Messages in this thread Patch in this message | | | Date | Wed, 15 Nov 2023 17:16:37 +0000 | Subject | [PATCH v3 07/10] arm64: ptdump: Parse the host stage-2 page-tables from the snapshot | From | Sebastian Ene <> |
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Add a walker function which configures ptdump to parse the page-tables from the snapshot. Define the attributes used by the stage-2 parser and build a description of an array which holds the name of the level. Walk the entire address space configured in the pagetable and parse the attribute descriptors.
Signed-off-by: Sebastian Ene <sebastianene@google.com> --- arch/arm64/mm/ptdump.c | 157 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 157 insertions(+)
diff --git a/arch/arm64/mm/ptdump.c b/arch/arm64/mm/ptdump.c index 0b4cb54e43ff..9f88542d5312 100644 --- a/arch/arm64/mm/ptdump.c +++ b/arch/arm64/mm/ptdump.c @@ -86,6 +86,7 @@ struct pg_state { bool check_wx; unsigned long wx_pages; unsigned long uxn_pages; + struct ptdump_info_file_priv *f_priv; }; struct prot_bits { @@ -174,6 +175,66 @@ static const struct prot_bits pte_bits[] = { } }; +static const struct prot_bits stage2_pte_bits[] = { + { + .mask = PTE_VALID, + .val = PTE_VALID, + .set = " ", + .clear = "F", + }, { + .mask = KVM_PTE_LEAF_ATTR_HI_S2_XN, + .val = KVM_PTE_LEAF_ATTR_HI_S2_XN, + .set = "XN", + .clear = " ", + }, { + .mask = KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R, + .val = KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R, + .set = "R", + .clear = " ", + }, { + .mask = KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W, + .val = KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W, + .set = "W", + .clear = " ", + }, { + .mask = KVM_PTE_LEAF_ATTR_LO_S2_AF, + .val = KVM_PTE_LEAF_ATTR_LO_S2_AF, + .set = "AF", + .clear = " ", + }, { + .mask = PTE_NG, + .val = PTE_NG, + .set = "FnXS", + .clear = " ", + }, { + .mask = PTE_CONT, + .val = PTE_CONT, + .set = "CON", + .clear = " ", + }, { + .mask = PTE_TABLE_BIT, + .val = PTE_TABLE_BIT, + .set = " ", + .clear = "BLK", + }, { + .mask = KVM_PGTABLE_PROT_SW0, + .val = KVM_PGTABLE_PROT_SW0, + .set = "SW0", /* PKVM_PAGE_SHARED_OWNED */ + }, { + .mask = KVM_PGTABLE_PROT_SW1, + .val = KVM_PGTABLE_PROT_SW1, + .set = "SW1", /* PKVM_PAGE_SHARED_BORROWED */ + }, { + .mask = KVM_PGTABLE_PROT_SW2, + .val = KVM_PGTABLE_PROT_SW2, + .set = "SW2", + }, { + .mask = KVM_PGTABLE_PROT_SW3, + .val = KVM_PGTABLE_PROT_SW3, + .set = "SW3", + }, +}; + struct pg_level { const struct prot_bits *bits; const char *name; @@ -286,6 +347,7 @@ static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level, delta >>= 10; unit++; } + pt_dump_seq_printf(st->seq, "%9lu%c %s", delta, *unit, pg_info[st->level].name); if (st->current_prot && pg_info[st->level].bits) @@ -394,6 +456,11 @@ static void *ptdump_host_va(phys_addr_t phys) return __va(phys); } +static struct kvm_pgtable_mm_ops host_mmops = { + .phys_to_virt = ptdump_host_va, + .virt_to_phys = ptdump_host_pa, +}; + static size_t stage2_get_pgd_len(void) { u64 mmfr0, mmfr1, vtcr; @@ -528,6 +595,95 @@ static void stage2_ptdump_end_walk(void *file_priv) f_priv->file_priv = NULL; } +static int stage2_ptdump_visitor(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) +{ + struct pg_state *st = ctx->arg; + struct ptdump_state *pt_st = &st->ptdump; + + pt_st->note_page(pt_st, ctx->addr, ctx->level, ctx->old); + + return 0; +} + +static void stage2_ptdump_build_levels(struct pg_level *level, + size_t num_levels, + unsigned int start_level) +{ + static const char * const lvl_names[] = {"PGD", "PUD", "PMD", "PTE"}; + int i, j, name_index; + + if (num_levels > KVM_PGTABLE_MAX_LEVELS && start_level > 2) { + pr_warn("invalid configuration %lu levels start_lvl %u\n", + num_levels, start_level); + return; + } + + for (i = start_level; i < num_levels; i++) { + name_index = i - start_level; + name_index = name_index * start_level + name_index; + + level[i].name = lvl_names[name_index]; + level[i].num = ARRAY_SIZE(stage2_pte_bits); + level[i].bits = stage2_pte_bits; + + for (j = 0; j < level[i].num; j++) + level[i].mask |= level[i].bits[j].mask; + } +} + +static void stage2_ptdump_walk(struct seq_file *s, struct ptdump_info *info) +{ + struct ptdump_info_file_priv *f_priv = + container_of(info, struct ptdump_info_file_priv, info); + struct kvm_pgtable_snapshot *snapshot = f_priv->file_priv; + struct pg_state st; + struct kvm_pgtable *pgtable; + u64 start_ipa = 0, end_ipa; + struct addr_marker ipa_address_markers[3]; + struct pg_level stage2_pg_level[KVM_PGTABLE_MAX_LEVELS] = {0}; + struct kvm_pgtable_walker walker = (struct kvm_pgtable_walker) { + .cb = stage2_ptdump_visitor, + .arg = &st, + .flags = KVM_PGTABLE_WALK_LEAF, + }; + + if (snapshot == NULL || !snapshot->pgtable.pgd) + return; + + pgtable = &snapshot->pgtable; + pgtable->mm_ops = &host_mmops; + end_ipa = BIT(pgtable->ia_bits) - 1; + + memset(&ipa_address_markers[0], 0, sizeof(ipa_address_markers)); + + ipa_address_markers[0].start_address = start_ipa; + ipa_address_markers[0].name = "IPA start"; + + ipa_address_markers[1].start_address = end_ipa; + ipa_address_markers[1].name = "IPA end"; + + stage2_ptdump_build_levels(stage2_pg_level, KVM_PGTABLE_MAX_LEVELS, + pgtable->start_level); + + st = (struct pg_state) { + .seq = s, + .marker = &ipa_address_markers[0], + .level = -1, + .pg_level = &stage2_pg_level[0], + .f_priv = f_priv, + .ptdump = { + .note_page = note_page, + .range = (struct ptdump_range[]) { + {start_ipa, end_ipa}, + {0, 0}, + }, + }, + }; + + kvm_pgtable_walk(pgtable, start_ipa, end_ipa, &walker); +} + void ptdump_register_host_stage2(void) { if (!is_protected_kvm_enabled()) @@ -537,6 +693,7 @@ void ptdump_register_host_stage2(void) .mc_len = host_s2_pgtable_pages(), .ptdump_prepare_walk = stage2_ptdump_prepare_walk, .ptdump_end_walk = stage2_ptdump_end_walk, + .ptdump_walk = stage2_ptdump_walk, }; ptdump_debugfs_kvm_register(&stage2_kernel_ptdump_info, -- 2.43.0.rc0.421.g78406f8d94-goog
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