xen/debugfs: Add 'p2m' file for printing out the P2M layout.

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

Only enabled if CONFIG_XEN_DEBUG_FS is set.

[v2: UNKN->UNKNOWN, use uninitialized_var]
[v3: Rebased on top of mmu->p2m code split]
[v4: Fixed the else if]
Reviewed-by: Ian Campbell <Ian.Campbell@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Konrad Rzeszutek Wilk 2010-12-22 08:57:30 -05:00
parent 68df0da7f4
commit 2222e71bd6
3 changed files with 95 additions and 0 deletions

View file

@ -52,6 +52,9 @@ extern int m2p_remove_override(struct page *page);
extern struct page *m2p_find_override(unsigned long mfn);
extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn);
#ifdef CONFIG_XEN_DEBUG_FS
extern int p2m_dump_show(struct seq_file *m, void *v);
#endif
static inline unsigned long pfn_to_mfn(unsigned long pfn)
{
unsigned long mfn;

View file

@ -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>
@ -2367,6 +2368,18 @@ EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
#ifdef CONFIG_XEN_DEBUG_FS
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)
@ -2422,6 +2435,7 @@ 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);

View file

@ -153,6 +153,7 @@
#include <linux/list.h>
#include <linux/hash.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <asm/cache.h>
#include <asm/setup.h>
@ -758,3 +759,80 @@ unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn)
return ret;
}
EXPORT_SYMBOL_GPL(m2p_find_override_pfn);
#ifdef CONFIG_XEN_DEBUG_FS
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_UNKNOWN 3
unsigned long pfn, prev_pfn_type = 0, prev_pfn_level = 0;
unsigned int uninitialized_var(prev_level);
unsigned int uninitialized_var(prev_type);
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_UNKNOWN;
if (p2m_top[topidx] == p2m_mid_missing) {
lvl = 0; type = TYPE_MISSING;
} else if (p2m_top[topidx] == NULL) {
lvl = 0; type = TYPE_UNKNOWN;
} else if (p2m_top[topidx][mididx] == NULL) {
lvl = 1; type = TYPE_UNKNOWN;
} else if (p2m_top[topidx][mididx] == p2m_identity) {
lvl = 1; type = TYPE_IDENTITY;
} else if (p2m_top[topidx][mididx] == p2m_missing) {
lvl = 1; type = TYPE_MISSING;
} else if (p2m_top[topidx][mididx][idx] == 0) {
lvl = 2; type = TYPE_UNKNOWN;
} else if (p2m_top[topidx][mididx][idx] == IDENTITY_FRAME(pfn)) {
lvl = 2; type = TYPE_IDENTITY;
} 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;
} 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_UNKNOWN;
}
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;
#undef TYPE_IDENTITY
#undef TYPE_MISSING
#undef TYPE_PFN
#undef TYPE_UNKNOWN
}
#endif