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Message-ID: <20231115171639.2852644-9-sebastianene@google.com>
Date: Wed, 15 Nov 2023 17:16:37 +0000
From: Sebastian Ene <sebastianene@...gle.com>
To: will@...nel.org, Oliver Upton <oliver.upton@...ux.dev>,
James Morse <james.morse@....com>,
Suzuki K Poulose <suzuki.poulose@....com>,
Zenghui Yu <yuzenghui@...wei.com>, catalin.marinas@....com,
mark.rutland@....com, akpm@...ux-foundation.org, maz@...nel.org
Cc: kvmarm@...ts.linux.dev, linux-arm-kernel@...ts.infradead.org,
linux-kernel@...r.kernel.org, kernel-team@...roid.com,
vdonnefort@...gle.com, qperret@...gle.com, smostafa@...gle.com,
Sebastian Ene <sebastianene@...gle.com>
Subject: [PATCH v3 07/10] arm64: ptdump: Parse the host stage-2 page-tables
from the snapshot
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@...gle.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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