From 73d49df2c3e7cad5bf64c92ec03ce9e3823898b9 Mon Sep 17 00:00:00 2001 From: Quentin Perret Date: Fri, 11 Sep 2020 14:25:20 +0100 Subject: [PATCH] KVM: arm64: Add support for stage-2 write-protect in generic page-table Add a stage-2 wrprotect() operation to the generic page-table code. Signed-off-by: Quentin Perret Signed-off-by: Will Deacon Signed-off-by: Marc Zyngier Reviewed-by: Gavin Shan Cc: Marc Zyngier Link: https://lore.kernel.org/r/20200911132529.19844-13-will@kernel.org --- arch/arm64/include/asm/kvm_pgtable.h | 18 ++++++++++++++++++ arch/arm64/kvm/hyp/pgtable.c | 6 ++++++ 2 files changed, 24 insertions(+) diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index 50782128c861..5ae6006a6098 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -187,6 +187,24 @@ int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size, int kvm_pgtable_stage2_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size); /** + * kvm_pgtable_stage2_wrprotect() - Write-protect guest stage-2 address range + * without TLB invalidation. + * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init(). + * @addr: Intermediate physical address from which to write-protect, + * @size: Size of the range. + * + * The offset of @addr within a page is ignored and @size is rounded-up to + * the next page boundary. + * + * Note that it is the caller's responsibility to invalidate the TLB after + * calling this function to ensure that the updated permissions are visible + * to the CPUs. + * + * Return: 0 on success, negative error code on failure. + */ +int kvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size); + +/** * kvm_pgtable_stage2_mkyoung() - Set the access flag in a page-table entry. * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init(). * @addr: Intermediate physical address to identify the page-table entry. diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index af60ea8ee29d..480b95030f54 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -746,6 +746,12 @@ static int stage2_update_leaf_attrs(struct kvm_pgtable *pgt, u64 addr, return 0; } +int kvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size) +{ + return stage2_update_leaf_attrs(pgt, addr, size, 0, + KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W, NULL); +} + kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr) { kvm_pte_t pte = 0; -- 2.11.0