diff options
| -rw-r--r-- | arch/arm64/include/asm/kvm_pgtable.h | 14 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 2 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/include/nvhe/mm.h | 4 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/mem_protect.c | 1 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/mm.c | 104 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/setup.c | 4 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/pgtable.c | 12 |
7 files changed, 128 insertions, 13 deletions
diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index 15c389db1931..34cb93f3c96d 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -42,6 +42,8 @@ typedef u64 kvm_pte_t; #define KVM_PTE_ADDR_MASK GENMASK(47, PAGE_SHIFT) #define KVM_PTE_ADDR_51_48 GENMASK(15, 12) +#define KVM_PHYS_INVALID (-1ULL) + static inline bool kvm_pte_valid(kvm_pte_t pte) { return pte & KVM_PTE_VALID; @@ -57,6 +59,18 @@ static inline u64 kvm_pte_to_phys(kvm_pte_t pte) return pa; } +static inline kvm_pte_t kvm_phys_to_pte(u64 pa) +{ + kvm_pte_t pte = pa & KVM_PTE_ADDR_MASK; + + if (PAGE_SHIFT == 16) { + pa &= GENMASK(51, 48); + pte |= FIELD_PREP(KVM_PTE_ADDR_51_48, pa >> 48); + } + + return pte; +} + static inline u64 kvm_granule_shift(u32 level) { /* Assumes KVM_PGTABLE_MAX_LEVELS is 4 */ diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h index ce9a796a85ee..ef31a1872c93 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h +++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h @@ -59,6 +59,8 @@ enum pkvm_component_id { PKVM_ID_HYP, }; +extern unsigned long hyp_nr_cpus; + int __pkvm_prot_finalize(void); int __pkvm_host_share_hyp(u64 pfn); int __pkvm_host_unshare_hyp(u64 pfn); diff --git a/arch/arm64/kvm/hyp/include/nvhe/mm.h b/arch/arm64/kvm/hyp/include/nvhe/mm.h index b2ee6d5df55b..d5ec972b5c1e 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/mm.h +++ b/arch/arm64/kvm/hyp/include/nvhe/mm.h @@ -13,6 +13,10 @@ extern struct kvm_pgtable pkvm_pgtable; extern hyp_spinlock_t pkvm_pgd_lock; +int hyp_create_pcpu_fixmap(void); +void *hyp_fixmap_map(phys_addr_t phys); +void hyp_fixmap_unmap(void); + int hyp_create_idmap(u32 hyp_va_bits); int hyp_map_vectors(void); int hyp_back_vmemmap(phys_addr_t back); diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index 459957b3082e..8b4d3f0aa7a0 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -21,7 +21,6 @@ #define KVM_HOST_S2_FLAGS (KVM_PGTABLE_S2_NOFWB | KVM_PGTABLE_S2_IDMAP) -extern unsigned long hyp_nr_cpus; struct host_mmu host_mmu; static struct hyp_pool host_s2_pool; diff --git a/arch/arm64/kvm/hyp/nvhe/mm.c b/arch/arm64/kvm/hyp/nvhe/mm.c index d3a3b47181de..5648ac21e62d 100644 --- a/arch/arm64/kvm/hyp/nvhe/mm.c +++ b/arch/arm64/kvm/hyp/nvhe/mm.c @@ -14,6 +14,7 @@ #include <nvhe/early_alloc.h> #include <nvhe/gfp.h> #include <nvhe/memory.h> +#include <nvhe/mem_protect.h> #include <nvhe/mm.h> #include <nvhe/spinlock.h> @@ -25,6 +26,12 @@ unsigned int hyp_memblock_nr; static u64 __io_map_base; +struct hyp_fixmap_slot { + u64 addr; + kvm_pte_t *ptep; +}; +static DEFINE_PER_CPU(struct hyp_fixmap_slot, fixmap_slots); + static int __pkvm_create_mappings(unsigned long start, unsigned long size, unsigned long phys, enum kvm_pgtable_prot prot) { @@ -212,6 +219,103 @@ int hyp_map_vectors(void) return 0; } +void *hyp_fixmap_map(phys_addr_t phys) +{ + struct hyp_fixmap_slot *slot = this_cpu_ptr(&fixmap_slots); + kvm_pte_t pte, *ptep = slot->ptep; + + pte = *ptep; + pte &= ~kvm_phys_to_pte(KVM_PHYS_INVALID); + pte |= kvm_phys_to_pte(phys) | KVM_PTE_VALID; + WRITE_ONCE(*ptep, pte); + dsb(ishst); + + return (void *)slot->addr; +} + +static void fixmap_clear_slot(struct hyp_fixmap_slot *slot) +{ + kvm_pte_t *ptep = slot->ptep; + u64 addr = slot->addr; + + WRITE_ONCE(*ptep, *ptep & ~KVM_PTE_VALID); + + /* + * Irritatingly, the architecture requires that we use inner-shareable + * broadcast TLB invalidation here in case another CPU speculates + * through our fixmap and decides to create an "amalagamation of the + * values held in the TLB" due to the apparent lack of a + * break-before-make sequence. + * + * https://lore.kernel.org/kvm/20221017115209.2099-1-will@kernel.org/T/#mf10dfbaf1eaef9274c581b81c53758918c1d0f03 + */ + dsb(ishst); + __tlbi_level(vale2is, __TLBI_VADDR(addr, 0), (KVM_PGTABLE_MAX_LEVELS - 1)); + dsb(ish); + isb(); +} + +void hyp_fixmap_unmap(void) +{ + fixmap_clear_slot(this_cpu_ptr(&fixmap_slots)); +} + +static int __create_fixmap_slot_cb(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, + enum kvm_pgtable_walk_flags flag, + void * const arg) +{ + struct hyp_fixmap_slot *slot = per_cpu_ptr(&fixmap_slots, (u64)arg); + + if (!kvm_pte_valid(*ptep) || level != KVM_PGTABLE_MAX_LEVELS - 1) + return -EINVAL; + + slot->addr = addr; + slot->ptep = ptep; + + /* + * Clear the PTE, but keep the page-table page refcount elevated to + * prevent it from ever being freed. This lets us manipulate the PTEs + * by hand safely without ever needing to allocate memory. + */ + fixmap_clear_slot(slot); + + return 0; +} + +static int create_fixmap_slot(u64 addr, u64 cpu) +{ + struct kvm_pgtable_walker walker = { + .cb = __create_fixmap_slot_cb, + .flags = KVM_PGTABLE_WALK_LEAF, + .arg = (void *)cpu, + }; + + return kvm_pgtable_walk(&pkvm_pgtable, addr, PAGE_SIZE, &walker); +} + +int hyp_create_pcpu_fixmap(void) +{ + unsigned long addr, i; + int ret; + + for (i = 0; i < hyp_nr_cpus; i++) { + ret = pkvm_alloc_private_va_range(PAGE_SIZE, &addr); + if (ret) + return ret; + + ret = kvm_pgtable_hyp_map(&pkvm_pgtable, addr, PAGE_SIZE, + __hyp_pa(__hyp_bss_start), PAGE_HYP); + if (ret) + return ret; + + ret = create_fixmap_slot(addr, i); + if (ret) + return ret; + } + + return 0; +} + int hyp_create_idmap(u32 hyp_va_bits) { unsigned long start, end; diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c index 2be72fbe7279..0f69c1393416 100644 --- a/arch/arm64/kvm/hyp/nvhe/setup.c +++ b/arch/arm64/kvm/hyp/nvhe/setup.c @@ -321,6 +321,10 @@ void __noreturn __pkvm_init_finalise(void) if (ret) goto out; + ret = hyp_create_pcpu_fixmap(); + if (ret) + goto out; + pkvm_hyp_vm_table_init(vm_table_base); out: /* diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index a1a27f88a312..2bcb2d5903ba 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -57,8 +57,6 @@ struct kvm_pgtable_walk_data { u64 end; }; -#define KVM_PHYS_INVALID (-1ULL) - static bool kvm_phys_is_valid(u64 phys) { return phys < BIT(id_aa64mmfr0_parange_to_phys_shift(ID_AA64MMFR0_EL1_PARANGE_MAX)); @@ -122,16 +120,6 @@ static bool kvm_pte_table(kvm_pte_t pte, u32 level) return FIELD_GET(KVM_PTE_TYPE, pte) == KVM_PTE_TYPE_TABLE; } -static kvm_pte_t kvm_phys_to_pte(u64 pa) -{ - kvm_pte_t pte = pa & KVM_PTE_ADDR_MASK; - - if (PAGE_SHIFT == 16) - pte |= FIELD_PREP(KVM_PTE_ADDR_51_48, pa >> 48); - - return pte; -} - static kvm_pte_t *kvm_pte_follow(kvm_pte_t pte, struct kvm_pgtable_mm_ops *mm_ops) { return mm_ops->phys_to_virt(kvm_pte_to_phys(pte)); |