Re: [PATCH v7 05/12] KVM: Move kvm_arch_flush_remote_tlbs_memslot() to common code
From: Anup Patel
Date: Mon Aug 07 2023 - 00:07:03 EST
On Sat, Jul 22, 2023 at 7:53 AM Raghavendra Rao Ananta
<rananta@xxxxxxxxxx> wrote:
>
> From: David Matlack <dmatlack@xxxxxxxxxx>
>
> 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 slots_lock being held when
> calling kvm_flush_remote_tlbs_memslot(), which was previously only
> asserted on x86. MIPS has calls to kvm_flush_remote_tlbs_memslot(),
> but they all hold the slots_lock, so the lockdep assertion continues to
> hold true.
>
> Also drop the CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT ifdef gating
> kvm_flush_remote_tlbs_memslot(), since it is no longer necessary.
>
> Signed-off-by: David Matlack <dmatlack@xxxxxxxxxx>
> Signed-off-by: Raghavendra Rao Ananta <rananta@xxxxxxxxxx>
> Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx>
> Reviewed-by: Shaoqin Huang <shahuang@xxxxxxxxxx>
For KVM RISC-V:
Acked-by: Anup Patel <anup@xxxxxxxxxxxxxx>
Thanks,
Anup
> ---
> 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 | 18 ++++++++++++++++--
> 7 files changed, 23 insertions(+), 42 deletions(-)
>
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index c2c14059f6a8..ed7bef4d970b 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -1525,12 +1525,6 @@ 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 4b7bc39a4173..231ac052b506 100644
> --- a/arch/mips/kvm/mips.c
> +++ b/arch/mips/kvm/mips.c
> @@ -199,7 +199,7 @@ 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);
> }
>
> @@ -235,7 +235,7 @@ 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);
> }
> }
> @@ -987,12 +987,6 @@ int kvm_arch_flush_remote_tlbs(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);
> -}
> -
> int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
> {
> int r;
> diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c
> index f2eb47925806..97e129620686 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 eb88d25f9896..efbe394da1a6 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -6669,7 +6669,7 @@ static void kvm_rmap_zap_collapsible_sptes(struct kvm *kvm,
> */
> if (walk_slot_rmaps(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,
> @@ -6688,20 +6688,6 @@ 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 a6b9bea62fb8..faeb2e307b36 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -12751,7 +12751,7 @@ 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 a731967b24ff..45899ce9ed31 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -1360,6 +1360,8 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu, bool yield_to_kernel_mode);
>
> void kvm_flush_remote_tlbs(struct kvm *kvm);
> void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t 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);
> @@ -1388,10 +1390,7 @@ 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 804470fccac7..58213cc4b9b9 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -379,6 +379,20 @@ void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t gfn, u64 pages)
> 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);
> @@ -2191,7 +2205,7 @@ 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;
> @@ -2308,7 +2322,7 @@ 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;
> }
> --
> 2.41.0.487.g6d72f3e995-goog
>