sched: Define and initialize a flag to identify valid PASID in the task

mainline inclusion
from mainline-v5.18
commit a3d29e82
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I596WO


CVE: NA

Intel-SIG: commit a3d29e82 sched: Define and initialize a flag to identify valid PASID in the task.
Incremental backporting patches for DSA/IAA on Intel Xeon platform.

--------------------------------

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 <peterz@infradead.org>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220207230254.3342514-8-fenghua.yu@intel.com


Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>