration with memory-hotplug if destination doesn't support it

If destination libvirt doesn't support memory hotplug since all the support was introduced by adding new elements the destination would attempt to start qemu with an invalid configuration. The worse part is that qemu might hang in such situation. Fix this by sending a required migration feature called 'memory-hotplug' to the destination. If the destination doesn't recognize it it will fail the migration. Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1248350 --- src/qemu/qemu_migration.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index f5866c4..824126f 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -86,6 +86,7 @@ enum qemuMigrationCookieFlags { QEMU_MIGRATION_COOKIE_FLAG_NETWORK, QEMU_MIGRATION_COOKIE_FLAG_NBD, QEMU_MIGRATION_COOKIE_FLAG_STATS, + QEMU_MIGRATION_COOKIE_FLAG_MEMORY_HOTPLUG, QEMU_MIGRATION_COOKIE_FLAG_LAST }; @@ -98,7 +99,8 @@ VIR_ENUM_IMPL(qemuMigrationCookieFlag, "persistent", "network", "nbd", - "statistics"); + "statistics", + "memory-hotplug"); enum qemuMigrationCookieFeatures { QEMU_MIGRATION_COOKIE_GRAPHICS = (1 << QEMU_MIGRATION_COOKIE_FLAG_GRAPHICS), @@ -107,6 +109,7 @@ enum qemuMigrationCookieFeatures { QEMU_MIGRATION_COOKIE_NETWORK = (1 << QEMU_MIGRATION_COOKIE_FLAG_NETWORK), QEMU_MIGRATION_COOKIE_NBD = (1 << QEMU_MIGRATION_COOKIE_FLAG_NBD), QEMU_MIGRATION_COOKIE_STATS = (1 << QEMU_MIGRATION_COOKIE_FLAG_STATS), + QEMU_MIGRATION_COOKIE_MEMORY_HOTPLUG = (1 << QEMU_MIGRATION_COOKIE_FLAG_MEMORY_HOTPLUG), }; typedef struct _qemuMigrationCookieGraphics qemuMigrationCookieGraphics; @@ -1352,6 +1355,9 @@ qemuMigrationBakeCookie(qemuMigrationCookiePtr mig, qemuMigrationCookieAddStatistics(mig, dom) < 0) return -1; + if (flags & QEMU_MIGRATION_COOKIE_MEMORY_HOTPLUG) + mig->flagsMandatory |= QEMU_MIGRATION_COOKIE_MEMORY_HOTPLUG; + if (!(*cookieout = qemuMigrationCookieXMLFormatStr(driver, mig))) return -1; @@ -2974,6 +2980,11 @@ qemuMigrationBeginPhase(virQEMUDriverPtr driver, } } + if (vm->def->mem.max_memory || + (vm->newDef && + vm->newDef->mem.max_memory)) + cookieFlags |= QEMU_MIGRATION_COOKIE_MEMORY_HOTPLUG; + if (!(mig = qemuMigrationEatCookie(driver, vm, NULL, 0, 0))) goto cleanup; -- 2.4.5

On Thu, Jul 30, 2015 at 16:47:02 +0200, Peter Krempa wrote:
If destination libvirt doesn't support memory hotplug since all the support was introduced by adding new elements the destination would attempt to start qemu with an invalid configuration. The worse part is that qemu might hang in such situation.
Fix this by sending a required migration feature called 'memory-hotplug' to the destination. If the destination doesn't recognize it it will fail the migration.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1248350
ACK Jirka

On Fri, Jul 31, 2015 at 14:20:09 +0200, Jiri Denemark wrote:
On Thu, Jul 30, 2015 at 16:47:02 +0200, Peter Krempa wrote:
If destination libvirt doesn't support memory hotplug since all the support was introduced by adding new elements the destination would attempt to start qemu with an invalid configuration. The worse part is that qemu might hang in such situation.
Fix this by sending a required migration feature called 'memory-hotplug' to the destination. If the destination doesn't recognize it it will fail the migration.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1248350
ACK
Pushed; Thanks. Peter
participants (2)
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Jiri Denemark
-
Peter Krempa