| Message ID | 20250223194943.3518952-9-riel@surriel.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | AMD broadcast TLB invalidation | expand |
Hi Rik, kernel test robot noticed the following build errors: [auto build test ERROR on tip/x86/core] [also build test ERROR on tip/x86/mm tip/master linus/master v6.14-rc4 next-20250221] [cannot apply to tip/auto-latest] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Rik-van-Riel/x86-mm-consolidate-full-flush-threshold-decision/20250224-035335 base: tip/x86/core patch link: https://lore.kernel.org/r/20250223194943.3518952-9-riel%40surriel.com patch subject: [PATCH v13 08/14] x86/mm: global ASID context switch & TLB flush handling config: x86_64-buildonly-randconfig-004-20250224 (https://download.01.org/0day-ci/archive/20250224/202502240650.kzshiji7-lkp@intel.com/config) compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250224/202502240650.kzshiji7-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202502240650.kzshiji7-lkp@intel.com/ All errors (new ones prefixed by >>): In file included from <command-line>: arch/x86/include/asm/tlbflush.h: In function 'in_asid_transition': >> arch/x86/include/asm/tlbflush.h:253:43: error: 'mm_context_t' has no member named 'asid_transition' 253 | return mm && READ_ONCE(mm->context.asid_transition); | ^ include/linux/compiler_types.h:522:23: note: in definition of macro '__compiletime_assert' 522 | if (!(condition)) \ | ^~~~~~~~~ include/linux/compiler_types.h:542:9: note: in expansion of macro '_compiletime_assert' 542 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) | ^~~~~~~~~~~~~~~~~~~ include/asm-generic/rwonce.h:36:9: note: in expansion of macro 'compiletime_assert' 36 | compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \ | ^~~~~~~~~~~~~~~~~~ include/asm-generic/rwonce.h:36:28: note: in expansion of macro '__native_word' 36 | compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \ | ^~~~~~~~~~~~~ include/asm-generic/rwonce.h:49:9: note: in expansion of macro 'compiletime_assert_rwonce_type' 49 | compiletime_assert_rwonce_type(x); \ | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/x86/include/asm/tlbflush.h:253:22: note: in expansion of macro 'READ_ONCE' 253 | return mm && READ_ONCE(mm->context.asid_transition); | ^~~~~~~~~ >> arch/x86/include/asm/tlbflush.h:253:43: error: 'mm_context_t' has no member named 'asid_transition' 253 | return mm && READ_ONCE(mm->context.asid_transition); | ^ include/linux/compiler_types.h:522:23: note: in definition of macro '__compiletime_assert' 522 | if (!(condition)) \ | ^~~~~~~~~ include/linux/compiler_types.h:542:9: note: in expansion of macro '_compiletime_assert' 542 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) | ^~~~~~~~~~~~~~~~~~~ include/asm-generic/rwonce.h:36:9: note: in expansion of macro 'compiletime_assert' 36 | compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \ | ^~~~~~~~~~~~~~~~~~ include/asm-generic/rwonce.h:36:28: note: in expansion of macro '__native_word' 36 | compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \ | ^~~~~~~~~~~~~ include/asm-generic/rwonce.h:49:9: note: in expansion of macro 'compiletime_assert_rwonce_type' 49 | compiletime_assert_rwonce_type(x); \ | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/x86/include/asm/tlbflush.h:253:22: note: in expansion of macro 'READ_ONCE' 253 | return mm && READ_ONCE(mm->context.asid_transition); | ^~~~~~~~~ >> arch/x86/include/asm/tlbflush.h:253:43: error: 'mm_context_t' has no member named 'asid_transition' 253 | return mm && READ_ONCE(mm->context.asid_transition); | ^ include/linux/compiler_types.h:522:23: note: in definition of macro '__compiletime_assert' 522 | if (!(condition)) \ | ^~~~~~~~~ include/linux/compiler_types.h:542:9: note: in expansion of macro '_compiletime_assert' 542 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) | ^~~~~~~~~~~~~~~~~~~ include/asm-generic/rwonce.h:36:9: note: in expansion of macro 'compiletime_assert' 36 | compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \ | ^~~~~~~~~~~~~~~~~~ include/asm-generic/rwonce.h:36:28: note: in expansion of macro '__native_word' 36 | compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \ | ^~~~~~~~~~~~~ include/asm-generic/rwonce.h:49:9: note: in expansion of macro 'compiletime_assert_rwonce_type' 49 | compiletime_assert_rwonce_type(x); \ | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/x86/include/asm/tlbflush.h:253:22: note: in expansion of macro 'READ_ONCE' 253 | return mm && READ_ONCE(mm->context.asid_transition); | ^~~~~~~~~ >> arch/x86/include/asm/tlbflush.h:253:43: error: 'mm_context_t' has no member named 'asid_transition' 253 | return mm && READ_ONCE(mm->context.asid_transition); | ^ include/linux/compiler_types.h:522:23: note: in definition of macro '__compiletime_assert' 522 | if (!(condition)) \ | ^~~~~~~~~ include/linux/compiler_types.h:542:9: note: in expansion of macro '_compiletime_assert' 542 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) | ^~~~~~~~~~~~~~~~~~~ include/asm-generic/rwonce.h:36:9: note: in expansion of macro 'compiletime_assert' 36 | compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \ | ^~~~~~~~~~~~~~~~~~ include/asm-generic/rwonce.h:36:28: note: in expansion of macro '__native_word' 36 | compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \ | ^~~~~~~~~~~~~ include/asm-generic/rwonce.h:49:9: note: in expansion of macro 'compiletime_assert_rwonce_type' 49 | compiletime_assert_rwonce_type(x); \ | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/x86/include/asm/tlbflush.h:253:22: note: in expansion of macro 'READ_ONCE' 253 | return mm && READ_ONCE(mm->context.asid_transition); | ^~~~~~~~~ >> arch/x86/include/asm/tlbflush.h:253:43: error: 'mm_context_t' has no member named 'asid_transition' 253 | return mm && READ_ONCE(mm->context.asid_transition); | ^ include/linux/compiler_types.h:522:23: note: in definition of macro '__compiletime_assert' 522 | if (!(condition)) \ | ^~~~~~~~~ include/linux/compiler_types.h:542:9: note: in expansion of macro '_compiletime_assert' 542 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) | ^~~~~~~~~~~~~~~~~~~ include/asm-generic/rwonce.h:36:9: note: in expansion of macro 'compiletime_assert' 36 | compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \ | ^~~~~~~~~~~~~~~~~~ include/asm-generic/rwonce.h:49:9: note: in expansion of macro 'compiletime_assert_rwonce_type' 49 | compiletime_assert_rwonce_type(x); \ | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/x86/include/asm/tlbflush.h:253:22: note: in expansion of macro 'READ_ONCE' 253 | return mm && READ_ONCE(mm->context.asid_transition); | ^~~~~~~~~ >> arch/x86/include/asm/tlbflush.h:253:43: error: 'mm_context_t' has no member named 'asid_transition' 253 | return mm && READ_ONCE(mm->context.asid_transition); | ^ include/linux/compiler_types.h:498:27: note: in definition of macro '__unqual_scalar_typeof' 498 | _Generic((x), \ | ^ include/asm-generic/rwonce.h:50:9: note: in expansion of macro '__READ_ONCE' 50 | __READ_ONCE(x); \ | ^~~~~~~~~~~ arch/x86/include/asm/tlbflush.h:253:22: note: in expansion of macro 'READ_ONCE' 253 | return mm && READ_ONCE(mm->context.asid_transition); | ^~~~~~~~~ In file included from ./arch/x86/include/generated/asm/rwonce.h:1, from include/linux/compiler.h:354, from include/linux/build_bug.h:5, from include/linux/container_of.h:5, from include/linux/list.h:5, from include/linux/swait.h:5, from include/linux/completion.h:12, from include/linux/crypto.h:15, from arch/x86/kernel/asm-offsets.c:9: >> arch/x86/include/asm/tlbflush.h:253:43: error: 'mm_context_t' has no member named 'asid_transition' 253 | return mm && READ_ONCE(mm->context.asid_transition); | ^ include/asm-generic/rwonce.h:44:73: note: in definition of macro '__READ_ONCE' 44 | #define __READ_ONCE(x) (*(const volatile __unqual_scalar_typeof(x) *)&(x)) | ^ arch/x86/include/asm/tlbflush.h:253:22: note: in expansion of macro 'READ_ONCE' 253 | return mm && READ_ONCE(mm->context.asid_transition); | ^~~~~~~~~ make[3]: *** [scripts/Makefile.build:102: arch/x86/kernel/asm-offsets.s] Error 1 shuffle=3847572294 make[3]: Target 'prepare' not remade because of errors. make[2]: *** [Makefile:1264: prepare0] Error 2 shuffle=3847572294 make[2]: Target 'prepare' not remade because of errors. make[1]: *** [Makefile:251: __sub-make] Error 2 shuffle=3847572294 make[1]: Target 'prepare' not remade because of errors. make: *** [Makefile:251: __sub-make] Error 2 shuffle=3847572294 make: Target 'prepare' not remade because of errors. vim +253 arch/x86/include/asm/tlbflush.h 247 248 static inline bool in_asid_transition(struct mm_struct *mm) 249 { 250 if (!cpu_feature_enabled(X86_FEATURE_INVLPGB)) 251 return false; 252 > 253 return mm && READ_ONCE(mm->context.asid_transition); 254 } 255
diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h index 83f1da2f1e4a..f1f82571249b 100644 --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -240,6 +240,19 @@ static inline bool is_dyn_asid(u16 asid) return asid < TLB_NR_DYN_ASIDS; } +static inline bool is_global_asid(u16 asid) +{ + return !is_dyn_asid(asid); +} + +static inline bool in_asid_transition(struct mm_struct *mm) +{ + if (!cpu_feature_enabled(X86_FEATURE_INVLPGB)) + return false; + + return mm && READ_ONCE(mm->context.asid_transition); +} + #ifdef CONFIG_X86_BROADCAST_TLB_FLUSH static inline u16 mm_global_asid(struct mm_struct *mm) { diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index 405630479b90..d8a04e398615 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -227,6 +227,20 @@ static void choose_new_asid(struct mm_struct *next, u64 next_tlb_gen, return; } + /* + * TLB consistency for global ASIDs is maintained with hardware assisted + * remote TLB flushing. Global ASIDs are always up to date. + */ + if (static_cpu_has(X86_FEATURE_INVLPGB)) { + u16 global_asid = mm_global_asid(next); + + if (global_asid) { + *new_asid = global_asid; + *need_flush = false; + return; + } + } + if (this_cpu_read(cpu_tlbstate.invalidate_other)) clear_asid_other(); @@ -389,6 +403,23 @@ void destroy_context_free_global_asid(struct mm_struct *mm) global_asid_available++; } +/* + * Is the mm transitioning from a CPU-local ASID to a global ASID? + */ +static bool needs_global_asid_reload(struct mm_struct *next, u16 prev_asid) +{ + u16 global_asid = mm_global_asid(next); + + if (!static_cpu_has(X86_FEATURE_INVLPGB)) + return false; + + /* Process is transitioning to a global ASID */ + if (global_asid && prev_asid != global_asid) + return true; + + return false; +} + /* * Given an ASID, flush the corresponding user ASID. We can delay this * until the next time we switch to it. @@ -694,7 +725,8 @@ void switch_mm_irqs_off(struct mm_struct *unused, struct mm_struct *next, */ if (prev == next) { /* Not actually switching mm's */ - VM_WARN_ON(this_cpu_read(cpu_tlbstate.ctxs[prev_asid].ctx_id) != + VM_WARN_ON(is_dyn_asid(prev_asid) && + this_cpu_read(cpu_tlbstate.ctxs[prev_asid].ctx_id) != next->context.ctx_id); /* @@ -711,6 +743,20 @@ void switch_mm_irqs_off(struct mm_struct *unused, struct mm_struct *next, !cpumask_test_cpu(cpu, mm_cpumask(next)))) cpumask_set_cpu(cpu, mm_cpumask(next)); + /* Check if the current mm is transitioning to a global ASID */ + if (needs_global_asid_reload(next, prev_asid)) { + next_tlb_gen = atomic64_read(&next->context.tlb_gen); + choose_new_asid(next, next_tlb_gen, &new_asid, &need_flush); + goto reload_tlb; + } + + /* + * Broadcast TLB invalidation keeps this PCID up to date + * all the time. + */ + if (is_global_asid(prev_asid)) + return; + /* * If the CPU is not in lazy TLB mode, we are just switching * from one thread in a process to another thread in the same @@ -744,6 +790,13 @@ void switch_mm_irqs_off(struct mm_struct *unused, struct mm_struct *next, */ cond_mitigation(tsk); + /* + * Let nmi_uaccess_okay() and finish_asid_transition() + * know that we're changing CR3. + */ + this_cpu_write(cpu_tlbstate.loaded_mm, LOADED_MM_SWITCHING); + barrier(); + /* * Leave this CPU in prev's mm_cpumask. Atomic writes to * mm_cpumask can be expensive under contention. The CPU @@ -758,14 +811,12 @@ void switch_mm_irqs_off(struct mm_struct *unused, struct mm_struct *next, next_tlb_gen = atomic64_read(&next->context.tlb_gen); choose_new_asid(next, next_tlb_gen, &new_asid, &need_flush); - - /* Let nmi_uaccess_okay() know that we're changing CR3. */ - this_cpu_write(cpu_tlbstate.loaded_mm, LOADED_MM_SWITCHING); - barrier(); } +reload_tlb: new_lam = mm_lam_cr3_mask(next); if (need_flush) { + VM_WARN_ON_ONCE(is_global_asid(new_asid)); this_cpu_write(cpu_tlbstate.ctxs[new_asid].ctx_id, next->context.ctx_id); this_cpu_write(cpu_tlbstate.ctxs[new_asid].tlb_gen, next_tlb_gen); load_new_mm_cr3(next->pgd, new_asid, new_lam, true); @@ -884,7 +935,7 @@ static void flush_tlb_func(void *info) const struct flush_tlb_info *f = info; struct mm_struct *loaded_mm = this_cpu_read(cpu_tlbstate.loaded_mm); u32 loaded_mm_asid = this_cpu_read(cpu_tlbstate.loaded_mm_asid); - u64 local_tlb_gen = this_cpu_read(cpu_tlbstate.ctxs[loaded_mm_asid].tlb_gen); + u64 local_tlb_gen; bool local = smp_processor_id() == f->initiating_cpu; unsigned long nr_invalidate = 0; u64 mm_tlb_gen; @@ -907,6 +958,16 @@ static void flush_tlb_func(void *info) if (unlikely(loaded_mm == &init_mm)) return; + /* Reload the ASID if transitioning into or out of a global ASID */ + if (needs_global_asid_reload(loaded_mm, loaded_mm_asid)) { + switch_mm_irqs_off(NULL, loaded_mm, NULL); + loaded_mm_asid = this_cpu_read(cpu_tlbstate.loaded_mm_asid); + } + + /* Broadcast ASIDs are always kept up to date with INVLPGB. */ + if (is_global_asid(loaded_mm_asid)) + return; + VM_WARN_ON(this_cpu_read(cpu_tlbstate.ctxs[loaded_mm_asid].ctx_id) != loaded_mm->context.ctx_id); @@ -924,6 +985,8 @@ static void flush_tlb_func(void *info) return; } + local_tlb_gen = this_cpu_read(cpu_tlbstate.ctxs[loaded_mm_asid].tlb_gen); + if (unlikely(f->new_tlb_gen != TLB_GENERATION_INVALID && f->new_tlb_gen <= local_tlb_gen)) { /* @@ -1091,7 +1154,7 @@ STATIC_NOPV void native_flush_tlb_multi(const struct cpumask *cpumask, * up on the new contents of what used to be page tables, while * doing a speculative memory access. */ - if (info->freed_tables) + if (info->freed_tables || in_asid_transition(info->mm)) on_each_cpu_mask(cpumask, flush_tlb_func, (void *)info, true); else on_each_cpu_cond_mask(should_flush_tlb, flush_tlb_func,
Context switch and TLB flush support for processes that use a global ASID & PCID across all CPUs. At both context switch time and TLB flush time, we need to check whether a task is switching to a global ASID, and reload the TLB with the new ASID as appropriate. In both code paths, we also short-circuit the TLB flush if we are using a global ASID, because the global ASIDs are always kept up to date across CPUs, even while the process is not running on a CPU. Signed-off-by: Rik van Riel <riel@surriel.com> --- arch/x86/include/asm/tlbflush.h | 13 ++++++ arch/x86/mm/tlb.c | 77 ++++++++++++++++++++++++++++++--- 2 files changed, 83 insertions(+), 7 deletions(-)