From 0f2c334fd25a95b2752345ce75839d5abc8b4567 Mon Sep 17 00:00:00 2001 From: Sebastian Ene Date: Fri, 6 Jan 2023 15:34:52 +0000 Subject: [PATCH] Revert "ANDROID: KVM: arm64: Coalesce host stage2 entries on ownership reclaim" This reverts commit 1af7ed3212d977869ed312e1f9b43ab259d36727. Bug: 264333547 Test: /data/local/tmp/sebastianene/tests/test_host_app Change-Id: Id88b705dd725cc8720913fd2909030c2f2fb597f Signed-off-by: Sebastian Ene --- arch/arm64/include/asm/kvm_pgtable.h | 18 ------------ arch/arm64/kvm/hyp/nvhe/mem_protect.c | 18 ++---------- arch/arm64/kvm/hyp/pgtable.c | 41 +-------------------------- 3 files changed, 3 insertions(+), 74 deletions(-) diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index 8e8cd6bc6433..054612a2a7fc 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -210,24 +210,6 @@ enum kvm_pgtable_prot { #define PKVM_HOST_MEM_PROT KVM_PGTABLE_PROT_RWX #define PKVM_HOST_MMIO_PROT KVM_PGTABLE_PROT_RW -#define KVM_HOST_S2_DEFAULT_ATTR (KVM_PTE_LEAF_ATTR_HI | \ - KVM_PTE_LEAF_ATTR_LO) - -#define KVM_HOST_S2_DEFAULT_MEM_PTE \ - (KVM_PTE_LEAF_ATTR_LO_S2_MEMATTR | \ - KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R | \ - KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W | \ - KVM_PTE_LEAF_ATTR_LO_S2_SH | \ - KVM_PTE_LEAF_ATTR_LO_S2_AF) - -#define KVM_HOST_S2_DEFAULT_MMIO_PTE \ - (KVM_PTE_LEAF_ATTR_LO_S2_MEMATTR | \ - KVM_PTE_LEAF_ATTR_HI_S2_XN | \ - KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R | \ - KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W | \ - KVM_PTE_LEAF_ATTR_LO_S2_SH | \ - KVM_PTE_LEAF_ATTR_LO_S2_AF) - #define PAGE_HYP KVM_PGTABLE_PROT_RW #define PAGE_HYP_EXEC (KVM_PGTABLE_PROT_R | KVM_PGTABLE_PROT_X) #define PAGE_HYP_RO (KVM_PGTABLE_PROT_R) diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index a0107f99abfa..098ff16f408d 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -181,7 +181,7 @@ static bool guest_stage2_force_pte_cb(u64 addr, u64 end, static bool guest_stage2_pte_is_counted(kvm_pte_t pte, u32 level) { - return !!pte; + return host_stage2_pte_is_counted(pte, level); } static void *guest_s2_zalloc_pages_exact(size_t size) @@ -668,26 +668,12 @@ static bool host_stage2_force_pte(u64 addr, u64 end, enum kvm_pgtable_prot prot) static bool host_stage2_pte_is_counted(kvm_pte_t pte, u32 level) { - u64 phys; - /* * The refcount tracks valid entries as well as invalid entries if they * encode ownership of a page to another entity than the page-table * owner, whose id is 0. */ - if (!kvm_pte_valid(pte)) - return !!pte; - - if (kvm_pte_table(pte, level)) - return true; - - phys = kvm_pte_to_phys(pte); - if (!addr_is_memory(phys)) - return (pte & KVM_HOST_S2_DEFAULT_ATTR) != - KVM_HOST_S2_DEFAULT_MMIO_PTE; - else - return (pte & KVM_HOST_S2_DEFAULT_ATTR) != - KVM_HOST_S2_DEFAULT_MEM_PTE; + return !!pte; } static int host_stage2_idmap(u64 addr) diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index 6aac30b3ba7f..e48b66b744d5 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -787,13 +787,6 @@ static int stage2_map_walk_leaf(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, */ if (pte_ops->pte_is_counted_cb(pte, level)) stage2_put_pte(ptep, data->mmu, addr, level, mm_ops); - else { - /* - * On non-refcounted PTEs we just clear them out without - * dropping the refcount. - */ - stage2_clear_pte(ptep, data->mmu, addr, level); - } kvm_set_table_pte(ptep, childp, mm_ops); mm_ops->get_page(ptep); @@ -801,35 +794,6 @@ static int stage2_map_walk_leaf(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, return 0; } -static void stage2_coalesce_walk_table_post(u64 addr, u64 end, u32 level, - kvm_pte_t *ptep, - struct stage2_map_data *data) -{ - struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops; - kvm_pte_t *childp = kvm_pte_follow(*ptep, mm_ops); - - /* - * Decrement the refcount only on the set ownership path to avoid a - * loop situation when the following happens: - * 1. We take a host stage2 fault and we create a small mapping which - * has default attributes (is not refcounted). - * 2. On the way back we execute the post handler and we zap the - * table that holds our mapping. - */ - if (kvm_phys_is_valid(data->phys) || - !kvm_level_supports_block_mapping(level)) - return; - - /* - * Free a page that is not referenced anymore and drop the reference - * of the page table page. - */ - if (mm_ops->page_count(childp) == 1) { - stage2_put_pte(ptep, data->mmu, addr, level, mm_ops); - mm_ops->put_page(childp); - } -} - static int stage2_map_walk_table_post(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, struct stage2_map_data *data) @@ -838,11 +802,8 @@ static int stage2_map_walk_table_post(u64 addr, u64 end, u32 level, kvm_pte_t *childp; int ret = 0; - if (!data->anchor) { - stage2_coalesce_walk_table_post(addr, end, level, ptep, - data); + if (!data->anchor) return 0; - } if (data->anchor == ptep) { childp = data->childp;