From: Peter Zijlstra <pet...@infradead.org>
Add a new single bit field to the task structure to track whether this task
has initialized the IA32_PASID MSR to the mm's PASID.
Initialize the field to zero when creating a new task with fork/clone.
Signed-off-by: Peter Zijlstra <pet...@infradead.org>
Co-developed-by: Fenghua Yu <fenghua...@intel.com>
Signed-off-by: Fenghua Yu <fenghua...@intel.com>
Reviewed-by: Tony Luck <tony.l...@intel.com>
Reviewed-by: Thomas Gleixner <t...@linutronix.de>
---
v4:
- Add "Reviewed-by: Thomas Gleixner <t...@linutronix.de>" (Thomas).
v2:
- Change condition to more accurate CONFIG_IOMMU_SVA (Jacob)
include/linux/sched.h | 3 +++
kernel/fork.c | 4 ++++
2 files changed, 7 insertions(+)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 75ba8aa60248..4e5de3aed410 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -938,6 +938,9 @@ struct task_struct {
/* Recursion prevention for eventfd_signal() */
unsigned in_eventfd_signal:1;
#endif
+#ifdef CONFIG_IOMMU_SVA
+ unsigned pasid_activated:1;
+#endif
unsigned long atomic_flags; /* Flags requiring atomic
access. */
diff --git a/kernel/fork.c b/kernel/fork.c
index c03c6682464c..51fd1df994b7 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -968,6 +968,10 @@ static struct task_struct *dup_task_struct(struct
task_struct *orig, int node)
tsk->use_memdelay = 0;
#endif
+#ifdef CONFIG_IOMMU_SVA
+ tsk->pasid_activated = 0;
+#endif
+
#ifdef CONFIG_MEMCG
tsk->active_memcg = NULL;
#endif
--
2.35.1
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