On Mon, Feb 04, 2019 at 14:41:05 +0100, Marc Hartmayer wrote:
On Mon, Feb 04, 2019 at 02:37 PM +0100, Marc Hartmayer <mhartmay@linux.ibm.com> wrote:
On Mon, Feb 04, 2019 at 01:41 PM +0100, Peter Krempa <pkrempa@redhat.com> wrote:
On Mon, Feb 04, 2019 at 13:36:24 +0100, Marc Hartmayer wrote:
For normal starts (no incoming migration) the refresh of the QEMU state must be done before the VCPUs getting started since otherwise there might be a race condition between a possible shutdown of the guest OS and the QEMU monitor queries.
This fixes "qemu: migration: Refresh device information after transferring state" (93db7eea1b864).
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com> --- src/qemu/qemu_process.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index dace5aaca102..2a3763f40d49 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -6929,10 +6929,17 @@ qemuProcessStart(virConnectPtr conn, } relabel = true;
- if (incoming && - incoming->deferredURI && - qemuMigrationDstRun(driver, vm, incoming->deferredURI, asyncJob) < 0) - goto stop; + if (incoming) { + if (incoming->deferredURI && + qemuMigrationDstRun(driver, vm, incoming->deferredURI, asyncJob) < 0) + goto stop; + } else {
This logic does not seem right ...
I’m not familiar with the usage of this function for migration… so there's a good chance I'm missing something.
+ /* Refresh state of devices from QEMU. During migration this + * needs to happen after the state information is fully + * transferred. */
as this comment clearly states that this should happen after migration.
Is qemuProcessFinishStartup ^^^^^^^^^^^^^^^^^^^^^^^^ qemuProcessRefreshState
not called explicitly in qemuMigrationFinish for migration?
Yes it is, in this case the comment is wrong/misleading so it should be fixed.
Here it would happen only when migration is not done.
Without this patch qemuProcessRefreshState is called after qemuProcessFinishStartup if (!incoming). Now it’s called directly before qemuProcessFinishStartup if (!incoming). Why should this be wrong now? What happens in qemuProcessFinishStartup?
Before your change in 93db7eea1b86408e the function call 'qemuProcessRefreshState' was done in qemuProcessFinishStartup (without any condition).
As I've said in the other thread I think this fix is okay if we fix the comment. I'll do this in a moment so you don't need to send another patch.