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-rw-r--r--virt/kvm/arm/mmu.c1958
1 files changed, 1958 insertions, 0 deletions
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
new file mode 100644
index 000000000000..efb4335aa5c4
--- /dev/null
+++ b/virt/kvm/arm/mmu.c
@@ -0,0 +1,1958 @@
+/*
+ * Copyright (C) 2012 - Virtual Open Systems and Columbia University
+ * Author: Christoffer Dall <c.dall@virtualopensystems.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include <linux/mman.h>
+#include <linux/kvm_host.h>
+#include <linux/io.h>
+#include <linux/hugetlb.h>
+#include <trace/events/kvm.h>
+#include <asm/pgalloc.h>
+#include <asm/cacheflush.h>
+#include <asm/kvm_arm.h>
+#include <asm/kvm_mmu.h>
+#include <asm/kvm_mmio.h>
+#include <asm/kvm_asm.h>
+#include <asm/kvm_emulate.h>
+#include <asm/virt.h>
+
+#include "trace.h"
+
+static pgd_t *boot_hyp_pgd;
+static pgd_t *hyp_pgd;
+static pgd_t *merged_hyp_pgd;
+static DEFINE_MUTEX(kvm_hyp_pgd_mutex);
+
+static unsigned long hyp_idmap_start;
+static unsigned long hyp_idmap_end;
+static phys_addr_t hyp_idmap_vector;
+
+#define S2_PGD_SIZE (PTRS_PER_S2_PGD * sizeof(pgd_t))
+#define hyp_pgd_order get_order(PTRS_PER_PGD * sizeof(pgd_t))
+
+#define KVM_S2PTE_FLAG_IS_IOMAP (1UL << 0)
+#define KVM_S2_FLAG_LOGGING_ACTIVE (1UL << 1)
+
+static bool memslot_is_logging(struct kvm_memory_slot *memslot)
+{
+ return memslot->dirty_bitmap && !(memslot->flags & KVM_MEM_READONLY);
+}
+
+/**
+ * kvm_flush_remote_tlbs() - flush all VM TLB entries for v7/8
+ * @kvm: pointer to kvm structure.
+ *
+ * Interface to HYP function to flush all VM TLB entries
+ */
+void kvm_flush_remote_tlbs(struct kvm *kvm)
+{
+ kvm_call_hyp(__kvm_tlb_flush_vmid, kvm);
+}
+
+static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
+{
+ kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa);
+}
+
+/*
+ * D-Cache management functions. They take the page table entries by
+ * value, as they are flushing the cache using the kernel mapping (or
+ * kmap on 32bit).
+ */
+static void kvm_flush_dcache_pte(pte_t pte)
+{
+ __kvm_flush_dcache_pte(pte);
+}
+
+static void kvm_flush_dcache_pmd(pmd_t pmd)
+{
+ __kvm_flush_dcache_pmd(pmd);
+}
+
+static void kvm_flush_dcache_pud(pud_t pud)
+{
+ __kvm_flush_dcache_pud(pud);
+}
+
+static bool kvm_is_device_pfn(unsigned long pfn)
+{
+ return !pfn_valid(pfn);
+}
+
+/**
+ * stage2_dissolve_pmd() - clear and flush huge PMD entry
+ * @kvm: pointer to kvm structure.
+ * @addr: IPA
+ * @pmd: pmd pointer for IPA
+ *
+ * Function clears a PMD entry, flushes addr 1st and 2nd stage TLBs. Marks all
+ * pages in the range dirty.
+ */
+static void stage2_dissolve_pmd(struct kvm *kvm, phys_addr_t addr, pmd_t *pmd)
+{
+ if (!pmd_thp_or_huge(*pmd))
+ return;
+
+ pmd_clear(pmd);
+ kvm_tlb_flush_vmid_ipa(kvm, addr);
+ put_page(virt_to_page(pmd));
+}
+
+static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
+ int min, int max)
+{
+ void *page;
+
+ BUG_ON(max > KVM_NR_MEM_OBJS);
+ if (cache->nobjs >= min)
+ return 0;
+ while (cache->nobjs < max) {
+ page = (void *)__get_free_page(PGALLOC_GFP);
+ if (!page)
+ return -ENOMEM;
+ cache->objects[cache->nobjs++] = page;
+ }
+ return 0;
+}
+
+static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
+{
+ while (mc->nobjs)
+ free_page((unsigned long)mc->objects[--mc->nobjs]);
+}
+
+static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc)
+{
+ void *p;
+
+ BUG_ON(!mc || !mc->nobjs);
+ p = mc->objects[--mc->nobjs];
+ return p;
+}
+
+static void clear_stage2_pgd_entry(struct kvm *kvm, pgd_t *pgd, phys_addr_t addr)
+{
+ pud_t *pud_table __maybe_unused = stage2_pud_offset(pgd, 0UL);
+ stage2_pgd_clear(pgd);
+ kvm_tlb_flush_vmid_ipa(kvm, addr);
+ stage2_pud_free(pud_table);
+ put_page(virt_to_page(pgd));
+}
+
+static void clear_stage2_pud_entry(struct kvm *kvm, pud_t *pud, phys_addr_t addr)
+{
+ pmd_t *pmd_table __maybe_unused = stage2_pmd_offset(pud, 0);
+ VM_BUG_ON(stage2_pud_huge(*pud));
+ stage2_pud_clear(pud);
+ kvm_tlb_flush_vmid_ipa(kvm, addr);
+ stage2_pmd_free(pmd_table);
+ put_page(virt_to_page(pud));
+}
+
+static void clear_stage2_pmd_entry(struct kvm *kvm, pmd_t *pmd, phys_addr_t addr)
+{
+ pte_t *pte_table = pte_offset_kernel(pmd, 0);
+ VM_BUG_ON(pmd_thp_or_huge(*pmd));
+ pmd_clear(pmd);
+ kvm_tlb_flush_vmid_ipa(kvm, addr);
+ pte_free_kernel(NULL, pte_table);
+ put_page(virt_to_page(pmd));
+}
+
+/*
+ * Unmapping vs dcache management:
+ *
+ * If a guest maps certain memory pages as uncached, all writes will
+ * bypass the data cache and go directly to RAM. However, the CPUs
+ * can still speculate reads (not writes) and fill cache lines with
+ * data.
+ *
+ * Those cache lines will be *clean* cache lines though, so a
+ * clean+invalidate operation is equivalent to an invalidate
+ * operation, because no cache lines are marked dirty.
+ *
+ * Those clean cache lines could be filled prior to an uncached write
+ * by the guest, and the cache coherent IO subsystem would therefore
+ * end up writing old data to disk.
+ *
+ * This is why right after unmapping a page/section and invalidating
+ * the corresponding TLBs, we call kvm_flush_dcache_p*() to make sure
+ * the IO subsystem will never hit in the cache.
+ */
+static void unmap_stage2_ptes(struct kvm *kvm, pmd_t *pmd,
+ phys_addr_t addr, phys_addr_t end)
+{
+ phys_addr_t start_addr = addr;
+ pte_t *pte, *start_pte;
+
+ start_pte = pte = pte_offset_kernel(pmd, addr);
+ do {
+ if (!pte_none(*pte)) {
+ pte_t old_pte = *pte;
+
+ kvm_set_pte(pte, __pte(0));
+ kvm_tlb_flush_vmid_ipa(kvm, addr);
+
+ /* No need to invalidate the cache for device mappings */
+ if (!kvm_is_device_pfn(pte_pfn(old_pte)))
+ kvm_flush_dcache_pte(old_pte);
+
+ put_page(virt_to_page(pte));
+ }
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+
+ if (stage2_pte_table_empty(start_pte))
+ clear_stage2_pmd_entry(kvm, pmd, start_addr);
+}
+
+static void unmap_stage2_pmds(struct kvm *kvm, pud_t *pud,
+ phys_addr_t addr, phys_addr_t end)
+{
+ phys_addr_t next, start_addr = addr;
+ pmd_t *pmd, *start_pmd;
+
+ start_pmd = pmd = stage2_pmd_offset(pud, addr);
+ do {
+ next = stage2_pmd_addr_end(addr, end);
+ if (!pmd_none(*pmd)) {
+ if (pmd_thp_or_huge(*pmd)) {
+ pmd_t old_pmd = *pmd;
+
+ pmd_clear(pmd);
+ kvm_tlb_flush_vmid_ipa(kvm, addr);
+
+ kvm_flush_dcache_pmd(old_pmd);
+
+ put_page(virt_to_page(pmd));
+ } else {
+ unmap_stage2_ptes(kvm, pmd, addr, next);
+ }
+ }
+ } while (pmd++, addr = next, addr != end);
+
+ if (stage2_pmd_table_empty(start_pmd))
+ clear_stage2_pud_entry(kvm, pud, start_addr);
+}
+
+static void unmap_stage2_puds(struct kvm *kvm, pgd_t *pgd,
+ phys_addr_t addr, phys_addr_t end)
+{
+ phys_addr_t next, start_addr = addr;
+ pud_t *pud, *start_pud;
+
+ start_pud = pud = stage2_pud_offset(pgd, addr);
+ do {
+ next = stage2_pud_addr_end(addr, end);
+ if (!stage2_pud_none(*pud)) {
+ if (stage2_pud_huge(*pud)) {
+ pud_t old_pud = *pud;
+
+ stage2_pud_clear(pud);
+ kvm_tlb_flush_vmid_ipa(kvm, addr);
+ kvm_flush_dcache_pud(old_pud);
+ put_page(virt_to_page(pud));
+ } else {
+ unmap_stage2_pmds(kvm, pud, addr, next);
+ }
+ }
+ } while (pud++, addr = next, addr != end);
+
+ if (stage2_pud_table_empty(start_pud))
+ clear_stage2_pgd_entry(kvm, pgd, start_addr);
+}
+
+/**
+ * unmap_stage2_range -- Clear stage2 page table entries to unmap a range
+ * @kvm: The VM pointer
+ * @start: The intermediate physical base address of the range to unmap
+ * @size: The size of the area to unmap
+ *
+ * Clear a range of stage-2 mappings, lowering the various ref-counts. Must
+ * be called while holding mmu_lock (unless for freeing the stage2 pgd before
+ * destroying the VM), otherwise another faulting VCPU may come in and mess
+ * with things behind our backs.
+ */
+static void unmap_stage2_range(struct kvm *kvm, phys_addr_t start, u64 size)
+{
+ pgd_t *pgd;
+ phys_addr_t addr = start, end = start + size;
+ phys_addr_t next;
+
+ pgd = kvm->arch.pgd + stage2_pgd_index(addr);
+ do {
+ next = stage2_pgd_addr_end(addr, end);
+ if (!stage2_pgd_none(*pgd))
+ unmap_stage2_puds(kvm, pgd, addr, next);
+ } while (pgd++, addr = next, addr != end);
+}
+
+static void stage2_flush_ptes(struct kvm *kvm, pmd_t *pmd,
+ phys_addr_t addr, phys_addr_t end)
+{
+ pte_t *pte;
+
+ pte = pte_offset_kernel(pmd, addr);
+ do {
+ if (!pte_none(*pte) && !kvm_is_device_pfn(pte_pfn(*pte)))
+ kvm_flush_dcache_pte(*pte);
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+}
+
+static void stage2_flush_pmds(struct kvm *kvm, pud_t *pud,
+ phys_addr_t addr, phys_addr_t end)
+{
+ pmd_t *pmd;
+ phys_addr_t next;
+
+ pmd = stage2_pmd_offset(pud, addr);
+ do {
+ next = stage2_pmd_addr_end(addr, end);
+ if (!pmd_none(*pmd)) {
+ if (pmd_thp_or_huge(*pmd))
+ kvm_flush_dcache_pmd(*pmd);
+ else
+ stage2_flush_ptes(kvm, pmd, addr, next);
+ }
+ } while (pmd++, addr = next, addr != end);
+}
+
+static void stage2_flush_puds(struct kvm *kvm, pgd_t *pgd,
+ phys_addr_t addr, phys_addr_t end)
+{
+ pud_t *pud;
+ phys_addr_t next;
+
+ pud = stage2_pud_offset(pgd, addr);
+ do {
+ next = stage2_pud_addr_end(addr, end);
+ if (!stage2_pud_none(*pud)) {
+ if (stage2_pud_huge(*pud))
+ kvm_flush_dcache_pud(*pud);
+ else
+ stage2_flush_pmds(kvm, pud, addr, next);
+ }
+ } while (pud++, addr = next, addr != end);
+}
+
+static void stage2_flush_memslot(struct kvm *kvm,
+ struct kvm_memory_slot *memslot)
+{
+ phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
+ phys_addr_t end = addr + PAGE_SIZE * memslot->npages;
+ phys_addr_t next;
+ pgd_t *pgd;
+
+ pgd = kvm->arch.pgd + stage2_pgd_index(addr);
+ do {
+ next = stage2_pgd_addr_end(addr, end);
+ stage2_flush_puds(kvm, pgd, addr, next);
+ } while (pgd++, addr = next, addr != end);
+}
+
+/**
+ * stage2_flush_vm - Invalidate cache for pages mapped in stage 2
+ * @kvm: The struct kvm pointer
+ *
+ * Go through the stage 2 page tables and invalidate any cache lines
+ * backing memory already mapped to the VM.
+ */
+static void stage2_flush_vm(struct kvm *kvm)
+{
+ struct kvm_memslots *slots;
+ struct kvm_memory_slot *memslot;
+ int idx;
+
+ idx = srcu_read_lock(&kvm->srcu);
+ spin_lock(&kvm->mmu_lock);
+
+ slots = kvm_memslots(kvm);
+ kvm_for_each_memslot(memslot, slots)
+ stage2_flush_memslot(kvm, memslot);
+
+ spin_unlock(&kvm->mmu_lock);
+ srcu_read_unlock(&kvm->srcu, idx);
+}
+
+static void clear_hyp_pgd_entry(pgd_t *pgd)
+{
+ pud_t *pud_table __maybe_unused = pud_offset(pgd, 0UL);
+ pgd_clear(pgd);
+ pud_free(NULL, pud_table);
+ put_page(virt_to_page(pgd));
+}
+
+static void clear_hyp_pud_entry(pud_t *pud)
+{
+ pmd_t *pmd_table __maybe_unused = pmd_offset(pud, 0);
+ VM_BUG_ON(pud_huge(*pud));
+ pud_clear(pud);
+ pmd_free(NULL, pmd_table);
+ put_page(virt_to_page(pud));
+}
+
+static void clear_hyp_pmd_entry(pmd_t *pmd)
+{
+ pte_t *pte_table = pte_offset_kernel(pmd, 0);
+ VM_BUG_ON(pmd_thp_or_huge(*pmd));
+ pmd_clear(pmd);
+ pte_free_kernel(NULL, pte_table);
+ put_page(virt_to_page(pmd));
+}
+
+static void unmap_hyp_ptes(pmd_t *pmd, phys_addr_t addr, phys_addr_t end)
+{
+ pte_t *pte, *start_pte;
+
+ start_pte = pte = pte_offset_kernel(pmd, addr);
+ do {
+ if (!pte_none(*pte)) {
+ kvm_set_pte(pte, __pte(0));
+ put_page(virt_to_page(pte));
+ }
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+
+ if (hyp_pte_table_empty(start_pte))
+ clear_hyp_pmd_entry(pmd);
+}
+
+static void unmap_hyp_pmds(pud_t *pud, phys_addr_t addr, phys_addr_t end)
+{
+ phys_addr_t next;
+ pmd_t *pmd, *start_pmd;
+
+ start_pmd = pmd = pmd_offset(pud, addr);
+ do {
+ next = pmd_addr_end(addr, end);
+ /* Hyp doesn't use huge pmds */
+ if (!pmd_none(*pmd))
+ unmap_hyp_ptes(pmd, addr, next);
+ } while (pmd++, addr = next, addr != end);
+
+ if (hyp_pmd_table_empty(start_pmd))
+ clear_hyp_pud_entry(pud);
+}
+
+static void unmap_hyp_puds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end)
+{
+ phys_addr_t next;
+ pud_t *pud, *start_pud;
+
+ start_pud = pud = pud_offset(pgd, addr);
+ do {
+ next = pud_addr_end(addr, end);
+ /* Hyp doesn't use huge puds */
+ if (!pud_none(*pud))
+ unmap_hyp_pmds(pud, addr, next);
+ } while (pud++, addr = next, addr != end);
+
+ if (hyp_pud_table_empty(start_pud))
+ clear_hyp_pgd_entry(pgd);
+}
+
+static void unmap_hyp_range(pgd_t *pgdp, phys_addr_t start, u64 size)
+{
+ pgd_t *pgd;
+ phys_addr_t addr = start, end = start + size;
+ phys_addr_t next;
+
+ /*
+ * We don't unmap anything from HYP, except at the hyp tear down.
+ * Hence, we don't have to invalidate the TLBs here.
+ */
+ pgd = pgdp + pgd_index(addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ if (!pgd_none(*pgd))
+ unmap_hyp_puds(pgd, addr, next);
+ } while (pgd++, addr = next, addr != end);
+}
+
+/**
+ * free_hyp_pgds - free Hyp-mode page tables
+ *
+ * Assumes hyp_pgd is a page table used strictly in Hyp-mode and
+ * therefore contains either mappings in the kernel memory area (above
+ * PAGE_OFFSET), or device mappings in the vmalloc range (from
+ * VMALLOC_START to VMALLOC_END).
+ *
+ * boot_hyp_pgd should only map two pages for the init code.
+ */
+void free_hyp_pgds(void)
+{
+ unsigned long addr;
+
+ mutex_lock(&kvm_hyp_pgd_mutex);
+
+ if (boot_hyp_pgd) {
+ unmap_hyp_range(boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE);
+ free_pages((unsigned long)boot_hyp_pgd, hyp_pgd_order);
+ boot_hyp_pgd = NULL;
+ }
+
+ if (hyp_pgd) {
+ unmap_hyp_range(hyp_pgd, hyp_idmap_start, PAGE_SIZE);
+ for (addr = PAGE_OFFSET; virt_addr_valid(addr); addr += PGDIR_SIZE)
+ unmap_hyp_range(hyp_pgd, kern_hyp_va(addr), PGDIR_SIZE);
+ for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE)
+ unmap_hyp_range(hyp_pgd, kern_hyp_va(addr), PGDIR_SIZE);
+
+ free_pages((unsigned long)hyp_pgd, hyp_pgd_order);
+ hyp_pgd = NULL;
+ }
+ if (merged_hyp_pgd) {
+ clear_page(merged_hyp_pgd);
+ free_page((unsigned long)merged_hyp_pgd);
+ merged_hyp_pgd = NULL;
+ }
+
+ mutex_unlock(&kvm_hyp_pgd_mutex);
+}
+
+static void create_hyp_pte_mappings(pmd_t *pmd, unsigned long start,
+ unsigned long end, unsigned long pfn,
+ pgprot_t prot)
+{
+ pte_t *pte;
+ unsigned long addr;
+
+ addr = start;
+ do {
+ pte = pte_offset_kernel(pmd, addr);
+ kvm_set_pte(pte, pfn_pte(pfn, prot));
+ get_page(virt_to_page(pte));
+ kvm_flush_dcache_to_poc(pte, sizeof(*pte));
+ pfn++;
+ } while (addr += PAGE_SIZE, addr != end);
+}
+
+static int create_hyp_pmd_mappings(pud_t *pud, unsigned long start,
+ unsigned long end, unsigned long pfn,
+ pgprot_t prot)
+{
+ pmd_t *pmd;
+ pte_t *pte;
+ unsigned long addr, next;
+
+ addr = start;
+ do {
+ pmd = pmd_offset(pud, addr);
+
+ BUG_ON(pmd_sect(*pmd));
+
+ if (pmd_none(*pmd)) {
+ pte = pte_alloc_one_kernel(NULL, addr);
+ if (!pte) {
+ kvm_err("Cannot allocate Hyp pte\n");
+ return -ENOMEM;
+ }
+ pmd_populate_kernel(NULL, pmd, pte);
+ get_page(virt_to_page(pmd));
+ kvm_flush_dcache_to_poc(pmd, sizeof(*pmd));
+ }
+
+ next = pmd_addr_end(addr, end);
+
+ create_hyp_pte_mappings(pmd, addr, next, pfn, prot);
+ pfn += (next - addr) >> PAGE_SHIFT;
+ } while (addr = next, addr != end);
+
+ return 0;
+}
+
+static int create_hyp_pud_mappings(pgd_t *pgd, unsigned long start,
+ unsigned long end, unsigned long pfn,
+ pgprot_t prot)
+{
+ pud_t *pud;
+ pmd_t *pmd;
+ unsigned long addr, next;
+ int ret;
+
+ addr = start;
+ do {
+ pud = pud_offset(pgd, addr);
+
+ if (pud_none_or_clear_bad(pud)) {
+ pmd = pmd_alloc_one(NULL, addr);
+ if (!pmd) {
+ kvm_err("Cannot allocate Hyp pmd\n");
+ return -ENOMEM;
+ }
+ pud_populate(NULL, pud, pmd);
+ get_page(virt_to_page(pud));
+ kvm_flush_dcache_to_poc(pud, sizeof(*pud));
+ }
+
+ next = pud_addr_end(addr, end);
+ ret = create_hyp_pmd_mappings(pud, addr, next, pfn, prot);
+ if (ret)
+ return ret;
+ pfn += (next - addr) >> PAGE_SHIFT;
+ } while (addr = next, addr != end);
+
+ return 0;
+}
+
+static int __create_hyp_mappings(pgd_t *pgdp,
+ unsigned long start, unsigned long end,
+ unsigned long pfn, pgprot_t prot)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ unsigned long addr, next;
+ int err = 0;
+
+ mutex_lock(&kvm_hyp_pgd_mutex);
+ addr = start & PAGE_MASK;
+ end = PAGE_ALIGN(end);
+ do {
+ pgd = pgdp + pgd_index(addr);
+
+ if (pgd_none(*pgd)) {
+ pud = pud_alloc_one(NULL, addr);
+ if (!pud) {
+ kvm_err("Cannot allocate Hyp pud\n");
+ err = -ENOMEM;
+ goto out;
+ }
+ pgd_populate(NULL, pgd, pud);
+ get_page(virt_to_page(pgd));
+ kvm_flush_dcache_to_poc(pgd, sizeof(*pgd));
+ }
+
+ next = pgd_addr_end(addr, end);
+ err = create_hyp_pud_mappings(pgd, addr, next, pfn, prot);
+ if (err)
+ goto out;
+ pfn += (next - addr) >> PAGE_SHIFT;
+ } while (addr = next, addr != end);
+out:
+ mutex_unlock(&kvm_hyp_pgd_mutex);
+ return err;
+}
+
+static phys_addr_t kvm_kaddr_to_phys(void *kaddr)
+{
+ if (!is_vmalloc_addr(kaddr)) {
+ BUG_ON(!virt_addr_valid(kaddr));
+ return __pa(kaddr);
+ } else {
+ return page_to_phys(vmalloc_to_page(kaddr)) +
+ offset_in_page(kaddr);
+ }
+}
+
+/**
+ * create_hyp_mappings - duplicate a kernel virtual address range in Hyp mode
+ * @from: The virtual kernel start address of the range
+ * @to: The virtual kernel end address of the range (exclusive)
+ * @prot: The protection to be applied to this range
+ *
+ * The same virtual address as the kernel virtual address is also used
+ * in Hyp-mode mapping (modulo HYP_PAGE_OFFSET) to the same underlying
+ * physical pages.
+ */
+int create_hyp_mappings(void *from, void *to, pgprot_t prot)
+{
+ phys_addr_t phys_addr;
+ unsigned long virt_addr;
+ unsigned long start = kern_hyp_va((unsigned long)from);
+ unsigned long end = kern_hyp_va((unsigned long)to);
+
+ if (is_kernel_in_hyp_mode())
+ return 0;
+
+ start = start & PAGE_MASK;
+ end = PAGE_ALIGN(end);
+
+ for (virt_addr = start; virt_addr < end; virt_addr += PAGE_SIZE) {
+ int err;
+
+ phys_addr = kvm_kaddr_to_phys(from + virt_addr - start);
+ err = __create_hyp_mappings(hyp_pgd, virt_addr,
+ virt_addr + PAGE_SIZE,
+ __phys_to_pfn(phys_addr),
+ prot);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+/**
+ * create_hyp_io_mappings - duplicate a kernel IO mapping into Hyp mode
+ * @from: The kernel start VA of the range
+ * @to: The kernel end VA of the range (exclusive)
+ * @phys_addr: The physical start address which gets mapped
+ *
+ * The resulting HYP VA is the same as the kernel VA, modulo
+ * HYP_PAGE_OFFSET.
+ */
+int create_hyp_io_mappings(void *from, void *to, phys_addr_t phys_addr)
+{
+ unsigned long start = kern_hyp_va((unsigned long)from);
+ unsigned long end = kern_hyp_va((unsigned long)to);
+
+ if (is_kernel_in_hyp_mode())
+ return 0;
+
+ /* Check for a valid kernel IO mapping */
+ if (!is_vmalloc_addr(from) || !is_vmalloc_addr(to - 1))
+ return -EINVAL;
+
+ return __create_hyp_mappings(hyp_pgd, start, end,
+ __phys_to_pfn(phys_addr), PAGE_HYP_DEVICE);
+}
+
+/**
+ * kvm_alloc_stage2_pgd - allocate level-1 table for stage-2 translation.
+ * @kvm: The KVM struct pointer for the VM.
+ *
+ * Allocates only the stage-2 HW PGD level table(s) (can support either full
+ * 40-bit input addresses or limited to 32-bit input addresses). Clears the
+ * allocated pages.
+ *
+ * Note we don't need locking here as this is only called when the VM is
+ * created, which can only be done once.
+ */
+int kvm_alloc_stage2_pgd(struct kvm *kvm)
+{
+ pgd_t *pgd;
+
+ if (kvm->arch.pgd != NULL) {
+ kvm_err("kvm_arch already initialized?\n");
+ return -EINVAL;
+ }
+
+ /* Allocate the HW PGD, making sure that each page gets its own refcount */
+ pgd = alloc_pages_exact(S2_PGD_SIZE, GFP_KERNEL | __GFP_ZERO);
+ if (!pgd)
+ return -ENOMEM;
+
+ kvm->arch.pgd = pgd;
+ return 0;
+}
+
+static void stage2_unmap_memslot(struct kvm *kvm,
+ struct kvm_memory_slot *memslot)
+{
+ hva_t hva = memslot->userspace_addr;
+ phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
+ phys_addr_t size = PAGE_SIZE * memslot->npages;
+ hva_t reg_end = hva + size;
+
+ /*
+ * A memory region could potentially cover multiple VMAs, and any holes
+ * between them, so iterate over all of them to find out if we should
+ * unmap any of them.
+ *
+ * +--------------------------------------------+
+ * +---------------+----------------+ +----------------+
+ * | : VMA 1 | VMA 2 | | VMA 3 : |
+ * +---------------+----------------+ +----------------+
+ * | memory region |
+ * +--------------------------------------------+
+ */
+ do {
+ struct vm_area_struct *vma = find_vma(current->mm, hva);
+ hva_t vm_start, vm_end;
+
+ if (!vma || vma->vm_start >= reg_end)
+ break;
+
+ /*
+ * Take the intersection of this VMA with the memory region
+ */
+ vm_start = max(hva, vma->vm_start);
+ vm_end = min(reg_end, vma->vm_end);
+
+ if (!(vma->vm_flags & VM_PFNMAP)) {
+ gpa_t gpa = addr + (vm_start - memslot->userspace_addr);
+ unmap_stage2_range(kvm, gpa, vm_end - vm_start);
+ }
+ hva = vm_end;
+ } while (hva < reg_end);
+}
+
+/**
+ * stage2_unmap_vm - Unmap Stage-2 RAM mappings
+ * @kvm: The struct kvm pointer
+ *
+ * Go through the memregions and unmap any reguler RAM
+ * backing memory already mapped to the VM.
+ */
+void stage2_unmap_vm(struct kvm *kvm)
+{
+ struct kvm_memslots *slots;
+ struct kvm_memory_slot *memslot;
+ int idx;
+
+ idx = srcu_read_lock(&kvm->srcu);
+ spin_lock(&kvm->mmu_lock);
+
+ slots = kvm_memslots(kvm);
+ kvm_for_each_memslot(memslot, slots)
+ stage2_unmap_memslot(kvm, memslot);
+
+ spin_unlock(&kvm->mmu_lock);
+ srcu_read_unlock(&kvm->srcu, idx);
+}
+
+/**
+ * kvm_free_stage2_pgd - free all stage-2 tables
+ * @kvm: The KVM struct pointer for the VM.
+ *
+ * Walks the level-1 page table pointed to by kvm->arch.pgd and frees all
+ * underlying level-2 and level-3 tables before freeing the actual level-1 table
+ * and setting the struct pointer to NULL.
+ *
+ * Note we don't need locking here as this is only called when the VM is
+ * destroyed, which can only be done once.
+ */
+void kvm_free_stage2_pgd(struct kvm *kvm)
+{
+ if (kvm->arch.pgd == NULL)
+ return;
+
+ unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE);
+ /* Free the HW pgd, one page at a time */
+ free_pages_exact(kvm->arch.pgd, S2_PGD_SIZE);
+ kvm->arch.pgd = NULL;
+}
+
+static pud_t *stage2_get_pud(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
+ phys_addr_t addr)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+
+ pgd = kvm->arch.pgd + stage2_pgd_index(addr);
+ if (WARN_ON(stage2_pgd_none(*pgd))) {
+ if (!cache)
+ return NULL;
+ pud = mmu_memory_cache_alloc(cache);
+ stage2_pgd_populate(pgd, pud);
+ get_page(virt_to_page(pgd));
+ }
+
+ return stage2_pud_offset(pgd, addr);
+}
+
+static pmd_t *stage2_get_pmd(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
+ phys_addr_t addr)
+{
+ pud_t *pud;
+ pmd_t *pmd;
+
+ pud = stage2_get_pud(kvm, cache, addr);
+ if (stage2_pud_none(*pud)) {
+ if (!cache)
+ return NULL;
+ pmd = mmu_memory_cache_alloc(cache);
+ stage2_pud_populate(pud, pmd);
+ get_page(virt_to_page(pud));
+ }
+
+ return stage2_pmd_offset(pud, addr);
+}
+
+static int stage2_set_pmd_huge(struct kvm *kvm, struct kvm_mmu_memory_cache
+ *cache, phys_addr_t addr, const pmd_t *new_pmd)
+{
+ pmd_t *pmd, old_pmd;
+
+ pmd = stage2_get_pmd(kvm, cache, addr);
+ VM_BUG_ON(!pmd);
+
+ /*
+ * Mapping in huge pages should only happen through a fault. If a
+ * page is merged into a transparent huge page, the individual
+ * subpages of that huge page should be unmapped through MMU
+ * notifiers before we get here.
+ *
+ * Merging of CompoundPages is not supported; they should become
+ * splitting first, unmapped, merged, and mapped back in on-demand.
+ */
+ VM_BUG_ON(pmd_present(*pmd) && pmd_pfn(*pmd) != pmd_pfn(*new_pmd));
+
+ old_pmd = *pmd;
+ if (pmd_present(old_pmd)) {
+ pmd_clear(pmd);
+ kvm_tlb_flush_vmid_ipa(kvm, addr);
+ } else {
+ get_page(virt_to_page(pmd));
+ }
+
+ kvm_set_pmd(pmd, *new_pmd);
+ return 0;
+}
+
+static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
+ phys_addr_t addr, const pte_t *new_pte,
+ unsigned long flags)
+{
+ pmd_t *pmd;
+ pte_t *pte, old_pte;
+ bool iomap = flags & KVM_S2PTE_FLAG_IS_IOMAP;
+ bool logging_active = flags & KVM_S2_FLAG_LOGGING_ACTIVE;
+
+ VM_BUG_ON(logging_active && !cache);
+
+ /* Create stage-2 page table mapping - Levels 0 and 1 */
+ pmd = stage2_get_pmd(kvm, cache, addr);
+ if (!pmd) {
+ /*
+ * Ignore calls from kvm_set_spte_hva for unallocated
+ * address ranges.
+ */
+ return 0;
+ }
+
+ /*
+ * While dirty page logging - dissolve huge PMD, then continue on to
+ * allocate page.
+ */
+ if (logging_active)
+ stage2_dissolve_pmd(kvm, addr, pmd);
+
+ /* Create stage-2 page mappings - Level 2 */
+ if (pmd_none(*pmd)) {
+ if (!cache)
+ return 0; /* ignore calls from kvm_set_spte_hva */
+ pte = mmu_memory_cache_alloc(cache);
+ pmd_populate_kernel(NULL, pmd, pte);
+ get_page(virt_to_page(pmd));
+ }
+
+ pte = pte_offset_kernel(pmd, addr);
+
+ if (iomap && pte_present(*pte))
+ return -EFAULT;
+
+ /* Create 2nd stage page table mapping - Level 3 */
+ old_pte = *pte;
+ if (pte_present(old_pte)) {
+ kvm_set_pte(pte, __pte(0));
+ kvm_tlb_flush_vmid_ipa(kvm, addr);
+ } else {
+ get_page(virt_to_page(pte));
+ }
+
+ kvm_set_pte(pte, *new_pte);
+ return 0;
+}
+
+#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
+static int stage2_ptep_test_and_clear_young(pte_t *pte)
+{
+ if (pte_young(*pte)) {
+ *pte = pte_mkold(*pte);
+ return 1;
+ }
+ return 0;
+}
+#else
+static int stage2_ptep_test_and_clear_young(pte_t *pte)
+{
+ return __ptep_test_and_clear_young(pte);
+}
+#endif
+
+static int stage2_pmdp_test_and_clear_young(pmd_t *pmd)
+{
+ return stage2_ptep_test_and_clear_young((pte_t *)pmd);
+}
+
+/**
+ * kvm_phys_addr_ioremap - map a device range to guest IPA
+ *
+ * @kvm: The KVM pointer
+ * @guest_ipa: The IPA at which to insert the mapping
+ * @pa: The physical address of the device
+ * @size: The size of the mapping
+ */
+int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
+ phys_addr_t pa, unsigned long size, bool writable)
+{
+ phys_addr_t addr, end;
+ int ret = 0;
+ unsigned long pfn;
+ struct kvm_mmu_memory_cache cache = { 0, };
+
+ end = (guest_ipa + size + PAGE_SIZE - 1) & PAGE_MASK;
+ pfn = __phys_to_pfn(pa);
+
+ for (addr = guest_ipa; addr < end; addr += PAGE_SIZE) {
+ pte_t pte = pfn_pte(pfn, PAGE_S2_DEVICE);
+
+ if (writable)
+ pte = kvm_s2pte_mkwrite(pte);
+
+ ret = mmu_topup_memory_cache(&cache, KVM_MMU_CACHE_MIN_PAGES,
+ KVM_NR_MEM_OBJS);
+ if (ret)
+ goto out;
+ spin_lock(&kvm->mmu_lock);
+ ret = stage2_set_pte(kvm, &cache, addr, &pte,
+ KVM_S2PTE_FLAG_IS_IOMAP);
+ spin_unlock(&kvm->mmu_lock);
+ if (ret)
+ goto out;
+
+ pfn++;
+ }
+
+out:
+ mmu_free_memory_cache(&cache);
+ return ret;
+}
+
+static bool transparent_hugepage_adjust(kvm_pfn_t *pfnp, phys_addr_t *ipap)
+{
+ kvm_pfn_t pfn = *pfnp;
+ gfn_t gfn = *ipap >> PAGE_SHIFT;
+
+ if (PageTransCompoundMap(pfn_to_page(pfn))) {
+ unsigned long mask;
+ /*
+ * The address we faulted on is backed by a transparent huge
+ * page. However, because we map the compound huge page and
+ * not the individual tail page, we need to transfer the
+ * refcount to the head page. We have to be careful that the
+ * THP doesn't start to split while we are adjusting the
+ * refcounts.
+ *
+ * We are sure this doesn't happen, because mmu_notifier_retry
+ * was successful and we are holding the mmu_lock, so if this
+ * THP is trying to split, it will be blocked in the mmu
+ * notifier before touching any of the pages, specifically
+ * before being able to call __split_huge_page_refcount().
+ *
+ * We can therefore safely transfer the refcount from PG_tail
+ * to PG_head and switch the pfn from a tail page to the head
+ * page accordingly.
+ */
+ mask = PTRS_PER_PMD - 1;
+ VM_BUG_ON((gfn & mask) != (pfn & mask));
+ if (pfn & mask) {
+ *ipap &= PMD_MASK;
+ kvm_release_pfn_clean(pfn);
+ pfn &= ~mask;
+ kvm_get_pfn(pfn);
+ *pfnp = pfn;
+ }
+
+ return true;
+ }
+
+ return false;
+}
+
+static bool kvm_is_write_fault(struct kvm_vcpu *vcpu)
+{
+ if (kvm_vcpu_trap_is_iabt(vcpu))
+ return false;
+
+ return kvm_vcpu_dabt_iswrite(vcpu);
+}
+
+/**
+ * stage2_wp_ptes - write protect PMD range
+ * @pmd: pointer to pmd entry
+ * @addr: range start address
+ * @end: range end address
+ */
+static void stage2_wp_ptes(pmd_t *pmd, phys_addr_t addr, phys_addr_t end)
+{
+ pte_t *pte;
+
+ pte = pte_offset_kernel(pmd, addr);
+ do {
+ if (!pte_none(*pte)) {
+ if (!kvm_s2pte_readonly(pte))
+ kvm_set_s2pte_readonly(pte);
+ }
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+}
+
+/**
+ * stage2_wp_pmds - write protect PUD range
+ * @pud: pointer to pud entry
+ * @addr: range start address
+ * @end: range end address
+ */
+static void stage2_wp_pmds(pud_t *pud, phys_addr_t addr, phys_addr_t end)
+{
+ pmd_t *pmd;
+ phys_addr_t next;
+
+ pmd = stage2_pmd_offset(pud, addr);
+
+ do {
+ next = stage2_pmd_addr_end(addr, end);
+ if (!pmd_none(*pmd)) {
+ if (pmd_thp_or_huge(*pmd)) {
+ if (!kvm_s2pmd_readonly(pmd))
+ kvm_set_s2pmd_readonly(pmd);
+ } else {
+ stage2_wp_ptes(pmd, addr, next);
+ }
+ }
+ } while (pmd++, addr = next, addr != end);
+}
+
+/**
+ * stage2_wp_puds - write protect PGD range
+ * @pgd: pointer to pgd entry
+ * @addr: range start address
+ * @end: range end address
+ *
+ * Process PUD entries, for a huge PUD we cause a panic.
+ */
+static void stage2_wp_puds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end)
+{
+ pud_t *pud;
+ phys_addr_t next;
+
+ pud = stage2_pud_offset(pgd, addr);
+ do {
+ next = stage2_pud_addr_end(addr, end);
+ if (!stage2_pud_none(*pud)) {
+ /* TODO:PUD not supported, revisit later if supported */
+ BUG_ON(stage2_pud_huge(*pud));
+ stage2_wp_pmds(pud, addr, next);
+ }
+ } while (pud++, addr = next, addr != end);
+}
+
+/**
+ * stage2_wp_range() - write protect stage2 memory region range
+ * @kvm: The KVM pointer
+ * @addr: Start address of range
+ * @end: End address of range
+ */
+static void stage2_wp_range(struct kvm *kvm, phys_addr_t addr, phys_addr_t end)
+{
+ pgd_t *pgd;
+ phys_addr_t next;
+
+ pgd = kvm->arch.pgd + stage2_pgd_index(addr);
+ do {
+ /*
+ * Release kvm_mmu_lock periodically if the memory region is
+ * large. Otherwise, we may see kernel panics with
+ * CONFIG_DETECT_HUNG_TASK, CONFIG_LOCKUP_DETECTOR,
+ * CONFIG_LOCKDEP. Additionally, holding the lock too long
+ * will also starve other vCPUs.
+ */
+ if (need_resched() || spin_needbreak(&kvm->mmu_lock))
+ cond_resched_lock(&kvm->mmu_lock);
+
+ next = stage2_pgd_addr_end(addr, end);
+ if (stage2_pgd_present(*pgd))
+ stage2_wp_puds(pgd, addr, next);
+ } while (pgd++, addr = next, addr != end);
+}
+
+/**
+ * kvm_mmu_wp_memory_region() - write protect stage 2 entries for memory slot
+ * @kvm: The KVM pointer
+ * @slot: The memory slot to write protect
+ *
+ * Called to start logging dirty pages after memory region
+ * KVM_MEM_LOG_DIRTY_PAGES operation is called. After this function returns
+ * all present PMD and PTEs are write protected in the memory region.
+ * Afterwards read of dirty page log can be called.
+ *
+ * Acquires kvm_mmu_lock. Called with kvm->slots_lock mutex acquired,
+ * serializing operations for VM memory regions.
+ */
+void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot)
+{
+ struct kvm_memslots *slots = kvm_memslots(kvm);
+ struct kvm_memory_slot *memslot = id_to_memslot(slots, slot);
+ phys_addr_t start = memslot->base_gfn << PAGE_SHIFT;
+ phys_addr_t end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT;
+
+ spin_lock(&kvm->mmu_lock);
+ stage2_wp_range(kvm, start, end);
+ spin_unlock(&kvm->mmu_lock);
+ kvm_flush_remote_tlbs(kvm);
+}
+
+/**
+ * kvm_mmu_write_protect_pt_masked() - write protect dirty pages
+ * @kvm: The KVM pointer
+ * @slot: The memory slot associated with mask
+ * @gfn_offset: The gfn offset in memory slot
+ * @mask: The mask of dirty pages at offset 'gfn_offset' in this memory
+ * slot to be write protected
+ *
+ * Walks bits set in mask write protects the associated pte's. Caller must
+ * acquire kvm_mmu_lock.
+ */
+static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm,
+ struct kvm_memory_slot *slot,
+ gfn_t gfn_offset, unsigned long mask)
+{
+ phys_addr_t base_gfn = slot->base_gfn + gfn_offset;
+ phys_addr_t start = (base_gfn + __ffs(mask)) << PAGE_SHIFT;
+ phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT;
+
+ stage2_wp_range(kvm, start, end);
+}
+
+/*
+ * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected
+ * dirty pages.
+ *
+ * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to
+ * enable dirty logging for them.
+ */
+void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
+ struct kvm_memory_slot *slot,
+ gfn_t gfn_offset, unsigned long mask)
+{
+ kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask);
+}
+
+static void coherent_cache_guest_page(struct kvm_vcpu *vcpu, kvm_pfn_t pfn,
+ unsigned long size)
+{
+ __coherent_cache_guest_page(vcpu, pfn, size);
+}
+
+static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
+ struct kvm_memory_slot *memslot, unsigned long hva,
+ unsigned long fault_status)
+{
+ int ret;
+ bool write_fault, writable, hugetlb = false, force_pte = false;
+ unsigned long mmu_seq;
+ gfn_t gfn = fault_ipa >> PAGE_SHIFT;
+ struct kvm *kvm = vcpu->kvm;
+ struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;
+ struct vm_area_struct *vma;
+ kvm_pfn_t pfn;
+ pgprot_t mem_type = PAGE_S2;
+ bool logging_active = memslot_is_logging(memslot);
+ unsigned long flags = 0;
+
+ write_fault = kvm_is_write_fault(vcpu);
+ if (fault_status == FSC_PERM && !write_fault) {
+ kvm_err("Unexpected L2 read permission error\n");
+ return -EFAULT;
+ }
+
+ /* Let's check if we will get back a huge page backed by hugetlbfs */
+ down_read(&current->mm->mmap_sem);
+ vma = find_vma_intersection(current->mm, hva, hva + 1);
+ if (unlikely(!vma)) {
+ kvm_err("Failed to find VMA for hva 0x%lx\n", hva);
+ up_read(&current->mm->mmap_sem);
+ return -EFAULT;
+ }
+
+ if (is_vm_hugetlb_page(vma) && !logging_active) {
+ hugetlb = true;
+ gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT;
+ } else {
+ /*
+ * Pages belonging to memslots that don't have the same
+ * alignment for userspace and IPA cannot be mapped using
+ * block descriptors even if the pages belong to a THP for
+ * the process, because the stage-2 block descriptor will
+ * cover more than a single THP and we loose atomicity for
+ * unmapping, updates, and splits of the THP or other pages
+ * in the stage-2 block range.
+ */
+ if ((memslot->userspace_addr & ~PMD_MASK) !=
+ ((memslot->base_gfn << PAGE_SHIFT) & ~PMD_MASK))
+ force_pte = true;
+ }
+ up_read(&current->mm->mmap_sem);
+
+ /* We need minimum second+third level pages */
+ ret = mmu_topup_memory_cache(memcache, KVM_MMU_CACHE_MIN_PAGES,
+ KVM_NR_MEM_OBJS);
+ if (ret)
+ return ret;
+
+ mmu_seq = vcpu->kvm->mmu_notifier_seq;
+ /*
+ * Ensure the read of mmu_notifier_seq happens before we call
+ * gfn_to_pfn_prot (which calls get_user_pages), so that we don't risk
+ * the page we just got a reference to gets unmapped before we have a
+ * chance to grab the mmu_lock, which ensure that if the page gets
+ * unmapped afterwards, the call to kvm_unmap_hva will take it away
+ * from us again properly. This smp_rmb() interacts with the smp_wmb()
+ * in kvm_mmu_notifier_invalidate_<page|range_end>.
+ */
+ smp_rmb();
+
+ pfn = gfn_to_pfn_prot(kvm, gfn, write_fault, &writable);
+ if (is_error_noslot_pfn(pfn))
+ return -EFAULT;
+
+ if (kvm_is_device_pfn(pfn)) {
+ mem_type = PAGE_S2_DEVICE;
+ flags |= KVM_S2PTE_FLAG_IS_IOMAP;
+ } else if (logging_active) {
+ /*
+ * Faults on pages in a memslot with logging enabled
+ * should not be mapped with huge pages (it introduces churn
+ * and performance degradation), so force a pte mapping.
+ */
+ force_pte = true;
+ flags |= KVM_S2_FLAG_LOGGING_ACTIVE;
+
+ /*
+ * Only actually map the page as writable if this was a write
+ * fault.
+ */
+ if (!write_fault)
+ writable = false;
+ }
+
+ spin_lock(&kvm->mmu_lock);
+ if (mmu_notifier_retry(kvm, mmu_seq))
+ goto out_unlock;
+
+ if (!hugetlb && !force_pte)
+ hugetlb = transparent_hugepage_adjust(&pfn, &fault_ipa);
+
+ if (hugetlb) {
+ pmd_t new_pmd = pfn_pmd(pfn, mem_type);
+ new_pmd = pmd_mkhuge(new_pmd);
+ if (writable) {
+ new_pmd = kvm_s2pmd_mkwrite(new_pmd);
+ kvm_set_pfn_dirty(pfn);
+ }
+ coherent_cache_guest_page(vcpu, pfn, PMD_SIZE);
+ ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd);
+ } else {
+ pte_t new_pte = pfn_pte(pfn, mem_type);
+
+ if (writable) {
+ new_pte = kvm_s2pte_mkwrite(new_pte);
+ kvm_set_pfn_dirty(pfn);
+ mark_page_dirty(kvm, gfn);
+ }
+ coherent_cache_guest_page(vcpu, pfn, PAGE_SIZE);
+ ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, flags);
+ }
+
+out_unlock:
+ spin_unlock(&kvm->mmu_lock);
+ kvm_set_pfn_accessed(pfn);
+ kvm_release_pfn_clean(pfn);
+ return ret;
+}
+
+/*
+ * Resolve the access fault by making the page young again.
+ * Note that because the faulting entry is guaranteed not to be
+ * cached in the TLB, we don't need to invalidate anything.
+ * Only the HW Access Flag updates are supported for Stage 2 (no DBM),
+ * so there is no need for atomic (pte|pmd)_mkyoung operations.
+ */
+static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
+{
+ pmd_t *pmd;
+ pte_t *pte;
+ kvm_pfn_t pfn;
+ bool pfn_valid = false;
+
+ trace_kvm_access_fault(fault_ipa);
+
+ spin_lock(&vcpu->kvm->mmu_lock);
+
+ pmd = stage2_get_pmd(vcpu->kvm, NULL, fault_ipa);
+ if (!pmd || pmd_none(*pmd)) /* Nothing there */
+ goto out;
+
+ if (pmd_thp_or_huge(*pmd)) { /* THP, HugeTLB */
+ *pmd = pmd_mkyoung(*pmd);
+ pfn = pmd_pfn(*pmd);
+ pfn_valid = true;
+ goto out;
+ }
+
+ pte = pte_offset_kernel(pmd, fault_ipa);
+ if (pte_none(*pte)) /* Nothing there either */
+ goto out;
+
+ *pte = pte_mkyoung(*pte); /* Just a page... */
+ pfn = pte_pfn(*pte);
+ pfn_valid = true;
+out:
+ spin_unlock(&vcpu->kvm->mmu_lock);
+ if (pfn_valid)
+ kvm_set_pfn_accessed(pfn);
+}
+
+/**
+ * kvm_handle_guest_abort - handles all 2nd stage aborts
+ * @vcpu: the VCPU pointer
+ * @run: the kvm_run structure
+ *
+ * Any abort that gets to the host is almost guaranteed to be caused by a
+ * missing second stage translation table entry, which can mean that either the
+ * guest simply needs more memory and we must allocate an appropriate page or it
+ * can mean that the guest tried to access I/O memory, which is emulated by user
+ * space. The distinction is based on the IPA causing the fault and whether this
+ * memory region has been registered as standard RAM by user space.
+ */
+int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+ unsigned long fault_status;
+ phys_addr_t fault_ipa;
+ struct kvm_memory_slot *memslot;
+ unsigned long hva;
+ bool is_iabt, write_fault, writable;
+ gfn_t gfn;
+ int ret, idx;
+
+ is_iabt = kvm_vcpu_trap_is_iabt(vcpu);
+ if (unlikely(!is_iabt && kvm_vcpu_dabt_isextabt(vcpu))) {
+ kvm_inject_vabt(vcpu);
+ return 1;
+ }
+
+ fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);
+
+ trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_hsr(vcpu),
+ kvm_vcpu_get_hfar(vcpu), fault_ipa);
+
+ /* Check the stage-2 fault is trans. fault or write fault */
+ fault_status = kvm_vcpu_trap_get_fault_type(vcpu);
+ if (fault_status != FSC_FAULT && fault_status != FSC_PERM &&
+ fault_status != FSC_ACCESS) {
+ kvm_err("Unsupported FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n",
+ kvm_vcpu_trap_get_class(vcpu),
+ (unsigned long)kvm_vcpu_trap_get_fault(vcpu),
+ (unsigned long)kvm_vcpu_get_hsr(vcpu));
+ return -EFAULT;
+ }
+
+ idx = srcu_read_lock(&vcpu->kvm->srcu);
+
+ gfn = fault_ipa >> PAGE_SHIFT;
+ memslot = gfn_to_memslot(vcpu->kvm, gfn);
+ hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable);
+ write_fault = kvm_is_write_fault(vcpu);
+ if (kvm_is_error_hva(hva) || (write_fault && !writable)) {
+ if (is_iabt) {
+ /* Prefetch Abort on I/O address */
+ kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu));
+ ret = 1;
+ goto out_unlock;
+ }
+
+ /*
+ * Check for a cache maintenance operation. Since we
+ * ended-up here, we know it is outside of any memory
+ * slot. But we can't find out if that is for a device,
+ * or if the guest is just being stupid. The only thing
+ * we know for sure is that this range cannot be cached.
+ *
+ * So let's assume that the guest is just being
+ * cautious, and skip the instruction.
+ */
+ if (kvm_vcpu_dabt_is_cm(vcpu)) {
+ kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
+ ret = 1;
+ goto out_unlock;
+ }
+
+ /*
+ * The IPA is reported as [MAX:12], so we need to
+ * complement it with the bottom 12 bits from the
+ * faulting VA. This is always 12 bits, irrespective
+ * of the page size.
+ */
+ fault_ipa |= kvm_vcpu_get_hfar(vcpu) & ((1 << 12) - 1);
+ ret = io_mem_abort(vcpu, run, fault_ipa);
+ goto out_unlock;
+ }
+
+ /* Userspace should not be able to register out-of-bounds IPAs */
+ VM_BUG_ON(fault_ipa >= KVM_PHYS_SIZE);
+
+ if (fault_status == FSC_ACCESS) {
+ handle_access_fault(vcpu, fault_ipa);
+ ret = 1;
+ goto out_unlock;
+ }
+
+ ret = user_mem_abort(vcpu, fault_ipa, memslot, hva, fault_status);
+ if (ret == 0)
+ ret = 1;
+out_unlock:
+ srcu_read_unlock(&vcpu->kvm->srcu, idx);
+ return ret;
+}
+
+static int handle_hva_to_gpa(struct kvm *kvm,
+ unsigned long start,
+ unsigned long end,
+ int (*handler)(struct kvm *kvm,
+ gpa_t gpa, u64 size,
+ void *data),
+ void *data)
+{
+ struct kvm_memslots *slots;
+ struct kvm_memory_slot *memslot;
+ int ret = 0;
+
+ slots = kvm_memslots(kvm);
+
+ /* we only care about the pages that the guest sees */
+ kvm_for_each_memslot(memslot, slots) {
+ unsigned long hva_start, hva_end;
+ gfn_t gpa;
+
+ hva_start = max(start, memslot->userspace_addr);
+ hva_end = min(end, memslot->userspace_addr +
+ (memslot->npages << PAGE_SHIFT));
+ if (hva_start >= hva_end)
+ continue;
+
+ gpa = hva_to_gfn_memslot(hva_start, memslot) << PAGE_SHIFT;
+ ret |= handler(kvm, gpa, (u64)(hva_end - hva_start), data);
+ }
+
+ return ret;
+}
+
+static int kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
+{
+ unmap_stage2_range(kvm, gpa, size);
+ return 0;
+}
+
+int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
+{
+ unsigned long end = hva + PAGE_SIZE;
+
+ if (!kvm->arch.pgd)
+ return 0;
+
+ trace_kvm_unmap_hva(hva);
+ handle_hva_to_gpa(kvm, hva, end, &kvm_unmap_hva_handler, NULL);
+ return 0;
+}
+
+int kvm_unmap_hva_range(struct kvm *kvm,
+ unsigned long start, unsigned long end)
+{
+ if (!kvm->arch.pgd)
+ return 0;
+
+ trace_kvm_unmap_hva_range(start, end);
+ handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, NULL);
+ return 0;
+}
+
+static int kvm_set_spte_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
+{
+ pte_t *pte = (pte_t *)data;
+
+ WARN_ON(size != PAGE_SIZE);
+ /*
+ * We can always call stage2_set_pte with KVM_S2PTE_FLAG_LOGGING_ACTIVE
+ * flag clear because MMU notifiers will have unmapped a huge PMD before
+ * calling ->change_pte() (which in turn calls kvm_set_spte_hva()) and
+ * therefore stage2_set_pte() never needs to clear out a huge PMD
+ * through this calling path.
+ */
+ stage2_set_pte(kvm, NULL, gpa, pte, 0);
+ return 0;
+}
+
+
+void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
+{
+ unsigned long end = hva + PAGE_SIZE;
+ pte_t stage2_pte;
+
+ if (!kvm->arch.pgd)
+ return;
+
+ trace_kvm_set_spte_hva(hva);
+ stage2_pte = pfn_pte(pte_pfn(pte), PAGE_S2);
+ handle_hva_to_gpa(kvm, hva, end, &kvm_set_spte_handler, &stage2_pte);
+}
+
+static int kvm_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
+{
+ pmd_t *pmd;
+ pte_t *pte;
+
+ WARN_ON(size != PAGE_SIZE && size != PMD_SIZE);
+ pmd = stage2_get_pmd(kvm, NULL, gpa);
+ if (!pmd || pmd_none(*pmd)) /* Nothing there */
+ return 0;
+
+ if (pmd_thp_or_huge(*pmd)) /* THP, HugeTLB */
+ return stage2_pmdp_test_and_clear_young(pmd);
+
+ pte = pte_offset_kernel(pmd, gpa);
+ if (pte_none(*pte))
+ return 0;
+
+ return stage2_ptep_test_and_clear_young(pte);
+}
+
+static int kvm_test_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
+{
+ pmd_t *pmd;
+ pte_t *pte;
+
+ WARN_ON(size != PAGE_SIZE && size != PMD_SIZE);
+ pmd = stage2_get_pmd(kvm, NULL, gpa);
+ if (!pmd || pmd_none(*pmd)) /* Nothing there */
+ return 0;
+
+ if (pmd_thp_or_huge(*pmd)) /* THP, HugeTLB */
+ return pmd_young(*pmd);
+
+ pte = pte_offset_kernel(pmd, gpa);
+ if (!pte_none(*pte)) /* Just a page... */
+ return pte_young(*pte);
+
+ return 0;
+}
+
+int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end)
+{
+ trace_kvm_age_hva(start, end);
+ return handle_hva_to_gpa(kvm, start, end, kvm_age_hva_handler, NULL);
+}
+
+int kvm_test_age_hva(struct kvm *kvm, unsigned long hva)
+{
+ trace_kvm_test_age_hva(hva);
+ return handle_hva_to_gpa(kvm, hva, hva, kvm_test_age_hva_handler, NULL);
+}
+
+void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu)
+{
+ mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
+}
+
+phys_addr_t kvm_mmu_get_httbr(void)
+{
+ if (__kvm_cpu_uses_extended_idmap())
+ return virt_to_phys(merged_hyp_pgd);
+ else
+ return virt_to_phys(hyp_pgd);
+}
+
+phys_addr_t kvm_get_idmap_vector(void)
+{
+ return hyp_idmap_vector;
+}
+
+static int kvm_map_idmap_text(pgd_t *pgd)
+{
+ int err;
+
+ /* Create the idmap in the boot page tables */
+ err = __create_hyp_mappings(pgd,
+ hyp_idmap_start, hyp_idmap_end,
+ __phys_to_pfn(hyp_idmap_start),
+ PAGE_HYP_EXEC);
+ if (err)
+ kvm_err("Failed to idmap %lx-%lx\n",
+ hyp_idmap_start, hyp_idmap_end);
+
+ return err;
+}
+
+int kvm_mmu_init(void)
+{
+ int err;
+
+ hyp_idmap_start = kvm_virt_to_phys(__hyp_idmap_text_start);
+ hyp_idmap_end = kvm_virt_to_phys(__hyp_idmap_text_end);
+ hyp_idmap_vector = kvm_virt_to_phys(__kvm_hyp_init);
+
+ /*
+ * We rely on the linker script to ensure at build time that the HYP
+ * init code does not cross a page boundary.
+ */
+ BUG_ON((hyp_idmap_start ^ (hyp_idmap_end - 1)) & PAGE_MASK);
+
+ kvm_info("IDMAP page: %lx\n", hyp_idmap_start);
+ kvm_info("HYP VA range: %lx:%lx\n",
+ kern_hyp_va(PAGE_OFFSET), kern_hyp_va(~0UL));
+
+ if (hyp_idmap_start >= kern_hyp_va(PAGE_OFFSET) &&
+ hyp_idmap_start < kern_hyp_va(~0UL) &&
+ hyp_idmap_start != (unsigned long)__hyp_idmap_text_start) {
+ /*
+ * The idmap page is intersecting with the VA space,
+ * it is not safe to continue further.
+ */
+ kvm_err("IDMAP intersecting with HYP VA, unable to continue\n");
+ err = -EINVAL;
+ goto out;
+ }
+
+ hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, hyp_pgd_order);
+ if (!hyp_pgd) {
+ kvm_err("Hyp mode PGD not allocated\n");
+ err = -ENOMEM;
+ goto out;
+ }
+
+ if (__kvm_cpu_uses_extended_idmap()) {
+ boot_hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
+ hyp_pgd_order);
+ if (!boot_hyp_pgd) {
+ kvm_err("Hyp boot PGD not allocated\n");
+ err = -ENOMEM;
+ goto out;
+ }
+
+ err = kvm_map_idmap_text(boot_hyp_pgd);
+ if (err)
+ goto out;
+
+ merged_hyp_pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
+ if (!merged_hyp_pgd) {
+ kvm_err("Failed to allocate extra HYP pgd\n");
+ goto out;
+ }
+ __kvm_extend_hypmap(boot_hyp_pgd, hyp_pgd, merged_hyp_pgd,
+ hyp_idmap_start);
+ } else {
+ err = kvm_map_idmap_text(hyp_pgd);
+ if (err)
+ goto out;
+ }
+
+ return 0;
+out:
+ free_hyp_pgds();
+ return err;
+}
+
+void kvm_arch_commit_memory_region(struct kvm *kvm,
+ const struct kvm_userspace_memory_region *mem,
+ const struct kvm_memory_slot *old,
+ const struct kvm_memory_slot *new,
+ enum kvm_mr_change change)
+{
+ /*
+ * At this point memslot has been committed and there is an
+ * allocated dirty_bitmap[], dirty pages will be be tracked while the
+ * memory slot is write protected.
+ */
+ if (change != KVM_MR_DELETE && mem->flags & KVM_MEM_LOG_DIRTY_PAGES)
+ kvm_mmu_wp_memory_region(kvm, mem->slot);
+}
+
+int kvm_arch_prepare_memory_region(struct kvm *kvm,
+ struct kvm_memory_slot *memslot,
+ const struct kvm_userspace_memory_region *mem,
+ enum kvm_mr_change change)
+{
+ hva_t hva = mem->userspace_addr;
+ hva_t reg_end = hva + mem->memory_size;
+ bool writable = !(mem->flags & KVM_MEM_READONLY);
+ int ret = 0;
+
+ if (change != KVM_MR_CREATE && change != KVM_MR_MOVE &&
+ change != KVM_MR_FLAGS_ONLY)
+ return 0;
+
+ /*
+ * Prevent userspace from creating a memory region outside of the IPA
+ * space addressable by the KVM guest IPA space.
+ */
+ if (memslot->base_gfn + memslot->npages >=
+ (KVM_PHYS_SIZE >> PAGE_SHIFT))
+ return -EFAULT;
+
+ /*
+ * A memory region could potentially cover multiple VMAs, and any holes
+ * between them, so iterate over all of them to find out if we can map
+ * any of them right now.
+ *
+ * +--------------------------------------------+
+ * +---------------+----------------+ +----------------+
+ * | : VMA 1 | VMA 2 | | VMA 3 : |
+ * +---------------+----------------+ +----------------+
+ * | memory region |
+ * +--------------------------------------------+
+ */
+ do {
+ struct vm_area_struct *vma = find_vma(current->mm, hva);
+ hva_t vm_start, vm_end;
+
+ if (!vma || vma->vm_start >= reg_end)
+ break;
+
+ /*
+ * Mapping a read-only VMA is only allowed if the
+ * memory region is configured as read-only.
+ */
+ if (writable && !(vma->vm_flags & VM_WRITE)) {
+ ret = -EPERM;
+ break;
+ }
+
+ /*
+ * Take the intersection of this VMA with the memory region
+ */
+ vm_start = max(hva, vma->vm_start);
+ vm_end = min(reg_end, vma->vm_end);
+
+ if (vma->vm_flags & VM_PFNMAP) {
+ gpa_t gpa = mem->guest_phys_addr +
+ (vm_start - mem->userspace_addr);
+ phys_addr_t pa;
+
+ pa = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT;
+ pa += vm_start - vma->vm_start;
+
+ /* IO region dirty page logging not allowed */
+ if (memslot->flags & KVM_MEM_LOG_DIRTY_PAGES)
+ return -EINVAL;
+
+ ret = kvm_phys_addr_ioremap(kvm, gpa, pa,
+ vm_end - vm_start,
+ writable);
+ if (ret)
+ break;
+ }
+ hva = vm_end;
+ } while (hva < reg_end);
+
+ if (change == KVM_MR_FLAGS_ONLY)
+ return ret;
+
+ spin_lock(&kvm->mmu_lock);
+ if (ret)
+ unmap_stage2_range(kvm, mem->guest_phys_addr, mem->memory_size);
+ else
+ stage2_flush_memslot(kvm, memslot);
+ spin_unlock(&kvm->mmu_lock);
+ return ret;
+}
+
+void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
+ struct kvm_memory_slot *dont)
+{
+}
+
+int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
+ unsigned long npages)
+{
+ return 0;
+}
+
+void kvm_arch_memslots_updated(struct kvm *kvm, struct kvm_memslots *slots)
+{
+}
+
+void kvm_arch_flush_shadow_all(struct kvm *kvm)
+{
+ kvm_free_stage2_pgd(kvm);
+}
+
+void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
+ struct kvm_memory_slot *slot)
+{
+ gpa_t gpa = slot->base_gfn << PAGE_SHIFT;
+ phys_addr_t size = slot->npages << PAGE_SHIFT;
+
+ spin_lock(&kvm->mmu_lock);
+ unmap_stage2_range(kvm, gpa, size);
+ spin_unlock(&kvm->mmu_lock);
+}
+
+/*
+ * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized).
+ *
+ * Main problems:
+ * - S/W ops are local to a CPU (not broadcast)
+ * - We have line migration behind our back (speculation)
+ * - System caches don't support S/W at all (damn!)
+ *
+ * In the face of the above, the best we can do is to try and convert
+ * S/W ops to VA ops. Because the guest is not allowed to infer the
+ * S/W to PA mapping, it can only use S/W to nuke the whole cache,
+ * which is a rather good thing for us.
+ *
+ * Also, it is only used when turning caches on/off ("The expected
+ * usage of the cache maintenance instructions that operate by set/way
+ * is associated with the cache maintenance instructions associated
+ * with the powerdown and powerup of caches, if this is required by
+ * the implementation.").
+ *
+ * We use the following policy:
+ *
+ * - If we trap a S/W operation, we enable VM trapping to detect
+ * caches being turned on/off, and do a full clean.
+ *
+ * - We flush the caches on both caches being turned on and off.
+ *
+ * - Once the caches are enabled, we stop trapping VM ops.
+ */
+void kvm_set_way_flush(struct kvm_vcpu *vcpu)
+{
+ unsigned long hcr = vcpu_get_hcr(vcpu);
+
+ /*
+ * If this is the first time we do a S/W operation
+ * (i.e. HCR_TVM not set) flush the whole memory, and set the
+ * VM trapping.
+ *
+ * Otherwise, rely on the VM trapping to wait for the MMU +
+ * Caches to be turned off. At that point, we'll be able to
+ * clean the caches again.
+ */
+ if (!(hcr & HCR_TVM)) {
+ trace_kvm_set_way_flush(*vcpu_pc(vcpu),
+ vcpu_has_cache_enabled(vcpu));
+ stage2_flush_vm(vcpu->kvm);
+ vcpu_set_hcr(vcpu, hcr | HCR_TVM);
+ }
+}
+
+void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled)
+{
+ bool now_enabled = vcpu_has_cache_enabled(vcpu);
+
+ /*
+ * If switching the MMU+caches on, need to invalidate the caches.
+ * If switching it off, need to clean the caches.
+ * Clean + invalidate does the trick always.
+ */
+ if (now_enabled != was_enabled)
+ stage2_flush_vm(vcpu->kvm);
+
+ /* Caches are now on, stop trapping VM ops (until a S/W op) */
+ if (now_enabled)
+ vcpu_set_hcr(vcpu, vcpu_get_hcr(vcpu) & ~HCR_TVM);
+
+ trace_kvm_toggle_cache(*vcpu_pc(vcpu), was_enabled, now_enabled);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-14 19:34:27 +0000