--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Debug helper used to dump the stage-2 pagetables of the system and their
+ * associated permissions.
+ *
+ * Copyright (C) Google, 2024
+ * Author: Sebastian Ene <sebastianene@google.com>
+ */
+#include <linux/debugfs.h>
+#include <linux/kvm_host.h>
+#include <linux/seq_file.h>
+
+#include <asm/kvm_mmu.h>
+#include <asm/kvm_pgtable.h>
+#include <asm/ptdump.h>
+
+#define MARKERS_LEN 2
+#define KVM_PGTABLE_MAX_LEVELS (KVM_PGTABLE_LAST_LEVEL + 1)
+
+struct kvm_ptdump_guest_state {
+ struct kvm *kvm;
+ struct ptdump_pg_state parser_state;
+ struct addr_marker ipa_marker[MARKERS_LEN];
+ struct ptdump_pg_level level[KVM_PGTABLE_MAX_LEVELS];
+ struct ptdump_range range[MARKERS_LEN];
+};
+
+static const struct ptdump_prot_bits stage2_pte_bits[] = {
+ {
+ .mask = PTE_VALID,
+ .val = PTE_VALID,
+ .set = " ",
+ .clear = "F",
+ }, {
+ .mask = KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R | PTE_VALID,
+ .val = KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R | PTE_VALID,
+ .set = "R",
+ .clear = " ",
+ }, {
+ .mask = KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W | PTE_VALID,
+ .val = KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W | PTE_VALID,
+ .set = "W",
+ .clear = " ",
+ }, {
+ .mask = KVM_PTE_LEAF_ATTR_HI_S2_XN | PTE_VALID,
+ .val = PTE_VALID,
+ .set = " ",
+ .clear = "X",
+ }, {
+ .mask = KVM_PTE_LEAF_ATTR_LO_S2_AF | PTE_VALID,
+ .val = KVM_PTE_LEAF_ATTR_LO_S2_AF | PTE_VALID,
+ .set = "AF",
+ .clear = " ",
+ }, {
+ .mask = PTE_TABLE_BIT | PTE_VALID,
+ .val = PTE_VALID,
+ .set = "BLK",
+ .clear = " ",
+ },
+};
+
+static int kvm_ptdump_visitor(const struct kvm_pgtable_visit_ctx *ctx,
+ enum kvm_pgtable_walk_flags visit)
+{
+ struct ptdump_pg_state *st = ctx->arg;
+ struct ptdump_state *pt_st = &st->ptdump;
+
+ note_page(pt_st, ctx->addr, ctx->level, ctx->old);
+
+ return 0;
+}
+
+static int kvm_ptdump_build_levels(struct ptdump_pg_level *level, u32 start_lvl)
+{
+ u32 i;
+ u64 mask;
+
+ if (WARN_ON_ONCE(start_lvl >= KVM_PGTABLE_LAST_LEVEL))
+ return -EINVAL;
+
+ mask = 0;
+ for (i = 0; i < ARRAY_SIZE(stage2_pte_bits); i++)
+ mask |= stage2_pte_bits[i].mask;
+
+ for (i = start_lvl; i < KVM_PGTABLE_MAX_LEVELS; i++) {
+ snprintf(level[i].name, sizeof(level[i].name), "%u", i);
+
+ level[i].num = ARRAY_SIZE(stage2_pte_bits);
+ level[i].bits = stage2_pte_bits;
+ level[i].mask = mask;
+ }
+
+ return 0;
+}
+
+static struct kvm_ptdump_guest_state *kvm_ptdump_parser_create(struct kvm *kvm)
+{
+ struct kvm_ptdump_guest_state *st;
+ struct kvm_s2_mmu *mmu = &kvm->arch.mmu;
+ struct kvm_pgtable *pgtable = mmu->pgt;
+ int ret;
+
+ st = kzalloc(sizeof(struct kvm_ptdump_guest_state), GFP_KERNEL_ACCOUNT);
+ if (!st)
+ return ERR_PTR(-ENOMEM);
+
+ ret = kvm_ptdump_build_levels(&st->level[0], pgtable->start_level);
+ if (ret) {
+ kfree(st);
+ return ERR_PTR(ret);
+ }
+
+ st->ipa_marker[0].name = "Guest IPA";
+ st->ipa_marker[1].start_address = BIT(pgtable->ia_bits);
+ st->range[0].end = BIT(pgtable->ia_bits);
+
+ st->kvm = kvm;
+ st->parser_state = (struct ptdump_pg_state) {
+ .marker = &st->ipa_marker[0],
+ .level = -1,
+ .pg_level = &st->level[0],
+ .ptdump.range = &st->range[0],
+ .start_address = 0,
+ };
+
+ return st;
+}
+
+static int kvm_ptdump_guest_show(struct seq_file *m, void *unused)
+{
+ int ret;
+ struct kvm_ptdump_guest_state *st = m->private;
+ struct kvm *kvm = st->kvm;
+ struct kvm_s2_mmu *mmu = &kvm->arch.mmu;
+ struct ptdump_pg_state *parser_state = &st->parser_state;
+ struct kvm_pgtable_walker walker = (struct kvm_pgtable_walker) {
+ .cb = kvm_ptdump_visitor,
+ .arg = parser_state,
+ .flags = KVM_PGTABLE_WALK_LEAF,
+ };
+
+ parser_state->seq = m;
+
+ write_lock(&kvm->mmu_lock);
+ ret = kvm_pgtable_walk(mmu->pgt, 0, BIT(mmu->pgt->ia_bits), &walker);
+ write_unlock(&kvm->mmu_lock);
+
+ return ret;
+}
+
+static int kvm_ptdump_guest_open(struct inode *m, struct file *file)
+{
+ struct kvm *kvm = m->i_private;
+ struct kvm_ptdump_guest_state *st;
+ int ret;
+
+ if (!kvm_get_kvm_safe(kvm))
+ return -ENOENT;
+
+ st = kvm_ptdump_parser_create(kvm);
+ if (IS_ERR(st)) {
+ ret = PTR_ERR(st);
+ goto err_with_kvm_ref;
+ }
+
+ ret = single_open(file, kvm_ptdump_guest_show, st);
+ if (!ret)
+ return 0;
+
+ kfree(st);
+err_with_kvm_ref:
+ kvm_put_kvm(kvm);
+ return ret;
+}
+
+static int kvm_ptdump_guest_close(struct inode *m, struct file *file)
+{
+ struct kvm *kvm = m->i_private;
+ void *st = ((struct seq_file *)file->private_data)->private;
+
+ kfree(st);
+ kvm_put_kvm(kvm);
+
+ return single_release(m, file);
+}
+
+static const struct file_operations kvm_ptdump_guest_fops = {
+ .open = kvm_ptdump_guest_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = kvm_ptdump_guest_close,
+};
+
+static int kvm_pgtable_range_show(struct seq_file *m, void *unused)
+{
+ struct kvm_pgtable *pgtable = m->private;
+
+ seq_printf(m, "%2u\n", pgtable->ia_bits);
+ return 0;
+}
+
+static int kvm_pgtable_levels_show(struct seq_file *m, void *unused)
+{
+ struct kvm_pgtable *pgtable = m->private;
+
+ seq_printf(m, "%1d\n", KVM_PGTABLE_MAX_LEVELS - pgtable->start_level);
+ return 0;
+}
+
+static int kvm_pgtable_debugfs_open(struct inode *m, struct file *file,
+ int (*show)(struct seq_file *, void *))
+{
+ struct kvm *kvm = m->i_private;
+ struct kvm_pgtable *pgtable;
+ int ret;
+
+ if (!kvm_get_kvm_safe(kvm))
+ return -ENOENT;
+
+ pgtable = kvm->arch.mmu.pgt;
+
+ ret = single_open(file, show, pgtable);
+ if (ret < 0)
+ kvm_put_kvm(kvm);
+ return ret;
+}
+
+static int kvm_pgtable_range_open(struct inode *m, struct file *file)
+{
+ return kvm_pgtable_debugfs_open(m, file, kvm_pgtable_range_show);
+}
+
+static int kvm_pgtable_levels_open(struct inode *m, struct file *file)
+{
+ return kvm_pgtable_debugfs_open(m, file, kvm_pgtable_levels_show);
+}
+
+static int kvm_pgtable_debugfs_close(struct inode *m, struct file *file)
+{
+ struct kvm *kvm = m->i_private;
+
+ kvm_put_kvm(kvm);
+ return single_release(m, file);
+}
+
+static const struct file_operations kvm_pgtable_range_fops = {
+ .open = kvm_pgtable_range_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = kvm_pgtable_debugfs_close,
+};
+
+static const struct file_operations kvm_pgtable_levels_fops = {
+ .open = kvm_pgtable_levels_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = kvm_pgtable_debugfs_close,
+};
+
+void kvm_s2_ptdump_create_debugfs(struct kvm *kvm)
+{
+ debugfs_create_file("stage2_page_tables", 0400, kvm->debugfs_dentry,
+ kvm, &kvm_ptdump_guest_fops);
+ debugfs_create_file("ipa_range", 0400, kvm->debugfs_dentry, kvm,
+ &kvm_pgtable_range_fops);
+ debugfs_create_file("stage2_levels", 0400, kvm->debugfs_dentry,
+ kvm, &kvm_pgtable_levels_fops);
+}
projects / thirdparty / linux.git / commitdiff
