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-rw-r--r--arch/riscv/kvm/mmu.c802
1 files changed, 802 insertions, 0 deletions
diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c
new file mode 100644
index 000000000..e47aeb6f0
--- /dev/null
+++ b/arch/riscv/kvm/mmu.c
@@ -0,0 +1,802 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ * Anup Patel <anup.patel@wdc.com>
+ */
+
+#include <linux/bitops.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/hugetlb.h>
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <linux/vmalloc.h>
+#include <linux/kvm_host.h>
+#include <linux/sched/signal.h>
+#include <asm/csr.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+
+#ifdef CONFIG_64BIT
+static unsigned long gstage_mode = (HGATP_MODE_SV39X4 << HGATP_MODE_SHIFT);
+static unsigned long gstage_pgd_levels = 3;
+#define gstage_index_bits 9
+#else
+static unsigned long gstage_mode = (HGATP_MODE_SV32X4 << HGATP_MODE_SHIFT);
+static unsigned long gstage_pgd_levels = 2;
+#define gstage_index_bits 10
+#endif
+
+#define gstage_pgd_xbits 2
+#define gstage_pgd_size (1UL << (HGATP_PAGE_SHIFT + gstage_pgd_xbits))
+#define gstage_gpa_bits (HGATP_PAGE_SHIFT + \
+ (gstage_pgd_levels * gstage_index_bits) + \
+ gstage_pgd_xbits)
+#define gstage_gpa_size ((gpa_t)(1ULL << gstage_gpa_bits))
+
+#define gstage_pte_leaf(__ptep) \
+ (pte_val(*(__ptep)) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC))
+
+static inline unsigned long gstage_pte_index(gpa_t addr, u32 level)
+{
+ unsigned long mask;
+ unsigned long shift = HGATP_PAGE_SHIFT + (gstage_index_bits * level);
+
+ if (level == (gstage_pgd_levels - 1))
+ mask = (PTRS_PER_PTE * (1UL << gstage_pgd_xbits)) - 1;
+ else
+ mask = PTRS_PER_PTE - 1;
+
+ return (addr >> shift) & mask;
+}
+
+static inline unsigned long gstage_pte_page_vaddr(pte_t pte)
+{
+ return (unsigned long)pfn_to_virt(__page_val_to_pfn(pte_val(pte)));
+}
+
+static int gstage_page_size_to_level(unsigned long page_size, u32 *out_level)
+{
+ u32 i;
+ unsigned long psz = 1UL << 12;
+
+ for (i = 0; i < gstage_pgd_levels; i++) {
+ if (page_size == (psz << (i * gstage_index_bits))) {
+ *out_level = i;
+ return 0;
+ }
+ }
+
+ return -EINVAL;
+}
+
+static int gstage_level_to_page_order(u32 level, unsigned long *out_pgorder)
+{
+ if (gstage_pgd_levels < level)
+ return -EINVAL;
+
+ *out_pgorder = 12 + (level * gstage_index_bits);
+ return 0;
+}
+
+static int gstage_level_to_page_size(u32 level, unsigned long *out_pgsize)
+{
+ int rc;
+ unsigned long page_order = PAGE_SHIFT;
+
+ rc = gstage_level_to_page_order(level, &page_order);
+ if (rc)
+ return rc;
+
+ *out_pgsize = BIT(page_order);
+ return 0;
+}
+
+static bool gstage_get_leaf_entry(struct kvm *kvm, gpa_t addr,
+ pte_t **ptepp, u32 *ptep_level)
+{
+ pte_t *ptep;
+ u32 current_level = gstage_pgd_levels - 1;
+
+ *ptep_level = current_level;
+ ptep = (pte_t *)kvm->arch.pgd;
+ ptep = &ptep[gstage_pte_index(addr, current_level)];
+ while (ptep && pte_val(*ptep)) {
+ if (gstage_pte_leaf(ptep)) {
+ *ptep_level = current_level;
+ *ptepp = ptep;
+ return true;
+ }
+
+ if (current_level) {
+ current_level--;
+ *ptep_level = current_level;
+ ptep = (pte_t *)gstage_pte_page_vaddr(*ptep);
+ ptep = &ptep[gstage_pte_index(addr, current_level)];
+ } else {
+ ptep = NULL;
+ }
+ }
+
+ return false;
+}
+
+static void gstage_remote_tlb_flush(struct kvm *kvm, u32 level, gpa_t addr)
+{
+ unsigned long order = PAGE_SHIFT;
+
+ if (gstage_level_to_page_order(level, &order))
+ return;
+ addr &= ~(BIT(order) - 1);
+
+ kvm_riscv_hfence_gvma_vmid_gpa(kvm, -1UL, 0, addr, BIT(order), order);
+}
+
+static int gstage_set_pte(struct kvm *kvm, u32 level,
+ struct kvm_mmu_memory_cache *pcache,
+ gpa_t addr, const pte_t *new_pte)
+{
+ u32 current_level = gstage_pgd_levels - 1;
+ pte_t *next_ptep = (pte_t *)kvm->arch.pgd;
+ pte_t *ptep = &next_ptep[gstage_pte_index(addr, current_level)];
+
+ if (current_level < level)
+ return -EINVAL;
+
+ while (current_level != level) {
+ if (gstage_pte_leaf(ptep))
+ return -EEXIST;
+
+ if (!pte_val(*ptep)) {
+ if (!pcache)
+ return -ENOMEM;
+ next_ptep = kvm_mmu_memory_cache_alloc(pcache);
+ if (!next_ptep)
+ return -ENOMEM;
+ *ptep = pfn_pte(PFN_DOWN(__pa(next_ptep)),
+ __pgprot(_PAGE_TABLE));
+ } else {
+ if (gstage_pte_leaf(ptep))
+ return -EEXIST;
+ next_ptep = (pte_t *)gstage_pte_page_vaddr(*ptep);
+ }
+
+ current_level--;
+ ptep = &next_ptep[gstage_pte_index(addr, current_level)];
+ }
+
+ *ptep = *new_pte;
+ if (gstage_pte_leaf(ptep))
+ gstage_remote_tlb_flush(kvm, current_level, addr);
+
+ return 0;
+}
+
+static int gstage_map_page(struct kvm *kvm,
+ struct kvm_mmu_memory_cache *pcache,
+ gpa_t gpa, phys_addr_t hpa,
+ unsigned long page_size,
+ bool page_rdonly, bool page_exec)
+{
+ int ret;
+ u32 level = 0;
+ pte_t new_pte;
+ pgprot_t prot;
+
+ ret = gstage_page_size_to_level(page_size, &level);
+ if (ret)
+ return ret;
+
+ /*
+ * A RISC-V implementation can choose to either:
+ * 1) Update 'A' and 'D' PTE bits in hardware
+ * 2) Generate page fault when 'A' and/or 'D' bits are not set
+ * PTE so that software can update these bits.
+ *
+ * We support both options mentioned above. To achieve this, we
+ * always set 'A' and 'D' PTE bits at time of creating G-stage
+ * mapping. To support KVM dirty page logging with both options
+ * mentioned above, we will write-protect G-stage PTEs to track
+ * dirty pages.
+ */
+
+ if (page_exec) {
+ if (page_rdonly)
+ prot = PAGE_READ_EXEC;
+ else
+ prot = PAGE_WRITE_EXEC;
+ } else {
+ if (page_rdonly)
+ prot = PAGE_READ;
+ else
+ prot = PAGE_WRITE;
+ }
+ new_pte = pfn_pte(PFN_DOWN(hpa), prot);
+ new_pte = pte_mkdirty(new_pte);
+
+ return gstage_set_pte(kvm, level, pcache, gpa, &new_pte);
+}
+
+enum gstage_op {
+ GSTAGE_OP_NOP = 0, /* Nothing */
+ GSTAGE_OP_CLEAR, /* Clear/Unmap */
+ GSTAGE_OP_WP, /* Write-protect */
+};
+
+static void gstage_op_pte(struct kvm *kvm, gpa_t addr,
+ pte_t *ptep, u32 ptep_level, enum gstage_op op)
+{
+ int i, ret;
+ pte_t *next_ptep;
+ u32 next_ptep_level;
+ unsigned long next_page_size, page_size;
+
+ ret = gstage_level_to_page_size(ptep_level, &page_size);
+ if (ret)
+ return;
+
+ BUG_ON(addr & (page_size - 1));
+
+ if (!pte_val(*ptep))
+ return;
+
+ if (ptep_level && !gstage_pte_leaf(ptep)) {
+ next_ptep = (pte_t *)gstage_pte_page_vaddr(*ptep);
+ next_ptep_level = ptep_level - 1;
+ ret = gstage_level_to_page_size(next_ptep_level,
+ &next_page_size);
+ if (ret)
+ return;
+
+ if (op == GSTAGE_OP_CLEAR)
+ set_pte(ptep, __pte(0));
+ for (i = 0; i < PTRS_PER_PTE; i++)
+ gstage_op_pte(kvm, addr + i * next_page_size,
+ &next_ptep[i], next_ptep_level, op);
+ if (op == GSTAGE_OP_CLEAR)
+ put_page(virt_to_page(next_ptep));
+ } else {
+ if (op == GSTAGE_OP_CLEAR)
+ set_pte(ptep, __pte(0));
+ else if (op == GSTAGE_OP_WP)
+ set_pte(ptep, __pte(pte_val(*ptep) & ~_PAGE_WRITE));
+ gstage_remote_tlb_flush(kvm, ptep_level, addr);
+ }
+}
+
+static void gstage_unmap_range(struct kvm *kvm, gpa_t start,
+ gpa_t size, bool may_block)
+{
+ int ret;
+ pte_t *ptep;
+ u32 ptep_level;
+ bool found_leaf;
+ unsigned long page_size;
+ gpa_t addr = start, end = start + size;
+
+ while (addr < end) {
+ found_leaf = gstage_get_leaf_entry(kvm, addr,
+ &ptep, &ptep_level);
+ ret = gstage_level_to_page_size(ptep_level, &page_size);
+ if (ret)
+ break;
+
+ if (!found_leaf)
+ goto next;
+
+ if (!(addr & (page_size - 1)) && ((end - addr) >= page_size))
+ gstage_op_pte(kvm, addr, ptep,
+ ptep_level, GSTAGE_OP_CLEAR);
+
+next:
+ addr += page_size;
+
+ /*
+ * If the range is too large, release the kvm->mmu_lock
+ * to prevent starvation and lockup detector warnings.
+ */
+ if (may_block && addr < end)
+ cond_resched_lock(&kvm->mmu_lock);
+ }
+}
+
+static void gstage_wp_range(struct kvm *kvm, gpa_t start, gpa_t end)
+{
+ int ret;
+ pte_t *ptep;
+ u32 ptep_level;
+ bool found_leaf;
+ gpa_t addr = start;
+ unsigned long page_size;
+
+ while (addr < end) {
+ found_leaf = gstage_get_leaf_entry(kvm, addr,
+ &ptep, &ptep_level);
+ ret = gstage_level_to_page_size(ptep_level, &page_size);
+ if (ret)
+ break;
+
+ if (!found_leaf)
+ goto next;
+
+ if (!(addr & (page_size - 1)) && ((end - addr) >= page_size))
+ gstage_op_pte(kvm, addr, ptep,
+ ptep_level, GSTAGE_OP_WP);
+
+next:
+ addr += page_size;
+ }
+}
+
+static void gstage_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);
+ gstage_wp_range(kvm, start, end);
+ spin_unlock(&kvm->mmu_lock);
+ kvm_flush_remote_tlbs(kvm);
+}
+
+int kvm_riscv_gstage_ioremap(struct kvm *kvm, gpa_t gpa,
+ phys_addr_t hpa, unsigned long size,
+ bool writable, bool in_atomic)
+{
+ pte_t pte;
+ int ret = 0;
+ unsigned long pfn;
+ phys_addr_t addr, end;
+ struct kvm_mmu_memory_cache pcache = {
+ .gfp_custom = (in_atomic) ? GFP_ATOMIC | __GFP_ACCOUNT : 0,
+ .gfp_zero = __GFP_ZERO,
+ };
+
+ end = (gpa + size + PAGE_SIZE - 1) & PAGE_MASK;
+ pfn = __phys_to_pfn(hpa);
+
+ for (addr = gpa; addr < end; addr += PAGE_SIZE) {
+ pte = pfn_pte(pfn, PAGE_KERNEL_IO);
+
+ if (!writable)
+ pte = pte_wrprotect(pte);
+
+ ret = kvm_mmu_topup_memory_cache(&pcache, gstage_pgd_levels);
+ if (ret)
+ goto out;
+
+ spin_lock(&kvm->mmu_lock);
+ ret = gstage_set_pte(kvm, 0, &pcache, addr, &pte);
+ spin_unlock(&kvm->mmu_lock);
+ if (ret)
+ goto out;
+
+ pfn++;
+ }
+
+out:
+ kvm_mmu_free_memory_cache(&pcache);
+ return ret;
+}
+
+void kvm_riscv_gstage_iounmap(struct kvm *kvm, gpa_t gpa, unsigned long size)
+{
+ spin_lock(&kvm->mmu_lock);
+ gstage_unmap_range(kvm, gpa, size, false);
+ spin_unlock(&kvm->mmu_lock);
+}
+
+void kvm_arch_mmu_enable_log_dirty_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;
+
+ gstage_wp_range(kvm, start, end);
+}
+
+void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot)
+{
+}
+
+void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
+ const struct kvm_memory_slot *memslot)
+{
+ kvm_flush_remote_tlbs(kvm);
+}
+
+void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free)
+{
+}
+
+void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen)
+{
+}
+
+void kvm_arch_flush_shadow_all(struct kvm *kvm)
+{
+ kvm_riscv_gstage_free_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);
+ gstage_unmap_range(kvm, gpa, size, false);
+ spin_unlock(&kvm->mmu_lock);
+}
+
+void kvm_arch_commit_memory_region(struct kvm *kvm,
+ 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 tracked while
+ * the memory slot is write protected.
+ */
+ if (change != KVM_MR_DELETE && new->flags & KVM_MEM_LOG_DIRTY_PAGES)
+ gstage_wp_memory_region(kvm, new->id);
+}
+
+int kvm_arch_prepare_memory_region(struct kvm *kvm,
+ const struct kvm_memory_slot *old,
+ struct kvm_memory_slot *new,
+ enum kvm_mr_change change)
+{
+ hva_t hva, reg_end, size;
+ gpa_t base_gpa;
+ bool writable;
+ 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 GPA
+ * space addressable by the KVM guest GPA space.
+ */
+ if ((new->base_gfn + new->npages) >=
+ (gstage_gpa_size >> PAGE_SHIFT))
+ return -EFAULT;
+
+ hva = new->userspace_addr;
+ size = new->npages << PAGE_SHIFT;
+ reg_end = hva + size;
+ base_gpa = new->base_gfn << PAGE_SHIFT;
+ writable = !(new->flags & KVM_MEM_READONLY);
+
+ mmap_read_lock(current->mm);
+
+ /*
+ * 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 = base_gpa + (vm_start - hva);
+ 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 (new->flags & KVM_MEM_LOG_DIRTY_PAGES) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = kvm_riscv_gstage_ioremap(kvm, gpa, pa,
+ vm_end - vm_start,
+ writable, false);
+ if (ret)
+ break;
+ }
+ hva = vm_end;
+ } while (hva < reg_end);
+
+ if (change == KVM_MR_FLAGS_ONLY)
+ goto out;
+
+ spin_lock(&kvm->mmu_lock);
+ if (ret)
+ gstage_unmap_range(kvm, base_gpa, size, false);
+ spin_unlock(&kvm->mmu_lock);
+
+out:
+ mmap_read_unlock(current->mm);
+ return ret;
+}
+
+bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
+{
+ if (!kvm->arch.pgd)
+ return false;
+
+ gstage_unmap_range(kvm, range->start << PAGE_SHIFT,
+ (range->end - range->start) << PAGE_SHIFT,
+ range->may_block);
+ return false;
+}
+
+bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
+{
+ int ret;
+ kvm_pfn_t pfn = pte_pfn(range->pte);
+
+ if (!kvm->arch.pgd)
+ return false;
+
+ WARN_ON(range->end - range->start != 1);
+
+ ret = gstage_map_page(kvm, NULL, range->start << PAGE_SHIFT,
+ __pfn_to_phys(pfn), PAGE_SIZE, true, true);
+ if (ret) {
+ kvm_debug("Failed to map G-stage page (error %d)\n", ret);
+ return true;
+ }
+
+ return false;
+}
+
+bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
+{
+ pte_t *ptep;
+ u32 ptep_level = 0;
+ u64 size = (range->end - range->start) << PAGE_SHIFT;
+
+ if (!kvm->arch.pgd)
+ return false;
+
+ WARN_ON(size != PAGE_SIZE && size != PMD_SIZE && size != PGDIR_SIZE);
+
+ if (!gstage_get_leaf_entry(kvm, range->start << PAGE_SHIFT,
+ &ptep, &ptep_level))
+ return false;
+
+ return ptep_test_and_clear_young(NULL, 0, ptep);
+}
+
+bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
+{
+ pte_t *ptep;
+ u32 ptep_level = 0;
+ u64 size = (range->end - range->start) << PAGE_SHIFT;
+
+ if (!kvm->arch.pgd)
+ return false;
+
+ WARN_ON(size != PAGE_SIZE && size != PMD_SIZE && size != PGDIR_SIZE);
+
+ if (!gstage_get_leaf_entry(kvm, range->start << PAGE_SHIFT,
+ &ptep, &ptep_level))
+ return false;
+
+ return pte_young(*ptep);
+}
+
+int kvm_riscv_gstage_map(struct kvm_vcpu *vcpu,
+ struct kvm_memory_slot *memslot,
+ gpa_t gpa, unsigned long hva, bool is_write)
+{
+ int ret;
+ kvm_pfn_t hfn;
+ bool writable;
+ short vma_pageshift;
+ gfn_t gfn = gpa >> PAGE_SHIFT;
+ struct vm_area_struct *vma;
+ struct kvm *kvm = vcpu->kvm;
+ struct kvm_mmu_memory_cache *pcache = &vcpu->arch.mmu_page_cache;
+ bool logging = (memslot->dirty_bitmap &&
+ !(memslot->flags & KVM_MEM_READONLY)) ? true : false;
+ unsigned long vma_pagesize, mmu_seq;
+
+ /* We need minimum second+third level pages */
+ ret = kvm_mmu_topup_memory_cache(pcache, gstage_pgd_levels);
+ if (ret) {
+ kvm_err("Failed to topup G-stage cache\n");
+ return ret;
+ }
+
+ mmap_read_lock(current->mm);
+
+ vma = find_vma_intersection(current->mm, hva, hva + 1);
+ if (unlikely(!vma)) {
+ kvm_err("Failed to find VMA for hva 0x%lx\n", hva);
+ mmap_read_unlock(current->mm);
+ return -EFAULT;
+ }
+
+ if (is_vm_hugetlb_page(vma))
+ vma_pageshift = huge_page_shift(hstate_vma(vma));
+ else
+ vma_pageshift = PAGE_SHIFT;
+ vma_pagesize = 1ULL << vma_pageshift;
+ if (logging || (vma->vm_flags & VM_PFNMAP))
+ vma_pagesize = PAGE_SIZE;
+
+ if (vma_pagesize == PMD_SIZE || vma_pagesize == PGDIR_SIZE)
+ gfn = (gpa & huge_page_mask(hstate_vma(vma))) >> PAGE_SHIFT;
+
+ /*
+ * Read mmu_invalidate_seq so that KVM can detect if the results of
+ * vma_lookup() or gfn_to_pfn_prot() become stale priort to acquiring
+ * kvm->mmu_lock.
+ *
+ * Rely on mmap_read_unlock() for an implicit smp_rmb(), which pairs
+ * with the smp_wmb() in kvm_mmu_invalidate_end().
+ */
+ mmu_seq = kvm->mmu_invalidate_seq;
+ mmap_read_unlock(current->mm);
+
+ if (vma_pagesize != PGDIR_SIZE &&
+ vma_pagesize != PMD_SIZE &&
+ vma_pagesize != PAGE_SIZE) {
+ kvm_err("Invalid VMA page size 0x%lx\n", vma_pagesize);
+ return -EFAULT;
+ }
+
+ hfn = gfn_to_pfn_prot(kvm, gfn, is_write, &writable);
+ if (hfn == KVM_PFN_ERR_HWPOISON) {
+ send_sig_mceerr(BUS_MCEERR_AR, (void __user *)hva,
+ vma_pageshift, current);
+ return 0;
+ }
+ if (is_error_noslot_pfn(hfn))
+ return -EFAULT;
+
+ /*
+ * If logging is active then we allow writable pages only
+ * for write faults.
+ */
+ if (logging && !is_write)
+ writable = false;
+
+ spin_lock(&kvm->mmu_lock);
+
+ if (mmu_invalidate_retry(kvm, mmu_seq))
+ goto out_unlock;
+
+ if (writable) {
+ kvm_set_pfn_dirty(hfn);
+ mark_page_dirty(kvm, gfn);
+ ret = gstage_map_page(kvm, pcache, gpa, hfn << PAGE_SHIFT,
+ vma_pagesize, false, true);
+ } else {
+ ret = gstage_map_page(kvm, pcache, gpa, hfn << PAGE_SHIFT,
+ vma_pagesize, true, true);
+ }
+
+ if (ret)
+ kvm_err("Failed to map in G-stage\n");
+
+out_unlock:
+ spin_unlock(&kvm->mmu_lock);
+ kvm_set_pfn_accessed(hfn);
+ kvm_release_pfn_clean(hfn);
+ return ret;
+}
+
+int kvm_riscv_gstage_alloc_pgd(struct kvm *kvm)
+{
+ struct page *pgd_page;
+
+ if (kvm->arch.pgd != NULL) {
+ kvm_err("kvm_arch already initialized?\n");
+ return -EINVAL;
+ }
+
+ pgd_page = alloc_pages(GFP_KERNEL | __GFP_ZERO,
+ get_order(gstage_pgd_size));
+ if (!pgd_page)
+ return -ENOMEM;
+ kvm->arch.pgd = page_to_virt(pgd_page);
+ kvm->arch.pgd_phys = page_to_phys(pgd_page);
+
+ return 0;
+}
+
+void kvm_riscv_gstage_free_pgd(struct kvm *kvm)
+{
+ void *pgd = NULL;
+
+ spin_lock(&kvm->mmu_lock);
+ if (kvm->arch.pgd) {
+ gstage_unmap_range(kvm, 0UL, gstage_gpa_size, false);
+ pgd = READ_ONCE(kvm->arch.pgd);
+ kvm->arch.pgd = NULL;
+ kvm->arch.pgd_phys = 0;
+ }
+ spin_unlock(&kvm->mmu_lock);
+
+ if (pgd)
+ free_pages((unsigned long)pgd, get_order(gstage_pgd_size));
+}
+
+void kvm_riscv_gstage_update_hgatp(struct kvm_vcpu *vcpu)
+{
+ unsigned long hgatp = gstage_mode;
+ struct kvm_arch *k = &vcpu->kvm->arch;
+
+ hgatp |= (READ_ONCE(k->vmid.vmid) << HGATP_VMID_SHIFT) &
+ HGATP_VMID_MASK;
+ hgatp |= (k->pgd_phys >> PAGE_SHIFT) & HGATP_PPN;
+
+ csr_write(CSR_HGATP, hgatp);
+
+ if (!kvm_riscv_gstage_vmid_bits())
+ kvm_riscv_local_hfence_gvma_all();
+}
+
+void kvm_riscv_gstage_mode_detect(void)
+{
+#ifdef CONFIG_64BIT
+ /* Try Sv57x4 G-stage mode */
+ csr_write(CSR_HGATP, HGATP_MODE_SV57X4 << HGATP_MODE_SHIFT);
+ if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV57X4) {
+ gstage_mode = (HGATP_MODE_SV57X4 << HGATP_MODE_SHIFT);
+ gstage_pgd_levels = 5;
+ goto skip_sv48x4_test;
+ }
+
+ /* Try Sv48x4 G-stage mode */
+ csr_write(CSR_HGATP, HGATP_MODE_SV48X4 << HGATP_MODE_SHIFT);
+ if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV48X4) {
+ gstage_mode = (HGATP_MODE_SV48X4 << HGATP_MODE_SHIFT);
+ gstage_pgd_levels = 4;
+ }
+skip_sv48x4_test:
+
+ csr_write(CSR_HGATP, 0);
+ kvm_riscv_local_hfence_gvma_all();
+#endif
+}
+
+unsigned long kvm_riscv_gstage_mode(void)
+{
+ return gstage_mode >> HGATP_MODE_SHIFT;
+}
+
+int kvm_riscv_gstage_gpa_bits(void)
+{
+ return gstage_gpa_bits;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-01 10:01:58 +0000