From a6cbd44093ef305b02ad5f80ed54abf0148a696c Mon Sep 17 00:00:00 2001 From: Fenghua Yu Date: Mon, 7 Feb 2022 15:02:47 -0800 Subject: kernel/fork: Initialize mm's PASID A new mm doesn't have a PASID yet when it's created. Initialize the mm's PASID on fork() or for init_mm to INVALID_IOASID (-1). INIT_PASID (0) is reserved for kernel legacy DMA PASID. It cannot be allocated to a user process. Initializing the process's PASID to 0 may cause confusion that's why the process uses the reserved kernel legacy DMA PASID. Initializing the PASID to INVALID_IOASID (-1) explicitly tells the process doesn't have a valid PASID yet. Even though the only user of mm_pasid_init() is in fork.c, define it in as the first of three mm/pasid life cycle functions (init/set/drop) to keep these all together. Suggested-by: Dave Hansen Signed-off-by: Fenghua Yu Signed-off-by: Borislav Petkov Reviewed-by: Tony Luck Reviewed-by: Thomas Gleixner Link: https://lore.kernel.org/r/20220207230254.3342514-5-fenghua.yu@intel.com --- mm/init-mm.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'mm/init-mm.c') diff --git a/mm/init-mm.c b/mm/init-mm.c index b4a6f38fb51ddc..fbe7844d0912f5 100644 --- a/mm/init-mm.c +++ b/mm/init-mm.c @@ -10,6 +10,7 @@ #include #include +#include #include #ifndef INIT_MM_CONTEXT @@ -38,6 +39,9 @@ struct mm_struct init_mm = { .mmlist = LIST_HEAD_INIT(init_mm.mmlist), .user_ns = &init_user_ns, .cpu_bitmap = CPU_BITS_NONE, +#ifdef CONFIG_IOMMU_SVA + .pasid = INVALID_IOASID, +#endif INIT_MM_CONTEXT(init_mm) }; -- cgit 1.2.3-korg