search for: cpu_tlbstate

vhost net module wants to do copy to/from user from a kernel thread, which needs switch_mm (like what fs/aio has). export cpu_tlbstate to make this possible Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- arch/x86/mm/tlb.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index 821e970..e33a5f0 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -...

vhost net module wants to do copy to/from user from a kernel thread, which needs switch_mm (like what fs/aio has). export cpu_tlbstate to make this possible Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- arch/x86/mm/tlb.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index 821e970..e33a5f0 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -...

Twitter user stintel, in this thread: https://twitter.com/stintel/status/948499157282623488 mentions a possible problem with the new patches and the nvidia driver: "As if the @Intel bug isn't bad enough, #KPTI renders @nvidia driver incompatible due to GPL-only symbol 'cpu_tlbstate'. #epicfail" Also: https://twitter.com/tomasz_gwozdz/status/948590364679655429 https://twitter.com/BitsAndChipsEng/status/948578609761054721 Cheers, Zube

Seems to work OK for native and Xen. I had to play a bit with the paravirt-sched-clock patch to deal with the VMI changes. Zach, can you check that it still works? Thanks, J

Seems to work OK for native and Xen. I had to play a bit with the paravirt-sched-clock patch to deal with the VMI changes. Zach, can you check that it still works? Thanks, J

...re, with native_flush_tlb_others skipping + * This should be rare, with native_flush_tlb_multi skipping * IPIs to lazy TLB mode CPUs. */ switch_mm_irqs_off(NULL, &init_mm, NULL); @@ -635,9 +635,12 @@ static void flush_tlb_func_common(const struct flush_tlb_info *f, this_cpu_write(cpu_tlbstate.ctxs[loaded_mm_asid].tlb_gen, mm_tlb_gen); } -static void flush_tlb_func_local(const void *info, enum tlb_flush_reason reason) +static void flush_tlb_func_local(void *info) { const struct flush_tlb_info *f = info; + enum tlb_flush_reason reason; + + reason = (f->mm == NULL) ? TLB_LOCAL_SHO...

...re, with native_flush_tlb_others skipping + * This should be rare, with native_flush_tlb_multi skipping * IPIs to lazy TLB mode CPUs. */ switch_mm_irqs_off(NULL, &init_mm, NULL); @@ -635,9 +635,12 @@ static void flush_tlb_func_common(const struct flush_tlb_info *f, this_cpu_write(cpu_tlbstate.ctxs[loaded_mm_asid].tlb_gen, mm_tlb_gen); } -static void flush_tlb_func_local(const void *info, enum tlb_flush_reason reason) +static void flush_tlb_func_local(void *info) { const struct flush_tlb_info *f = info; + enum tlb_flush_reason reason; + + reason = (f->mm == NULL) ? TLB_LOCAL_SHO...

...sh_reason reason = TLB_REMOTE_SHOOTDOWN; + bool local = false; + + if (f->cpu == smp_processor_id()) { + local = true; + reason = (f->mm == NULL) ? TLB_LOCAL_SHOOTDOWN : TLB_LOCAL_MM_SHOOTDOWN; + } else { + inc_irq_stat(irq_tlb_count); + + if (f->mm && f->mm != this_cpu_read(cpu_tlbstate.loaded_mm)) + return; + + count_vm_tlb_event(NR_TLB_REMOTE_FLUSH_RECEIVED); + } + + flush_tlb_func_common(f, local, reason); +} + static bool tlb_is_not_lazy(int cpu) { return !per_cpu(cpu_tlbstate_shared.is_lazy, cpu);

...sh_reason reason = TLB_REMOTE_SHOOTDOWN; + bool local = false; + + if (f->cpu == smp_processor_id()) { + local = true; + reason = (f->mm == NULL) ? TLB_LOCAL_SHOOTDOWN : TLB_LOCAL_MM_SHOOTDOWN; + } else { + inc_irq_stat(irq_tlb_count); + + if (f->mm && f->mm != this_cpu_read(cpu_tlbstate.loaded_mm)) + return; + + count_vm_tlb_event(NR_TLB_REMOTE_FLUSH_RECEIVED); + } + + flush_tlb_func_common(f, local, reason); +} + static bool tlb_is_not_lazy(int cpu) { return !per_cpu(cpu_tlbstate_shared.is_lazy, cpu);

...e, with native_flush_tlb_others skipping + * This should be rare, with native_flush_tlb_multi() skipping * IPIs to lazy TLB mode CPUs. */ switch_mm_irqs_off(NULL, &init_mm, NULL); @@ -635,7 +635,7 @@ static void flush_tlb_func_common(const struct flush_tlb_info *f, this_cpu_write(cpu_tlbstate.ctxs[loaded_mm_asid].tlb_gen, mm_tlb_gen); } -static void flush_tlb_func_local(void *info) +static void __flush_tlb_func_local(void *info) { const struct flush_tlb_info *f = info; enum tlb_flush_reason reason; @@ -645,6 +645,11 @@ static void flush_tlb_func_local(void *info) flush_tlb_fun...

....org Nadav Amit (9): smp: Run functions concurrently in smp_call_function_many() x86/mm/tlb: Remove reason as argument for flush_tlb_func_local() x86/mm/tlb: Open-code on_each_cpu_cond_mask() for tlb_is_not_lazy() x86/mm/tlb: Flush remote and local TLBs concurrently x86/mm/tlb: Privatize cpu_tlbstate x86/mm/tlb: Do not make is_lazy dirty for no reason cpumask: Mark functions as pure x86/mm/tlb: Remove UV special case x86/mm/tlb: Remove unnecessary uses of the inline keyword arch/x86/hyperv/mmu.c | 13 ++- arch/x86/include/asm/paravirt.h | 6 +- arch/x86/includ...

....org Nadav Amit (9): smp: Run functions concurrently in smp_call_function_many() x86/mm/tlb: Remove reason as argument for flush_tlb_func_local() x86/mm/tlb: Open-code on_each_cpu_cond_mask() for tlb_is_not_lazy() x86/mm/tlb: Flush remote and local TLBs concurrently x86/mm/tlb: Privatize cpu_tlbstate x86/mm/tlb: Do not make is_lazy dirty for no reason cpumask: Mark functions as pure x86/mm/tlb: Remove UV special case x86/mm/tlb: Remove unnecessary uses of the inline keyword arch/x86/hyperv/mmu.c | 10 +- arch/x86/include/asm/paravirt.h | 6 +- arch/x86/include...

...s. > */ Nit, since we're messing with this, it can now be "native_flush_tlb_multi()" since it is a function. > switch_mm_irqs_off(NULL, &init_mm, NULL); > @@ -635,9 +635,12 @@ static void flush_tlb_func_common(const struct flush_tlb_info *f, > this_cpu_write(cpu_tlbstate.ctxs[loaded_mm_asid].tlb_gen, mm_tlb_gen); > } > > -static void flush_tlb_func_local(const void *info, enum tlb_flush_reason reason) > +static void flush_tlb_func_local(void *info) > { > const struct flush_tlb_info *f = info; > + enum tlb_flush_reason reason; > + >...

...n this thread: > > https://twitter.com/stintel/status/948499157282623488 > > mentions a possible problem with the new patches and the > nvidia driver: > > "As if the @Intel bug isn't bad enough, #KPTI renders @nvidia driver > incompatible due to GPL-only symbol 'cpu_tlbstate'. #epicfail" > > Also: > > https://twitter.com/tomasz_gwozdz/status/948590364679655429 > > https://twitter.com/BitsAndChipsEng/status/948578609761054721 I've seen no obvious problems with kernel-3.10.0-693.11.6.el7.x86_64 and nvidia-x11-drv-384.98-2.el7.elrepo.x86_64...

...ome more detailed description attached to the patch itself. The patches are against 2.6.31-rc4. I'd like them to go into linux-next and down the road 2.6.32 if possible. Please comment. Userspace bits using this driver will be posted to kvm at vger shortly. Michael S. Tsirkin (2): export cpu_tlbstate to modules vhost_net: a kernel-level virtio server MAINTAINERS | 10 + arch/x86/kvm/Kconfig | 1 + arch/x86/mm/tlb.c | 1 + drivers/Makefile | 1 + drivers/block/virtio_blk.c | 3 + drivers/vhost/Kconfig | 11 + drivers/vhost/Makefile...

...ome more detailed description attached to the patch itself. The patches are against 2.6.31-rc4. I'd like them to go into linux-next and down the road 2.6.32 if possible. Please comment. Userspace bits using this driver will be posted to kvm at vger shortly. Michael S. Tsirkin (2): export cpu_tlbstate to modules vhost_net: a kernel-level virtio server MAINTAINERS | 10 + arch/x86/kvm/Kconfig | 1 + arch/x86/mm/tlb.c | 1 + drivers/Makefile | 1 + drivers/block/virtio_blk.c | 3 + drivers/vhost/Kconfig | 11 + drivers/vhost/Makefile...

...+ bool local = false; > + > + if (f->cpu == smp_processor_id()) { > + local = true; > + reason = (f->mm == NULL) ? TLB_LOCAL_SHOOTDOWN : TLB_LOCAL_MM_SHOOTDOWN; > + } else { > + inc_irq_stat(irq_tlb_count); > + > + if (f->mm && f->mm != this_cpu_read(cpu_tlbstate.loaded_mm)) > + return; > + > + count_vm_tlb_event(NR_TLB_REMOTE_FLUSH_RECEIVED); > + } > + > + flush_tlb_func_common(f, local, reason); > +} > + > static bool tlb_is_not_lazy(int cpu) > { > return !per_cpu(cpu_tlbstate_shared.is_lazy, cpu); Nice! I will add it...

...we're messing with this, it can now be > "native_flush_tlb_multi()" since it is a function. Sure. > >> switch_mm_irqs_off(NULL, &init_mm, NULL); >> @@ -635,9 +635,12 @@ static void flush_tlb_func_common(const struct flush_tlb_info *f, >> this_cpu_write(cpu_tlbstate.ctxs[loaded_mm_asid].tlb_gen, mm_tlb_gen); >> } >> >> -static void flush_tlb_func_local(const void *info, enum tlb_flush_reason reason) >> +static void flush_tlb_func_local(void *info) >> { >> const struct flush_tlb_info *f = info; >> + enum tlb_flush_rea...

...we're messing with this, it can now be > "native_flush_tlb_multi()" since it is a function. Sure. > >> switch_mm_irqs_off(NULL, &init_mm, NULL); >> @@ -635,9 +635,12 @@ static void flush_tlb_func_common(const struct flush_tlb_info *f, >> this_cpu_write(cpu_tlbstate.ctxs[loaded_mm_asid].tlb_gen, mm_tlb_gen); >> } >> >> -static void flush_tlb_func_local(const void *info, enum tlb_flush_reason reason) >> +static void flush_tlb_func_local(void *info) >> { >> const struct flush_tlb_info *f = info; >> + enum tlb_flush_rea...

...mask, flush_tlb_func_remote, + flush_tlb_func_local, (void *)info, 1); } } @@ -818,16 +827,20 @@ void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start, info = get_flush_tlb_info(mm, start, end, stride_shift, freed_tables, new_tlb_gen); - if (mm == this_cpu_read(cpu_tlbstate.loaded_mm)) { + /* + * flush_tlb_multi() is not optimized for the common case in which only + * a local TLB flush is needed. Optimize this use-case by calling + * flush_tlb_func_local() directly in this case. + */ + if (cpumask_any_but(mm_cpumask(mm), cpu) < nr_cpu_ids) { + flush_tlb_multi(...