| Message ID | 20221208193857.4090582-34-dmatlack@google.com |
|---|---|
| State | RFC |
| Headers | show |
| Series | KVM: Refactor the KVM/x86 TDP MMU into common code | expand |
On Thu, Dec 8, 2022 at 11:40 AM David Matlack <dmatlack@google.com> wrote: > > Move kvm_arch_flush_remote_tlbs_memslot() to common code and drop > "arch_" from the name. kvm_arch_flush_remote_tlbs_memslot() is just a > range-based TLB invalidation where the range is defined by the memslot. > Now that kvm_flush_remote_tlbs_range() can be called from common code we > can just use that and drop a bunch of duplicate code from the arch > directories. > > Note this adds a lockdep assertion for slot_lock being held when calling > kvm_flush_remote_tlbs_memslot(), which was previously only asserted on > x86. Besides the one lockdep assertion, is there any benefit to having this wrapper function? Open-coding "kvm_flush_remote_tlbs_range(kvm, memslot->base_gfn, memslot->npages);" is only a slightly longer line and, IMO, just as readable. I'm happy to see this cleanup, but it might be just as easy to drop the function. > > Signed-off-by: David Matlack <dmatlack@google.com> > --- > arch/arm64/kvm/arm.c | 6 ------ > arch/mips/kvm/mips.c | 10 ++-------- > arch/riscv/kvm/mmu.c | 6 ------ > arch/x86/kvm/mmu/mmu.c | 16 +--------------- > arch/x86/kvm/x86.c | 2 +- > include/linux/kvm_host.h | 7 +++---- > virt/kvm/kvm_main.c | 17 +++++++++++++++-- > 7 files changed, 22 insertions(+), 42 deletions(-) > > diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c > index 0e0d4c4f79a2..4f1549c1d2d2 100644 > --- a/arch/arm64/kvm/arm.c > +++ b/arch/arm64/kvm/arm.c > @@ -1430,12 +1430,6 @@ void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot) > > } > > -void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, > - const struct kvm_memory_slot *memslot) > -{ > - kvm_flush_remote_tlbs(kvm); > -} > - > static int kvm_vm_ioctl_set_device_addr(struct kvm *kvm, > struct kvm_arm_device_addr *dev_addr) > { > diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c > index a25e0b73ee70..ecd8a051fd6b 100644 > --- a/arch/mips/kvm/mips.c > +++ b/arch/mips/kvm/mips.c > @@ -209,7 +209,7 @@ void kvm_arch_flush_shadow_memslot(struct kvm *kvm, > /* Flush slot from GPA */ > kvm_mips_flush_gpa_pt(kvm, slot->base_gfn, > slot->base_gfn + slot->npages - 1); > - kvm_arch_flush_remote_tlbs_memslot(kvm, slot); > + kvm_flush_remote_tlbs_memslot(kvm, slot); > spin_unlock(&kvm->mmu_lock); > } > > @@ -245,7 +245,7 @@ void kvm_arch_commit_memory_region(struct kvm *kvm, > needs_flush = kvm_mips_mkclean_gpa_pt(kvm, new->base_gfn, > new->base_gfn + new->npages - 1); > if (needs_flush) > - kvm_arch_flush_remote_tlbs_memslot(kvm, new); > + kvm_flush_remote_tlbs_memslot(kvm, new); > spin_unlock(&kvm->mmu_lock); > } > } > @@ -997,12 +997,6 @@ int kvm_arch_flush_remote_tlb(struct kvm *kvm) > return 1; > } > > -void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, > - const struct kvm_memory_slot *memslot) > -{ > - kvm_flush_remote_tlbs(kvm); > -} > - > long kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) > { > long r; > diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c > index a8281a65cb3d..98bf3719a396 100644 > --- a/arch/riscv/kvm/mmu.c > +++ b/arch/riscv/kvm/mmu.c > @@ -406,12 +406,6 @@ void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot) > { > } > > -void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, > - const struct kvm_memory_slot *memslot) > -{ > - kvm_flush_remote_tlbs(kvm); > -} > - > void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free) > { > } > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > index 19963ed83484..f2602ee1771f 100644 > --- a/arch/x86/kvm/mmu/mmu.c > +++ b/arch/x86/kvm/mmu/mmu.c > @@ -6524,7 +6524,7 @@ static void kvm_rmap_zap_collapsible_sptes(struct kvm *kvm, > */ > if (slot_handle_level(kvm, slot, kvm_mmu_zap_collapsible_spte, > PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL - 1, true)) > - kvm_arch_flush_remote_tlbs_memslot(kvm, slot); > + kvm_flush_remote_tlbs_memslot(kvm, slot); > } > > void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, > @@ -6543,20 +6543,6 @@ void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, > } > } > > -void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, > - const struct kvm_memory_slot *memslot) > -{ > - /* > - * All current use cases for flushing the TLBs for a specific memslot > - * related to dirty logging, and many do the TLB flush out of mmu_lock. > - * The interaction between the various operations on memslot must be > - * serialized by slots_locks to ensure the TLB flush from one operation > - * is observed by any other operation on the same memslot. > - */ > - lockdep_assert_held(&kvm->slots_lock); > - kvm_flush_remote_tlbs_range(kvm, memslot->base_gfn, memslot->npages); > -} > - > void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, > const struct kvm_memory_slot *memslot) > { > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 517c8ed33542..95ff95da55d5 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -12574,7 +12574,7 @@ static void kvm_mmu_slot_apply_flags(struct kvm *kvm, > * See is_writable_pte() for more details (the case involving > * access-tracked SPTEs is particularly relevant). > */ > - kvm_arch_flush_remote_tlbs_memslot(kvm, new); > + kvm_flush_remote_tlbs_memslot(kvm, new); > } > } > > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > index d9a7f559d2c5..46ed0ef4fb79 100644 > --- a/include/linux/kvm_host.h > +++ b/include/linux/kvm_host.h > @@ -1366,6 +1366,8 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu, bool usermode_vcpu_not_eligible); > > void kvm_flush_remote_tlbs(struct kvm *kvm); > void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn, u64 pages); > +void kvm_flush_remote_tlbs_memslot(struct kvm *kvm, > + const struct kvm_memory_slot *memslot); > > #ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE > int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min); > @@ -1394,10 +1396,7 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, > unsigned long mask); > void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot); > > -#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT > -void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, > - const struct kvm_memory_slot *memslot); > -#else /* !CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */ > +#ifndef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT > int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log); > int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log, > int *is_dirty, struct kvm_memory_slot **memslot); > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 662ca280c0cf..39c2efd15504 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -388,6 +388,19 @@ void __weak kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn, u64 pa > kvm_flush_remote_tlbs(kvm); > } > > +void kvm_flush_remote_tlbs_memslot(struct kvm *kvm, const struct kvm_memory_slot *memslot) > +{ > + /* > + * All current use cases for flushing the TLBs for a specific memslot > + * related to dirty logging, and many do the TLB flush out of mmu_lock. > + * The interaction between the various operations on memslot must be > + * serialized by slots_locks to ensure the TLB flush from one operation > + * is observed by any other operation on the same memslot. > + */ > + lockdep_assert_held(&kvm->slots_lock); > + kvm_flush_remote_tlbs_range(kvm, memslot->base_gfn, memslot->npages); > +} > + > static void kvm_flush_shadow_all(struct kvm *kvm) > { > kvm_arch_flush_shadow_all(kvm); > @@ -2197,7 +2210,7 @@ static int kvm_get_dirty_log_protect(struct kvm *kvm, struct kvm_dirty_log *log) > } > > if (flush) > - kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); > + kvm_flush_remote_tlbs_memslot(kvm, memslot); > > if (copy_to_user(log->dirty_bitmap, dirty_bitmap_buffer, n)) > return -EFAULT; > @@ -2314,7 +2327,7 @@ static int kvm_clear_dirty_log_protect(struct kvm *kvm, > KVM_MMU_UNLOCK(kvm); > > if (flush) > - kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); > + kvm_flush_remote_tlbs_memslot(kvm, memslot); > > return 0; > } > -- > 2.39.0.rc1.256.g54fd8350bd-goog >
On Mon, Dec 12, 2022 at 2:03 PM Ben Gardon <bgardon@google.com> wrote: > > On Thu, Dec 8, 2022 at 11:40 AM David Matlack <dmatlack@google.com> wrote: > > > > Move kvm_arch_flush_remote_tlbs_memslot() to common code and drop > > "arch_" from the name. kvm_arch_flush_remote_tlbs_memslot() is just a > > range-based TLB invalidation where the range is defined by the memslot. > > Now that kvm_flush_remote_tlbs_range() can be called from common code we > > can just use that and drop a bunch of duplicate code from the arch > > directories. > > > > Note this adds a lockdep assertion for slot_lock being held when calling > > kvm_flush_remote_tlbs_memslot(), which was previously only asserted on > > x86. > > Besides the one lockdep assertion, is there any benefit to having this > wrapper function? Open-coding "kvm_flush_remote_tlbs_range(kvm, > memslot->base_gfn, memslot->npages);" is only a slightly longer line > and, IMO, just as readable. I'm happy to see this cleanup, but it > might be just as easy to drop the function. The wrapper makes lines shorter, adds a lockdep assertion, and is just as readable. What's the reason to drop it?
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 0e0d4c4f79a2..4f1549c1d2d2 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1430,12 +1430,6 @@ void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot) } -void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, - const struct kvm_memory_slot *memslot) -{ - kvm_flush_remote_tlbs(kvm); -} - static int kvm_vm_ioctl_set_device_addr(struct kvm *kvm, struct kvm_arm_device_addr *dev_addr) { diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c index a25e0b73ee70..ecd8a051fd6b 100644 --- a/arch/mips/kvm/mips.c +++ b/arch/mips/kvm/mips.c @@ -209,7 +209,7 @@ void kvm_arch_flush_shadow_memslot(struct kvm *kvm, /* Flush slot from GPA */ kvm_mips_flush_gpa_pt(kvm, slot->base_gfn, slot->base_gfn + slot->npages - 1); - kvm_arch_flush_remote_tlbs_memslot(kvm, slot); + kvm_flush_remote_tlbs_memslot(kvm, slot); spin_unlock(&kvm->mmu_lock); } @@ -245,7 +245,7 @@ void kvm_arch_commit_memory_region(struct kvm *kvm, needs_flush = kvm_mips_mkclean_gpa_pt(kvm, new->base_gfn, new->base_gfn + new->npages - 1); if (needs_flush) - kvm_arch_flush_remote_tlbs_memslot(kvm, new); + kvm_flush_remote_tlbs_memslot(kvm, new); spin_unlock(&kvm->mmu_lock); } } @@ -997,12 +997,6 @@ int kvm_arch_flush_remote_tlb(struct kvm *kvm) return 1; } -void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, - const struct kvm_memory_slot *memslot) -{ - kvm_flush_remote_tlbs(kvm); -} - long kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { long r; diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c index a8281a65cb3d..98bf3719a396 100644 --- a/arch/riscv/kvm/mmu.c +++ b/arch/riscv/kvm/mmu.c @@ -406,12 +406,6 @@ void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot) { } -void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, - const struct kvm_memory_slot *memslot) -{ - kvm_flush_remote_tlbs(kvm); -} - void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free) { } diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 19963ed83484..f2602ee1771f 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -6524,7 +6524,7 @@ static void kvm_rmap_zap_collapsible_sptes(struct kvm *kvm, */ if (slot_handle_level(kvm, slot, kvm_mmu_zap_collapsible_spte, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL - 1, true)) - kvm_arch_flush_remote_tlbs_memslot(kvm, slot); + kvm_flush_remote_tlbs_memslot(kvm, slot); } void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, @@ -6543,20 +6543,6 @@ void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, } } -void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, - const struct kvm_memory_slot *memslot) -{ - /* - * All current use cases for flushing the TLBs for a specific memslot - * related to dirty logging, and many do the TLB flush out of mmu_lock. - * The interaction between the various operations on memslot must be - * serialized by slots_locks to ensure the TLB flush from one operation - * is observed by any other operation on the same memslot. - */ - lockdep_assert_held(&kvm->slots_lock); - kvm_flush_remote_tlbs_range(kvm, memslot->base_gfn, memslot->npages); -} - void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, const struct kvm_memory_slot *memslot) { diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 517c8ed33542..95ff95da55d5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -12574,7 +12574,7 @@ static void kvm_mmu_slot_apply_flags(struct kvm *kvm, * See is_writable_pte() for more details (the case involving * access-tracked SPTEs is particularly relevant). */ - kvm_arch_flush_remote_tlbs_memslot(kvm, new); + kvm_flush_remote_tlbs_memslot(kvm, new); } } diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index d9a7f559d2c5..46ed0ef4fb79 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1366,6 +1366,8 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu, bool usermode_vcpu_not_eligible); void kvm_flush_remote_tlbs(struct kvm *kvm); void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn, u64 pages); +void kvm_flush_remote_tlbs_memslot(struct kvm *kvm, + const struct kvm_memory_slot *memslot); #ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min); @@ -1394,10 +1396,7 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, unsigned long mask); void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot); -#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT -void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, - const struct kvm_memory_slot *memslot); -#else /* !CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */ +#ifndef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log); int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log, int *is_dirty, struct kvm_memory_slot **memslot); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 662ca280c0cf..39c2efd15504 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -388,6 +388,19 @@ void __weak kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn, u64 pa kvm_flush_remote_tlbs(kvm); } +void kvm_flush_remote_tlbs_memslot(struct kvm *kvm, const struct kvm_memory_slot *memslot) +{ + /* + * All current use cases for flushing the TLBs for a specific memslot + * related to dirty logging, and many do the TLB flush out of mmu_lock. + * The interaction between the various operations on memslot must be + * serialized by slots_locks to ensure the TLB flush from one operation + * is observed by any other operation on the same memslot. + */ + lockdep_assert_held(&kvm->slots_lock); + kvm_flush_remote_tlbs_range(kvm, memslot->base_gfn, memslot->npages); +} + static void kvm_flush_shadow_all(struct kvm *kvm) { kvm_arch_flush_shadow_all(kvm); @@ -2197,7 +2210,7 @@ static int kvm_get_dirty_log_protect(struct kvm *kvm, struct kvm_dirty_log *log) } if (flush) - kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); + kvm_flush_remote_tlbs_memslot(kvm, memslot); if (copy_to_user(log->dirty_bitmap, dirty_bitmap_buffer, n)) return -EFAULT; @@ -2314,7 +2327,7 @@ static int kvm_clear_dirty_log_protect(struct kvm *kvm, KVM_MMU_UNLOCK(kvm); if (flush) - kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); + kvm_flush_remote_tlbs_memslot(kvm, memslot); return 0; }
Move kvm_arch_flush_remote_tlbs_memslot() to common code and drop "arch_" from the name. kvm_arch_flush_remote_tlbs_memslot() is just a range-based TLB invalidation where the range is defined by the memslot. Now that kvm_flush_remote_tlbs_range() can be called from common code we can just use that and drop a bunch of duplicate code from the arch directories. Note this adds a lockdep assertion for slot_lock being held when calling kvm_flush_remote_tlbs_memslot(), which was previously only asserted on x86. Signed-off-by: David Matlack <dmatlack@google.com> --- arch/arm64/kvm/arm.c | 6 ------ arch/mips/kvm/mips.c | 10 ++-------- arch/riscv/kvm/mmu.c | 6 ------ arch/x86/kvm/mmu/mmu.c | 16 +--------------- arch/x86/kvm/x86.c | 2 +- include/linux/kvm_host.h | 7 +++---- virt/kvm/kvm_main.c | 17 +++++++++++++++-- 7 files changed, 22 insertions(+), 42 deletions(-)