[PATCH 5/8] xen/debug: Print out all pages in the P2M.

Konrad Rzeszutek Wilk
2010-12-30T19:49:20Z

We walk over the whole P2M and constructing a simplified view of which
regions belong to what level and what type they are.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
arch/x86/xen/mmu.c | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 84 insertions(+), 0 deletions(-)

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 36bdd2d..e9dfdd6 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -46,6 +46,7 @@
#include <linux/module.h>
#include <linux/gfp.h>
#include <linux/memblock.h>
+#include <linux/seq_file.h>

#include <asm/pgtable.h>
#include <asm/tlbflush.h>
@@ -2764,6 +2765,88 @@ EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);

#ifdef CONFIG_XEN_DEBUG_FS

+static int p2m_dump_show(struct seq_file *m, void *v)
+{
+ static const char * const level_name[] = { "top", "middle",
+ "entry", "abnormal" };
+ static const char * const type_name[] = { "identity", "missing",
+ "pfn", "abnormal"};
+#define TYPE_IDENTITY 0
+#define TYPE_MISSING 1
+#define TYPE_PFN 2
+#define TYPE_UNKN 3
+ unsigned long pfn, prev_pfn_type = 0, prev_pfn_level = 0;
+ unsigned int prev_level = 0;
+ unsigned int prev_type = TYPE_UNKN;
+
+ if (!p2m_top)
+ return 0;
+
+ for (pfn = 0; pfn < MAX_DOMAIN_PAGES; pfn++) {
+ unsigned topidx = p2m_top_index(pfn);
+ unsigned mididx = p2m_mid_index(pfn);
+ unsigned idx = p2m_index(pfn);
+ unsigned lvl, type;
+
+ lvl = 4;
+ type = TYPE_UNKN;
+ if (p2m_top[topidx] == p2m_mid_missing) {
+ lvl = 0; type = TYPE_MISSING;
+ } else if (p2m_top[topidx] == p2m_mid_identity) {
+ lvl = 0; type = TYPE_IDENTITY;
+ } else if (p2m_top[topidx][mididx] == p2m_identity) {
+ lvl = 1; type = TYPE_IDENTITY;
+ } else if (p2m_top[topidx][mididx][idx] == pfn) {
+ lvl = 2; type = TYPE_IDENTITY;
+ } else if (p2m_top[topidx] == NULL) {
+ lvl = 0; type = TYPE_UNKN;
+ } else if (p2m_top[topidx][mididx] == NULL) {
+ lvl = 1; type = TYPE_UNKN;
+ } else if (p2m_top[topidx][mididx][idx] == 0) {
+ lvl = 2; type = TYPE_UNKN;
+ } else if (p2m_top[topidx][mididx] == p2m_missing) {
+ lvl = 1; type = TYPE_MISSING;
+ } else if (p2m_top[topidx][mididx][idx] == INVALID_P2M_ENTRY) {
+ lvl = 2; type = TYPE_MISSING;
+ } else if (p2m_top[topidx][mididx][idx] != pfn) {
+ lvl = 2; type = TYPE_PFN;
+ }
+ if (pfn == 0) {
+ prev_level = lvl;
+ prev_type = type;
+ }
+ if (pfn == MAX_DOMAIN_PAGES-1) {
+ lvl = 3;
+ type = TYPE_UNKN;
+ }
+ if (prev_type != type) {
+ seq_printf(m, " [0x%lx->0x%lx] %s\n",
+ prev_pfn_type, pfn, type_name[prev_type]);
+ prev_pfn_type = pfn;
+ prev_type = type;
+ }
+ if (prev_level != lvl) {
+ seq_printf(m, " [0x%lx->0x%lx] level %s\n",
+ prev_pfn_level, pfn, level_name[prev_level]);
+ prev_pfn_level = pfn;
+ prev_level = lvl;
+ }
+ }
+ return 0;
+}
+
+static int p2m_dump_open(struct inode *inode, struct file *filp)
+{
+ return single_open(filp, p2m_dump_show, NULL);
+}
+
+static const struct file_operations p2m_dump_fops = {
+ .open = p2m_dump_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
static struct dentry *d_mmu_debug;

static int __init xen_mmu_debugfs(void)
@@ -2819,6 +2902,7 @@ static int __init xen_mmu_debugfs(void)
debugfs_create_u32("prot_commit_batched", 0444, d_mmu_debug,
&mmu_stats.prot_commit_batched);

+ debugfs_create_file("p2m", 0600, d_mmu_debug, NULL, &p2m_dump_fops);
return 0;
}
fs_initcall(xen_mmu_debugfs);
--
1.7.1