Commit 2222e71b authored by Konrad Rzeszutek Wilk's avatar Konrad Rzeszutek Wilk
Browse files

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: default avatarIan Campbell <Ian.Campbell@eu.citrix.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent 68df0da7

arch/x86/include/asm/xen/page.h

+3 −0
Original line number Diff line number Diff line
@@ -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;

arch/x86/xen/mmu.c

+14 −0
Original line number Diff line number Diff line
@@ -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);

arch/x86/xen/p2m.c

+78 −0
Original line number Diff line number Diff line
@@ -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

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