[RFC PATCH 3/3] powerpc/pseries/vas: Use migration_in_progress to disable DLPAR
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STALE1731d
SUPERSEDED
From: Haren Myneni <haren@linux.ibm.com>
Date: 2021-12-27 11:00:59
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
Revision rfc of 7 in this series.
Revisions (7)
Before migration starts, all secondary CPUs will be offline which can invoke VAS DLPAR event. So disable VAS DLPAR event with migration_in_progress flag during suspend and enable after resume operations. The current partition migration implementation does not freeze the user space and the user space can continue open VAS windows. So when migration_in_progress flag is enabled, VAS open window API returns -EBUSY. Signed-off-by: Haren Myneni <haren@linux.ibm.com> --- arch/powerpc/platforms/pseries/vas.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/vas.c b/arch/powerpc/platforms/pseries/vas.c
index d2d7202a4f4e..1a10c1904aaa 100644
--- a/arch/powerpc/platforms/pseries/vas.c
+++ b/arch/powerpc/platforms/pseries/vas.c@@ -30,6 +30,7 @@ static bool copypaste_feat; static struct vas_caps vascaps[VAS_MAX_FEAT_TYPE]; static DEFINE_MUTEX(vas_pseries_mutex); +static bool migration_in_progress; static long hcall_return_busy_check(long rc) {
@@ -349,8 +350,11 @@ static struct vas_window *vas_allocate_window(int vas_id, u64 flags, * same fault IRQ is not freed by the OS before. */ mutex_lock(&vas_pseries_mutex); - rc = allocate_setup_window(txwin, (u64 *)&domain[0], - cop_feat_caps->win_type); + if (migration_in_progress) + rc = -EBUSY; + else + rc = allocate_setup_window(txwin, (u64 *)&domain[0], + cop_feat_caps->win_type); mutex_unlock(&vas_pseries_mutex); if (rc) goto out;
@@ -771,6 +775,9 @@ int vas_reconfig_capabilties(u8 type) return -ENOMEM; mutex_lock(&vas_pseries_mutex); + if (migration_in_progress) + goto out; + rc = h_query_vas_capabilities(H_QUERY_VAS_CAPABILITIES, vcaps->feat, (u64)virt_to_phys(hv_caps)); if (rc)
@@ -866,6 +873,11 @@ static int vas_migrate_windows(bool suspend) mutex_lock(&vas_pseries_mutex); + if (suspend) + migration_in_progress = true; + else + migration_in_progress = false; + for (i = 0; i < VAS_MAX_FEAT_TYPE; i++) { vcaps = &vascaps[i]; caps = &vcaps->caps;
--
2.27.0