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authorHaren Myneni <haren@linux.ibm.com>2022-09-22 01:27:07 -0700
committerMichael Ellerman <mpe@ellerman.id.au>2022-09-28 19:22:12 +1000
commit465dda9d320d1cb9424f1015b0520ec4c4f0d279 (patch)
treecc5f1bf8600d1d402d465a41535e31c61c0c8d6f
parent1da5351f9eb9b72a7d25316b4d38bf10b6e671b1 (diff)
downloadlinux-465dda9d320d1cb9424f1015b0520ec4c4f0d279.tar.bz2
powerpc/pseries: Move vas_migration_handler early during migration
When the migration is initiated, the hypervisor changes VAS mappings as part of pre-migration event. Then the OS gets the migration event which closes all VAS windows before the migration starts. NX generates continuous faults until windows are closed and the user space can not differentiate these NX faults coming from the actual migration. So to reduce this time window, close VAS windows first in pseries_migrate_partition(). Signed-off-by: Haren Myneni <haren@linux.ibm.com> Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d8efade91dda831c9ed4abb226dab627da594c5f.camel@linux.ibm.com
-rw-r--r--arch/powerpc/platforms/pseries/mobility.c15
1 files changed, 12 insertions, 3 deletions
diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
index c92c78332303..634fac5db3f9 100644
--- a/arch/powerpc/platforms/pseries/mobility.c
+++ b/arch/powerpc/platforms/pseries/mobility.c
@@ -740,11 +740,19 @@ static int pseries_migrate_partition(u64 handle)
#ifdef CONFIG_PPC_WATCHDOG
factor = nmi_wd_lpm_factor;
#endif
+ /*
+ * When the migration is initiated, the hypervisor changes VAS
+ * mappings to prepare before OS gets the notification and
+ * closes all VAS windows. NX generates continuous faults during
+ * this time and the user space can not differentiate these
+ * faults from the migration event. So reduce this time window
+ * by closing VAS windows at the beginning of this function.
+ */
+ vas_migration_handler(VAS_SUSPEND);
+
ret = wait_for_vasi_session_suspending(handle);
if (ret)
- return ret;
-
- vas_migration_handler(VAS_SUSPEND);
+ goto out;
if (factor)
watchdog_nmi_set_timeout_pct(factor);
@@ -765,6 +773,7 @@ static int pseries_migrate_partition(u64 handle)
if (factor)
watchdog_nmi_set_timeout_pct(0);
+out:
vas_migration_handler(VAS_RESUME);
return ret;