From bc224df155c466178128a2950af16cba37b6f218 Mon Sep 17 00:00:00 2001 From: Quentin Perret Date: Fri, 19 Mar 2021 10:01:40 +0000 Subject: KVM: arm64: Introduce KVM_PGTABLE_S2_NOFWB stage 2 flag In order to further configure stage 2 page-tables, pass flags to the init function using a new enum. The first of these flags allows to disable FWB even if the hardware supports it as we will need to do so for the host stage 2. Signed-off-by: Quentin Perret Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210319100146.1149909-33-qperret@google.com --- arch/arm64/include/asm/kvm_pgtable.h | 43 ++++++++++++++++++--------- arch/arm64/include/asm/pgtable-prot.h | 4 +-- arch/arm64/kvm/hyp/pgtable.c | 56 +++++++++++++++++++---------------- 3 files changed, 62 insertions(+), 41 deletions(-) diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index e1fed14aee17..55452f4831d2 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -56,6 +56,15 @@ struct kvm_pgtable_mm_ops { phys_addr_t (*virt_to_phys)(void *addr); }; +/** + * enum kvm_pgtable_stage2_flags - Stage-2 page-table flags. + * @KVM_PGTABLE_S2_NOFWB: Don't enforce Normal-WB even if the CPUs have + * ARM64_HAS_STAGE2_FWB. + */ +enum kvm_pgtable_stage2_flags { + KVM_PGTABLE_S2_NOFWB = BIT(0), +}; + /** * struct kvm_pgtable - KVM page-table. * @ia_bits: Maximum input address size, in bits. @@ -72,6 +81,7 @@ struct kvm_pgtable { /* Stage-2 only */ struct kvm_s2_mmu *mmu; + enum kvm_pgtable_stage2_flags flags; }; /** @@ -196,20 +206,25 @@ int kvm_pgtable_hyp_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys, u64 kvm_get_vtcr(u64 mmfr0, u64 mmfr1, u32 phys_shift); /** - * kvm_pgtable_stage2_init() - Initialise a guest stage-2 page-table. + * kvm_pgtable_stage2_init_flags() - Initialise a guest stage-2 page-table. * @pgt: Uninitialised page-table structure to initialise. * @arch: Arch-specific KVM structure representing the guest virtual * machine. * @mm_ops: Memory management callbacks. + * @flags: Stage-2 configuration flags. * * Return: 0 on success, negative error code on failure. */ -int kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_arch *arch, - struct kvm_pgtable_mm_ops *mm_ops); +int kvm_pgtable_stage2_init_flags(struct kvm_pgtable *pgt, struct kvm_arch *arch, + struct kvm_pgtable_mm_ops *mm_ops, + enum kvm_pgtable_stage2_flags flags); + +#define kvm_pgtable_stage2_init(pgt, arch, mm_ops) \ + kvm_pgtable_stage2_init_flags(pgt, arch, mm_ops, 0) /** * kvm_pgtable_stage2_destroy() - Destroy an unused guest stage-2 page-table. - * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init(). + * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*(). * * The page-table is assumed to be unreachable by any hardware walkers prior * to freeing and therefore no TLB invalidation is performed. @@ -218,7 +233,7 @@ void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt); /** * kvm_pgtable_stage2_map() - Install a mapping in a guest stage-2 page-table. - * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init(). + * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*(). * @addr: Intermediate physical address at which to place the mapping. * @size: Size of the mapping. * @phys: Physical address of the memory to map. @@ -251,7 +266,7 @@ int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size, /** * kvm_pgtable_stage2_set_owner() - Unmap and annotate pages in the IPA space to * track ownership. - * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init(). + * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*(). * @addr: Base intermediate physical address to annotate. * @size: Size of the annotated range. * @mc: Cache of pre-allocated and zeroed memory from which to allocate @@ -270,7 +285,7 @@ int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, u64 addr, u64 size, /** * kvm_pgtable_stage2_unmap() - Remove a mapping from a guest stage-2 page-table. - * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init(). + * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*(). * @addr: Intermediate physical address from which to remove the mapping. * @size: Size of the mapping. * @@ -290,7 +305,7 @@ 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(). + * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*(). * @addr: Intermediate physical address from which to write-protect, * @size: Size of the range. * @@ -307,7 +322,7 @@ 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(). + * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*(). * @addr: Intermediate physical address to identify the page-table entry. * * The offset of @addr within a page is ignored. @@ -321,7 +336,7 @@ kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr); /** * kvm_pgtable_stage2_mkold() - Clear the access flag in a page-table entry. - * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init(). + * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*(). * @addr: Intermediate physical address to identify the page-table entry. * * The offset of @addr within a page is ignored. @@ -340,7 +355,7 @@ kvm_pte_t kvm_pgtable_stage2_mkold(struct kvm_pgtable *pgt, u64 addr); /** * kvm_pgtable_stage2_relax_perms() - Relax the permissions enforced by a * page-table entry. - * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init(). + * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*(). * @addr: Intermediate physical address to identify the page-table entry. * @prot: Additional permissions to grant for the mapping. * @@ -359,7 +374,7 @@ int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr, /** * kvm_pgtable_stage2_is_young() - Test whether a page-table entry has the * access flag set. - * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init(). + * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*(). * @addr: Intermediate physical address to identify the page-table entry. * * The offset of @addr within a page is ignored. @@ -372,7 +387,7 @@ bool kvm_pgtable_stage2_is_young(struct kvm_pgtable *pgt, u64 addr); * kvm_pgtable_stage2_flush_range() - Clean and invalidate data cache to Point * of Coherency for guest stage-2 address * range. - * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init(). + * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*(). * @addr: Intermediate physical address from which to flush. * @size: Size of the range. * @@ -411,7 +426,7 @@ int kvm_pgtable_walk(struct kvm_pgtable *pgt, u64 addr, u64 size, * kvm_pgtable_stage2_find_range() - Find a range of Intermediate Physical * Addresses with compatible permission * attributes. - * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init(). + * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*(). * @addr: Address that must be covered by the range. * @prot: Protection attributes that the range must be compatible with. * @range: Range structure used to limit the search space at call time and diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h index 9a65fb528110..079f4e9a3e84 100644 --- a/arch/arm64/include/asm/pgtable-prot.h +++ b/arch/arm64/include/asm/pgtable-prot.h @@ -71,10 +71,10 @@ extern bool arm64_use_ng_mappings; #define PAGE_KERNEL_EXEC __pgprot(PROT_NORMAL & ~PTE_PXN) #define PAGE_KERNEL_EXEC_CONT __pgprot((PROT_NORMAL & ~PTE_PXN) | PTE_CONT) -#define PAGE_S2_MEMATTR(attr) \ +#define PAGE_S2_MEMATTR(attr, has_fwb) \ ({ \ u64 __val; \ - if (cpus_have_const_cap(ARM64_HAS_STAGE2_FWB)) \ + if (has_fwb) \ __val = PTE_S2_MEMATTR(MT_S2_FWB_ ## attr); \ else \ __val = PTE_S2_MEMATTR(MT_S2_ ## attr); \ diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index dc6ef2cfe3eb..b22b4860630c 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -508,11 +508,22 @@ u64 kvm_get_vtcr(u64 mmfr0, u64 mmfr1, u32 phys_shift) return vtcr; } -static int stage2_set_prot_attr(enum kvm_pgtable_prot prot, kvm_pte_t *ptep) +static bool stage2_has_fwb(struct kvm_pgtable *pgt) +{ + if (!cpus_have_const_cap(ARM64_HAS_STAGE2_FWB)) + return false; + + return !(pgt->flags & KVM_PGTABLE_S2_NOFWB); +} + +#define KVM_S2_MEMATTR(pgt, attr) PAGE_S2_MEMATTR(attr, stage2_has_fwb(pgt)) + +static int stage2_set_prot_attr(struct kvm_pgtable *pgt, enum kvm_pgtable_prot prot, + kvm_pte_t *ptep) { bool device = prot & KVM_PGTABLE_PROT_DEVICE; - kvm_pte_t attr = device ? PAGE_S2_MEMATTR(DEVICE_nGnRE) : - PAGE_S2_MEMATTR(NORMAL); + kvm_pte_t attr = device ? KVM_S2_MEMATTR(pgt, DEVICE_nGnRE) : + KVM_S2_MEMATTR(pgt, NORMAL); u32 sh = KVM_PTE_LEAF_ATTR_LO_S2_SH_IS; if (!(prot & KVM_PGTABLE_PROT_X)) @@ -749,7 +760,7 @@ int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size, .arg = &map_data, }; - ret = stage2_set_prot_attr(prot, &map_data.attr); + ret = stage2_set_prot_attr(pgt, prot, &map_data.attr); if (ret) return ret; @@ -784,18 +795,10 @@ int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, u64 addr, u64 size, return ret; } -static void stage2_flush_dcache(void *addr, u64 size) -{ - if (cpus_have_const_cap(ARM64_HAS_STAGE2_FWB)) - return; - - __flush_dcache_area(addr, size); -} - -static bool stage2_pte_cacheable(kvm_pte_t pte) +static bool stage2_pte_cacheable(struct kvm_pgtable *pgt, kvm_pte_t pte) { u64 memattr = pte & KVM_PTE_LEAF_ATTR_LO_S2_MEMATTR; - return memattr == PAGE_S2_MEMATTR(NORMAL); + return memattr == KVM_S2_MEMATTR(pgt, NORMAL); } static int stage2_unmap_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, @@ -821,8 +824,8 @@ static int stage2_unmap_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, if (mm_ops->page_count(childp) != 1) return 0; - } else if (stage2_pte_cacheable(pte)) { - need_flush = true; + } else if (stage2_pte_cacheable(pgt, pte)) { + need_flush = !stage2_has_fwb(pgt); } /* @@ -833,7 +836,7 @@ static int stage2_unmap_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, stage2_put_pte(ptep, mmu, addr, level, mm_ops); if (need_flush) { - stage2_flush_dcache(kvm_pte_follow(pte, mm_ops), + __flush_dcache_area(kvm_pte_follow(pte, mm_ops), kvm_granule_size(level)); } @@ -979,13 +982,14 @@ static int stage2_flush_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, enum kvm_pgtable_walk_flags flag, void * const arg) { - struct kvm_pgtable_mm_ops *mm_ops = arg; + struct kvm_pgtable *pgt = arg; + struct kvm_pgtable_mm_ops *mm_ops = pgt->mm_ops; kvm_pte_t pte = *ptep; - if (!kvm_pte_valid(pte) || !stage2_pte_cacheable(pte)) + if (!kvm_pte_valid(pte) || !stage2_pte_cacheable(pgt, pte)) return 0; - stage2_flush_dcache(kvm_pte_follow(pte, mm_ops), kvm_granule_size(level)); + __flush_dcache_area(kvm_pte_follow(pte, mm_ops), kvm_granule_size(level)); return 0; } @@ -994,17 +998,18 @@ int kvm_pgtable_stage2_flush(struct kvm_pgtable *pgt, u64 addr, u64 size) struct kvm_pgtable_walker walker = { .cb = stage2_flush_walker, .flags = KVM_PGTABLE_WALK_LEAF, - .arg = pgt->mm_ops, + .arg = pgt, }; - if (cpus_have_const_cap(ARM64_HAS_STAGE2_FWB)) + if (stage2_has_fwb(pgt)) return 0; return kvm_pgtable_walk(pgt, addr, size, &walker); } -int kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_arch *arch, - struct kvm_pgtable_mm_ops *mm_ops) +int kvm_pgtable_stage2_init_flags(struct kvm_pgtable *pgt, struct kvm_arch *arch, + struct kvm_pgtable_mm_ops *mm_ops, + enum kvm_pgtable_stage2_flags flags) { size_t pgd_sz; u64 vtcr = arch->vtcr; @@ -1021,6 +1026,7 @@ int kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_arch *arch, pgt->start_level = start_level; pgt->mm_ops = mm_ops; pgt->mmu = &arch->mmu; + pgt->flags = flags; /* Ensure zeroed PGD pages are visible to the hardware walker */ dsb(ishst); @@ -1101,7 +1107,7 @@ int kvm_pgtable_stage2_find_range(struct kvm_pgtable *pgt, u64 addr, u32 level; int ret; - ret = stage2_set_prot_attr(prot, &attr); + ret = stage2_set_prot_attr(pgt, prot, &attr); if (ret) return ret; attr &= KVM_PTE_LEAF_S2_COMPAT_MASK; -- cgit v1.2.3-59-g8ed1b