1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
4 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
7 #include <linux/mman.h>
8 #include <linux/kvm_host.h>
10 #include <linux/hugetlb.h>
11 #include <linux/sched/signal.h>
12 #include <trace/events/kvm.h>
13 #include <asm/pgalloc.h>
14 #include <asm/cacheflush.h>
15 #include <asm/kvm_arm.h>
16 #include <asm/kvm_mmu.h>
17 #include <asm/kvm_pgtable.h>
18 #include <asm/kvm_ras.h>
19 #include <asm/kvm_asm.h>
20 #include <asm/kvm_emulate.h>
25 static struct kvm_pgtable *hyp_pgtable;
26 static DEFINE_MUTEX(kvm_hyp_pgd_mutex);
28 static unsigned long hyp_idmap_start;
29 static unsigned long hyp_idmap_end;
30 static phys_addr_t hyp_idmap_vector;
32 static unsigned long io_map_base;
36 * Release kvm_mmu_lock periodically if the memory region is large. Otherwise,
37 * we may see kernel panics with CONFIG_DETECT_HUNG_TASK,
38 * CONFIG_LOCKUP_DETECTOR, CONFIG_LOCKDEP. Additionally, holding the lock too
39 * long will also starve other vCPUs. We have to also make sure that the page
40 * tables are not freed while we released the lock.
42 static int stage2_apply_range(struct kvm *kvm, phys_addr_t addr,
44 int (*fn)(struct kvm_pgtable *, u64, u64),
51 struct kvm_pgtable *pgt = kvm->arch.mmu.pgt;
55 next = stage2_pgd_addr_end(kvm, addr, end);
56 ret = fn(pgt, addr, next - addr);
60 if (resched && next != end)
61 cond_resched_rwlock_write(&kvm->mmu_lock);
62 } while (addr = next, addr != end);
67 #define stage2_apply_range_resched(kvm, addr, end, fn) \
68 stage2_apply_range(kvm, addr, end, fn, true)
70 static bool memslot_is_logging(struct kvm_memory_slot *memslot)
72 return memslot->dirty_bitmap && !(memslot->flags & KVM_MEM_READONLY);
76 * kvm_flush_remote_tlbs() - flush all VM TLB entries for v7/8
77 * @kvm: pointer to kvm structure.
79 * Interface to HYP function to flush all VM TLB entries
81 void kvm_flush_remote_tlbs(struct kvm *kvm)
83 ++kvm->stat.generic.remote_tlb_flush_requests;
84 kvm_call_hyp(__kvm_tlb_flush_vmid, &kvm->arch.mmu);
87 static bool kvm_is_device_pfn(unsigned long pfn)
89 return !pfn_is_map_memory(pfn);
92 static void *stage2_memcache_zalloc_page(void *arg)
94 struct kvm_mmu_memory_cache *mc = arg;
96 /* Allocated with __GFP_ZERO, so no need to zero */
97 return kvm_mmu_memory_cache_alloc(mc);
100 static void *kvm_host_zalloc_pages_exact(size_t size)
102 return alloc_pages_exact(size, GFP_KERNEL_ACCOUNT | __GFP_ZERO);
105 static void kvm_host_get_page(void *addr)
107 get_page(virt_to_page(addr));
110 static void kvm_host_put_page(void *addr)
112 put_page(virt_to_page(addr));
115 static int kvm_host_page_count(void *addr)
117 return page_count(virt_to_page(addr));
120 static phys_addr_t kvm_host_pa(void *addr)
125 static void *kvm_host_va(phys_addr_t phys)
130 static void clean_dcache_guest_page(void *va, size_t size)
132 __clean_dcache_guest_page(va, size);
135 static void invalidate_icache_guest_page(void *va, size_t size)
137 __invalidate_icache_guest_page(va, size);
141 * Unmapping vs dcache management:
143 * If a guest maps certain memory pages as uncached, all writes will
144 * bypass the data cache and go directly to RAM. However, the CPUs
145 * can still speculate reads (not writes) and fill cache lines with
148 * Those cache lines will be *clean* cache lines though, so a
149 * clean+invalidate operation is equivalent to an invalidate
150 * operation, because no cache lines are marked dirty.
152 * Those clean cache lines could be filled prior to an uncached write
153 * by the guest, and the cache coherent IO subsystem would therefore
154 * end up writing old data to disk.
156 * This is why right after unmapping a page/section and invalidating
157 * the corresponding TLBs, we flush to make sure the IO subsystem will
158 * never hit in the cache.
160 * This is all avoided on systems that have ARM64_HAS_STAGE2_FWB, as
161 * we then fully enforce cacheability of RAM, no matter what the guest
165 * unmap_stage2_range -- Clear stage2 page table entries to unmap a range
166 * @mmu: The KVM stage-2 MMU pointer
167 * @start: The intermediate physical base address of the range to unmap
168 * @size: The size of the area to unmap
169 * @may_block: Whether or not we are permitted to block
171 * Clear a range of stage-2 mappings, lowering the various ref-counts. Must
172 * be called while holding mmu_lock (unless for freeing the stage2 pgd before
173 * destroying the VM), otherwise another faulting VCPU may come in and mess
174 * with things behind our backs.
176 static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size,
179 struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu);
180 phys_addr_t end = start + size;
182 lockdep_assert_held_write(&kvm->mmu_lock);
183 WARN_ON(size & ~PAGE_MASK);
184 WARN_ON(stage2_apply_range(kvm, start, end, kvm_pgtable_stage2_unmap,
188 static void unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size)
190 __unmap_stage2_range(mmu, start, size, true);
193 static void stage2_flush_memslot(struct kvm *kvm,
194 struct kvm_memory_slot *memslot)
196 phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
197 phys_addr_t end = addr + PAGE_SIZE * memslot->npages;
199 stage2_apply_range_resched(kvm, addr, end, kvm_pgtable_stage2_flush);
203 * stage2_flush_vm - Invalidate cache for pages mapped in stage 2
204 * @kvm: The struct kvm pointer
206 * Go through the stage 2 page tables and invalidate any cache lines
207 * backing memory already mapped to the VM.
209 static void stage2_flush_vm(struct kvm *kvm)
211 struct kvm_memslots *slots;
212 struct kvm_memory_slot *memslot;
215 idx = srcu_read_lock(&kvm->srcu);
216 write_lock(&kvm->mmu_lock);
218 slots = kvm_memslots(kvm);
219 kvm_for_each_memslot(memslot, bkt, slots)
220 stage2_flush_memslot(kvm, memslot);
222 write_unlock(&kvm->mmu_lock);
223 srcu_read_unlock(&kvm->srcu, idx);
227 * free_hyp_pgds - free Hyp-mode page tables
229 void free_hyp_pgds(void)
231 mutex_lock(&kvm_hyp_pgd_mutex);
233 kvm_pgtable_hyp_destroy(hyp_pgtable);
237 mutex_unlock(&kvm_hyp_pgd_mutex);
240 static bool kvm_host_owns_hyp_mappings(void)
242 if (is_kernel_in_hyp_mode())
245 if (static_branch_likely(&kvm_protected_mode_initialized))
249 * This can happen at boot time when __create_hyp_mappings() is called
250 * after the hyp protection has been enabled, but the static key has
251 * not been flipped yet.
253 if (!hyp_pgtable && is_protected_kvm_enabled())
256 WARN_ON(!hyp_pgtable);
261 static int __create_hyp_mappings(unsigned long start, unsigned long size,
262 unsigned long phys, enum kvm_pgtable_prot prot)
266 if (WARN_ON(!kvm_host_owns_hyp_mappings()))
269 mutex_lock(&kvm_hyp_pgd_mutex);
270 err = kvm_pgtable_hyp_map(hyp_pgtable, start, size, phys, prot);
271 mutex_unlock(&kvm_hyp_pgd_mutex);
276 static phys_addr_t kvm_kaddr_to_phys(void *kaddr)
278 if (!is_vmalloc_addr(kaddr)) {
279 BUG_ON(!virt_addr_valid(kaddr));
282 return page_to_phys(vmalloc_to_page(kaddr)) +
283 offset_in_page(kaddr);
287 struct hyp_shared_pfn {
293 static DEFINE_MUTEX(hyp_shared_pfns_lock);
294 static struct rb_root hyp_shared_pfns = RB_ROOT;
296 static struct hyp_shared_pfn *find_shared_pfn(u64 pfn, struct rb_node ***node,
297 struct rb_node **parent)
299 struct hyp_shared_pfn *this;
301 *node = &hyp_shared_pfns.rb_node;
304 this = container_of(**node, struct hyp_shared_pfn, node);
307 *node = &((**node)->rb_left);
308 else if (this->pfn > pfn)
309 *node = &((**node)->rb_right);
317 static int share_pfn_hyp(u64 pfn)
319 struct rb_node **node, *parent;
320 struct hyp_shared_pfn *this;
323 mutex_lock(&hyp_shared_pfns_lock);
324 this = find_shared_pfn(pfn, &node, &parent);
330 this = kzalloc(sizeof(*this), GFP_KERNEL);
338 rb_link_node(&this->node, parent, node);
339 rb_insert_color(&this->node, &hyp_shared_pfns);
340 ret = kvm_call_hyp_nvhe(__pkvm_host_share_hyp, pfn, 1);
342 mutex_unlock(&hyp_shared_pfns_lock);
347 static int unshare_pfn_hyp(u64 pfn)
349 struct rb_node **node, *parent;
350 struct hyp_shared_pfn *this;
353 mutex_lock(&hyp_shared_pfns_lock);
354 this = find_shared_pfn(pfn, &node, &parent);
355 if (WARN_ON(!this)) {
364 rb_erase(&this->node, &hyp_shared_pfns);
366 ret = kvm_call_hyp_nvhe(__pkvm_host_unshare_hyp, pfn, 1);
368 mutex_unlock(&hyp_shared_pfns_lock);
373 int kvm_share_hyp(void *from, void *to)
375 phys_addr_t start, end, cur;
379 if (is_kernel_in_hyp_mode())
383 * The share hcall maps things in the 'fixed-offset' region of the hyp
384 * VA space, so we can only share physically contiguous data-structures
387 if (is_vmalloc_or_module_addr(from) || is_vmalloc_or_module_addr(to))
390 if (kvm_host_owns_hyp_mappings())
391 return create_hyp_mappings(from, to, PAGE_HYP);
393 start = ALIGN_DOWN(__pa(from), PAGE_SIZE);
394 end = PAGE_ALIGN(__pa(to));
395 for (cur = start; cur < end; cur += PAGE_SIZE) {
396 pfn = __phys_to_pfn(cur);
397 ret = share_pfn_hyp(pfn);
405 void kvm_unshare_hyp(void *from, void *to)
407 phys_addr_t start, end, cur;
410 if (is_kernel_in_hyp_mode() || kvm_host_owns_hyp_mappings() || !from)
413 start = ALIGN_DOWN(__pa(from), PAGE_SIZE);
414 end = PAGE_ALIGN(__pa(to));
415 for (cur = start; cur < end; cur += PAGE_SIZE) {
416 pfn = __phys_to_pfn(cur);
417 WARN_ON(unshare_pfn_hyp(pfn));
422 * create_hyp_mappings - duplicate a kernel virtual address range in Hyp mode
423 * @from: The virtual kernel start address of the range
424 * @to: The virtual kernel end address of the range (exclusive)
425 * @prot: The protection to be applied to this range
427 * The same virtual address as the kernel virtual address is also used
428 * in Hyp-mode mapping (modulo HYP_PAGE_OFFSET) to the same underlying
431 int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot)
433 phys_addr_t phys_addr;
434 unsigned long virt_addr;
435 unsigned long start = kern_hyp_va((unsigned long)from);
436 unsigned long end = kern_hyp_va((unsigned long)to);
438 if (is_kernel_in_hyp_mode())
441 if (!kvm_host_owns_hyp_mappings())
444 start = start & PAGE_MASK;
445 end = PAGE_ALIGN(end);
447 for (virt_addr = start; virt_addr < end; virt_addr += PAGE_SIZE) {
450 phys_addr = kvm_kaddr_to_phys(from + virt_addr - start);
451 err = __create_hyp_mappings(virt_addr, PAGE_SIZE, phys_addr,
460 static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size,
461 unsigned long *haddr,
462 enum kvm_pgtable_prot prot)
467 if (!kvm_host_owns_hyp_mappings()) {
468 base = kvm_call_hyp_nvhe(__pkvm_create_private_mapping,
469 phys_addr, size, prot);
470 if (IS_ERR_OR_NULL((void *)base))
471 return PTR_ERR((void *)base);
477 mutex_lock(&kvm_hyp_pgd_mutex);
480 * This assumes that we have enough space below the idmap
481 * page to allocate our VAs. If not, the check below will
482 * kick. A potential alternative would be to detect that
483 * overflow and switch to an allocation above the idmap.
485 * The allocated size is always a multiple of PAGE_SIZE.
487 size = PAGE_ALIGN(size + offset_in_page(phys_addr));
488 base = io_map_base - size;
491 * Verify that BIT(VA_BITS - 1) hasn't been flipped by
492 * allocating the new area, as it would indicate we've
493 * overflowed the idmap/IO address range.
495 if ((base ^ io_map_base) & BIT(VA_BITS - 1))
500 mutex_unlock(&kvm_hyp_pgd_mutex);
505 ret = __create_hyp_mappings(base, size, phys_addr, prot);
509 *haddr = base + offset_in_page(phys_addr);
515 * create_hyp_io_mappings - Map IO into both kernel and HYP
516 * @phys_addr: The physical start address which gets mapped
517 * @size: Size of the region being mapped
518 * @kaddr: Kernel VA for this mapping
519 * @haddr: HYP VA for this mapping
521 int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size,
522 void __iomem **kaddr,
523 void __iomem **haddr)
528 if (is_protected_kvm_enabled())
531 *kaddr = ioremap(phys_addr, size);
535 if (is_kernel_in_hyp_mode()) {
540 ret = __create_hyp_private_mapping(phys_addr, size,
541 &addr, PAGE_HYP_DEVICE);
549 *haddr = (void __iomem *)addr;
554 * create_hyp_exec_mappings - Map an executable range into HYP
555 * @phys_addr: The physical start address which gets mapped
556 * @size: Size of the region being mapped
557 * @haddr: HYP VA for this mapping
559 int create_hyp_exec_mappings(phys_addr_t phys_addr, size_t size,
565 BUG_ON(is_kernel_in_hyp_mode());
567 ret = __create_hyp_private_mapping(phys_addr, size,
568 &addr, PAGE_HYP_EXEC);
574 *haddr = (void *)addr;
578 static struct kvm_pgtable_mm_ops kvm_user_mm_ops = {
579 /* We shouldn't need any other callback to walk the PT */
580 .phys_to_virt = kvm_host_va,
583 static int get_user_mapping_size(struct kvm *kvm, u64 addr)
585 struct kvm_pgtable pgt = {
586 .pgd = (kvm_pte_t *)kvm->mm->pgd,
588 .start_level = (KVM_PGTABLE_MAX_LEVELS -
589 CONFIG_PGTABLE_LEVELS),
590 .mm_ops = &kvm_user_mm_ops,
592 kvm_pte_t pte = 0; /* Keep GCC quiet... */
596 ret = kvm_pgtable_get_leaf(&pgt, addr, &pte, &level);
598 VM_BUG_ON(level >= KVM_PGTABLE_MAX_LEVELS);
599 VM_BUG_ON(!(pte & PTE_VALID));
601 return BIT(ARM64_HW_PGTABLE_LEVEL_SHIFT(level));
604 static struct kvm_pgtable_mm_ops kvm_s2_mm_ops = {
605 .zalloc_page = stage2_memcache_zalloc_page,
606 .zalloc_pages_exact = kvm_host_zalloc_pages_exact,
607 .free_pages_exact = free_pages_exact,
608 .get_page = kvm_host_get_page,
609 .put_page = kvm_host_put_page,
610 .page_count = kvm_host_page_count,
611 .phys_to_virt = kvm_host_va,
612 .virt_to_phys = kvm_host_pa,
613 .dcache_clean_inval_poc = clean_dcache_guest_page,
614 .icache_inval_pou = invalidate_icache_guest_page,
618 * kvm_init_stage2_mmu - Initialise a S2 MMU structure
619 * @kvm: The pointer to the KVM structure
620 * @mmu: The pointer to the s2 MMU structure
622 * Allocates only the stage-2 HW PGD level table(s).
623 * Note we don't need locking here as this is only called when the VM is
624 * created, which can only be done once.
626 int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu)
629 struct kvm_pgtable *pgt;
631 if (mmu->pgt != NULL) {
632 kvm_err("kvm_arch already initialized?\n");
636 pgt = kzalloc(sizeof(*pgt), GFP_KERNEL_ACCOUNT);
640 mmu->arch = &kvm->arch;
641 err = kvm_pgtable_stage2_init(pgt, mmu, &kvm_s2_mm_ops);
643 goto out_free_pgtable;
645 mmu->last_vcpu_ran = alloc_percpu(typeof(*mmu->last_vcpu_ran));
646 if (!mmu->last_vcpu_ran) {
648 goto out_destroy_pgtable;
651 for_each_possible_cpu(cpu)
652 *per_cpu_ptr(mmu->last_vcpu_ran, cpu) = -1;
655 mmu->pgd_phys = __pa(pgt->pgd);
659 kvm_pgtable_stage2_destroy(pgt);
665 static void stage2_unmap_memslot(struct kvm *kvm,
666 struct kvm_memory_slot *memslot)
668 hva_t hva = memslot->userspace_addr;
669 phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
670 phys_addr_t size = PAGE_SIZE * memslot->npages;
671 hva_t reg_end = hva + size;
674 * A memory region could potentially cover multiple VMAs, and any holes
675 * between them, so iterate over all of them to find out if we should
678 * +--------------------------------------------+
679 * +---------------+----------------+ +----------------+
680 * | : VMA 1 | VMA 2 | | VMA 3 : |
681 * +---------------+----------------+ +----------------+
683 * +--------------------------------------------+
686 struct vm_area_struct *vma;
687 hva_t vm_start, vm_end;
689 vma = find_vma_intersection(current->mm, hva, reg_end);
694 * Take the intersection of this VMA with the memory region
696 vm_start = max(hva, vma->vm_start);
697 vm_end = min(reg_end, vma->vm_end);
699 if (!(vma->vm_flags & VM_PFNMAP)) {
700 gpa_t gpa = addr + (vm_start - memslot->userspace_addr);
701 unmap_stage2_range(&kvm->arch.mmu, gpa, vm_end - vm_start);
704 } while (hva < reg_end);
708 * stage2_unmap_vm - Unmap Stage-2 RAM mappings
709 * @kvm: The struct kvm pointer
711 * Go through the memregions and unmap any regular RAM
712 * backing memory already mapped to the VM.
714 void stage2_unmap_vm(struct kvm *kvm)
716 struct kvm_memslots *slots;
717 struct kvm_memory_slot *memslot;
720 idx = srcu_read_lock(&kvm->srcu);
721 mmap_read_lock(current->mm);
722 write_lock(&kvm->mmu_lock);
724 slots = kvm_memslots(kvm);
725 kvm_for_each_memslot(memslot, bkt, slots)
726 stage2_unmap_memslot(kvm, memslot);
728 write_unlock(&kvm->mmu_lock);
729 mmap_read_unlock(current->mm);
730 srcu_read_unlock(&kvm->srcu, idx);
733 void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu)
735 struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu);
736 struct kvm_pgtable *pgt = NULL;
738 write_lock(&kvm->mmu_lock);
743 free_percpu(mmu->last_vcpu_ran);
745 write_unlock(&kvm->mmu_lock);
748 kvm_pgtable_stage2_destroy(pgt);
754 * kvm_phys_addr_ioremap - map a device range to guest IPA
756 * @kvm: The KVM pointer
757 * @guest_ipa: The IPA at which to insert the mapping
758 * @pa: The physical address of the device
759 * @size: The size of the mapping
760 * @writable: Whether or not to create a writable mapping
762 int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
763 phys_addr_t pa, unsigned long size, bool writable)
767 struct kvm_mmu_memory_cache cache = { 0, __GFP_ZERO, NULL, };
768 struct kvm_pgtable *pgt = kvm->arch.mmu.pgt;
769 enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_DEVICE |
771 (writable ? KVM_PGTABLE_PROT_W : 0);
773 if (is_protected_kvm_enabled())
776 size += offset_in_page(guest_ipa);
777 guest_ipa &= PAGE_MASK;
779 for (addr = guest_ipa; addr < guest_ipa + size; addr += PAGE_SIZE) {
780 ret = kvm_mmu_topup_memory_cache(&cache,
781 kvm_mmu_cache_min_pages(kvm));
785 write_lock(&kvm->mmu_lock);
786 ret = kvm_pgtable_stage2_map(pgt, addr, PAGE_SIZE, pa, prot,
788 write_unlock(&kvm->mmu_lock);
795 kvm_mmu_free_memory_cache(&cache);
800 * stage2_wp_range() - write protect stage2 memory region range
801 * @mmu: The KVM stage-2 MMU pointer
802 * @addr: Start address of range
803 * @end: End address of range
805 static void stage2_wp_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end)
807 struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu);
808 stage2_apply_range_resched(kvm, addr, end, kvm_pgtable_stage2_wrprotect);
812 * kvm_mmu_wp_memory_region() - write protect stage 2 entries for memory slot
813 * @kvm: The KVM pointer
814 * @slot: The memory slot to write protect
816 * Called to start logging dirty pages after memory region
817 * KVM_MEM_LOG_DIRTY_PAGES operation is called. After this function returns
818 * all present PUD, PMD and PTEs are write protected in the memory region.
819 * Afterwards read of dirty page log can be called.
821 * Acquires kvm_mmu_lock. Called with kvm->slots_lock mutex acquired,
822 * serializing operations for VM memory regions.
824 static void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot)
826 struct kvm_memslots *slots = kvm_memslots(kvm);
827 struct kvm_memory_slot *memslot = id_to_memslot(slots, slot);
828 phys_addr_t start, end;
830 if (WARN_ON_ONCE(!memslot))
833 start = memslot->base_gfn << PAGE_SHIFT;
834 end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT;
836 write_lock(&kvm->mmu_lock);
837 stage2_wp_range(&kvm->arch.mmu, start, end);
838 write_unlock(&kvm->mmu_lock);
839 kvm_flush_remote_tlbs(kvm);
843 * kvm_mmu_write_protect_pt_masked() - write protect dirty pages
844 * @kvm: The KVM pointer
845 * @slot: The memory slot associated with mask
846 * @gfn_offset: The gfn offset in memory slot
847 * @mask: The mask of dirty pages at offset 'gfn_offset' in this memory
848 * slot to be write protected
850 * Walks bits set in mask write protects the associated pte's. Caller must
851 * acquire kvm_mmu_lock.
853 static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm,
854 struct kvm_memory_slot *slot,
855 gfn_t gfn_offset, unsigned long mask)
857 phys_addr_t base_gfn = slot->base_gfn + gfn_offset;
858 phys_addr_t start = (base_gfn + __ffs(mask)) << PAGE_SHIFT;
859 phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT;
861 stage2_wp_range(&kvm->arch.mmu, start, end);
865 * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected
868 * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to
869 * enable dirty logging for them.
871 void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
872 struct kvm_memory_slot *slot,
873 gfn_t gfn_offset, unsigned long mask)
875 kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask);
878 static void kvm_send_hwpoison_signal(unsigned long address, short lsb)
880 send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, lsb, current);
883 static bool fault_supports_stage2_huge_mapping(struct kvm_memory_slot *memslot,
885 unsigned long map_size)
888 hva_t uaddr_start, uaddr_end;
891 /* The memslot and the VMA are guaranteed to be aligned to PAGE_SIZE */
892 if (map_size == PAGE_SIZE)
895 size = memslot->npages * PAGE_SIZE;
897 gpa_start = memslot->base_gfn << PAGE_SHIFT;
899 uaddr_start = memslot->userspace_addr;
900 uaddr_end = uaddr_start + size;
903 * Pages belonging to memslots that don't have the same alignment
904 * within a PMD/PUD for userspace and IPA cannot be mapped with stage-2
905 * PMD/PUD entries, because we'll end up mapping the wrong pages.
907 * Consider a layout like the following:
909 * memslot->userspace_addr:
910 * +-----+--------------------+--------------------+---+
911 * |abcde|fgh Stage-1 block | Stage-1 block tv|xyz|
912 * +-----+--------------------+--------------------+---+
914 * memslot->base_gfn << PAGE_SHIFT:
915 * +---+--------------------+--------------------+-----+
916 * |abc|def Stage-2 block | Stage-2 block |tvxyz|
917 * +---+--------------------+--------------------+-----+
919 * If we create those stage-2 blocks, we'll end up with this incorrect
925 if ((gpa_start & (map_size - 1)) != (uaddr_start & (map_size - 1)))
929 * Next, let's make sure we're not trying to map anything not covered
930 * by the memslot. This means we have to prohibit block size mappings
931 * for the beginning and end of a non-block aligned and non-block sized
932 * memory slot (illustrated by the head and tail parts of the
933 * userspace view above containing pages 'abcde' and 'xyz',
936 * Note that it doesn't matter if we do the check using the
937 * userspace_addr or the base_gfn, as both are equally aligned (per
938 * the check above) and equally sized.
940 return (hva & ~(map_size - 1)) >= uaddr_start &&
941 (hva & ~(map_size - 1)) + map_size <= uaddr_end;
945 * Check if the given hva is backed by a transparent huge page (THP) and
946 * whether it can be mapped using block mapping in stage2. If so, adjust
947 * the stage2 PFN and IPA accordingly. Only PMD_SIZE THPs are currently
948 * supported. This will need to be updated to support other THP sizes.
950 * Returns the size of the mapping.
953 transparent_hugepage_adjust(struct kvm *kvm, struct kvm_memory_slot *memslot,
954 unsigned long hva, kvm_pfn_t *pfnp,
957 kvm_pfn_t pfn = *pfnp;
960 * Make sure the adjustment is done only for THP pages. Also make
961 * sure that the HVA and IPA are sufficiently aligned and that the
962 * block map is contained within the memslot.
964 if (fault_supports_stage2_huge_mapping(memslot, hva, PMD_SIZE) &&
965 get_user_mapping_size(kvm, hva) >= PMD_SIZE) {
967 * The address we faulted on is backed by a transparent huge
968 * page. However, because we map the compound huge page and
969 * not the individual tail page, we need to transfer the
970 * refcount to the head page. We have to be careful that the
971 * THP doesn't start to split while we are adjusting the
974 * We are sure this doesn't happen, because mmu_notifier_retry
975 * was successful and we are holding the mmu_lock, so if this
976 * THP is trying to split, it will be blocked in the mmu
977 * notifier before touching any of the pages, specifically
978 * before being able to call __split_huge_page_refcount().
980 * We can therefore safely transfer the refcount from PG_tail
981 * to PG_head and switch the pfn from a tail page to the head
985 kvm_release_pfn_clean(pfn);
986 pfn &= ~(PTRS_PER_PMD - 1);
987 get_page(pfn_to_page(pfn));
993 /* Use page mapping if we cannot use block mapping. */
997 static int get_vma_page_shift(struct vm_area_struct *vma, unsigned long hva)
1001 if (is_vm_hugetlb_page(vma) && !(vma->vm_flags & VM_PFNMAP))
1002 return huge_page_shift(hstate_vma(vma));
1004 if (!(vma->vm_flags & VM_PFNMAP))
1007 VM_BUG_ON(is_vm_hugetlb_page(vma));
1009 pa = (vma->vm_pgoff << PAGE_SHIFT) + (hva - vma->vm_start);
1011 #ifndef __PAGETABLE_PMD_FOLDED
1012 if ((hva & (PUD_SIZE - 1)) == (pa & (PUD_SIZE - 1)) &&
1013 ALIGN_DOWN(hva, PUD_SIZE) >= vma->vm_start &&
1014 ALIGN(hva, PUD_SIZE) <= vma->vm_end)
1018 if ((hva & (PMD_SIZE - 1)) == (pa & (PMD_SIZE - 1)) &&
1019 ALIGN_DOWN(hva, PMD_SIZE) >= vma->vm_start &&
1020 ALIGN(hva, PMD_SIZE) <= vma->vm_end)
1027 * The page will be mapped in stage 2 as Normal Cacheable, so the VM will be
1028 * able to see the page's tags and therefore they must be initialised first. If
1029 * PG_mte_tagged is set, tags have already been initialised.
1031 * The race in the test/set of the PG_mte_tagged flag is handled by:
1032 * - preventing VM_SHARED mappings in a memslot with MTE preventing two VMs
1033 * racing to santise the same page
1034 * - mmap_lock protects between a VM faulting a page in and the VMM performing
1035 * an mprotect() to add VM_MTE
1037 static int sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
1040 unsigned long i, nr_pages = size >> PAGE_SHIFT;
1043 if (!kvm_has_mte(kvm))
1047 * pfn_to_online_page() is used to reject ZONE_DEVICE pages
1048 * that may not support tags.
1050 page = pfn_to_online_page(pfn);
1055 for (i = 0; i < nr_pages; i++, page++) {
1056 if (!test_bit(PG_mte_tagged, &page->flags)) {
1057 mte_clear_page_tags(page_address(page));
1058 set_bit(PG_mte_tagged, &page->flags);
1065 static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
1066 struct kvm_memory_slot *memslot, unsigned long hva,
1067 unsigned long fault_status)
1070 bool write_fault, writable, force_pte = false;
1072 bool device = false;
1074 unsigned long mmu_seq;
1075 struct kvm *kvm = vcpu->kvm;
1076 struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;
1077 struct vm_area_struct *vma;
1081 bool logging_active = memslot_is_logging(memslot);
1082 bool logging_perm_fault = false;
1083 unsigned long fault_level = kvm_vcpu_trap_get_fault_level(vcpu);
1084 unsigned long vma_pagesize, fault_granule;
1085 enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_R;
1086 struct kvm_pgtable *pgt;
1088 fault_granule = 1UL << ARM64_HW_PGTABLE_LEVEL_SHIFT(fault_level);
1089 write_fault = kvm_is_write_fault(vcpu);
1090 exec_fault = kvm_vcpu_trap_is_exec_fault(vcpu);
1091 VM_BUG_ON(write_fault && exec_fault);
1093 if (fault_status == FSC_PERM && !write_fault && !exec_fault) {
1094 kvm_err("Unexpected L2 read permission error\n");
1099 * Let's check if we will get back a huge page backed by hugetlbfs, or
1100 * get block mapping for device MMIO region.
1102 mmap_read_lock(current->mm);
1103 vma = vma_lookup(current->mm, hva);
1104 if (unlikely(!vma)) {
1105 kvm_err("Failed to find VMA for hva 0x%lx\n", hva);
1106 mmap_read_unlock(current->mm);
1111 * logging_active is guaranteed to never be true for VM_PFNMAP
1114 if (logging_active) {
1116 vma_shift = PAGE_SHIFT;
1117 logging_perm_fault = (fault_status == FSC_PERM && write_fault);
1119 vma_shift = get_vma_page_shift(vma, hva);
1122 shared = (vma->vm_flags & VM_SHARED);
1124 switch (vma_shift) {
1125 #ifndef __PAGETABLE_PMD_FOLDED
1127 if (fault_supports_stage2_huge_mapping(memslot, hva, PUD_SIZE))
1131 case CONT_PMD_SHIFT:
1132 vma_shift = PMD_SHIFT;
1135 if (fault_supports_stage2_huge_mapping(memslot, hva, PMD_SIZE))
1138 case CONT_PTE_SHIFT:
1139 vma_shift = PAGE_SHIFT;
1145 WARN_ONCE(1, "Unknown vma_shift %d", vma_shift);
1148 vma_pagesize = 1UL << vma_shift;
1149 if (vma_pagesize == PMD_SIZE || vma_pagesize == PUD_SIZE)
1150 fault_ipa &= ~(vma_pagesize - 1);
1152 gfn = fault_ipa >> PAGE_SHIFT;
1153 mmap_read_unlock(current->mm);
1156 * Permission faults just need to update the existing leaf entry,
1157 * and so normally don't require allocations from the memcache. The
1158 * only exception to this is when dirty logging is enabled at runtime
1159 * and a write fault needs to collapse a block entry into a table.
1161 if (fault_status != FSC_PERM || (logging_active && write_fault)) {
1162 ret = kvm_mmu_topup_memory_cache(memcache,
1163 kvm_mmu_cache_min_pages(kvm));
1168 mmu_seq = vcpu->kvm->mmu_notifier_seq;
1170 * Ensure the read of mmu_notifier_seq happens before we call
1171 * gfn_to_pfn_prot (which calls get_user_pages), so that we don't risk
1172 * the page we just got a reference to gets unmapped before we have a
1173 * chance to grab the mmu_lock, which ensure that if the page gets
1174 * unmapped afterwards, the call to kvm_unmap_gfn will take it away
1175 * from us again properly. This smp_rmb() interacts with the smp_wmb()
1176 * in kvm_mmu_notifier_invalidate_<page|range_end>.
1178 * Besides, __gfn_to_pfn_memslot() instead of gfn_to_pfn_prot() is
1179 * used to avoid unnecessary overhead introduced to locate the memory
1180 * slot because it's always fixed even @gfn is adjusted for huge pages.
1184 pfn = __gfn_to_pfn_memslot(memslot, gfn, false, NULL,
1185 write_fault, &writable, NULL);
1186 if (pfn == KVM_PFN_ERR_HWPOISON) {
1187 kvm_send_hwpoison_signal(hva, vma_shift);
1190 if (is_error_noslot_pfn(pfn))
1193 if (kvm_is_device_pfn(pfn)) {
1195 * If the page was identified as device early by looking at
1196 * the VMA flags, vma_pagesize is already representing the
1197 * largest quantity we can map. If instead it was mapped
1198 * via gfn_to_pfn_prot(), vma_pagesize is set to PAGE_SIZE
1199 * and must not be upgraded.
1201 * In both cases, we don't let transparent_hugepage_adjust()
1202 * change things at the last minute.
1205 } else if (logging_active && !write_fault) {
1207 * Only actually map the page as writable if this was a write
1213 if (exec_fault && device)
1217 * To reduce MMU contentions and enhance concurrency during dirty
1218 * logging dirty logging, only acquire read lock for permission
1221 if (logging_perm_fault)
1222 read_lock(&kvm->mmu_lock);
1224 write_lock(&kvm->mmu_lock);
1225 pgt = vcpu->arch.hw_mmu->pgt;
1226 if (mmu_notifier_retry(kvm, mmu_seq))
1230 * If we are not forced to use page mapping, check if we are
1231 * backed by a THP and thus use block mapping if possible.
1233 if (vma_pagesize == PAGE_SIZE && !(force_pte || device)) {
1234 if (fault_status == FSC_PERM && fault_granule > PAGE_SIZE)
1235 vma_pagesize = fault_granule;
1237 vma_pagesize = transparent_hugepage_adjust(kvm, memslot,
1242 if (fault_status != FSC_PERM && !device && kvm_has_mte(kvm)) {
1243 /* Check the VMM hasn't introduced a new VM_SHARED VMA */
1245 ret = sanitise_mte_tags(kvm, pfn, vma_pagesize);
1253 prot |= KVM_PGTABLE_PROT_W;
1256 prot |= KVM_PGTABLE_PROT_X;
1259 prot |= KVM_PGTABLE_PROT_DEVICE;
1260 else if (cpus_have_const_cap(ARM64_HAS_CACHE_DIC))
1261 prot |= KVM_PGTABLE_PROT_X;
1264 * Under the premise of getting a FSC_PERM fault, we just need to relax
1265 * permissions only if vma_pagesize equals fault_granule. Otherwise,
1266 * kvm_pgtable_stage2_map() should be called to change block size.
1268 if (fault_status == FSC_PERM && vma_pagesize == fault_granule) {
1269 ret = kvm_pgtable_stage2_relax_perms(pgt, fault_ipa, prot);
1271 ret = kvm_pgtable_stage2_map(pgt, fault_ipa, vma_pagesize,
1272 __pfn_to_phys(pfn), prot,
1276 /* Mark the page dirty only if the fault is handled successfully */
1277 if (writable && !ret) {
1278 kvm_set_pfn_dirty(pfn);
1279 mark_page_dirty_in_slot(kvm, memslot, gfn);
1283 if (logging_perm_fault)
1284 read_unlock(&kvm->mmu_lock);
1286 write_unlock(&kvm->mmu_lock);
1287 kvm_set_pfn_accessed(pfn);
1288 kvm_release_pfn_clean(pfn);
1289 return ret != -EAGAIN ? ret : 0;
1292 /* Resolve the access fault by making the page young again. */
1293 static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
1297 struct kvm_s2_mmu *mmu;
1299 trace_kvm_access_fault(fault_ipa);
1301 write_lock(&vcpu->kvm->mmu_lock);
1302 mmu = vcpu->arch.hw_mmu;
1303 kpte = kvm_pgtable_stage2_mkyoung(mmu->pgt, fault_ipa);
1304 write_unlock(&vcpu->kvm->mmu_lock);
1308 kvm_set_pfn_accessed(pte_pfn(pte));
1312 * kvm_handle_guest_abort - handles all 2nd stage aborts
1313 * @vcpu: the VCPU pointer
1315 * Any abort that gets to the host is almost guaranteed to be caused by a
1316 * missing second stage translation table entry, which can mean that either the
1317 * guest simply needs more memory and we must allocate an appropriate page or it
1318 * can mean that the guest tried to access I/O memory, which is emulated by user
1319 * space. The distinction is based on the IPA causing the fault and whether this
1320 * memory region has been registered as standard RAM by user space.
1322 int kvm_handle_guest_abort(struct kvm_vcpu *vcpu)
1324 unsigned long fault_status;
1325 phys_addr_t fault_ipa;
1326 struct kvm_memory_slot *memslot;
1328 bool is_iabt, write_fault, writable;
1332 fault_status = kvm_vcpu_trap_get_fault_type(vcpu);
1334 fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);
1335 is_iabt = kvm_vcpu_trap_is_iabt(vcpu);
1337 /* Synchronous External Abort? */
1338 if (kvm_vcpu_abt_issea(vcpu)) {
1340 * For RAS the host kernel may handle this abort.
1341 * There is no need to pass the error into the guest.
1343 if (kvm_handle_guest_sea(fault_ipa, kvm_vcpu_get_esr(vcpu)))
1344 kvm_inject_vabt(vcpu);
1349 trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_esr(vcpu),
1350 kvm_vcpu_get_hfar(vcpu), fault_ipa);
1352 /* Check the stage-2 fault is trans. fault or write fault */
1353 if (fault_status != FSC_FAULT && fault_status != FSC_PERM &&
1354 fault_status != FSC_ACCESS) {
1355 kvm_err("Unsupported FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n",
1356 kvm_vcpu_trap_get_class(vcpu),
1357 (unsigned long)kvm_vcpu_trap_get_fault(vcpu),
1358 (unsigned long)kvm_vcpu_get_esr(vcpu));
1362 idx = srcu_read_lock(&vcpu->kvm->srcu);
1364 gfn = fault_ipa >> PAGE_SHIFT;
1365 memslot = gfn_to_memslot(vcpu->kvm, gfn);
1366 hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable);
1367 write_fault = kvm_is_write_fault(vcpu);
1368 if (kvm_is_error_hva(hva) || (write_fault && !writable)) {
1370 * The guest has put either its instructions or its page-tables
1371 * somewhere it shouldn't have. Userspace won't be able to do
1372 * anything about this (there's no syndrome for a start), so
1373 * re-inject the abort back into the guest.
1380 if (kvm_vcpu_abt_iss1tw(vcpu)) {
1381 kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu));
1387 * Check for a cache maintenance operation. Since we
1388 * ended-up here, we know it is outside of any memory
1389 * slot. But we can't find out if that is for a device,
1390 * or if the guest is just being stupid. The only thing
1391 * we know for sure is that this range cannot be cached.
1393 * So let's assume that the guest is just being
1394 * cautious, and skip the instruction.
1396 if (kvm_is_error_hva(hva) && kvm_vcpu_dabt_is_cm(vcpu)) {
1403 * The IPA is reported as [MAX:12], so we need to
1404 * complement it with the bottom 12 bits from the
1405 * faulting VA. This is always 12 bits, irrespective
1408 fault_ipa |= kvm_vcpu_get_hfar(vcpu) & ((1 << 12) - 1);
1409 ret = io_mem_abort(vcpu, fault_ipa);
1413 /* Userspace should not be able to register out-of-bounds IPAs */
1414 VM_BUG_ON(fault_ipa >= kvm_phys_size(vcpu->kvm));
1416 if (fault_status == FSC_ACCESS) {
1417 handle_access_fault(vcpu, fault_ipa);
1422 ret = user_mem_abort(vcpu, fault_ipa, memslot, hva, fault_status);
1426 if (ret == -ENOEXEC) {
1427 kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu));
1431 srcu_read_unlock(&vcpu->kvm->srcu, idx);
1435 bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
1437 if (!kvm->arch.mmu.pgt)
1440 __unmap_stage2_range(&kvm->arch.mmu, range->start << PAGE_SHIFT,
1441 (range->end - range->start) << PAGE_SHIFT,
1447 bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
1449 kvm_pfn_t pfn = pte_pfn(range->pte);
1452 if (!kvm->arch.mmu.pgt)
1455 WARN_ON(range->end - range->start != 1);
1457 ret = sanitise_mte_tags(kvm, pfn, PAGE_SIZE);
1462 * We've moved a page around, probably through CoW, so let's treat
1463 * it just like a translation fault and the map handler will clean
1464 * the cache to the PoC.
1466 * The MMU notifiers will have unmapped a huge PMD before calling
1467 * ->change_pte() (which in turn calls kvm_set_spte_gfn()) and
1468 * therefore we never need to clear out a huge PMD through this
1469 * calling path and a memcache is not required.
1471 kvm_pgtable_stage2_map(kvm->arch.mmu.pgt, range->start << PAGE_SHIFT,
1472 PAGE_SIZE, __pfn_to_phys(pfn),
1473 KVM_PGTABLE_PROT_R, NULL);
1478 bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
1480 u64 size = (range->end - range->start) << PAGE_SHIFT;
1484 if (!kvm->arch.mmu.pgt)
1487 WARN_ON(size != PAGE_SIZE && size != PMD_SIZE && size != PUD_SIZE);
1489 kpte = kvm_pgtable_stage2_mkold(kvm->arch.mmu.pgt,
1490 range->start << PAGE_SHIFT);
1492 return pte_valid(pte) && pte_young(pte);
1495 bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
1497 if (!kvm->arch.mmu.pgt)
1500 return kvm_pgtable_stage2_is_young(kvm->arch.mmu.pgt,
1501 range->start << PAGE_SHIFT);
1504 phys_addr_t kvm_mmu_get_httbr(void)
1506 return __pa(hyp_pgtable->pgd);
1509 phys_addr_t kvm_get_idmap_vector(void)
1511 return hyp_idmap_vector;
1514 static int kvm_map_idmap_text(void)
1516 unsigned long size = hyp_idmap_end - hyp_idmap_start;
1517 int err = __create_hyp_mappings(hyp_idmap_start, size, hyp_idmap_start,
1520 kvm_err("Failed to idmap %lx-%lx\n",
1521 hyp_idmap_start, hyp_idmap_end);
1526 static void *kvm_hyp_zalloc_page(void *arg)
1528 return (void *)get_zeroed_page(GFP_KERNEL);
1531 static struct kvm_pgtable_mm_ops kvm_hyp_mm_ops = {
1532 .zalloc_page = kvm_hyp_zalloc_page,
1533 .get_page = kvm_host_get_page,
1534 .put_page = kvm_host_put_page,
1535 .phys_to_virt = kvm_host_va,
1536 .virt_to_phys = kvm_host_pa,
1539 int kvm_mmu_init(u32 *hyp_va_bits)
1543 hyp_idmap_start = __pa_symbol(__hyp_idmap_text_start);
1544 hyp_idmap_start = ALIGN_DOWN(hyp_idmap_start, PAGE_SIZE);
1545 hyp_idmap_end = __pa_symbol(__hyp_idmap_text_end);
1546 hyp_idmap_end = ALIGN(hyp_idmap_end, PAGE_SIZE);
1547 hyp_idmap_vector = __pa_symbol(__kvm_hyp_init);
1550 * We rely on the linker script to ensure at build time that the HYP
1551 * init code does not cross a page boundary.
1553 BUG_ON((hyp_idmap_start ^ (hyp_idmap_end - 1)) & PAGE_MASK);
1555 *hyp_va_bits = 64 - ((idmap_t0sz & TCR_T0SZ_MASK) >> TCR_T0SZ_OFFSET);
1556 kvm_debug("Using %u-bit virtual addresses at EL2\n", *hyp_va_bits);
1557 kvm_debug("IDMAP page: %lx\n", hyp_idmap_start);
1558 kvm_debug("HYP VA range: %lx:%lx\n",
1559 kern_hyp_va(PAGE_OFFSET),
1560 kern_hyp_va((unsigned long)high_memory - 1));
1562 if (hyp_idmap_start >= kern_hyp_va(PAGE_OFFSET) &&
1563 hyp_idmap_start < kern_hyp_va((unsigned long)high_memory - 1) &&
1564 hyp_idmap_start != (unsigned long)__hyp_idmap_text_start) {
1566 * The idmap page is intersecting with the VA space,
1567 * it is not safe to continue further.
1569 kvm_err("IDMAP intersecting with HYP VA, unable to continue\n");
1574 hyp_pgtable = kzalloc(sizeof(*hyp_pgtable), GFP_KERNEL);
1576 kvm_err("Hyp mode page-table not allocated\n");
1581 err = kvm_pgtable_hyp_init(hyp_pgtable, *hyp_va_bits, &kvm_hyp_mm_ops);
1583 goto out_free_pgtable;
1585 err = kvm_map_idmap_text();
1587 goto out_destroy_pgtable;
1589 io_map_base = hyp_idmap_start;
1592 out_destroy_pgtable:
1593 kvm_pgtable_hyp_destroy(hyp_pgtable);
1601 void kvm_arch_commit_memory_region(struct kvm *kvm,
1602 struct kvm_memory_slot *old,
1603 const struct kvm_memory_slot *new,
1604 enum kvm_mr_change change)
1607 * At this point memslot has been committed and there is an
1608 * allocated dirty_bitmap[], dirty pages will be tracked while the
1609 * memory slot is write protected.
1611 if (change != KVM_MR_DELETE && new->flags & KVM_MEM_LOG_DIRTY_PAGES) {
1613 * If we're with initial-all-set, we don't need to write
1614 * protect any pages because they're all reported as dirty.
1615 * Huge pages and normal pages will be write protect gradually.
1617 if (!kvm_dirty_log_manual_protect_and_init_set(kvm)) {
1618 kvm_mmu_wp_memory_region(kvm, new->id);
1623 int kvm_arch_prepare_memory_region(struct kvm *kvm,
1624 const struct kvm_memory_slot *old,
1625 struct kvm_memory_slot *new,
1626 enum kvm_mr_change change)
1631 if (change != KVM_MR_CREATE && change != KVM_MR_MOVE &&
1632 change != KVM_MR_FLAGS_ONLY)
1636 * Prevent userspace from creating a memory region outside of the IPA
1637 * space addressable by the KVM guest IPA space.
1639 if ((new->base_gfn + new->npages) > (kvm_phys_size(kvm) >> PAGE_SHIFT))
1642 hva = new->userspace_addr;
1643 reg_end = hva + (new->npages << PAGE_SHIFT);
1645 mmap_read_lock(current->mm);
1647 * A memory region could potentially cover multiple VMAs, and any holes
1648 * between them, so iterate over all of them.
1650 * +--------------------------------------------+
1651 * +---------------+----------------+ +----------------+
1652 * | : VMA 1 | VMA 2 | | VMA 3 : |
1653 * +---------------+----------------+ +----------------+
1655 * +--------------------------------------------+
1658 struct vm_area_struct *vma;
1660 vma = find_vma_intersection(current->mm, hva, reg_end);
1665 * VM_SHARED mappings are not allowed with MTE to avoid races
1666 * when updating the PG_mte_tagged page flag, see
1667 * sanitise_mte_tags for more details.
1669 if (kvm_has_mte(kvm) && vma->vm_flags & VM_SHARED) {
1674 if (vma->vm_flags & VM_PFNMAP) {
1675 /* IO region dirty page logging not allowed */
1676 if (new->flags & KVM_MEM_LOG_DIRTY_PAGES) {
1681 hva = min(reg_end, vma->vm_end);
1682 } while (hva < reg_end);
1684 mmap_read_unlock(current->mm);
1688 void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)
1692 void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen)
1696 void kvm_arch_flush_shadow_all(struct kvm *kvm)
1698 kvm_free_stage2_pgd(&kvm->arch.mmu);
1701 void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
1702 struct kvm_memory_slot *slot)
1704 gpa_t gpa = slot->base_gfn << PAGE_SHIFT;
1705 phys_addr_t size = slot->npages << PAGE_SHIFT;
1707 write_lock(&kvm->mmu_lock);
1708 unmap_stage2_range(&kvm->arch.mmu, gpa, size);
1709 write_unlock(&kvm->mmu_lock);
1713 * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized).
1716 * - S/W ops are local to a CPU (not broadcast)
1717 * - We have line migration behind our back (speculation)
1718 * - System caches don't support S/W at all (damn!)
1720 * In the face of the above, the best we can do is to try and convert
1721 * S/W ops to VA ops. Because the guest is not allowed to infer the
1722 * S/W to PA mapping, it can only use S/W to nuke the whole cache,
1723 * which is a rather good thing for us.
1725 * Also, it is only used when turning caches on/off ("The expected
1726 * usage of the cache maintenance instructions that operate by set/way
1727 * is associated with the cache maintenance instructions associated
1728 * with the powerdown and powerup of caches, if this is required by
1729 * the implementation.").
1731 * We use the following policy:
1733 * - If we trap a S/W operation, we enable VM trapping to detect
1734 * caches being turned on/off, and do a full clean.
1736 * - We flush the caches on both caches being turned on and off.
1738 * - Once the caches are enabled, we stop trapping VM ops.
1740 void kvm_set_way_flush(struct kvm_vcpu *vcpu)
1742 unsigned long hcr = *vcpu_hcr(vcpu);
1745 * If this is the first time we do a S/W operation
1746 * (i.e. HCR_TVM not set) flush the whole memory, and set the
1749 * Otherwise, rely on the VM trapping to wait for the MMU +
1750 * Caches to be turned off. At that point, we'll be able to
1751 * clean the caches again.
1753 if (!(hcr & HCR_TVM)) {
1754 trace_kvm_set_way_flush(*vcpu_pc(vcpu),
1755 vcpu_has_cache_enabled(vcpu));
1756 stage2_flush_vm(vcpu->kvm);
1757 *vcpu_hcr(vcpu) = hcr | HCR_TVM;
1761 void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled)
1763 bool now_enabled = vcpu_has_cache_enabled(vcpu);
1766 * If switching the MMU+caches on, need to invalidate the caches.
1767 * If switching it off, need to clean the caches.
1768 * Clean + invalidate does the trick always.
1770 if (now_enabled != was_enabled)
1771 stage2_flush_vm(vcpu->kvm);
1773 /* Caches are now on, stop trapping VM ops (until a S/W op) */
1775 *vcpu_hcr(vcpu) &= ~HCR_TVM;
1777 trace_kvm_toggle_cache(*vcpu_pc(vcpu), was_enabled, now_enabled);