diff options
Diffstat (limited to 'arch/arm64/kvm/hyp')
| -rw-r--r-- | arch/arm64/kvm/hyp/hyp-constants.c | 3 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 25 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/include/nvhe/memory.h | 27 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/include/nvhe/mm.h | 18 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/include/nvhe/pkvm.h | 68 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/include/nvhe/spinlock.h | 10 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/cache.S | 11 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/hyp-main.c | 110 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/hyp-smp.c | 2 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/mem_protect.c | 521 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/mm.c | 167 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/page_alloc.c | 29 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/pkvm.c | 436 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/setup.c | 98 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/pgtable.c | 652 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/vhe/Makefile | 2 |
16 files changed, 1741 insertions, 438 deletions
diff --git a/arch/arm64/kvm/hyp/hyp-constants.c b/arch/arm64/kvm/hyp/hyp-constants.c index b3742a6691e8..b257a3b4bfc5 100644 --- a/arch/arm64/kvm/hyp/hyp-constants.c +++ b/arch/arm64/kvm/hyp/hyp-constants.c @@ -2,9 +2,12 @@ #include <linux/kbuild.h> #include <nvhe/memory.h> +#include <nvhe/pkvm.h> int main(void) { DEFINE(STRUCT_HYP_PAGE_SIZE, sizeof(struct hyp_page)); + DEFINE(PKVM_HYP_VM_SIZE, sizeof(struct pkvm_hyp_vm)); + DEFINE(PKVM_HYP_VCPU_SIZE, sizeof(struct pkvm_hyp_vcpu)); return 0; } diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h index 80e99836eac7..b7bdbe63deed 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h +++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h @@ -8,8 +8,10 @@ #define __KVM_NVHE_MEM_PROTECT__ #include <linux/kvm_host.h> #include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> #include <asm/kvm_pgtable.h> #include <asm/virt.h> +#include <nvhe/pkvm.h> #include <nvhe/spinlock.h> /* @@ -43,30 +45,45 @@ static inline enum pkvm_page_state pkvm_getstate(enum kvm_pgtable_prot prot) return prot & PKVM_PAGE_STATE_PROT_MASK; } -struct host_kvm { +struct host_mmu { struct kvm_arch arch; struct kvm_pgtable pgt; struct kvm_pgtable_mm_ops mm_ops; hyp_spinlock_t lock; }; -extern struct host_kvm host_kvm; +extern struct host_mmu host_mmu; -extern const u8 pkvm_hyp_id; +/* This corresponds to page-table locking order */ +enum pkvm_component_id { + PKVM_ID_HOST, + 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); +int __pkvm_host_donate_hyp(u64 pfn, u64 nr_pages); +int __pkvm_hyp_donate_host(u64 pfn, u64 nr_pages); bool addr_is_memory(phys_addr_t phys); int host_stage2_idmap_locked(phys_addr_t addr, u64 size, enum kvm_pgtable_prot prot); int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id); int kvm_host_prepare_stage2(void *pgt_pool_base); +int kvm_guest_prepare_stage2(struct pkvm_hyp_vm *vm, void *pgd); void handle_host_mem_abort(struct kvm_cpu_context *host_ctxt); +int hyp_pin_shared_mem(void *from, void *to); +void hyp_unpin_shared_mem(void *from, void *to); +void reclaim_guest_pages(struct pkvm_hyp_vm *vm, struct kvm_hyp_memcache *mc); +int refill_memcache(struct kvm_hyp_memcache *mc, unsigned long min_pages, + struct kvm_hyp_memcache *host_mc); + static __always_inline void __load_host_stage2(void) { if (static_branch_likely(&kvm_protected_mode_initialized)) - __load_stage2(&host_kvm.arch.mmu, &host_kvm.arch); + __load_stage2(&host_mmu.arch.mmu, &host_mmu.arch); else write_sysreg(0, vttbr_el2); } diff --git a/arch/arm64/kvm/hyp/include/nvhe/memory.h b/arch/arm64/kvm/hyp/include/nvhe/memory.h index 592b7edb3edb..ab205c4d6774 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/memory.h +++ b/arch/arm64/kvm/hyp/include/nvhe/memory.h @@ -38,6 +38,10 @@ static inline phys_addr_t hyp_virt_to_phys(void *addr) #define hyp_page_to_virt(page) __hyp_va(hyp_page_to_phys(page)) #define hyp_page_to_pool(page) (((struct hyp_page *)page)->pool) +/* + * Refcounting for 'struct hyp_page'. + * hyp_pool::lock must be held if atomic access to the refcount is required. + */ static inline int hyp_page_count(void *addr) { struct hyp_page *p = hyp_virt_to_page(addr); @@ -45,4 +49,27 @@ static inline int hyp_page_count(void *addr) return p->refcount; } +static inline void hyp_page_ref_inc(struct hyp_page *p) +{ + BUG_ON(p->refcount == USHRT_MAX); + p->refcount++; +} + +static inline void hyp_page_ref_dec(struct hyp_page *p) +{ + BUG_ON(!p->refcount); + p->refcount--; +} + +static inline int hyp_page_ref_dec_and_test(struct hyp_page *p) +{ + hyp_page_ref_dec(p); + return (p->refcount == 0); +} + +static inline void hyp_set_page_refcounted(struct hyp_page *p) +{ + BUG_ON(p->refcount); + p->refcount = 1; +} #endif /* __KVM_HYP_MEMORY_H */ diff --git a/arch/arm64/kvm/hyp/include/nvhe/mm.h b/arch/arm64/kvm/hyp/include/nvhe/mm.h index 42d8eb9bfe72..d5ec972b5c1e 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/mm.h +++ b/arch/arm64/kvm/hyp/include/nvhe/mm.h @@ -13,9 +13,13 @@ 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 phys, unsigned long size, phys_addr_t back); +int hyp_back_vmemmap(phys_addr_t back); int pkvm_cpu_set_vector(enum arm64_hyp_spectre_vector slot); int pkvm_create_mappings(void *from, void *to, enum kvm_pgtable_prot prot); int pkvm_create_mappings_locked(void *from, void *to, enum kvm_pgtable_prot prot); @@ -24,16 +28,4 @@ int __pkvm_create_private_mapping(phys_addr_t phys, size_t size, unsigned long *haddr); int pkvm_alloc_private_va_range(size_t size, unsigned long *haddr); -static inline void hyp_vmemmap_range(phys_addr_t phys, unsigned long size, - unsigned long *start, unsigned long *end) -{ - unsigned long nr_pages = size >> PAGE_SHIFT; - struct hyp_page *p = hyp_phys_to_page(phys); - - *start = (unsigned long)p; - *end = *start + nr_pages * sizeof(struct hyp_page); - *start = ALIGN_DOWN(*start, PAGE_SIZE); - *end = ALIGN(*end, PAGE_SIZE); -} - #endif /* __KVM_HYP_MM_H */ diff --git a/arch/arm64/kvm/hyp/include/nvhe/pkvm.h b/arch/arm64/kvm/hyp/include/nvhe/pkvm.h new file mode 100644 index 000000000000..82b3d62538a6 --- /dev/null +++ b/arch/arm64/kvm/hyp/include/nvhe/pkvm.h @@ -0,0 +1,68 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2021 Google LLC + * Author: Fuad Tabba <tabba@google.com> + */ + +#ifndef __ARM64_KVM_NVHE_PKVM_H__ +#define __ARM64_KVM_NVHE_PKVM_H__ + +#include <asm/kvm_pkvm.h> + +#include <nvhe/gfp.h> +#include <nvhe/spinlock.h> + +/* + * Holds the relevant data for maintaining the vcpu state completely at hyp. + */ +struct pkvm_hyp_vcpu { + struct kvm_vcpu vcpu; + + /* Backpointer to the host's (untrusted) vCPU instance. */ + struct kvm_vcpu *host_vcpu; +}; + +/* + * Holds the relevant data for running a protected vm. + */ +struct pkvm_hyp_vm { + struct kvm kvm; + + /* Backpointer to the host's (untrusted) KVM instance. */ + struct kvm *host_kvm; + + /* The guest's stage-2 page-table managed by the hypervisor. */ + struct kvm_pgtable pgt; + struct kvm_pgtable_mm_ops mm_ops; + struct hyp_pool pool; + hyp_spinlock_t lock; + + /* + * The number of vcpus initialized and ready to run. + * Modifying this is protected by 'vm_table_lock'. + */ + unsigned int nr_vcpus; + + /* Array of the hyp vCPU structures for this VM. */ + struct pkvm_hyp_vcpu *vcpus[]; +}; + +static inline struct pkvm_hyp_vm * +pkvm_hyp_vcpu_to_hyp_vm(struct pkvm_hyp_vcpu *hyp_vcpu) +{ + return container_of(hyp_vcpu->vcpu.kvm, struct pkvm_hyp_vm, kvm); +} + +void pkvm_hyp_vm_table_init(void *tbl); + +int __pkvm_init_vm(struct kvm *host_kvm, unsigned long vm_hva, + unsigned long pgd_hva); +int __pkvm_init_vcpu(pkvm_handle_t handle, struct kvm_vcpu *host_vcpu, + unsigned long vcpu_hva); +int __pkvm_teardown_vm(pkvm_handle_t handle); + +struct pkvm_hyp_vcpu *pkvm_load_hyp_vcpu(pkvm_handle_t handle, + unsigned int vcpu_idx); +void pkvm_put_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu); + +#endif /* __ARM64_KVM_NVHE_PKVM_H__ */ diff --git a/arch/arm64/kvm/hyp/include/nvhe/spinlock.h b/arch/arm64/kvm/hyp/include/nvhe/spinlock.h index 4652fd04bdbe..7c7ea8c55405 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/spinlock.h +++ b/arch/arm64/kvm/hyp/include/nvhe/spinlock.h @@ -28,9 +28,17 @@ typedef union hyp_spinlock { }; } hyp_spinlock_t; +#define __HYP_SPIN_LOCK_INITIALIZER \ + { .__val = 0 } + +#define __HYP_SPIN_LOCK_UNLOCKED \ + ((hyp_spinlock_t) __HYP_SPIN_LOCK_INITIALIZER) + +#define DEFINE_HYP_SPINLOCK(x) hyp_spinlock_t x = __HYP_SPIN_LOCK_UNLOCKED + #define hyp_spin_lock_init(l) \ do { \ - *(l) = (hyp_spinlock_t){ .__val = 0 }; \ + *(l) = __HYP_SPIN_LOCK_UNLOCKED; \ } while (0) static inline void hyp_spin_lock(hyp_spinlock_t *lock) diff --git a/arch/arm64/kvm/hyp/nvhe/cache.S b/arch/arm64/kvm/hyp/nvhe/cache.S index 0c367eb5f4e2..85936c17ae40 100644 --- a/arch/arm64/kvm/hyp/nvhe/cache.S +++ b/arch/arm64/kvm/hyp/nvhe/cache.S @@ -12,3 +12,14 @@ SYM_FUNC_START(__pi_dcache_clean_inval_poc) ret SYM_FUNC_END(__pi_dcache_clean_inval_poc) SYM_FUNC_ALIAS(dcache_clean_inval_poc, __pi_dcache_clean_inval_poc) + +SYM_FUNC_START(__pi_icache_inval_pou) +alternative_if ARM64_HAS_CACHE_DIC + isb + ret +alternative_else_nop_endif + + invalidate_icache_by_line x0, x1, x2, x3 + ret +SYM_FUNC_END(__pi_icache_inval_pou) +SYM_FUNC_ALIAS(icache_inval_pou, __pi_icache_inval_pou) diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 3cea4b6ac23e..728e01d4536b 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -15,17 +15,93 @@ #include <nvhe/mem_protect.h> #include <nvhe/mm.h> +#include <nvhe/pkvm.h> #include <nvhe/trap_handler.h> DEFINE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params); void __kvm_hyp_host_forward_smc(struct kvm_cpu_context *host_ctxt); +static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) +{ + struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu; + + hyp_vcpu->vcpu.arch.ctxt = host_vcpu->arch.ctxt; + + hyp_vcpu->vcpu.arch.sve_state = kern_hyp_va(host_vcpu->arch.sve_state); + hyp_vcpu->vcpu.arch.sve_max_vl = host_vcpu->arch.sve_max_vl; + + hyp_vcpu->vcpu.arch.hw_mmu = host_vcpu->arch.hw_mmu; + + hyp_vcpu->vcpu.arch.hcr_el2 = host_vcpu->arch.hcr_el2; + hyp_vcpu->vcpu.arch.mdcr_el2 = host_vcpu->arch.mdcr_el2; + hyp_vcpu->vcpu.arch.cptr_el2 = host_vcpu->arch.cptr_el2; + + hyp_vcpu->vcpu.arch.iflags = host_vcpu->arch.iflags; + hyp_vcpu->vcpu.arch.fp_state = host_vcpu->arch.fp_state; + + hyp_vcpu->vcpu.arch.debug_ptr = kern_hyp_va(host_vcpu->arch.debug_ptr); + hyp_vcpu->vcpu.arch.host_fpsimd_state = host_vcpu->arch.host_fpsimd_state; + + hyp_vcpu->vcpu.arch.vsesr_el2 = host_vcpu->arch.vsesr_el2; + + hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3 = host_vcpu->arch.vgic_cpu.vgic_v3; +} + +static void sync_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) +{ + struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu; + struct vgic_v3_cpu_if *hyp_cpu_if = &hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3; + struct vgic_v3_cpu_if *host_cpu_if = &host_vcpu->arch.vgic_cpu.vgic_v3; + unsigned int i; + + host_vcpu->arch.ctxt = hyp_vcpu->vcpu.arch.ctxt; + + host_vcpu->arch.hcr_el2 = hyp_vcpu->vcpu.arch.hcr_el2; + host_vcpu->arch.cptr_el2 = hyp_vcpu->vcpu.arch.cptr_el2; + + host_vcpu->arch.fault = hyp_vcpu->vcpu.arch.fault; + + host_vcpu->arch.iflags = hyp_vcpu->vcpu.arch.iflags; + host_vcpu->arch.fp_state = hyp_vcpu->vcpu.arch.fp_state; + + host_cpu_if->vgic_hcr = hyp_cpu_if->vgic_hcr; + for (i = 0; i < hyp_cpu_if->used_lrs; ++i) + host_cpu_if->vgic_lr[i] = hyp_cpu_if->vgic_lr[i]; +} + static void handle___kvm_vcpu_run(struct kvm_cpu_context *host_ctxt) { - DECLARE_REG(struct kvm_vcpu *, vcpu, host_ctxt, 1); + DECLARE_REG(struct kvm_vcpu *, host_vcpu, host_ctxt, 1); + int ret; - cpu_reg(host_ctxt, 1) = __kvm_vcpu_run(kern_hyp_va(vcpu)); + host_vcpu = kern_hyp_va(host_vcpu); + + if (unlikely(is_protected_kvm_enabled())) { + struct pkvm_hyp_vcpu *hyp_vcpu; + struct kvm *host_kvm; + + host_kvm = kern_hyp_va(host_vcpu->kvm); + hyp_vcpu = pkvm_load_hyp_vcpu(host_kvm->arch.pkvm.handle, + host_vcpu->vcpu_idx); + if (!hyp_vcpu) { + ret = -EINVAL; + goto out; + } + + flush_hyp_vcpu(hyp_vcpu); + + ret = __kvm_vcpu_run(&hyp_vcpu->vcpu); + + sync_hyp_vcpu(hyp_vcpu); + pkvm_put_hyp_vcpu(hyp_vcpu); + } else { + /* The host is fully trusted, run its vCPU directly. */ + ret = __kvm_vcpu_run(host_vcpu); + } + +out: + cpu_reg(host_ctxt, 1) = ret; } static void handle___kvm_adjust_pc(struct kvm_cpu_context *host_ctxt) @@ -191,6 +267,33 @@ static void handle___pkvm_vcpu_init_traps(struct kvm_cpu_context *host_ctxt) __pkvm_vcpu_init_traps(kern_hyp_va(vcpu)); } +static void handle___pkvm_init_vm(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(struct kvm *, host_kvm, host_ctxt, 1); + DECLARE_REG(unsigned long, vm_hva, host_ctxt, 2); + DECLARE_REG(unsigned long, pgd_hva, host_ctxt, 3); + + host_kvm = kern_hyp_va(host_kvm); + cpu_reg(host_ctxt, 1) = __pkvm_init_vm(host_kvm, vm_hva, pgd_hva); +} + +static void handle___pkvm_init_vcpu(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1); + DECLARE_REG(struct kvm_vcpu *, host_vcpu, host_ctxt, 2); + DECLARE_REG(unsigned long, vcpu_hva, host_ctxt, 3); + + host_vcpu = kern_hyp_va(host_vcpu); + cpu_reg(host_ctxt, 1) = __pkvm_init_vcpu(handle, host_vcpu, vcpu_hva); +} + +static void handle___pkvm_teardown_vm(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1); + + cpu_reg(host_ctxt, 1) = __pkvm_teardown_vm(handle); +} + typedef void (*hcall_t)(struct kvm_cpu_context *); #define HANDLE_FUNC(x) [__KVM_HOST_SMCCC_FUNC_##x] = (hcall_t)handle_##x @@ -220,6 +323,9 @@ static const hcall_t host_hcall[] = { HANDLE_FUNC(__vgic_v3_save_aprs), HANDLE_FUNC(__vgic_v3_restore_aprs), HANDLE_FUNC(__pkvm_vcpu_init_traps), + HANDLE_FUNC(__pkvm_init_vm), + HANDLE_FUNC(__pkvm_init_vcpu), + HANDLE_FUNC(__pkvm_teardown_vm), }; static void handle_host_hcall(struct kvm_cpu_context *host_ctxt) diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-smp.c b/arch/arm64/kvm/hyp/nvhe/hyp-smp.c index 9f54833af400..04d194583f1e 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-smp.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-smp.c @@ -23,6 +23,8 @@ u64 cpu_logical_map(unsigned int cpu) return hyp_cpu_logical_map[cpu]; } +unsigned long __ro_after_init kvm_arm_hyp_percpu_base[NR_CPUS]; + unsigned long __hyp_per_cpu_offset(unsigned int cpu) { unsigned long *cpu_base_array; diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index 07f9dc9848ef..552653fa18be 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -21,21 +21,33 @@ #define KVM_HOST_S2_FLAGS (KVM_PGTABLE_S2_NOFWB | KVM_PGTABLE_S2_IDMAP) -extern unsigned long hyp_nr_cpus; -struct host_kvm host_kvm; +struct host_mmu host_mmu; static struct hyp_pool host_s2_pool; -const u8 pkvm_hyp_id = 1; +static DEFINE_PER_CPU(struct pkvm_hyp_vm *, __current_vm); +#define current_vm (*this_cpu_ptr(&__current_vm)) + +static void guest_lock_component(struct pkvm_hyp_vm *vm) +{ + hyp_spin_lock(&vm->lock); + current_vm = vm; +} + +static void guest_unlock_component(struct pkvm_hyp_vm *vm) +{ + current_vm = NULL; + hyp_spin_unlock(&vm->lock); +} static void host_lock_component(void) { - hyp_spin_lock(&host_kvm.lock); + hyp_spin_lock(&host_mmu.lock); } static void host_unlock_component(void) { - hyp_spin_unlock(&host_kvm.lock); + hyp_spin_unlock(&host_mmu.lock); } static void hyp_lock_component(void) @@ -79,6 +91,11 @@ static void host_s2_put_page(void *addr) hyp_put_page(&host_s2_pool, addr); } +static void host_s2_free_removed_table(void *addr, u32 level) +{ + kvm_pgtable_stage2_free_removed(&host_mmu.mm_ops, addr, level); +} + static int prepare_s2_pool(void *pgt_pool_base) { unsigned long nr_pages, pfn; @@ -90,9 +107,10 @@ static int prepare_s2_pool(void *pgt_pool_base) if (ret) return ret; - host_kvm.mm_ops = (struct kvm_pgtable_mm_ops) { + host_mmu.mm_ops = (struct kvm_pgtable_mm_ops) { .zalloc_pages_exact = host_s2_zalloc_pages_exact, .zalloc_page = host_s2_zalloc_page, + .free_removed_table = host_s2_free_removed_table, .phys_to_virt = hyp_phys_to_virt, .virt_to_phys = hyp_virt_to_phys, .page_count = hyp_page_count, @@ -111,7 +129,7 @@ static void prepare_host_vtcr(void) parange = kvm_get_parange(id_aa64mmfr0_el1_sys_val); phys_shift = id_aa64mmfr0_parange_to_phys_shift(parange); - host_kvm.arch.vtcr = kvm_get_vtcr(id_aa64mmfr0_el1_sys_val, + host_mmu.arch.vtcr = kvm_get_vtcr(id_aa64mmfr0_el1_sys_val, id_aa64mmfr1_el1_sys_val, phys_shift); } @@ -119,45 +137,170 @@ static bool host_stage2_force_pte_cb(u64 addr, u64 end, enum kvm_pgtable_prot pr int kvm_host_prepare_stage2(void *pgt_pool_base) { - struct kvm_s2_mmu *mmu = &host_kvm.arch.mmu; + struct kvm_s2_mmu *mmu = &host_mmu.arch.mmu; int ret; prepare_host_vtcr(); - hyp_spin_lock_init(&host_kvm.lock); - mmu->arch = &host_kvm.arch; + hyp_spin_lock_init(&host_mmu.lock); + mmu->arch = &host_mmu.arch; ret = prepare_s2_pool(pgt_pool_base); if (ret) return ret; - ret = __kvm_pgtable_stage2_init(&host_kvm.pgt, mmu, - &host_kvm.mm_ops, KVM_HOST_S2_FLAGS, + ret = __kvm_pgtable_stage2_init(&host_mmu.pgt, mmu, + &host_mmu.mm_ops, KVM_HOST_S2_FLAGS, host_stage2_force_pte_cb); if (ret) return ret; - mmu->pgd_phys = __hyp_pa(host_kvm.pgt.pgd); - mmu->pgt = &host_kvm.pgt; + mmu->pgd_phys = __hyp_pa(host_mmu.pgt.pgd); + mmu->pgt = &host_mmu.pgt; atomic64_set(&mmu->vmid.id, 0); return 0; } +static bool guest_stage2_force_pte_cb(u64 addr, u64 end, + enum kvm_pgtable_prot prot) +{ + return true; +} + +static void *guest_s2_zalloc_pages_exact(size_t size) +{ + void *addr = hyp_alloc_pages(¤t_vm->pool, get_order(size)); + + WARN_ON(size != (PAGE_SIZE << get_order(size))); + hyp_split_page(hyp_virt_to_page(addr)); + + return addr; +} + +static void guest_s2_free_pages_exact(void *addr, unsigned long size) +{ + u8 order = get_order(size); + unsigned int i; + + for (i = 0; i < (1 << order); i++) + hyp_put_page(¤t_vm->pool, addr + (i * PAGE_SIZE)); +} + +static void *guest_s2_zalloc_page(void *mc) +{ + struct hyp_page *p; + void *addr; + + addr = hyp_alloc_pages(¤t_vm->pool, 0); + if (addr) + return addr; + + addr = pop_hyp_memcache(mc, hyp_phys_to_virt); + if (!addr) + return addr; + + memset(addr, 0, PAGE_SIZE); + p = hyp_virt_to_page(addr); + memset(p, 0, sizeof(*p)); + p->refcount = 1; + + return addr; +} + +static void guest_s2_get_page(void *addr) +{ + hyp_get_page(¤t_vm->pool, addr); +} + +static void guest_s2_put_page(void *addr) +{ + hyp_put_page(¤t_vm->pool, addr); +} + +static void clean_dcache_guest_page(void *va, size_t size) +{ + __clean_dcache_guest_page(hyp_fixmap_map(__hyp_pa(va)), size); + hyp_fixmap_unmap(); +} + +static void invalidate_icache_guest_page(void *va, size_t size) +{ + __invalidate_icache_guest_page(hyp_fixmap_map(__hyp_pa(va)), size); + hyp_fixmap_unmap(); +} + +int kvm_guest_prepare_stage2(struct pkvm_hyp_vm *vm, void *pgd) +{ + struct kvm_s2_mmu *mmu = &vm->kvm.arch.mmu; + unsigned long nr_pages; + int ret; + + nr_pages = kvm_pgtable_stage2_pgd_size(vm->kvm.arch.vtcr) >> PAGE_SHIFT; + ret = hyp_pool_init(&vm->pool, hyp_virt_to_pfn(pgd), nr_pages, 0); + if (ret) + return ret; + + hyp_spin_lock_init(&vm->lock); + vm->mm_ops = (struct kvm_pgtable_mm_ops) { + .zalloc_pages_exact = guest_s2_zalloc_pages_exact, + .free_pages_exact = guest_s2_free_pages_exact, + .zalloc_page = guest_s2_zalloc_page, + .phys_to_virt = hyp_phys_to_virt, + .virt_to_phys = hyp_virt_to_phys, + .page_count = hyp_page_count, + .get_page = guest_s2_get_page, + .put_page = guest_s2_put_page, + .dcache_clean_inval_poc = clean_dcache_guest_page, + .icache_inval_pou = invalidate_icache_guest_page, + }; + + guest_lock_component(vm); + ret = __kvm_pgtable_stage2_init(mmu->pgt, mmu, &vm->mm_ops, 0, + guest_stage2_force_pte_cb); + guest_unlock_component(vm); + if (ret) + return ret; + + vm->kvm.arch.mmu.pgd_phys = __hyp_pa(vm->pgt.pgd); + + return 0; +} + +void reclaim_guest_pages(struct pkvm_hyp_vm *vm, struct kvm_hyp_memcache *mc) +{ + void *addr; + + /* Dump all pgtable pages in the hyp_pool */ + guest_lock_component(vm); + kvm_pgtable_stage2_destroy(&vm->pgt); + vm->kvm.arch.mmu.pgd_phys = 0ULL; + guest_unlock_component(vm); + + /* Drain the hyp_pool into the memcache */ + addr = hyp_alloc_pages(&vm->pool, 0); + while (addr) { + memset(hyp_virt_to_page(addr), 0, sizeof(struct hyp_page)); + push_hyp_memcache(mc, addr, hyp_virt_to_phys); + WARN_ON(__pkvm_hyp_donate_host(hyp_virt_to_pfn(addr), 1)); + addr = hyp_alloc_pages(&vm->pool, 0); + } +} + int __pkvm_prot_finalize(void) { - struct kvm_s2_mmu *mmu = &host_kvm.arch.mmu; + struct kvm_s2_mmu *mmu = &host_mmu.arch.mmu; struct kvm_nvhe_init_params *params = this_cpu_ptr(&kvm_init_params); if (params->hcr_el2 & HCR_VM) return -EPERM; params->vttbr = kvm_get_vttbr(mmu); - params->vtcr = host_kvm.arch.vtcr; + params->vtcr = host_mmu.arch.vtcr; params->hcr_el2 |= HCR_VM; kvm_flush_dcache_to_poc(params, sizeof(*params)); write_sysreg(params->hcr_el2, hcr_el2); - __load_stage2(&host_kvm.arch.mmu, &host_kvm.arch); + __load_stage2(&host_mmu.arch.mmu, &host_mmu.arch); /* * Make sure to have an ISB before the TLB maintenance below but only @@ -175,7 +318,7 @@ int __pkvm_prot_finalize(void) static int host_stage2_unmap_dev_all(void) { - struct kvm_pgtable *pgt = &host_kvm.pgt; + struct kvm_pgtable *pgt = &host_mmu.pgt; struct memblock_region *reg; u64 addr = 0; int i, ret; @@ -195,7 +338,7 @@ struct kvm_mem_range { u64 end; }; -static bool find_mem_range(phys_addr_t addr, struct kvm_mem_range *range) +static struct memblock_region *find_mem_range(phys_addr_t addr, struct kvm_mem_range *range) { int cur, left = 0, right = hyp_memblock_nr; struct memblock_region *reg; @@ -218,18 +361,28 @@ static bool find_mem_range(phys_addr_t addr, struct kvm_mem_range *range) } else { range->start = reg->base; range->end = end; - return true; + return reg; } } - return false; + return NULL; } bool addr_is_memory(phys_addr_t phys) { struct kvm_mem_range range; - return find_mem_range(phys, &range); + return !!find_mem_range(phys, &range); +} + +static bool addr_is_allowed_memory(phys_addr_t phys) +{ + struct memblock_region *reg; + struct kvm_mem_range range; + + reg = find_mem_range(phys, &range); + + return reg && !(reg->flags & MEMBLOCK_NOMAP); } static bool is_in_mem_range(u64 addr, struct kvm_mem_range *range) @@ -250,8 +403,8 @@ static bool range_is_memory(u64 start, u64 end) static inline int __host_stage2_idmap(u64 start, u64 end, enum kvm_pgtable_prot prot) { - return kvm_pgtable_stage2_map(&host_kvm.pgt, start, end - start, start, - prot, &host_s2_pool); + return kvm_pgtable_stage2_map(&host_mmu.pgt, start, end - start, start, + prot, &host_s2_pool, 0); } /* @@ -263,7 +416,7 @@ static inline int __host_stage2_idmap(u64 start, u64 end, #define host_stage2_try(fn, ...) \ ({ \ int __ret; \ - hyp_assert_lock_held(&host_kvm.lock); \ + hyp_assert_lock_held(&host_mmu.lock); \ __ret = fn(__VA_ARGS__); \ if (__ret == -ENOMEM) { \ __ret = host_stage2_unmap_dev_all(); \ @@ -286,8 +439,8 @@ static int host_stage2_adjust_range(u64 addr, struct kvm_mem_range *range) u32 level; int ret; - hyp_assert_lock_held(&host_kvm.lock); - ret = kvm_pgtable_get_leaf(&host_kvm.pgt, addr, &pte, &level); + hyp_assert_lock_held(&host_mmu.lock); + ret = kvm_pgtable_get_leaf(&host_mmu.pgt, addr, &pte, &level); if (ret) return ret; @@ -319,7 +472,7 @@ int host_stage2_idmap_locked(phys_addr_t addr, u64 size, int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id) { - return host_stage2_try(kvm_pgtable_stage2_set_owner, &host_kvm.pgt, + return host_stage2_try(kvm_pgtable_stage2_set_owner, &host_mmu.pgt, addr, size, &host_s2_pool, owner_id); } @@ -348,7 +501,7 @@ static bool host_stage2_force_pte_cb(u64 addr, u64 end, enum kvm_pgtable_prot pr static int host_stage2_idmap(u64 addr) { struct kvm_mem_range range; - bool is_memory = find_mem_range(addr, &range); + bool is_memory = !!find_mem_range(addr, &range); enum kvm_pgtable_prot prot; int ret; @@ -380,12 +533,6 @@ void handle_host_mem_abort(struct kvm_cpu_context *host_ctxt) BUG_ON(ret && ret != -EAGAIN); } -/* This corresponds to locking order */ -enum pkvm_component_id { - PKVM_ID_HOST, - PKVM_ID_HYP, -}; - struct pkvm_mem_transition { u64 nr_pages; @@ -399,6 +546,9 @@ struct pkvm_mem_transition { /* Address in the completer's address space */ u64 completer_addr; } host; + struct { + u64 completer_addr; + } hyp; }; } initiator; @@ -412,23 +562,24 @@ struct pkvm_mem_share { const enum kvm_pgtable_prot completer_prot; }; +struct pkvm_mem_donation { + const struct pkvm_mem_transition tx; +}; + struct check_walk_data { enum pkvm_page_state desired; enum pkvm_page_state (*get_page_state)(kvm_pte_t pte); }; -static int __check_page_state_visitor(u64 addr, u64 end, u32 level, - kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag, - void * const arg) +static int __check_page_state_visitor(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) { - struct check_walk_data *d = arg; - kvm_pte_t pte = *ptep; + struct check_walk_data *d = ctx->arg; - if (kvm_pte_valid(pte) && !addr_is_memory(kvm_pte_to_phys(pte))) + if (kvm_pte_valid(ctx->old) && !addr_is_allowed_memory(kvm_pte_to_phys(ctx->old))) return -EINVAL; - return d->get_page_state(pte) == d->desired ? 0 : -EPERM; + return d->get_page_state(ctx->old) == d->desired ? 0 : -EPERM; } static int check_page_state_range(struct kvm_pgtable *pgt, u64 addr, u64 size, @@ -459,8 +610,8 @@ static int __host_check_page_state_range(u64 addr, u64 size, .get_page_state = host_get_page_state, }; - hyp_assert_lock_held(&host_kvm.lock); - return check_page_state_range(&host_kvm.pgt, addr, size, &d); + hyp_assert_lock_held(&host_mmu.lock); + return check_page_state_range(&host_mmu.pgt, addr, size, &d); } static int __host_set_page_state_range(u64 addr, u64 size, @@ -511,6 +662,46 @@ static int host_initiate_unshare(u64 *completer_addr, return __host_set_page_state_range(addr, size, PKVM_PAGE_OWNED); } +static int host_initiate_donation(u64 *completer_addr, + const struct pkvm_mem_transition *tx) +{ + u8 owner_id = tx->completer.id; + u64 size = tx->nr_pages * PAGE_SIZE; + + *completer_addr = tx->initiator.host.completer_addr; + return host_stage2_set_owner_locked(tx->initiator.addr, size, owner_id); +} + +static bool __host_ack_skip_pgtable_check(const struct pkvm_mem_transition *tx) +{ + return !(IS_ENABLED(CONFIG_NVHE_EL2_DEBUG) || + tx->initiator.id != PKVM_ID_HYP); +} + +static int __host_ack_transition(u64 addr, const struct pkvm_mem_transition *tx, + enum pkvm_page_state state) +{ + u64 size = tx->nr_pages * PAGE_SIZE; + + if (__host_ack_skip_pgtable_check(tx)) + return 0; + + return __host_check_page_state_range(addr, size, state); +} + +static int host_ack_donation(u64 addr, const struct pkvm_mem_transition *tx) +{ + return __host_ack_transition(addr, tx, PKVM_NOPAGE); +} + +static int host_complete_donation(u64 addr, const struct pkvm_mem_transition *tx) +{ + u64 size = tx->nr_pages * PAGE_SIZE; + u8 host_id = tx->completer.id; + + return host_stage2_set_owner_locked(addr, size, host_id); +} + static enum pkvm_page_state hyp_get_page_state(kvm_pte_t pte) { if (!kvm_pte_valid(pte)) @@ -531,6 +722,27 @@ static int __hyp_check_page_state_range(u64 addr, u64 size, return check_page_state_range(&pkvm_pgtable, addr, size, &d); } +static int hyp_request_donation(u64 *completer_addr, + const struct pkvm_mem_transition *tx) +{ + u64 size = tx->nr_pages * PAGE_SIZE; + u64 addr = tx->initiator.addr; + + *completer_addr = tx->initiator.hyp.completer_addr; + return __hyp_check_page_state_range(addr, size, PKVM_PAGE_OWNED); +} + +static int hyp_initiate_donation(u64 *completer_addr, + const struct pkvm_mem_transition *tx) +{ + u64 size = tx->nr_pages * PAGE_SIZE; + int ret; + + *completer_addr = tx->initiator.hyp.completer_addr; + ret = kvm_pgtable_hyp_unmap(&pkvm_pgtable, tx->initiator.addr, size); + return (ret != size) ? -EFAULT : 0; +} + static bool __hyp_ack_skip_pgtable_check(const struct pkvm_mem_transition *tx) { return !(IS_ENABLED(CONFIG_NVHE_EL2_DEBUG) || @@ -555,6 +767,9 @@ static int hyp_ack_unshare(u64 addr, const struct pkvm_mem_transition *tx) { u64 size = tx->nr_pages * PAGE_SIZE; + if (tx->initiator.id == PKVM_ID_HOST && hyp_page_count((void *)addr)) + return -EBUSY; + if (__hyp_ack_skip_pgtable_check(tx)) return 0; @@ -562,6 +777,16 @@ static int hyp_ack_unshare(u64 addr, const struct pkvm_mem_transition *tx) PKVM_PAGE_SHARED_BORROWED); } +static int hyp_ack_donation(u64 addr, const struct pkvm_mem_transition *tx) +{ + u64 size = tx->nr_pages * PAGE_SIZE; + + if (__hyp_ack_skip_pgtable_check(tx)) + return 0; + + return __hyp_check_page_state_range(addr, size, PKVM_NOPAGE); +} + static int hyp_complete_share(u64 addr, const struct pkvm_mem_transition *tx, enum kvm_pgtable_prot perms) { @@ -580,6 +805,15 @@ static int hyp_complete_unshare(u64 addr, const struct pkvm_mem_transition *tx) return (ret != size) ? -EFAULT : 0; } +static int hyp_complete_donation(u64 addr, + const struct pkvm_mem_transition *tx) +{ + void *start = (void *)addr, *end = start + (tx->nr_pages * PAGE_SIZE); + enum kvm_pgtable_prot prot = pkvm_mkstate(PAGE_HYP, PKVM_PAGE_OWNED); + + return pkvm_create_mappings_locked(start, end, prot); +} + static int check_share(struct pkvm_mem_share *share) { const struct pkvm_mem_transition *tx = &share->tx; @@ -732,6 +966,94 @@ static int do_unshare(struct pkvm_mem_share *share) return WARN_ON(__do_unshare(share)); } +static int check_donation(struct pkvm_mem_donation *donation) +{ + const struct pkvm_mem_transition *tx = &donation->tx; + u64 completer_addr; + int ret; + + switch (tx->initiator.id) { + case PKVM_ID_HOST: + ret = host_request_owned_transition(&completer_addr, tx); + break; + case PKVM_ID_HYP: + ret = hyp_request_donation(&completer_addr, tx); + break; + default: + ret = -EINVAL; + } + + if (ret) + return ret; + + switch (tx->completer.id) { + case PKVM_ID_HOST: + ret = host_ack_donation(completer_addr, tx); + break; + case PKVM_ID_HYP: + ret = hyp_ack_donation(completer_addr, tx); + break; + default: + ret = -EINVAL; + } + + return ret; +} + +static int __do_donate(struct pkvm_mem_donation *donation) +{ + const struct pkvm_mem_transition *tx = &donation->tx; + u64 completer_addr; + int ret; + + switch (tx->initiator.id) { + case PKVM_ID_HOST: + ret = host_initiate_donation(&completer_addr, tx); + break; + case PKVM_ID_HYP: + ret = hyp_initiate_donation(&completer_addr, tx); + break; + default: + ret = -EINVAL; + } + + if (ret) + return ret; + + switch (tx->completer.id) { + case PKVM_ID_HOST: + ret = host_complete_donation(completer_addr, tx); + break; + case PKVM_ID_HYP: + ret = hyp_complete_donation(completer_addr, tx); + break; + default: + ret = -EINVAL; + } + + return ret; +} + +/* + * do_donate(): + * + * The page owner transfers ownership to another component, losing access + * as a consequence. + * + * Initiator: OWNED => NOPAGE + * Completer: NOPAGE => OWNED + */ +static int do_donate(struct pkvm_mem_donation *donation) +{ + int ret; + + ret = check_donation(donation); + if (ret) + return ret; + + return WARN_ON(__do_donate(donation)); +} + int __pkvm_host_share_hyp(u64 pfn) { int ret; @@ -797,3 +1119,112 @@ int __pkvm_host_unshare_hyp(u64 pfn) return ret; } + +int __pkvm_host_donate_hyp(u64 pfn, u64 nr_pages) +{ + int ret; + u64 host_addr = hyp_pfn_to_phys(pfn); + u64 hyp_addr = (u64)__hyp_va(host_addr); + struct pkvm_mem_donation donation = { + .tx = { + .nr_pages = nr_pages, + .initiator = { + .id = PKVM_ID_HOST, + .addr = host_addr, + .host = { + .completer_addr = hyp_addr, + }, + }, + .completer = { + .id = PKVM_ID_HYP, + }, + }, + }; + + host_lock_component(); + hyp_lock_component(); + + ret = do_donate(&donation); + + hyp_unlock_component(); + host_unlock_component(); + + return ret; +} + +int __pkvm_hyp_donate_host(u64 pfn, u64 nr_pages) +{ + int ret; + u64 host_addr = hyp_pfn_to_phys(pfn); + u64 hyp_addr = (u64)__hyp_va(host_addr); + struct pkvm_mem_donation donation = { + .tx = { + .nr_pages = nr_pages, + .initiator = { + .id = PKVM_ID_HYP, + .addr = hyp_addr, + .hyp = { + .completer_addr = host_addr, + }, + }, + .completer = { + .id = PKVM_ID_HOST, + }, + }, + }; + + host_lock_component(); + hyp_lock_component(); + + ret = do_donate(&donation); + + hyp_unlock_component(); + host_unlock_component(); + + return ret; +} + +int hyp_pin_shared_mem(void *from, void *to) +{ + u64 cur, start = ALIGN_DOWN((u64)from, PAGE_SIZE); + u64 end = PAGE_ALIGN((u64)to); + u64 size = end - start; + int ret; + + host_lock_component(); + hyp_lock_component(); + + ret = __host_check_page_state_range(__hyp_pa(start), size, + PKVM_PAGE_SHARED_OWNED); + if (ret) + goto unlock; + + ret = __hyp_check_page_state_range(start, size, + PKVM_PAGE_SHARED_BORROWED); + if (ret) + goto unlock; + + for (cur = start; cur < end; cur += PAGE_SIZE) + hyp_page_ref_inc(hyp_virt_to_page(cur)); + +unlock: + hyp_unlock_component(); + host_unlock_component(); + + return ret; +} + +void hyp_unpin_shared_mem(void *from, void *to) +{ + u64 cur, start = ALIGN_DOWN((u64)from, PAGE_SIZE); + u64 end = PAGE_ALIGN((u64)to); + + host_lock_component(); + hyp_lock_component(); + + for (cur = start; cur < end; cur += PAGE_SIZE) + hyp_page_ref_dec(hyp_virt_to_page(cur)); + + hyp_unlock_component(); + host_unlock_component(); +} diff --git a/arch/arm64/kvm/hyp/nvhe/mm.c b/arch/arm64/kvm/hyp/nvhe/mm.c index 96193cb31a39..318298eb3d6b 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) { @@ -129,13 +136,36 @@ int pkvm_create_mappings(void *from, void *to, enum kvm_pgtable_prot prot) return ret; } -int hyp_back_vmemmap(phys_addr_t phys, unsigned long size, phys_addr_t back) +int hyp_back_vmemmap(phys_addr_t back) { - unsigned long start, end; + unsigned long i, start, size, end = 0; + int ret; - hyp_vmemmap_range(phys, size, &start, &end); + for (i = 0; i < hyp_memblock_nr; i++) { + start = hyp_memory[i].base; + start = ALIGN_DOWN((u64)hyp_phys_to_page(start), PAGE_SIZE); + /* + * The begining of the hyp_vmemmap region for the current + * memblock may already be backed by the page backing the end + * the previous region, so avoid mapping it twice. + */ + start = max(start, end); + + end = hyp_memory[i].base + hyp_memory[i].size; + end = PAGE_ALIGN((u64)hyp_phys_to_page(end)); + if (start >= end) + continue; + + size = end - start; + ret = __pkvm_create_mappings(start, size, back, PAGE_HYP); + if (ret) + return ret; + + memset(hyp_phys_to_virt(back), 0, size); + back += size; + } - return __pkvm_create_mappings(start, end - start, back, PAGE_HYP); + return 0; } static void *__hyp_bp_vect_base; @@ -189,6 +219,102 @@ 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(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) +{ + struct hyp_fixmap_slot *slot = per_cpu_ptr(&fixmap_slots, (u64)ctx->arg); + + if (!kvm_pte_valid(ctx->old) || ctx->level != KVM_PGTABLE_MAX_LEVELS - 1) + return -EINVAL; + + slot->addr = ctx->addr; + slot->ptep = ctx->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; @@ -213,3 +339,36 @@ int hyp_create_idmap(u32 hyp_va_bits) return __pkvm_create_mappings(start, end - start, start, PAGE_HYP_EXEC); } + +static void *admit_host_page(void *arg) +{ + struct kvm_hyp_memcache *host_mc = arg; + + if (!host_mc->nr_pages) + return NULL; + + /* + * The host still owns the pages in its memcache, so we need to go + * through a full host-to-hyp donation cycle to change it. Fortunately, + * __pkvm_host_donate_hyp() takes care of races for us, so if it + * succeeds we're good to go. + */ + if (__pkvm_host_donate_hyp(hyp_phys_to_pfn(host_mc->head), 1)) + return NULL; + + return pop_hyp_memcache(host_mc, hyp_phys_to_virt); +} + +/* Refill our local memcache by poping pages from the one provided by the host. */ +int refill_memcache(struct kvm_hyp_memcache *mc, unsigned long min_pages, + struct kvm_hyp_memcache *host_mc) +{ + struct kvm_hyp_memcache tmp = *host_mc; + int ret; + + ret = __topup_hyp_memcache(mc, min_pages, admit_host_page, + hyp_virt_to_phys, &tmp); + *host_mc = tmp; + + return ret; +} diff --git a/arch/arm64/kvm/hyp/nvhe/page_alloc.c b/arch/arm64/kvm/hyp/nvhe/page_alloc.c index d40f0b30b534..803ba3222e75 100644 --- a/arch/arm64/kvm/hyp/nvhe/page_alloc.c +++ b/arch/arm64/kvm/hyp/nvhe/page_alloc.c @@ -93,11 +93,16 @@ static inline struct hyp_page *node_to_page(struct list_head *node) static void __hyp_attach_page(struct hyp_pool *pool, struct hyp_page *p) { + phys_addr_t phys = hyp_page_to_phys(p); unsigned short order = p->order; struct hyp_page *buddy; memset(hyp_page_to_virt(p), 0, PAGE_SIZE << p->order); + /* Skip coalescing for 'external' pages being freed into the pool. */ + if (phys < pool->range_start || phys >= pool->range_end) + goto insert; + /* * Only the first struct hyp_page of a high-order page (otherwise known * as the 'head') should have p->order set. The non-head pages should @@ -116,6 +121,7 @@ static void __hyp_attach_page(struct hyp_pool *pool, p = min(p, buddy); } +insert: /* Mark the new head, and insert it */ p->order = order; page_add_to_list(p, &pool->free_area[order]); @@ -144,25 +150,6 @@ static struct hyp_page *__hyp_extract_page(struct hyp_pool *pool, return p; } -static inline void hyp_page_ref_inc(struct hyp_page *p) -{ - BUG_ON(p->refcount == USHRT_MAX); - p->refcount++; -} - -static inline int hyp_page_ref_dec_and_test(struct hyp_page *p) -{ - BUG_ON(!p->refcount); - p->refcount--; - return (p->refcount == 0); -} - -static inline void hyp_set_page_refcounted(struct hyp_page *p) -{ - BUG_ON(p->refcount); - p->refcount = 1; -} - static void __hyp_put_page(struct hyp_pool *pool, struct hyp_page *p) { if (hyp_page_ref_dec_and_test(p)) @@ -249,10 +236,8 @@ int hyp_pool_init(struct hyp_pool *pool, u64 pfn, unsigned int nr_pages, /* Init the vmemmap portion */ p = hyp_phys_to_page(phys); - for (i = 0; i < nr_pages; i++) { - p[i].order = 0; + for (i = 0; i < nr_pages; i++) hyp_set_page_refcounted(&p[i]); - } /* Attach the unused pages to the buddy tree */ for (i = reserved_pages; i < nr_pages; i++) diff --git a/arch/arm64/kvm/hyp/nvhe/pkvm.c b/arch/arm64/kvm/hyp/nvhe/pkvm.c index 85d3b7ae720f..a06ece14a6d8 100644 --- a/arch/arm64/kvm/hyp/nvhe/pkvm.c +++ b/arch/arm64/kvm/hyp/nvhe/pkvm.c @@ -7,8 +7,17 @@ #include <linux/kvm_host.h> #include <linux/mm.h> #include <nvhe/fixed_config.h> +#include <nvhe/mem_protect.h> +#include <nvhe/memory.h> +#include <nvhe/pkvm.h> #include <nvhe/trap_handler.h> +/* Used by icache_is_vpipt(). */ +unsigned long __icache_flags; + +/* Used by kvm_get_vttbr(). */ +unsigned int kvm_arm_vmid_bits; + /* * Set trap register values based on features in ID_AA64PFR0. */ @@ -183,3 +192,430 @@ void __pkvm_vcpu_init_traps(struct kvm_vcpu *vcpu) pvm_init_traps_aa64mmfr0(vcpu); pvm_init_traps_aa64mmfr1(vcpu); } + +/* + * Start the VM table handle at the offset defined instead of at 0. + * Mainly for sanity checking and debugging. + */ +#define HANDLE_OFFSET 0x1000 + +static unsigned int vm_handle_to_idx(pkvm_handle_t handle) +{ + return handle - HANDLE_OFFSET; +} + +static pkvm_handle_t idx_to_vm_handle(unsigned int idx) +{ + return idx + HANDLE_OFFSET; +} + +/* + * Spinlock for protecting state related to the VM table. Protects writes + * to 'vm_table' and 'nr_table_entries' as well as reads and writes to + * 'last_hyp_vcpu_lookup'. + */ +static DEFINE_HYP_SPINLOCK(vm_table_lock); + +/* + * The table of VM entries for protected VMs in hyp. + * Allocated at hyp initialization and setup. + */ +static struct pkvm_hyp_vm **vm_table; + +void pkvm_hyp_vm_table_init(void *tbl) +{ + WARN_ON(vm_table); + vm_table = tbl; +} + +/* + * Return the hyp vm structure corresponding to the handle. + */ +static struct pkvm_hyp_vm *get_vm_by_handle(pkvm_handle_t handle) +{ + unsigned int idx = vm_handle_to_idx(handle); + + if (unlikely(idx >= KVM_MAX_PVMS)) + return NULL; + + return vm_table[idx]; +} + +struct pkvm_hyp_vcpu *pkvm_load_hyp_vcpu(pkvm_handle_t handle, + unsigned int vcpu_idx) +{ + struct pkvm_hyp_vcpu *hyp_vcpu = NULL; + struct pkvm_hyp_vm *hyp_vm; + + hyp_spin_lock(&vm_table_lock); + hyp_vm = get_vm_by_handle(handle); + if (!hyp_vm || hyp_vm->nr_vcpus <= vcpu_idx) + goto unlock; + + hyp_vcpu = hyp_vm->vcpus[vcpu_idx]; + hyp_page_ref_inc(hyp_virt_to_page(hyp_vm)); +unlock: + hyp_spin_unlock(&vm_table_lock); + return hyp_vcpu; +} + +void pkvm_put_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) +{ + struct pkvm_hyp_vm *hyp_vm = pkvm_hyp_vcpu_to_hyp_vm(hyp_vcpu); + + hyp_spin_lock(&vm_table_lock); + hyp_page_ref_dec(hyp_virt_to_page(hyp_vm)); + hyp_spin_unlock(&vm_table_lock); +} + +static void unpin_host_vcpu(struct kvm_vcpu *host_vcpu) +{ + if (host_vcpu) + hyp_unpin_shared_mem(host_vcpu, host_vcpu + 1); +} + +static void unpin_host_vcpus(struct pkvm_hyp_vcpu *hyp_vcpus[], + unsigned int nr_vcpus) +{ + int i; + + for (i = 0; i < nr_vcpus; i++) + unpin_host_vcpu(hyp_vcpus[i]->host_vcpu); +} + +static void init_pkvm_hyp_vm(struct kvm *host_kvm, struct pkvm_hyp_vm *hyp_vm, + unsigned int nr_vcpus) +{ + hyp_vm->host_kvm = host_kvm; + hyp_vm->kvm.created_vcpus = nr_vcpus; + hyp_vm->kvm.arch.vtcr = host_mmu.arch.vtcr; +} + +static int init_pkvm_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu, + struct pkvm_hyp_vm *hyp_vm, + struct kvm_vcpu *host_vcpu, + unsigned int vcpu_idx) +{ + int ret = 0; + + if (hyp_pin_shared_mem(host_vcpu, host_vcpu + 1)) + return -EBUSY; + + if (host_vcpu->vcpu_idx != vcpu_idx) { + ret = -EINVAL; + goto done; + } + + hyp_vcpu->host_vcpu = host_vcpu; + + hyp_vcpu->vcpu.kvm = &hyp_vm->kvm; + hyp_vcpu->vcpu.vcpu_id = READ_ONCE(host_vcpu->vcpu_id); + hyp_vcpu->vcpu.vcpu_idx = vcpu_idx; + + hyp_vcpu->vcpu.arch.hw_mmu = &hyp_vm->kvm.arch.mmu; + hyp_vcpu->vcpu.arch.cflags = READ_ONCE(host_vcpu->arch.cflags); +done: + if (ret) + unpin_host_vcpu(host_vcpu); + return ret; +} + +static int find_free_vm_table_entry(struct kvm *host_kvm) +{ + int i; + + for (i = 0; i < KVM_MAX_PVMS; ++i) { + if (!vm_table[i]) + return i; + } + + return -ENOMEM; +} + +/* + * Allocate a VM table entry and insert a pointer to the new vm. + * + * Return a unique handle to the protected VM on success, + * negative error code on failure. + */ +static pkvm_handle_t insert_vm_table_entry(struct kvm *host_kvm, + struct pkvm_hyp_vm *hyp_vm) +{ + struct kvm_s2_mmu *mmu = &hyp_vm->kvm.arch.mmu; + int idx; + + hyp_assert_lock_held(&vm_table_lock); + + /* + * Initializing protected state might have failed, yet a malicious + * host could trigger this function. Thus, ensure that 'vm_table' + * exists. + */ + if (unlikely(!vm_table)) + return -EINVAL; + + idx = find_free_vm_table_entry(host_kvm); + if (idx < 0) + return idx; + + hyp_vm->kvm.arch.pkvm.handle = idx_to_vm_handle(idx); + + /* VMID 0 is reserved for the host */ + atomic64_set(&mmu->vmid.id, idx + 1); + + mmu->arch = &hyp_vm->kvm.arch; + mmu->pgt = &hyp_vm->pgt; + + vm_table[idx] = hyp_vm; + return hyp_vm->kvm.arch.pkvm.handle; +} + +/* + * Deallocate and remove the VM table entry corresponding to the handle. + */ +static void remove_vm_table_entry(pkvm_handle_t handle) +{ + hyp_assert_lock_held(&vm_table_lock); + vm_table[vm_handle_to_idx(handle)] = NULL; +} + +static size_t pkvm_get_hyp_vm_size(unsigned int nr_vcpus) +{ + return size_add(sizeof(struct pkvm_hyp_vm), + size_mul(sizeof(struct pkvm_hyp_vcpu *), nr_vcpus)); +} + +static void *map_donated_memory_noclear(unsigned long host_va, size_t size) +{ + void *va = (void *)kern_hyp_va(host_va); + + if (!PAGE_ALIGNED(va)) + return NULL; + + if (__pkvm_host_donate_hyp(hyp_virt_to_pfn(va), + PAGE_ALIGN(size) >> PAGE_SHIFT)) + return NULL; + + return va; +} + +static void *map_donated_memory(unsigned long host_va, size_t size) +{ + void *va = map_donated_memory_noclear(host_va, size); + + if (va) + memset(va, 0, size); + + return va; +} + +static void __unmap_donated_memory(void *va, size_t size) +{ + WARN_ON(__pkvm_hyp_donate_host(hyp_virt_to_pfn(va), + PAGE_ALIGN(size) >> PAGE_SHIFT)); +} + +static void unmap_donated_memory(void *va, size_t size) +{ + if (!va) + return; + + memset(va, 0, size); + __unmap_donated_memory(va, size); +} + +static void unmap_donated_memory_noclear(void *va, size_t size) +{ + if (!va) + return; + + __unmap_donated_memory(va, size); +} + +/* + * Initialize the hypervisor copy of the protected VM state using the + * memory donated by the host. + * + * Unmaps the donated memory from the host at stage 2. + * + * host_kvm: A pointer to the host's struct kvm. + * vm_hva: The host va of the area being donated for the VM state. + * Must be page aligned. + * pgd_hva: The host va of the area being donated for the stage-2 PGD for + * the VM. Must be page aligned. Its size is implied by the VM's + * VTCR. + * + * Return a unique handle to the protected VM on success, + * negative error code on failure. + */ +int __pkvm_init_vm(struct kvm *host_kvm, unsigned long vm_hva, + unsigned long pgd_hva) +{ + struct pkvm_hyp_vm *hyp_vm = NULL; + size_t vm_size, pgd_size; + unsigned int nr_vcpus; + void *pgd = NULL; + int ret; + + ret = hyp_pin_shared_mem(host_kvm, host_kvm + 1); + if (ret) + return ret; + + nr_vcpus = READ_ONCE(host_kvm->created_vcpus); + if (nr_vcpus < 1) { + ret = -EINVAL; + goto err_unpin_kvm; + } + + vm_size = pkvm_get_hyp_vm_size(nr_vcpus); + pgd_size = kvm_pgtable_stage2_pgd_size(host_mmu.arch.vtcr); + + ret = -ENOMEM; + + hyp_vm = map_donated_memory(vm_hva, vm_size); + if (!hyp_vm) + goto err_remove_mappings; + + pgd = map_donated_memory_noclear(pgd_hva, pgd_size); + if (!pgd) + goto err_remove_mappings; + + init_pkvm_hyp_vm(host_kvm, hyp_vm, nr_vcpus); + + hyp_spin_lock(&vm_table_lock); + ret = insert_vm_table_entry(host_kvm, hyp_vm); + if (ret < 0) + goto err_unlock; + + ret = kvm_guest_prepare_stage2(hyp_vm, pgd); + if (ret) + goto err_remove_vm_table_entry; + hyp_spin_unlock(&vm_table_lock); + + return hyp_vm->kvm.arch.pkvm.handle; + +err_remove_vm_table_entry: + remove_vm_table_entry(hyp_vm->kvm.arch.pkvm.handle); +err_unlock: + hyp_spin_unlock(&vm_table_lock); +err_remove_mappings: + unmap_donated_memory(hyp_vm, vm_size); + unmap_donated_memory(pgd, pgd_size); +err_unpin_kvm: + hyp_unpin_shared_mem(host_kvm, host_kvm + 1); + return ret; +} + +/* + * Initialize the hypervisor copy of the protected vCPU state using the + * memory donated by the host. + * + * handle: The handle for the protected vm. + * host_vcpu: A pointer to the corresponding host vcpu. + * vcpu_hva: The host va of the area being donated for the vcpu state. + * Must be page aligned. The size of the area must be equal to + * the page-aligned size of 'struct pkvm_hyp_vcpu'. + * Return 0 on success, negative error code on failure. + */ +int __pkvm_init_vcpu(pkvm_handle_t handle, struct kvm_vcpu *host_vcpu, + unsigned long vcpu_hva) +{ + struct pkvm_hyp_vcpu *hyp_vcpu; + struct pkvm_hyp_vm *hyp_vm; + unsigned int idx; + int ret; + + hyp_vcpu = map_donated_memory(vcpu_hva, sizeof(*hyp_vcpu)); + if (!hyp_vcpu) + return -ENOMEM; + + hyp_spin_lock(&vm_table_lock); + + hyp_vm = get_vm_by_handle(handle); + if (!hyp_vm) { + ret = -ENOENT; + goto unlock; + } + + idx = hyp_vm->nr_vcpus; + if (idx >= hyp_vm->kvm.created_vcpus) { + ret = -EINVAL; + goto unlock; + } + + ret = init_pkvm_hyp_vcpu(hyp_vcpu, hyp_vm, host_vcpu, idx); + if (ret) + goto unlock; + + hyp_vm->vcpus[idx] = hyp_vcpu; + hyp_vm->nr_vcpus++; +unlock: + hyp_spin_unlock(&vm_table_lock); + + if (ret) + unmap_donated_memory(hyp_vcpu, sizeof(*hyp_vcpu)); + + return ret; +} + +static void +teardown_donated_memory(struct kvm_hyp_memcache *mc, void *addr, size_t size) +{ + size = PAGE_ALIGN(size); + memset(addr, 0, size); + + for (void *start = addr; start < addr + size; start += PAGE_SIZE) + push_hyp_memcache(mc, start, hyp_virt_to_phys); + + unmap_donated_memory_noclear(addr, size); +} + +int __pkvm_teardown_vm(pkvm_handle_t handle) +{ + struct kvm_hyp_memcache *mc; + struct pkvm_hyp_vm *hyp_vm; + struct kvm *host_kvm; + unsigned int idx; + size_t vm_size; + int err; + + hyp_spin_lock(&vm_table_lock); + hyp_vm = get_vm_by_handle(handle); + if (!hyp_vm) { + err = -ENOENT; + goto err_unlock; + } + + if (WARN_ON(hyp_page_count(hyp_vm))) { + err = -EBUSY; + goto err_unlock; + } + + host_kvm = hyp_vm->host_kvm; + + /* Ensure the VMID is clean before it can be reallocated */ + __kvm_tlb_flush_vmid(&hyp_vm->kvm.arch.mmu); + remove_vm_table_entry(handle); + hyp_spin_unlock(&vm_table_lock); + + /* Reclaim guest pages (including page-table pages) */ + mc = &host_kvm->arch.pkvm.teardown_mc; + reclaim_guest_pages(hyp_vm, mc); + unpin_host_vcpus(hyp_vm->vcpus, hyp_vm->nr_vcpus); + + /* Push the metadata pages to the teardown memcache */ + for (idx = 0; idx < hyp_vm->nr_vcpus; ++idx) { + struct pkvm_hyp_vcpu *hyp_vcpu = hyp_vm->vcpus[idx]; + + teardown_donated_memory(mc, hyp_vcpu, sizeof(*hyp_vcpu)); + } + + vm_size = pkvm_get_hyp_vm_size(hyp_vm->kvm.created_vcpus); + teardown_donated_memory(mc, hyp_vm, vm_size); + hyp_unpin_shared_mem(host_kvm, host_kvm + 1); + return 0; + +err_unlock: + hyp_spin_unlock(&vm_table_lock); + return err; +} diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c index e8d4ea2fcfa0..110f04627785 100644 --- a/arch/arm64/kvm/hyp/nvhe/setup.c +++ b/arch/arm64/kvm/hyp/nvhe/setup.c @@ -16,6 +16,7 @@ #include <nvhe/memory.h> #include <nvhe/mem_protect.h> #include <nvhe/mm.h> +#include <nvhe/pkvm.h> #include <nvhe/trap_handler.h> unsigned long hyp_nr_cpus; @@ -24,6 +25,7 @@ unsigned long hyp_nr_cpus; (unsigned long)__per_cpu_start) static void *vmemmap_base; +static void *vm_table_base; static void *hyp_pgt_base; static void *host_s2_pgt_base; static struct kvm_pgtable_mm_ops pkvm_pgtable_mm_ops; @@ -31,16 +33,20 @@ static struct hyp_pool hpool; static int divide_memory_pool(void *virt, unsigned long size) { - unsigned long vstart, vend, nr_pages; + unsigned long nr_pages; hyp_early_alloc_init(virt, size); - hyp_vmemmap_range(__hyp_pa(virt), size, &vstart, &vend); - nr_pages = (vend - vstart) >> PAGE_SHIFT; + nr_pages = hyp_vmemmap_pages(sizeof(struct hyp_page)); vmemmap_base = hyp_early_alloc_contig(nr_pages); if (!vmemmap_base) return -ENOMEM; + nr_pages = hyp_vm_table_pages(); + vm_table_base = hyp_early_alloc_contig(nr_pages); + if (!vm_table_base) + return -ENOMEM; + nr_pages = hyp_s1_pgtable_pages(); hyp_pgt_base = hyp_early_alloc_contig(nr_pages); if (!hyp_pgt_base) @@ -78,7 +84,7 @@ static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size, if (ret) return ret; - ret = hyp_back_vmemmap(phys, size, hyp_virt_to_phys(vmemmap_base)); + ret = hyp_back_vmemmap(hyp_virt_to_phys(vmemmap_base)); if (ret) return ret; @@ -138,20 +144,17 @@ static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size, } /* - * Map the host's .bss and .rodata sections RO in the hypervisor, but - * transfer the ownership from the host to the hypervisor itself to - * make sure it can't be donated or shared with another entity. + * Map the host sections RO in the hypervisor, but transfer the + * ownership from the host to the hypervisor itself to make sure they + * can't be donated or shared with another entity. * * The ownership transition requires matching changes in the host * stage-2. This will be done later (see finalize_host_mappings()) once * the hyp_vmemmap is addressable. */ prot = pkvm_mkstate(PAGE_HYP_RO, PKVM_PAGE_SHARED_OWNED); - ret = pkvm_create_mappings(__start_rodata, __end_rodata, prot); - if (ret) - return ret; - - ret = pkvm_create_mappings(__hyp_bss_end, __bss_stop, prot); + ret = pkvm_create_mappings(&kvm_vgic_global_state, + &kvm_vgic_global_state + 1, prot); if (ret) return ret; @@ -186,33 +189,20 @@ static void hpool_put_page(void *addr) hyp_put_page(&hpool, addr); } -static int finalize_host_mappings_walker(u64 addr, u64 end, u32 level, - kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag, - void * const arg) +static int fix_host_ownership_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) { - struct kvm_pgtable_mm_ops *mm_ops = arg; enum kvm_pgtable_prot prot; enum pkvm_page_state state; - kvm_pte_t pte = *ptep; phys_addr_t phys; - if (!kvm_pte_valid(pte)) + if (!kvm_pte_valid(ctx->old)) return 0; - /* - * Fix-up the refcount for the page-table pages as the early allocator - * was unable to access the hyp_vmemmap and so the buddy allocator has - * initialised the refcount to '1'. - */ - mm_ops->get_page(ptep); - if (flag != KVM_PGTABLE_WALK_LEAF) - return 0; - - if (level != (KVM_PGTABLE_MAX_LEVELS - 1)) + if (ctx->level != (KVM_PGTABLE_MAX_LEVELS - 1)) return -EINVAL; - phys = kvm_pte_to_phys(pte); + phys = kvm_pte_to_phys(ctx->old); if (!addr_is_memory(phys)) return -EINVAL; @@ -220,10 +210,10 @@ static int finalize_host_mappings_walker(u64 addr, u64 end, u32 level, * Adjust the host stage-2 mappings to match the ownership attributes * configured in the hypervisor stage-1. */ - state = pkvm_getstate(kvm_pgtable_hyp_pte_prot(pte)); + state = pkvm_getstate(kvm_pgtable_hyp_pte_prot(ctx->old)); switch (state) { case PKVM_PAGE_OWNED: - return host_stage2_set_owner_locked(phys, PAGE_SIZE, pkvm_hyp_id); + return host_stage2_set_owner_locked(phys, PAGE_SIZE, PKVM_ID_HYP); case PKVM_PAGE_SHARED_OWNED: prot = pkvm_mkstate(PKVM_HOST_MEM_PROT, PKVM_PAGE_SHARED_BORROWED); break; @@ -237,12 +227,25 @@ static int finalize_host_mappings_walker(u64 addr, u64 end, u32 level, return host_stage2_idmap_locked(phys, PAGE_SIZE, prot); } -static int finalize_host_mappings(void) +static int fix_hyp_pgtable_refcnt_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) +{ + /* + * Fix-up the refcount for the page-table pages as the early allocator + * was unable to access the hyp_vmemmap and so the buddy allocator has + * initialised the refcount to '1'. + */ + if (kvm_pte_valid(ctx->old)) + ctx->mm_ops->get_page(ctx->ptep); + + return 0; +} + +static int fix_host_ownership(void) { struct kvm_pgtable_walker walker = { - .cb = finalize_host_mappings_walker, - .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST, - .arg = pkvm_pgtable.mm_ops, + .cb = fix_host_ownership_walker, + .flags = KVM_PGTABLE_WALK_LEAF, }; int i, ret; @@ -258,6 +261,18 @@ static int finalize_host_mappings(void) return 0; } +static int fix_hyp_pgtable_refcnt(void) +{ + struct kvm_pgtable_walker walker = { + .cb = fix_hyp_pgtable_refcnt_walker, + .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST, + .arg = pkvm_pgtable.mm_ops, + }; + + return kvm_pgtable_walk(&pkvm_pgtable, 0, BIT(pkvm_pgtable.ia_bits), + &walker); +} + void __noreturn __pkvm_init_finalise(void) { struct kvm_host_data *host_data = this_cpu_ptr(&kvm_host_data); @@ -287,10 +302,19 @@ void __noreturn __pkvm_init_finalise(void) }; pkvm_pgtable.mm_ops = &pkvm_pgtable_mm_ops; - ret = finalize_host_mappings(); + ret = fix_host_ownership(); + if (ret) + goto out; + + ret = fix_hyp_pgtable_refcnt(); + if (ret) + goto out; + + ret = hyp_create_pcpu_fixmap(); if (ret) goto out; + pkvm_hyp_vm_table_init(vm_table_base); out: /* * We tail-called to here from handle___pkvm_init() and will not return, diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index cdf8e76b0be1..b11cf2c618a6 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -49,35 +49,38 @@ #define KVM_INVALID_PTE_OWNER_MASK GENMASK(9, 2) #define KVM_MAX_OWNER_ID 1 +/* + * Used to indicate a pte for which a 'break-before-make' sequence is in + * progress. + */ +#define KVM_INVALID_PTE_LOCKED BIT(10) + struct kvm_pgtable_walk_data { - struct kvm_pgtable *pgt; struct kvm_pgtable_walker *walker; u64 addr; 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)); } -static bool kvm_block_mapping_supported(u64 addr, u64 end, u64 phys, u32 level) +static bool kvm_block_mapping_supported(const struct kvm_pgtable_visit_ctx *ctx, u64 phys) { - u64 granule = kvm_granule_size(level); + u64 granule = kvm_granule_size(ctx->level); - if (!kvm_level_supports_block_mapping(level)) + if (!kvm_level_supports_block_mapping(ctx->level)) return false; - if (granule > (end - addr)) + if (granule > (ctx->end - ctx->addr)) return false; if (kvm_phys_is_valid(phys) && !IS_ALIGNED(phys, granule)) return false; - return IS_ALIGNED(addr, granule); + return IS_ALIGNED(ctx->addr, granule); } static u32 kvm_pgtable_idx(struct kvm_pgtable_walk_data *data, u32 level) @@ -88,7 +91,7 @@ static u32 kvm_pgtable_idx(struct kvm_pgtable_walk_data *data, u32 level) return (data->addr >> shift) & mask; } -static u32 __kvm_pgd_page_idx(struct kvm_pgtable *pgt, u64 addr) +static u32 kvm_pgd_page_idx(struct kvm_pgtable *pgt, u64 addr) { u64 shift = kvm_granule_shift(pgt->start_level - 1); /* May underflow */ u64 mask = BIT(pgt->ia_bits) - 1; @@ -96,11 +99,6 @@ static u32 __kvm_pgd_page_idx(struct kvm_pgtable *pgt, u64 addr) return (addr & mask) >> shift; } -static u32 kvm_pgd_page_idx(struct kvm_pgtable_walk_data *data) -{ - return __kvm_pgd_page_idx(data->pgt, data->addr); -} - static u32 kvm_pgd_pages(u32 ia_bits, u32 start_level) { struct kvm_pgtable pgt = { @@ -108,7 +106,7 @@ static u32 kvm_pgd_pages(u32 ia_bits, u32 start_level) .start_level = start_level, }; - return __kvm_pgd_page_idx(&pgt, -1ULL) + 1; + return kvm_pgd_page_idx(&pgt, -1ULL) + 1; } static bool kvm_pte_table(kvm_pte_t pte, u32 level) @@ -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)); @@ -142,16 +130,13 @@ static void kvm_clear_pte(kvm_pte_t *ptep) WRITE_ONCE(*ptep, 0); } -static void kvm_set_table_pte(kvm_pte_t *ptep, kvm_pte_t *childp, - struct kvm_pgtable_mm_ops *mm_ops) +static kvm_pte_t kvm_init_table_pte(kvm_pte_t *childp, struct kvm_pgtable_mm_ops *mm_ops) { - kvm_pte_t old = *ptep, pte = kvm_phys_to_pte(mm_ops->virt_to_phys(childp)); + kvm_pte_t pte = kvm_phys_to_pte(mm_ops->virt_to_phys(childp)); pte |= FIELD_PREP(KVM_PTE_TYPE, KVM_PTE_TYPE_TABLE); pte |= KVM_PTE_VALID; - - WARN_ON(kvm_pte_valid(old)); - smp_store_release(ptep, pte); + return pte; } static kvm_pte_t kvm_init_valid_leaf_pte(u64 pa, kvm_pte_t attr, u32 level) @@ -172,36 +157,47 @@ static kvm_pte_t kvm_init_invalid_leaf_owner(u8 owner_id) return FIELD_PREP(KVM_INVALID_PTE_OWNER_MASK, owner_id); } -static int kvm_pgtable_visitor_cb(struct kvm_pgtable_walk_data *data, u64 addr, - u32 level, kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag) +static int kvm_pgtable_visitor_cb(struct kvm_pgtable_walk_data *data, + const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) { struct kvm_pgtable_walker *walker = data->walker; - return walker->cb(addr, data->end, level, ptep, flag, walker->arg); + + /* Ensure the appropriate lock is held (e.g. RCU lock for stage-2 MMU) */ + WARN_ON_ONCE(kvm_pgtable_walk_shared(ctx) && !kvm_pgtable_walk_lock_held()); + return walker->cb(ctx, visit); } static int __kvm_pgtable_walk(struct kvm_pgtable_walk_data *data, - kvm_pte_t *pgtable, u32 level); + struct kvm_pgtable_mm_ops *mm_ops, kvm_pteref_t pgtable, u32 level); static inline int __kvm_pgtable_visit(struct kvm_pgtable_walk_data *data, - kvm_pte_t *ptep, u32 level) + struct kvm_pgtable_mm_ops *mm_ops, + kvm_pteref_t pteref, u32 level) { - int ret = 0; - u64 addr = data->addr; - kvm_pte_t *childp, pte = *ptep; - bool table = kvm_pte_table(pte, level); enum kvm_pgtable_walk_flags flags = data->walker->flags; + kvm_pte_t *ptep = kvm_dereference_pteref(data->walker, pteref); + struct kvm_pgtable_visit_ctx ctx = { + .ptep = ptep, + .old = READ_ONCE(*ptep), + .arg = data->walker->arg, + .mm_ops = mm_ops, + .addr = data->addr, + .end = data->end, + .level = level, + .flags = flags, + }; + int ret = 0; + kvm_pteref_t childp; + bool table = kvm_pte_table(ctx.old, level); - if (table && (flags & KVM_PGTABLE_WALK_TABLE_PRE)) { - ret = kvm_pgtable_visitor_cb(data, addr, level, ptep, - KVM_PGTABLE_WALK_TABLE_PRE); - } + if (table && (ctx.flags & KVM_PGTABLE_WALK_TABLE_PRE)) + ret = kvm_pgtable_visitor_cb(data, &ctx, KVM_PGTABLE_WALK_TABLE_PRE); - if (!table && (flags & KVM_PGTABLE_WALK_LEAF)) { - ret = kvm_pgtable_visitor_cb(data, addr, level, ptep, - KVM_PGTABLE_WALK_LEAF); - pte = *ptep; - table = kvm_pte_table(pte, level); + if (!table && (ctx.flags & KVM_PGTABLE_WALK_LEAF)) { + ret = kvm_pgtable_visitor_cb(data, &ctx, KVM_PGTABLE_WALK_LEAF); + ctx.old = READ_ONCE(*ptep); + table = kvm_pte_table(ctx.old, level); } if (ret) @@ -213,22 +209,20 @@ static inline int __kvm_pgtable_visit(struct kvm_pgtable_walk_data *data, goto out; } - childp = kvm_pte_follow(pte, data->pgt->mm_ops); - ret = __kvm_pgtable_walk(data, childp, level + 1); + childp = (kvm_pteref_t)kvm_pte_follow(ctx.old, mm_ops); + ret = __kvm_pgtable_walk(data, mm_ops, childp, level + 1); if (ret) goto out; - if (flags & KVM_PGTABLE_WALK_TABLE_POST) { - ret = kvm_pgtable_visitor_cb(data, addr, level, ptep, - KVM_PGTABLE_WALK_TABLE_POST); - } + if (ctx.flags & KVM_PGTABLE_WALK_TABLE_POST) + ret = kvm_pgtable_visitor_cb(data, &ctx, KVM_PGTABLE_WALK_TABLE_POST); out: return ret; } static int __kvm_pgtable_walk(struct kvm_pgtable_walk_data *data, - kvm_pte_t *pgtable, u32 level) + struct kvm_pgtable_mm_ops *mm_ops, kvm_pteref_t pgtable, u32 level) { u32 idx; int ret = 0; @@ -237,12 +231,12 @@ static int __kvm_pgtable_walk(struct kvm_pgtable_walk_data *data, return -EINVAL; for (idx = kvm_pgtable_idx(data, level); idx < PTRS_PER_PTE; ++idx) { - kvm_pte_t *ptep = &pgtable[idx]; + kvm_pteref_t pteref = &pgtable[idx]; if (data->addr >= data->end) break; - ret = __kvm_pgtable_visit(data, ptep, level); + ret = __kvm_pgtable_visit(data, mm_ops, pteref, level); if (ret) break; } @@ -250,11 +244,10 @@ static int __kvm_pgtable_walk(struct kvm_pgtable_walk_data *data, return ret; } -static int _kvm_pgtable_walk(struct kvm_pgtable_walk_data *data) +static int _kvm_pgtable_walk(struct kvm_pgtable *pgt, struct kvm_pgtable_walk_data *data) { u32 idx; int ret = 0; - struct kvm_pgtable *pgt = data->pgt; u64 limit = BIT(pgt->ia_bits); if (data->addr > limit || data->end > limit) @@ -263,10 +256,10 @@ static int _kvm_pgtable_walk(struct kvm_pgtable_walk_data *data) if (!pgt->pgd) return -EINVAL; - for (idx = kvm_pgd_page_idx(data); data->addr < data->end; ++idx) { - kvm_pte_t *ptep = &pgt->pgd[idx * PTRS_PER_PTE]; + for (idx = kvm_pgd_page_idx(pgt, data->addr); data->addr < data->end; ++idx) { + kvm_pteref_t pteref = &pgt->pgd[idx * PTRS_PER_PTE]; - ret = __kvm_pgtable_walk(data, ptep, pgt->start_level); + ret = __kvm_pgtable_walk(data, pgt->mm_ops, pteref, pgt->start_level); if (ret) break; } @@ -278,13 +271,20 @@ int kvm_pgtable_walk(struct kvm_pgtable *pgt, u64 addr, u64 size, struct kvm_pgtable_walker *walker) { struct kvm_pgtable_walk_data walk_data = { - .pgt = pgt, .addr = ALIGN_DOWN(addr, PAGE_SIZE), .end = PAGE_ALIGN(walk_data.addr + size), .walker = walker, }; + int r; - return _kvm_pgtable_walk(&walk_data); + r = kvm_pgtable_walk_begin(walker); + if (r) + return r; + + r = _kvm_pgtable_walk(pgt, &walk_data); + kvm_pgtable_walk_end(walker); + + return r; } struct leaf_walk_data { @@ -292,13 +292,13 @@ struct leaf_walk_data { u32 level; }; -static int leaf_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag, void * const arg) +static int leaf_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) { - struct leaf_walk_data *data = arg; + struct leaf_walk_data *data = ctx->arg; - data->pte = *ptep; - data->level = level; + data->pte = ctx->old; + data->level = ctx->level; return 0; } @@ -329,7 +329,6 @@ int kvm_pgtable_get_leaf(struct kvm_pgtable *pgt, u64 addr, struct hyp_map_data { u64 phys; kvm_pte_t attr; - struct kvm_pgtable_mm_ops *mm_ops; }; static int hyp_set_prot_attr(enum kvm_pgtable_prot prot, kvm_pte_t *ptep) @@ -383,47 +382,49 @@ enum kvm_pgtable_prot kvm_pgtable_hyp_pte_prot(kvm_pte_t pte) return prot; } -static bool hyp_map_walker_try_leaf(u64 addr, u64 end, u32 level, - kvm_pte_t *ptep, struct hyp_map_data *data) +static bool hyp_map_walker_try_leaf(const struct kvm_pgtable_visit_ctx *ctx, + struct hyp_map_data *data) { - kvm_pte_t new, old = *ptep; - u64 granule = kvm_granule_size(level), phys = data->phys; + kvm_pte_t new; + u64 granule = kvm_granule_size(ctx->level), phys = data->phys; - if (!kvm_block_mapping_supported(addr, end, phys, level)) + if (!kvm_block_mapping_supported(ctx, phys)) return false; data->phys += granule; - new = kvm_init_valid_leaf_pte(phys, data->attr, level); - if (old == new) + new = kvm_init_valid_leaf_pte(phys, data->attr, ctx->level); + if (ctx->old == new) return true; - if (!kvm_pte_valid(old)) - data->mm_ops->get_page(ptep); - else if (WARN_ON((old ^ new) & ~KVM_PTE_LEAF_ATTR_HI_SW)) + if (!kvm_pte_valid(ctx->old)) + ctx->mm_ops->get_page(ctx->ptep); + else if (WARN_ON((ctx->old ^ new) & ~KVM_PTE_LEAF_ATTR_HI_SW)) return false; - smp_store_release(ptep, new); + smp_store_release(ctx->ptep, new); return true; } -static int hyp_map_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag, void * const arg) +static int hyp_map_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) { - kvm_pte_t *childp; - struct hyp_map_data *data = arg; - struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops; + kvm_pte_t *childp, new; + struct hyp_map_data *data = ctx->arg; + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; - if (hyp_map_walker_try_leaf(addr, end, level, ptep, arg)) + if (hyp_map_walker_try_leaf(ctx, data)) return 0; - if (WARN_ON(level == KVM_PGTABLE_MAX_LEVELS - 1)) + if (WARN_ON(ctx->level == KVM_PGTABLE_MAX_LEVELS - 1)) return -EINVAL; childp = (kvm_pte_t *)mm_ops->zalloc_page(NULL); if (!childp) return -ENOMEM; - kvm_set_table_pte(ptep, childp, mm_ops); - mm_ops->get_page(ptep); + new = kvm_init_table_pte(childp, mm_ops); + mm_ops->get_page(ctx->ptep); + smp_store_release(ctx->ptep, new); + return 0; } @@ -433,7 +434,6 @@ int kvm_pgtable_hyp_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys, int ret; struct hyp_map_data map_data = { .phys = ALIGN_DOWN(phys, PAGE_SIZE), - .mm_ops = pgt->mm_ops, }; struct kvm_pgtable_walker walker = { .cb = hyp_map_walker, @@ -451,44 +451,39 @@ int kvm_pgtable_hyp_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys, return ret; } -struct hyp_unmap_data { - u64 unmapped; - struct kvm_pgtable_mm_ops *mm_ops; -}; - -static int hyp_unmap_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag, void * const arg) +static int hyp_unmap_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) { - kvm_pte_t pte = *ptep, *childp = NULL; - u64 granule = kvm_granule_size(level); - struct hyp_unmap_data *data = arg; - struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops; + kvm_pte_t *childp = NULL; + u64 granule = kvm_granule_size(ctx->level); + u64 *unmapped = ctx->arg; + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; - if (!kvm_pte_valid(pte)) + if (!kvm_pte_valid(ctx->old)) return -EINVAL; - if (kvm_pte_table(pte, level)) { - childp = kvm_pte_follow(pte, mm_ops); + if (kvm_pte_table(ctx->old, ctx->level)) { + childp = kvm_pte_follow(ctx->old, mm_ops); if (mm_ops->page_count(childp) != 1) return 0; - kvm_clear_pte(ptep); + kvm_clear_pte(ctx->ptep); dsb(ishst); - __tlbi_level(vae2is, __TLBI_VADDR(addr, 0), level); + __tlbi_level(vae2is, __TLBI_VADDR(ctx->addr, 0), ctx->level); } else { - if (end - addr < granule) + if (ctx->end - ctx->addr < granule) return -EINVAL; - kvm_clear_pte(ptep); + kvm_clear_pte(ctx->ptep); dsb(ishst); - __tlbi_level(vale2is, __TLBI_VADDR(addr, 0), level); - data->unmapped += granule; + __tlbi_level(vale2is, __TLBI_VADDR(ctx->addr, 0), ctx->level); + *unmapped += granule; } dsb(ish); isb(); - mm_ops->put_page(ptep); + mm_ops->put_page(ctx->ptep); if (childp) mm_ops->put_page(childp); @@ -498,12 +493,10 @@ static int hyp_unmap_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, u64 kvm_pgtable_hyp_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size) { - struct hyp_unmap_data unmap_data = { - .mm_ops = pgt->mm_ops, - }; + u64 unmapped = 0; struct kvm_pgtable_walker walker = { .cb = hyp_unmap_walker, - .arg = &unmap_data, + .arg = &unmapped, .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST, }; @@ -511,7 +504,7 @@ u64 kvm_pgtable_hyp_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size) return 0; kvm_pgtable_walk(pgt, addr, size, &walker); - return unmap_data.unmapped; + return unmapped; } int kvm_pgtable_hyp_init(struct kvm_pgtable *pgt, u32 va_bits, @@ -519,7 +512,7 @@ int kvm_pgtable_hyp_init(struct kvm_pgtable *pgt, u32 va_bits, { u64 levels = ARM64_HW_PGTABLE_LEVELS(va_bits); - pgt->pgd = (kvm_pte_t *)mm_ops->zalloc_page(NULL); + pgt->pgd = (kvm_pteref_t)mm_ops->zalloc_page(NULL); if (!pgt->pgd) return -ENOMEM; @@ -532,19 +525,18 @@ int kvm_pgtable_hyp_init(struct kvm_pgtable *pgt, u32 va_bits, return 0; } -static int hyp_free_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag, void * const arg) +static int hyp_free_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) { - struct kvm_pgtable_mm_ops *mm_ops = arg; - kvm_pte_t pte = *ptep; + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; - if (!kvm_pte_valid(pte)) + if (!kvm_pte_valid(ctx->old)) return 0; - mm_ops->put_page(ptep); + mm_ops->put_page(ctx->ptep); - if (kvm_pte_table(pte, level)) - mm_ops->put_page(kvm_pte_follow(pte, mm_ops)); + if (kvm_pte_table(ctx->old, ctx->level)) + mm_ops->put_page(kvm_pte_follow(ctx->old, mm_ops)); return 0; } @@ -554,11 +546,10 @@ void kvm_pgtable_hyp_destroy(struct kvm_pgtable *pgt) struct kvm_pgtable_walker walker = { .cb = hyp_free_walker, .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST, - .arg = pgt->mm_ops, }; WARN_ON(kvm_pgtable_walk(pgt, 0, BIT(pgt->ia_bits), &walker)); - pgt->mm_ops->put_page(pgt->pgd); + pgt->mm_ops->put_page(kvm_dereference_pteref(&walker, pgt->pgd)); pgt->pgd = NULL; } @@ -573,8 +564,6 @@ struct stage2_map_data { struct kvm_s2_mmu *mmu; void *memcache; - struct kvm_pgtable_mm_ops *mm_ops; - /* Force mappings to page granularity */ bool force_pte; }; @@ -682,19 +671,92 @@ static bool stage2_pte_is_counted(kvm_pte_t pte) return !!pte; } -static void stage2_put_pte(kvm_pte_t *ptep, struct kvm_s2_mmu *mmu, u64 addr, - u32 level, struct kvm_pgtable_mm_ops *mm_ops) +static bool stage2_pte_is_locked(kvm_pte_t pte) +{ + return !kvm_pte_valid(pte) && (pte & KVM_INVALID_PTE_LOCKED); +} + +static bool stage2_try_set_pte(const struct kvm_pgtable_visit_ctx *ctx, kvm_pte_t new) +{ + if (!kvm_pgtable_walk_shared(ctx)) { + WRITE_ONCE(*ctx->ptep, new); + return true; + } + + return cmpxchg(ctx->ptep, ctx->old, new) == ctx->old; +} + +/** + * stage2_try_break_pte() - Invalidates a pte according to the + * 'break-before-make' requirements of the + * architecture. + * + * @ctx: context of the visited pte. + * @mmu: stage-2 mmu + * + * Returns: true if the pte was successfully broken. + * + * If the removed pte was valid, performs the necessary serialization and TLB + * invalidation for the old value. For counted ptes, drops the reference count + * on the containing table page. + */ +static bool stage2_try_break_pte(const struct kvm_pgtable_visit_ctx *ctx, + struct kvm_s2_mmu *mmu) +{ + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; + + if (stage2_pte_is_locked(ctx->old)) { + /* + * Should never occur if this walker has exclusive access to the + * page tables. + */ + WARN_ON(!kvm_pgtable_walk_shared(ctx)); + return false; + } + + if (!stage2_try_set_pte(ctx, KVM_INVALID_PTE_LOCKED)) + return false; + + /* + * Perform the appropriate TLB invalidation based on the evicted pte + * value (if any). + */ + if (kvm_pte_table(ctx->old, ctx->level)) + kvm_call_hyp(__kvm_tlb_flush_vmid, mmu); + else if (kvm_pte_valid(ctx->old)) + kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu, ctx->addr, ctx->level); + + if (stage2_pte_is_counted(ctx->old)) + mm_ops->put_page(ctx->ptep); + + return true; +} + +static void stage2_make_pte(const struct kvm_pgtable_visit_ctx *ctx, kvm_pte_t new) +{ + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; + + WARN_ON(!stage2_pte_is_locked(*ctx->ptep)); + + if (stage2_pte_is_counted(new)) + mm_ops->get_page(ctx->ptep); + + smp_store_release(ctx->ptep, new); +} + +static void stage2_put_pte(const struct kvm_pgtable_visit_ctx *ctx, struct kvm_s2_mmu *mmu, + struct kvm_pgtable_mm_ops *mm_ops) { /* * Clear the existing PTE, and perform break-before-make with * TLB maintenance if it was valid. */ - if (kvm_pte_valid(*ptep)) { - kvm_clear_pte(ptep); - kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu, addr, level); + if (kvm_pte_valid(ctx->old)) { + kvm_clear_pte(ctx->ptep); + kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu, ctx->addr, ctx->level); } - mm_ops->put_page(ptep); + mm_ops->put_page(ctx->ptep); } static bool stage2_pte_cacheable(struct kvm_pgtable *pgt, kvm_pte_t pte) @@ -708,44 +770,42 @@ static bool stage2_pte_executable(kvm_pte_t pte) return !(pte & KVM_PTE_LEAF_ATTR_HI_S2_XN); } -static bool stage2_leaf_mapping_allowed(u64 addr, u64 end, u32 level, +static bool stage2_leaf_mapping_allowed(const struct kvm_pgtable_visit_ctx *ctx, struct stage2_map_data *data) { - if (data->force_pte && (level < (KVM_PGTABLE_MAX_LEVELS - 1))) + if (data->force_pte && (ctx->level < (KVM_PGTABLE_MAX_LEVELS - 1))) return false; - return kvm_block_mapping_supported(addr, end, data->phys, level); + return kvm_block_mapping_supported(ctx, data->phys); } -static int stage2_map_walker_try_leaf(u64 addr, u64 end, u32 level, - kvm_pte_t *ptep, +static int stage2_map_walker_try_leaf(const struct kvm_pgtable_visit_ctx *ctx, struct stage2_map_data *data) { - kvm_pte_t new, old = *ptep; - u64 granule = kvm_granule_size(level), phys = data->phys; + kvm_pte_t new; + u64 granule = kvm_granule_size(ctx->level), phys = data->phys; struct kvm_pgtable *pgt = data->mmu->pgt; - struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops; + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; - if (!stage2_leaf_mapping_allowed(addr, end, level, data)) + if (!stage2_leaf_mapping_allowed(ctx, data)) return -E2BIG; if (kvm_phys_is_valid(phys)) - new = kvm_init_valid_leaf_pte(phys, data->attr, level); + new = kvm_init_valid_leaf_pte(phys, data->attr, ctx->level); else new = kvm_init_invalid_leaf_owner(data->owner_id); - if (stage2_pte_is_counted(old)) { - /* - * Skip updating the PTE if we are trying to recreate the exact - * same mapping or only change the access permissions. Instead, - * the vCPU will exit one more time from guest if still needed - * and then go through the path of relaxing permissions. - */ - if (!stage2_pte_needs_update(old, new)) - return -EAGAIN; + /* + * Skip updating the PTE if we are trying to recreate the exact + * same mapping or only change the access permissions. Instead, + * the vCPU will exit one more time from guest if still needed + * and then go through the path of relaxing permissions. + */ + if (!stage2_pte_needs_update(ctx->old, new)) + return -EAGAIN; - stage2_put_pte(ptep, data->mmu, addr, level, mm_ops); - } + if (!stage2_try_break_pte(ctx, data->mmu)) + return -EAGAIN; /* Perform CMOs before installation of the guest stage-2 PTE */ if (mm_ops->dcache_clean_inval_poc && stage2_pte_cacheable(pgt, new)) @@ -755,56 +815,43 @@ static int stage2_map_walker_try_leaf(u64 addr, u64 end, u32 level, if (mm_ops->icache_inval_pou && stage2_pte_executable(new)) mm_ops->icache_inval_pou(kvm_pte_follow(new, mm_ops), granule); - smp_store_release(ptep, new); - if (stage2_pte_is_counted(new)) - mm_ops->get_page(ptep); + stage2_make_pte(ctx, new); + if (kvm_phys_is_valid(phys)) data->phys += granule; return 0; } -static int stage2_map_walk_table_pre(u64 addr, u64 end, u32 level, - kvm_pte_t *ptep, +static int stage2_map_walk_table_pre(const struct kvm_pgtable_visit_ctx *ctx, struct stage2_map_data *data) { - if (data->anchor) - return 0; + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; + kvm_pte_t *childp = kvm_pte_follow(ctx->old, mm_ops); + int ret; - if (!stage2_leaf_mapping_allowed(addr, end, level, data)) + if (!stage2_leaf_mapping_allowed(ctx, data)) return 0; - data->childp = kvm_pte_follow(*ptep, data->mm_ops); - kvm_clear_pte(ptep); + ret = stage2_map_walker_try_leaf(ctx, data); + if (ret) + return ret; - /* - * Invalidate the whole stage-2, as we may have numerous leaf - * entries below us which would otherwise need invalidating - * individually. - */ - kvm_call_hyp(__kvm_tlb_flush_vmid, data->mmu); - data->anchor = ptep; + mm_ops->free_removed_table(childp, ctx->level); return 0; } -static int stage2_map_walk_leaf(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, +static int stage2_map_walk_leaf(const struct kvm_pgtable_visit_ctx *ctx, struct stage2_map_data *data) { - struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops; - kvm_pte_t *childp, pte = *ptep; + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; + kvm_pte_t *childp, new; int ret; - if (data->anchor) { - if (stage2_pte_is_counted(pte)) - mm_ops->put_page(ptep); - - return 0; - } - - ret = stage2_map_walker_try_leaf(addr, end, level, ptep, data); + ret = stage2_map_walker_try_leaf(ctx, data); if (ret != -E2BIG) return ret; - if (WARN_ON(level == KVM_PGTABLE_MAX_LEVELS - 1)) + if (WARN_ON(ctx->level == KVM_PGTABLE_MAX_LEVELS - 1)) return -EINVAL; if (!data->memcache) @@ -814,99 +861,62 @@ static int stage2_map_walk_leaf(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, if (!childp) return -ENOMEM; + if (!stage2_try_break_pte(ctx, data->mmu)) { + mm_ops->put_page(childp); + return -EAGAIN; + } + /* * If we've run into an existing block mapping then replace it with * a table. Accesses beyond 'end' that fall within the new table * will be mapped lazily. */ - if (stage2_pte_is_counted(pte)) - stage2_put_pte(ptep, data->mmu, addr, level, mm_ops); - - kvm_set_table_pte(ptep, childp, mm_ops); - mm_ops->get_page(ptep); + new = kvm_init_table_pte(childp, mm_ops); + stage2_make_pte(ctx, new); return 0; } -static int stage2_map_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; - int ret = 0; - - if (!data->anchor) - return 0; - - if (data->anchor == ptep) { - childp = data->childp; - data->anchor = NULL; - data->childp = NULL; - ret = stage2_map_walk_leaf(addr, end, level, ptep, data); - } else { - childp = kvm_pte_follow(*ptep, mm_ops); - } - - mm_ops->put_page(childp); - mm_ops->put_page(ptep); - - return ret; -} - /* - * This is a little fiddly, as we use all three of the walk flags. The idea - * is that the TABLE_PRE callback runs for table entries on the way down, - * looking for table entries which we could conceivably replace with a - * block entry for this mapping. If it finds one, then it sets the 'anchor' - * field in 'struct stage2_map_data' to point at the table entry, before - * clearing the entry to zero and descending into the now detached table. + * The TABLE_PRE callback runs for table entries on the way down, looking + * for table entries which we could conceivably replace with a block entry + * for this mapping. If it finds one it replaces the entry and calls + * kvm_pgtable_mm_ops::free_removed_table() to tear down the detached table. * - * The behaviour of the LEAF callback then depends on whether or not the - * anchor has been set. If not, then we're not using a block mapping higher - * up the table and we perform the mapping at the existing leaves instead. - * If, on the other hand, the anchor _is_ set, then we drop references to - * all valid leaves so that the pages beneath the anchor can be freed. - * - * Finally, the TABLE_POST callback does nothing if the anchor has not - * been set, but otherwise frees the page-table pages while walking back up - * the page-table, installing the block entry when it revisits the anchor - * pointer and clearing the anchor to NULL. + * Otherwise, the LEAF callback performs the mapping at the existing leaves + * instead. */ -static int stage2_map_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag, void * const arg) +static int stage2_map_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) { - struct stage2_map_data *data = arg; + struct stage2_map_data *data = ctx->arg; - switch (flag) { + switch (visit) { case KVM_PGTABLE_WALK_TABLE_PRE: - return stage2_map_walk_table_pre(addr, end, level, ptep, data); + return stage2_map_walk_table_pre(ctx, data); case KVM_PGTABLE_WALK_LEAF: - return stage2_map_walk_leaf(addr, end, level, ptep, data); - case KVM_PGTABLE_WALK_TABLE_POST: - return stage2_map_walk_table_post(addr, end, level, ptep, data); + return stage2_map_walk_leaf(ctx, data); + default: + return -EINVAL; } - - return -EINVAL; } int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys, enum kvm_pgtable_prot prot, - void *mc) + void *mc, enum kvm_pgtable_walk_flags flags) { int ret; struct stage2_map_data map_data = { .phys = ALIGN_DOWN(phys, PAGE_SIZE), .mmu = pgt->mmu, .memcache = mc, - .mm_ops = pgt->mm_ops, .force_pte = pgt->force_pte_cb && pgt->force_pte_cb(addr, addr + size, prot), }; struct kvm_pgtable_walker walker = { .cb = stage2_map_walker, - .flags = KVM_PGTABLE_WALK_TABLE_PRE | - KVM_PGTABLE_WALK_LEAF | - KVM_PGTABLE_WALK_TABLE_POST, + .flags = flags | + KVM_PGTABLE_WALK_TABLE_PRE | + KVM_PGTABLE_WALK_LEAF, .arg = &map_data, }; @@ -930,15 +940,13 @@ int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, u64 addr, u64 size, .phys = KVM_PHYS_INVALID, .mmu = pgt->mmu, .memcache = mc, - .mm_ops = pgt->mm_ops, .owner_id = owner_id, .force_pte = true, }; struct kvm_pgtable_walker walker = { .cb = stage2_map_walker, .flags = KVM_PGTABLE_WALK_TABLE_PRE | - KVM_PGTABLE_WALK_LEAF | - KVM_PGTABLE_WALK_TABLE_POST, + KVM_PGTABLE_WALK_LEAF, .arg = &map_data, }; @@ -949,30 +957,29 @@ int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, u64 addr, u64 size, return ret; } -static int stage2_unmap_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag, - void * const arg) +static int stage2_unmap_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) { - struct kvm_pgtable *pgt = arg; + struct kvm_pgtable *pgt = ctx->arg; struct kvm_s2_mmu *mmu = pgt->mmu; - struct kvm_pgtable_mm_ops *mm_ops = pgt->mm_ops; - kvm_pte_t pte = *ptep, *childp = NULL; + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; + kvm_pte_t *childp = NULL; bool need_flush = false; - if (!kvm_pte_valid(pte)) { - if (stage2_pte_is_counted(pte)) { - kvm_clear_pte(ptep); - mm_ops->put_page(ptep); + if (!kvm_pte_valid(ctx->old)) { + if (stage2_pte_is_counted(ctx->old)) { + kvm_clear_pte(ctx->ptep); + mm_ops->put_page(ctx->ptep); } return 0; } - if (kvm_pte_table(pte, level)) { - childp = kvm_pte_follow(pte, mm_ops); + if (kvm_pte_table(ctx->old, ctx->level)) { + childp = kvm_pte_follow(ctx->old, mm_ops); if (mm_ops->page_count(childp) != 1) return 0; - } else if (stage2_pte_cacheable(pgt, pte)) { + } else if (stage2_pte_cacheable(pgt, ctx->old)) { need_flush = !stage2_has_fwb(pgt); } @@ -981,11 +988,11 @@ static int stage2_unmap_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, * block entry and rely on the remaining portions being faulted * back lazily. */ - stage2_put_pte(ptep, mmu, addr, level, mm_ops); + stage2_put_pte(ctx, mmu, mm_ops); if (need_flush && mm_ops->dcache_clean_inval_poc) - mm_ops->dcache_clean_inval_poc(kvm_pte_follow(pte, mm_ops), - kvm_granule_size(level)); + mm_ops->dcache_clean_inval_poc(kvm_pte_follow(ctx->old, mm_ops), + kvm_granule_size(ctx->level)); if (childp) mm_ops->put_page(childp); @@ -1009,21 +1016,19 @@ struct stage2_attr_data { kvm_pte_t attr_clr; kvm_pte_t pte; u32 level; - struct kvm_pgtable_mm_ops *mm_ops; }; -static int stage2_attr_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag, - void * const arg) +static int stage2_attr_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) { - kvm_pte_t pte = *ptep; - struct stage2_attr_data *data = arg; - struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops; + kvm_pte_t pte = ctx->old; + struct stage2_attr_data *data = ctx->arg; + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; - if (!kvm_pte_valid(pte)) + if (!kvm_pte_valid(ctx->old)) return 0; - data->level = level; + data->level = ctx->level; data->pte = pte; pte &= ~data->attr_clr; pte |= data->attr_set; @@ -1039,10 +1044,12 @@ static int stage2_attr_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, * stage-2 PTE if we are going to add executable permission. */ if (mm_ops->icache_inval_pou && - stage2_pte_executable(pte) && !stage2_pte_executable(*ptep)) + stage2_pte_executable(pte) && !stage2_pte_executable(ctx->old)) mm_ops->icache_inval_pou(kvm_pte_follow(pte, mm_ops), - kvm_granule_size(level)); - WRITE_ONCE(*ptep, pte); + kvm_granule_size(ctx->level)); + + if (!stage2_try_set_pte(ctx, pte)) + return -EAGAIN; } return 0; @@ -1051,19 +1058,18 @@ static int stage2_attr_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, static int stage2_update_leaf_attrs(struct kvm_pgtable *pgt, u64 addr, u64 size, kvm_pte_t attr_set, kvm_pte_t attr_clr, kvm_pte_t *orig_pte, - u32 *level) + u32 *level, enum kvm_pgtable_walk_flags flags) { int ret; kvm_pte_t attr_mask = KVM_PTE_LEAF_ATTR_LO | KVM_PTE_LEAF_ATTR_HI; struct stage2_attr_data data = { .attr_set = attr_set & attr_mask, .attr_clr = attr_clr & attr_mask, - .mm_ops = pgt->mm_ops, }; struct kvm_pgtable_walker walker = { .cb = stage2_attr_walker, .arg = &data, - .flags = KVM_PGTABLE_WALK_LEAF, + .flags = flags | KVM_PGTABLE_WALK_LEAF, }; ret = kvm_pgtable_walk(pgt, addr, size, &walker); @@ -1082,14 +1088,14 @@ 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, NULL); + NULL, NULL, 0); } kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr) { kvm_pte_t pte = 0; stage2_update_leaf_attrs(pgt, addr, 1, KVM_PTE_LEAF_ATTR_LO_S2_AF, 0, - &pte, NULL); + &pte, NULL, 0); dsb(ishst); return pte; } @@ -1098,7 +1104,7 @@ kvm_pte_t kvm_pgtable_stage2_mkold(struct kvm_pgtable *pgt, u64 addr) { kvm_pte_t pte = 0; stage2_update_leaf_attrs(pgt, addr, 1, 0, KVM_PTE_LEAF_ATTR_LO_S2_AF, - &pte, NULL); + &pte, NULL, 0); /* * "But where's the TLBI?!", you scream. * "Over in the core code", I sigh. @@ -1111,7 +1117,7 @@ kvm_pte_t kvm_pgtable_stage2_mkold(struct kvm_pgtable *pgt, u64 addr) bool kvm_pgtable_stage2_is_young(struct kvm_pgtable *pgt, u64 addr) { kvm_pte_t pte = 0; - stage2_update_leaf_attrs(pgt, addr, 1, 0, 0, &pte, NULL); + stage2_update_leaf_attrs(pgt, addr, 1, 0, 0, &pte, NULL, 0); return pte & KVM_PTE_LEAF_ATTR_LO_S2_AF; } @@ -1134,26 +1140,25 @@ int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr, if (prot & KVM_PGTABLE_PROT_X) clr |= KVM_PTE_LEAF_ATTR_HI_S2_XN; - ret = stage2_update_leaf_attrs(pgt, addr, 1, set, clr, NULL, &level); + ret = stage2_update_leaf_attrs(pgt, addr, 1, set, clr, NULL, &level, + KVM_PGTABLE_WALK_SHARED); if (!ret) kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, pgt->mmu, addr, level); return ret; } -static int stage2_flush_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag, - void * const arg) +static int stage2_flush_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) { - struct kvm_pgtable *pgt = arg; + struct kvm_pgtable *pgt = ctx->arg; struct kvm_pgtable_mm_ops *mm_ops = pgt->mm_ops; - kvm_pte_t pte = *ptep; - if (!kvm_pte_valid(pte) || !stage2_pte_cacheable(pgt, pte)) + if (!kvm_pte_valid(ctx->old) || !stage2_pte_cacheable(pgt, ctx->old)) return 0; if (mm_ops->dcache_clean_inval_poc) - mm_ops->dcache_clean_inval_poc(kvm_pte_follow(pte, mm_ops), - kvm_granule_size(level)); + mm_ops->dcache_clean_inval_poc(kvm_pte_follow(ctx->old, mm_ops), + kvm_granule_size(ctx->level)); return 0; } @@ -1184,7 +1189,7 @@ int __kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_s2_mmu *mmu, u32 start_level = VTCR_EL2_TGRAN_SL0_BASE - sl0; pgd_sz = kvm_pgd_pages(ia_bits, start_level) * PAGE_SIZE; - pgt->pgd = mm_ops->zalloc_pages_exact(pgd_sz); + pgt->pgd = (kvm_pteref_t)mm_ops->zalloc_pages_exact(pgd_sz); if (!pgt->pgd) return -ENOMEM; @@ -1200,20 +1205,27 @@ int __kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_s2_mmu *mmu, return 0; } -static int stage2_free_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag, - void * const arg) +size_t kvm_pgtable_stage2_pgd_size(u64 vtcr) +{ + u32 ia_bits = VTCR_EL2_IPA(vtcr); + u32 sl0 = FIELD_GET(VTCR_EL2_SL0_MASK, vtcr); + u32 start_level = VTCR_EL2_TGRAN_SL0_BASE - sl0; + + return kvm_pgd_pages(ia_bits, start_level) * PAGE_SIZE; +} + +static int stage2_free_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) { - struct kvm_pgtable_mm_ops *mm_ops = arg; - kvm_pte_t pte = *ptep; + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; - if (!stage2_pte_is_counted(pte)) + if (!stage2_pte_is_counted(ctx->old)) return 0; - mm_ops->put_page(ptep); + mm_ops->put_page(ctx->ptep); - if (kvm_pte_table(pte, level)) - mm_ops->put_page(kvm_pte_follow(pte, mm_ops)); + if (kvm_pte_table(ctx->old, ctx->level)) + mm_ops->put_page(kvm_pte_follow(ctx->old, mm_ops)); return 0; } @@ -1225,11 +1237,33 @@ void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt) .cb = stage2_free_walker, .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST, - .arg = pgt->mm_ops, }; WARN_ON(kvm_pgtable_walk(pgt, 0, BIT(pgt->ia_bits), &walker)); pgd_sz = kvm_pgd_pages(pgt->ia_bits, pgt->start_level) * PAGE_SIZE; - pgt->mm_ops->free_pages_exact(pgt->pgd, pgd_sz); + pgt->mm_ops->free_pages_exact(kvm_dereference_pteref(&walker, pgt->pgd), pgd_sz); pgt->pgd = NULL; } + +void kvm_pgtable_stage2_free_removed(struct kvm_pgtable_mm_ops *mm_ops, void *pgtable, u32 level) +{ + kvm_pteref_t ptep = (kvm_pteref_t)pgtable; + struct kvm_pgtable_walker walker = { + .cb = stage2_free_walker, + .flags = KVM_PGTABLE_WALK_LEAF | + KVM_PGTABLE_WALK_TABLE_POST, + }; + struct kvm_pgtable_walk_data data = { + .walker = &walker, + + /* + * At this point the IPA really doesn't matter, as the page + * table being traversed has already been removed from the stage + * 2. Set an appropriate range to cover the entire page table. + */ + .addr = 0, + .end = kvm_granule_size(level), + }; + + WARN_ON(__kvm_pgtable_walk(&data, mm_ops, ptep, level + 1)); +} diff --git a/arch/arm64/kvm/hyp/vhe/Makefile b/arch/arm64/kvm/hyp/vhe/Makefile index 96bec0ecf9dd..3b9e5464b5b3 100644 --- a/arch/arm64/kvm/hyp/vhe/Makefile +++ b/arch/arm64/kvm/hyp/vhe/Makefile @@ -1,6 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 # -# Makefile for Kernel-based Virtual Machine module, HYP/nVHE part +# Makefile for Kernel-based Virtual Machine module, HYP/VHE part # asflags-y := -D__KVM_VHE_HYPERVISOR__ |