From: Ricardo Koller Date: Wed, 26 Apr 2023 17:23:29 +0000 (+0000) Subject: KVM: arm64: Split huge pages during KVM_CLEAR_DIRTY_LOG X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=6acf51666d039857421b6f8a3660301c82649fa5;p=linux.git KVM: arm64: Split huge pages during KVM_CLEAR_DIRTY_LOG This is the arm64 counterpart of commit cb00a70bd4b7 ("KVM: x86/mmu: Split huge pages mapped by the TDP MMU during KVM_CLEAR_DIRTY_LOG"), which has the benefit of splitting the cost of splitting a memslot across multiple ioctls. Split huge pages on the range specified using KVM_CLEAR_DIRTY_LOG. And do not split when enabling dirty logging if KVM_DIRTY_LOG_INITIALLY_SET is set. Signed-off-by: Ricardo Koller Reviewed-by: Gavin Shan Link: https://lore.kernel.org/r/20230426172330.1439644-12-ricarkol@google.com Signed-off-by: Oliver Upton --- diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 272558f54101b..3386bd28d2670 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1114,8 +1114,8 @@ static void kvm_mmu_split_memory_region(struct kvm *kvm, int slot) * @mask: The mask of pages at offset 'gfn_offset' in this memory * slot to enable dirty logging on * - * Writes protect selected pages to enable dirty logging for them. Caller must - * acquire kvm->mmu_lock. + * Writes protect selected pages to enable dirty logging, and then + * splits them to PAGE_SIZE. Caller must acquire kvm->mmu_lock. */ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, struct kvm_memory_slot *slot, @@ -1128,6 +1128,17 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, lockdep_assert_held_write(&kvm->mmu_lock); stage2_wp_range(&kvm->arch.mmu, start, end); + + /* + * Eager-splitting is done when manual-protect is set. We + * also check for initially-all-set because we can avoid + * eager-splitting if initially-all-set is false. + * Initially-all-set equal false implies that huge-pages were + * already split when enabling dirty logging: no need to do it + * again. + */ + if (kvm_dirty_log_manual_protect_and_init_set(kvm)) + kvm_mmu_split_huge_pages(kvm, start, end); } static void kvm_send_hwpoison_signal(unsigned long address, short lsb)