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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-21 12:28:13 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-21 12:28:13 -0700 |
| commit | 3fd33273a4675e819544ccbbf8d769e14672666b (patch) | |
| tree | de1dc2f55a4d6f6445ac622eb67ed89103574403 /kernel/fork.c | |
| parent | eaa54b1458ca84092e513d554dd6d234245e6bef (diff) | |
| parent | 83aa52ffed5d35a08e24452d0471e1684075cdf8 (diff) | |
Merge tag 'x86-pasid-2022-03-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 PASID support from Thomas Gleixner:
"Reenable ENQCMD/PASID support:
- Simplify the PASID handling to allocate the PASID once, associate
it to the mm of a process and free it on mm_exit().
The previous attempt of refcounted PASIDs and dynamic
alloc()/free() turned out to be error prone and too complex. The
PASID space is 20bits, so the case of resource exhaustion is a pure
academic concern.
- Populate the PASID MSR on demand via #GP to avoid racy updates via
IPIs.
- Reenable ENQCMD and let objtool check for the forbidden usage of
ENQCMD in the kernel.
- Update the documentation for Shared Virtual Addressing accordingly"
* tag 'x86-pasid-2022-03-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
Documentation/x86: Update documentation for SVA (Shared Virtual Addressing)
tools/objtool: Check for use of the ENQCMD instruction in the kernel
x86/cpufeatures: Re-enable ENQCMD
x86/traps: Demand-populate PASID MSR via #GP
sched: Define and initialize a flag to identify valid PASID in the task
x86/fpu: Clear PASID when copying fpstate
iommu/sva: Assign a PASID to mm on PASID allocation and free it on mm exit
kernel/fork: Initialize mm's PASID
iommu/ioasid: Introduce a helper to check for valid PASIDs
mm: Change CONFIG option for mm->pasid field
iommu/sva: Rename CONFIG_IOMMU_SVA_LIB to CONFIG_IOMMU_SVA
Diffstat (limited to 'kernel/fork.c')
| -rw-r--r-- | kernel/fork.c | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index f1e89007f228..b441a81f5fa9 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -97,6 +97,7 @@ #include <linux/scs.h> #include <linux/io_uring.h> #include <linux/bpf.h> +#include <linux/sched/mm.h> #include <asm/pgalloc.h> #include <linux/uaccess.h> @@ -967,6 +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 @@ -1019,13 +1024,6 @@ static void mm_init_owner(struct mm_struct *mm, struct task_struct *p) #endif } -static void mm_init_pasid(struct mm_struct *mm) -{ -#ifdef CONFIG_IOMMU_SUPPORT - mm->pasid = INIT_PASID; -#endif -} - static void mm_init_uprobes_state(struct mm_struct *mm) { #ifdef CONFIG_UPROBES @@ -1054,7 +1052,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p, mm_init_cpumask(mm); mm_init_aio(mm); mm_init_owner(mm, p); - mm_init_pasid(mm); + mm_pasid_init(mm); RCU_INIT_POINTER(mm->exe_file, NULL); mmu_notifier_subscriptions_init(mm); init_tlb_flush_pending(mm); @@ -1121,6 +1119,7 @@ static inline void __mmput(struct mm_struct *mm) } if (mm->binfmt) module_put(mm->binfmt->module); + mm_pasid_drop(mm); mmdrop(mm); } |