On Thu, Oct 01, 2009 at 08:18:33PM +0200, Paolo Bonzini wrote:
> In order to correctly pass the paused/unpaused state on the remote side,
> we use the newly introduced return code of qemudDomainMigratePerform.
>
> The return code does not need to be public (it is internal to the QEMU
> driver). A return code of 0 specifies the old behavior.
>
> * src/qemu/qemu_driver.c (qemudDomainMigratePerform): Check if
> the machine will have to be resumed on the destination side,
> pass a return value to indicate this.
> (qemudDomainMigrateFinish2): Conditionalize resumption on
> the return code from qemudDomainMigratePerform.
> * src/qemu/qemu_driver.h (qemuDomainMigratePerformResult): New enum.
> ---
> src/qemu/qemu_driver.c | 14 ++++++++++----
> src/qemu/qemu_driver.h | 6 ++++++
> 2 files changed, 16 insertions(+), 4 deletions(-)
>
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index d2429de..5811ba2 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -37,6 +37,7 @@
> #include <errno.h>
> #include <sys/utsname.h>
> #include <sys/stat.h>
> +#include <assert.h>
> #include <fcntl.h>
> #include <signal.h>
> #include <paths.h>
> @@ -5969,7 +5970,9 @@ cleanup:
> return ret;
> }
>
> -/* Perform is the second step, and it runs on the source host. */
> +/* Perform is the second step, and it runs on the source host. It
> + returns a combination of actions that should (or should not) be
> + done by MigrateFinish2, currently QEMU_MIGRATE_NO_RESUME. */
> static int
> qemudDomainMigratePerform (virDomainPtr dom,
> const char *cookie ATTRIBUTE_UNUSED,
> @@ -5983,7 +5986,7 @@ qemudDomainMigratePerform (virDomainPtr dom,
> virDomainObjPtr vm;
> virDomainEventPtr event = NULL;
> int ret = -1;
> - int paused = 0;
> + int paused = 0, need_resume = 0;
> int status;
> xmlURIPtr uribits = NULL;
> unsigned long long transferred, remaining, total;
> @@ -6004,6 +6007,7 @@ qemudDomainMigratePerform (virDomainPtr dom,
> goto cleanup;
> }
>
> + need_resume = (vm->state == VIR_DOMAIN_RUNNING);
> if (!(flags & VIR_MIGRATE_LIVE)) {
> /* Pause domain for non-live migration */
> if (qemuMonitorStopCPUs(vm) < 0)
> @@ -6072,7 +6076,7 @@ qemudDomainMigratePerform (virDomainPtr dom,
> virDomainRemoveInactive(&driver->domains, vm);
> vm = NULL;
> }
> - ret = 0;
> + ret = need_resume ? 0 : QEMU_MIGRATE_NO_RESUME;
>
> cleanup:
> if (paused) {
> @@ -6131,7 +6135,9 @@ qemudDomainMigrateFinish2 (virConnectPtr dconn,
> if (retcode >= 0) {
> dom = virGetDomain (dconn, vm->def->name, vm->def->uuid);
>
> - if (!(flags & VIR_MIGRATE_PAUSED)) {
> + assert (vm->state == VIR_DOMAIN_PAUSED);
NACK ! an error in migration should not result in a dead daemon
assert/exit forbidden even in error handling paths.
> + if (!(retcode & QEMU_MIGRATE_NO_RESUME)
> + && !(flags & VIR_MIGRATE_PAUSED)) {
> /* run 'cont' on the destination, which allows migration on qemu
> * >= 0.10.6 to work properly. This isn't strictly necessary on
> * older qemu's, but it also doesn't hurt anything there
> diff --git a/src/qemu/qemu_driver.h b/src/qemu/qemu_driver.h
> index 17b184f..74ec089 100644
> --- a/src/qemu/qemu_driver.h
> +++ b/src/qemu/qemu_driver.h
> @@ -47,6 +47,12 @@
> # define KVM_CAP_NR_VCPUS 9 /* returns max vcpus per vm */
> #endif
>
> +/* Flags passed from virDomainMigratePerform to virDomainMigrateFinish. */
> +
> +typedef enum {
> + QEMU_MIGRATE_NO_RESUME = 1 /* destination domain should stay paused */
> +} qemuDomainMigratePerformResult;
> +
> int qemuRegister(void);
>
> #endif /* QEMUD_DRIVER_H */
> --
> 1.6.2.5
>
> --
> Libvir-list mailing list
> Libvir-list@redhat.com
> https://www.redhat.com/mailman/listinfo/libvir-list
--
Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/
dan...@veillard.com | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library http://libvirt.org/
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