Merge branches 'stable/p2m-identity.v4.9.1' and 'stable/e820' of... (c7146dd0) · Commits · 戴 / test

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

+37 −10

Original line number	Diff line number	Diff line
		@@ -29,8 +29,10 @@ typedef struct xpaddr {

		/** MACHINE <-> PHYSICAL CONVERSION MACROS **/
		#define INVALID_P2M_ENTRY (~0UL)
		#define FOREIGN_FRAME_BIT (1UL<<31)
		#define FOREIGN_FRAME_BIT (1UL<<(BITS_PER_LONG-1))
		#define IDENTITY_FRAME_BIT (1UL<<(BITS_PER_LONG-2))
		#define FOREIGN_FRAME(m) ((m) \| FOREIGN_FRAME_BIT)
		#define IDENTITY_FRAME(m) ((m) \| IDENTITY_FRAME_BIT)

		/* Maximum amount of memory we can handle in a domain in pages */
		#define MAX_DOMAIN_PAGES \
		@@ -41,12 +43,18 @@ extern unsigned int machine_to_phys_order;

		extern unsigned long get_phys_to_machine(unsigned long pfn);
		extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn);
		extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
		extern unsigned long set_phys_range_identity(unsigned long pfn_s,
		unsigned long pfn_e);

		extern int m2p_add_override(unsigned long mfn, struct page *page);
		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;
		@@ -57,7 +65,7 @@ static inline unsigned long pfn_to_mfn(unsigned long pfn)
		mfn = get_phys_to_machine(pfn);

		if (mfn != INVALID_P2M_ENTRY)
		mfn &= ~FOREIGN_FRAME_BIT;
		mfn &= ~(FOREIGN_FRAME_BIT \| IDENTITY_FRAME_BIT);

		return mfn;
		}
		@@ -73,25 +81,44 @@ static inline int phys_to_machine_mapping_valid(unsigned long pfn)
		static inline unsigned long mfn_to_pfn(unsigned long mfn)
		{
		unsigned long pfn;
		int ret = 0;

		if (xen_feature(XENFEAT_auto_translated_physmap))
		return mfn;

		if (unlikely((mfn >> machine_to_phys_order) != 0)) {
		pfn = ~0;
		goto try_override;
		}
		pfn = 0;
		/*
		* The array access can fail (e.g., device space beyond end of RAM).
		* In such cases it doesn't matter what we return (we return garbage),
		* but we must handle the fault without crashing!
		*/
		__get_user(pfn, &machine_to_phys_mapping[mfn]);

		ret = __get_user(pfn, &machine_to_phys_mapping[mfn]);
		try_override:
		/* ret might be < 0 if there are no entries in the m2p for mfn */
		if (ret < 0)
		pfn = ~0;
		else if (get_phys_to_machine(pfn) != mfn)
		/*
		* If this appears to be a foreign mfn (because the pfn
		* doesn't map back to the mfn), then check the local override
		* table to see if there's a better pfn to use.
		*
		* m2p_find_override_pfn returns ~0 if it doesn't find anything.
		*/
		if (get_phys_to_machine(pfn) != mfn)
		pfn = m2p_find_override_pfn(mfn, pfn);
		pfn = m2p_find_override_pfn(mfn, ~0);

		/*
		* pfn is ~0 if there are no entries in the m2p for mfn or if the
		* entry doesn't map back to the mfn and m2p_override doesn't have a
		* valid entry for it.
		*/
		if (pfn == ~0 &&
		get_phys_to_machine(mfn) == IDENTITY_FRAME(mfn))
		pfn = mfn;

		return pfn;
		}

arch/x86/xen/Kconfig

+8 −0

Original line number	Diff line number	Diff line
		@@ -48,3 +48,11 @@ config XEN_DEBUG_FS
		help
		Enable statistics output and various tuning options in debugfs.
		Enabling this option may incur a significant performance overhead.

		config XEN_DEBUG
		bool "Enable Xen debug checks"
		depends on XEN
		default n
		help
		Enable various WARN_ON checks in the Xen MMU code.
		Enabling this option WILL incur a significant performance overhead.

arch/x86/xen/mmu.c

+69 −3

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>
		@@ -416,8 +417,12 @@ static pteval_t pte_pfn_to_mfn(pteval_t val)
		if (val & _PAGE_PRESENT) {
		unsigned long pfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
		pteval_t flags = val & PTE_FLAGS_MASK;
		unsigned long mfn = pfn_to_mfn(pfn);
		unsigned long mfn;

		if (!xen_feature(XENFEAT_auto_translated_physmap))
		mfn = get_phys_to_machine(pfn);
		else
		mfn = pfn;
		/*
		* If there's no mfn for the pfn, then just create an
		* empty non-present pte. Unfortunately this loses
		@@ -427,8 +432,18 @@ static pteval_t pte_pfn_to_mfn(pteval_t val)
		if (unlikely(mfn == INVALID_P2M_ENTRY)) {
		mfn = 0;
		flags = 0;
		} else {
		/*
		* Paramount to do this test _after_ the
		* INVALID_P2M_ENTRY as INVALID_P2M_ENTRY &
		* IDENTITY_FRAME_BIT resolves to true.
		*/
		mfn &= ~FOREIGN_FRAME_BIT;
		if (mfn & IDENTITY_FRAME_BIT) {
		mfn &= ~IDENTITY_FRAME_BIT;
		flags \|= _PAGE_IOMAP;
		}
		}

		val = ((pteval_t)mfn << PAGE_SHIFT) \| flags;
		}

		@@ -532,6 +547,41 @@ pte_t xen_make_pte(pteval_t pte)
		}
		PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte);

		#ifdef CONFIG_XEN_DEBUG
		pte_t xen_make_pte_debug(pteval_t pte)
		{
		phys_addr_t addr = (pte & PTE_PFN_MASK);
		phys_addr_t other_addr;
		bool io_page = false;
		pte_t _pte;

		if (pte & _PAGE_IOMAP)
		io_page = true;

		_pte = xen_make_pte(pte);

		if (!addr)
		return _pte;

		if (io_page &&
		(xen_initial_domain() \|\| addr >= ISA_END_ADDRESS)) {
		other_addr = pfn_to_mfn(addr >> PAGE_SHIFT) << PAGE_SHIFT;
		WARN(addr != other_addr,
		"0x%lx is using VM_IO, but it is 0x%lx!\n",
		(unsigned long)addr, (unsigned long)other_addr);
		} else {
		pteval_t iomap_set = (_pte.pte & PTE_FLAGS_MASK) & _PAGE_IOMAP;
		other_addr = (_pte.pte & PTE_PFN_MASK);
		WARN((addr == other_addr) && (!io_page) && (!iomap_set),
		"0x%lx is missing VM_IO (and wasn't fixed)!\n",
		(unsigned long)addr);
		}

		return _pte;
		}
		PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte_debug);
		#endif

		pgd_t xen_make_pgd(pgdval_t pgd)
		{
		pgd = pte_pfn_to_mfn(pgd);
		@@ -1940,6 +1990,9 @@ __init void xen_ident_map_ISA(void)

		static __init void xen_post_allocator_init(void)
		{
		#ifdef CONFIG_XEN_DEBUG
		pv_mmu_ops.make_pte = PV_CALLEE_SAVE(xen_make_pte_debug);
		#endif
		pv_mmu_ops.set_pte = xen_set_pte;
		pv_mmu_ops.set_pmd = xen_set_pmd;
		pv_mmu_ops.set_pud = xen_set_pud;
		@@ -2072,7 +2125,7 @@ static void xen_zap_pfn_range(unsigned long vaddr, unsigned int order,
		in_frames[i] = virt_to_mfn(vaddr);

		MULTI_update_va_mapping(mcs.mc, vaddr, VOID_PTE, 0);
		set_phys_to_machine(virt_to_pfn(vaddr), INVALID_P2M_ENTRY);
		__set_phys_to_machine(virt_to_pfn(vaddr), INVALID_P2M_ENTRY);

		if (out_frames)
		out_frames[i] = virt_to_pfn(vaddr);
		@@ -2351,6 +2404,18 @@ 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)
		@@ -2406,6 +2471,7 @@ 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

+317 −7

Original line number	Diff line number	Diff line
		@@ -23,6 +23,129 @@
		* P2M_PER_PAGE depends on the architecture, as a mfn is always
		* unsigned long (8 bytes on 64-bit, 4 bytes on 32), leading to
		* 512 and 1024 entries respectively.
		*
		* In short, these structures contain the Machine Frame Number (MFN) of the PFN.
		*
		* However not all entries are filled with MFNs. Specifically for all other
		* leaf entries, or for the top root, or middle one, for which there is a void
		* entry, we assume it is "missing". So (for example)
		* pfn_to_mfn(0x90909090)=INVALID_P2M_ENTRY.
		*
		* We also have the possibility of setting 1-1 mappings on certain regions, so
		* that:
		* pfn_to_mfn(0xc0000)=0xc0000
		*
		* The benefit of this is, that we can assume for non-RAM regions (think
		* PCI BARs, or ACPI spaces), we can create mappings easily b/c we
		* get the PFN value to match the MFN.
		*
		* For this to work efficiently we have one new page p2m_identity and
		* allocate (via reserved_brk) any other pages we need to cover the sides
		* (1GB or 4MB boundary violations). All entries in p2m_identity are set to
		* INVALID_P2M_ENTRY type (Xen toolstack only recognizes that and MFNs,
		* no other fancy value).
		*
		* On lookup we spot that the entry points to p2m_identity and return the
		* identity value instead of dereferencing and returning INVALID_P2M_ENTRY.
		* If the entry points to an allocated page, we just proceed as before and
		* return the PFN. If the PFN has IDENTITY_FRAME_BIT set we unmask that in
		* appropriate functions (pfn_to_mfn).
		*
		* The reason for having the IDENTITY_FRAME_BIT instead of just returning the
		* PFN is that we could find ourselves where pfn_to_mfn(pfn)==pfn for a
		* non-identity pfn. To protect ourselves against we elect to set (and get) the
		* IDENTITY_FRAME_BIT on all identity mapped PFNs.
		*
		* This simplistic diagram is used to explain the more subtle piece of code.
		* There is also a digram of the P2M at the end that can help.
		* Imagine your E820 looking as so:
		*
		* 1GB 2GB
		* /-------------------+---------\/----\ /----------\ /---+-----\
		* \| System RAM \| Sys RAM \|\|ACPI\| \| reserved \| \| Sys RAM \|
		* \-------------------+---------/\----/ \----------/ \---+-----/
		* ^- 1029MB ^- 2001MB
		*
		* [1029MB = 263424 (0x40500), 2001MB = 512256 (0x7D100),
		* 2048MB = 524288 (0x80000)]
		*
		* And dom0_mem=max:3GB,1GB is passed in to the guest, meaning memory past 1GB
		* is actually not present (would have to kick the balloon driver to put it in).
		*
		* When we are told to set the PFNs for identity mapping (see patch: "xen/setup:
		* Set identity mapping for non-RAM E820 and E820 gaps.") we pass in the start
		* of the PFN and the end PFN (263424 and 512256 respectively). The first step
		* is to reserve_brk a top leaf page if the p2m[1] is missing. The top leaf page
		* covers 512^2 of page estate (1GB) and in case the start or end PFN is not
		* aligned on 512^2*PAGE_SIZE (1GB) we loop on aligned 1GB PFNs from start pfn
		* to end pfn. We reserve_brk top leaf pages if they are missing (means they
		* point to p2m_mid_missing).
		*
		* With the E820 example above, 263424 is not 1GB aligned so we allocate a
		* reserve_brk page which will cover the PFNs estate from 0x40000 to 0x80000.
		* Each entry in the allocate page is "missing" (points to p2m_missing).
		*
		* Next stage is to determine if we need to do a more granular boundary check
		* on the 4MB (or 2MB depending on architecture) off the start and end pfn's.
		* We check if the start pfn and end pfn violate that boundary check, and if
		* so reserve_brk a middle (p2m[x][y]) leaf page. This way we have a much finer
		* granularity of setting which PFNs are missing and which ones are identity.
		* In our example 263424 and 512256 both fail the check so we reserve_brk two
		* pages. Populate them with INVALID_P2M_ENTRY (so they both have "missing"
		* values) and assign them to p2m[1][2] and p2m[1][488] respectively.
		*
		* At this point we would at minimum reserve_brk one page, but could be up to
		* three. Each call to set_phys_range_identity has at maximum a three page
		* cost. If we were to query the P2M at this stage, all those entries from
		* start PFN through end PFN (so 1029MB -> 2001MB) would return
		* INVALID_P2M_ENTRY ("missing").
		*
		* The next step is to walk from the start pfn to the end pfn setting
		* the IDENTITY_FRAME_BIT on each PFN. This is done in set_phys_range_identity.
		* If we find that the middle leaf is pointing to p2m_missing we can swap it
		* over to p2m_identity - this way covering 4MB (or 2MB) PFN space. At this
		* point we do not need to worry about boundary aligment (so no need to
		* reserve_brk a middle page, figure out which PFNs are "missing" and which
		* ones are identity), as that has been done earlier. If we find that the
		* middle leaf is not occupied by p2m_identity or p2m_missing, we dereference
		* that page (which covers 512 PFNs) and set the appropriate PFN with
		* IDENTITY_FRAME_BIT. In our example 263424 and 512256 end up there, and we
		* set from p2m[1][2][256->511] and p2m[1][488][0->256] with
		* IDENTITY_FRAME_BIT set.
		*
		* All other regions that are void (or not filled) either point to p2m_missing
		* (considered missing) or have the default value of INVALID_P2M_ENTRY (also
		* considered missing). In our case, p2m[1][2][0->255] and p2m[1][488][257->511]
		* contain the INVALID_P2M_ENTRY value and are considered "missing."
		*
		* This is what the p2m ends up looking (for the E820 above) with this
		* fabulous drawing:
		*
		* p2m /--------------\
		* /-----\ \| &mfn_list[0],\| /-----------------\
		* \| 0 \|------>\| &mfn_list[1],\| /---------------\ \| ~0, ~0, .. \|
		* \|-----\| \| ..., ~0, ~0 \| \| ~0, ~0, [x]---+----->\| IDENTITY [@256] \|
		* \| 1 \|---\ \--------------/ \| [p2m_identity]+\ \| IDENTITY [@257] \|
		* \|-----\| \ \| [p2m_identity]+\\ \| .... \|
		* \| 2 \|--\ \-------------------->\| ... \| \\ \----------------/
		* \|-----\| \ \---------------/ \\
		* \| 3 \|\ \ \\ p2m_identity
		* \|-----\| \ \-------------------->/---------------\ /-----------------\
		* \| .. +->+ \| [p2m_identity]+-->\| ~0, ~0, ~0, ... \|
		* \-----/ / \| [p2m_identity]+-->\| ..., ~0 \|
		* / /---------------\ \| .... \| \-----------------/
		* / \| IDENTITY[@0] \| /-+-[x], ~0, ~0.. \|
		* / \| IDENTITY[@256]\|<----/ \---------------/
		* / \| ~0, ~0, .... \|
		* \| \---------------/
		* \|
		* p2m_missing p2m_missing
		* /------------------\ /------------\
		* \| [p2m_mid_missing]+---->\| ~0, ~0, ~0 \|
		* \| [p2m_mid_missing]+---->\| ..., ~0 \|
		* \------------------/ \------------/
		*
		* where ~0 is INVALID_P2M_ENTRY. IDENTITY is (PFN \| IDENTITY_BIT)
		*/

		#include <linux/init.h>
		@@ -30,6 +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>
		@@ -59,9 +183,15 @@ static RESERVE_BRK_ARRAY(unsigned long **, p2m_top, P2M_TOP_PER_PAGE);
		static RESERVE_BRK_ARRAY(unsigned long, p2m_top_mfn, P2M_TOP_PER_PAGE);
		static RESERVE_BRK_ARRAY(unsigned long *, p2m_top_mfn_p, P2M_TOP_PER_PAGE);

		static RESERVE_BRK_ARRAY(unsigned long, p2m_identity, P2M_PER_PAGE);

		RESERVE_BRK(p2m_mid, PAGE_SIZE * (MAX_DOMAIN_PAGES / (P2M_PER_PAGE * P2M_MID_PER_PAGE)));
		RESERVE_BRK(p2m_mid_mfn, PAGE_SIZE * (MAX_DOMAIN_PAGES / (P2M_PER_PAGE * P2M_MID_PER_PAGE)));

		/* We might hit two boundary violations at the start and end, at max each
		* boundary violation will require three middle nodes. */
		RESERVE_BRK(p2m_mid_identity, PAGE_SIZE * 2 * 3);

		static inline unsigned p2m_top_index(unsigned long pfn)
		{
		BUG_ON(pfn >= MAX_P2M_PFN);
		@@ -221,6 +351,9 @@ void __init xen_build_dynamic_phys_to_machine(void)
		p2m_top = extend_brk(PAGE_SIZE, PAGE_SIZE);
		p2m_top_init(p2m_top);

		p2m_identity = extend_brk(PAGE_SIZE, PAGE_SIZE);
		p2m_init(p2m_identity);

		/*
		* The domain builder gives us a pre-constructed p2m array in
		* mfn_list for all the pages initially given to us, so we just
		@@ -266,6 +399,14 @@ unsigned long get_phys_to_machine(unsigned long pfn)
		mididx = p2m_mid_index(pfn);
		idx = p2m_index(pfn);

		/*
		* The INVALID_P2M_ENTRY is filled in both p2m_*identity
		* and in p2m_*missing, so returning the INVALID_P2M_ENTRY
		* would be wrong.
		*/
		if (p2m_top[topidx][mididx] == p2m_identity)
		return IDENTITY_FRAME(pfn);

		return p2m_top[topidx][mididx][idx];
		}
		EXPORT_SYMBOL_GPL(get_phys_to_machine);
		@@ -335,9 +476,11 @@ static bool alloc_p2m(unsigned long pfn)
		p2m_top_mfn_p[topidx] = mid_mfn;
		}

		if (p2m_top[topidx][mididx] == p2m_missing) {
		if (p2m_top[topidx][mididx] == p2m_identity \|\|
		p2m_top[topidx][mididx] == p2m_missing) {
		/* p2m leaf page is missing */
		unsigned long *p2m;
		unsigned long *p2m_orig = p2m_top[topidx][mididx];

		p2m = alloc_p2m_page();
		if (!p2m)
		@@ -345,7 +488,7 @@ static bool alloc_p2m(unsigned long pfn)

		p2m_init(p2m);

		if (cmpxchg(&mid[mididx], p2m_missing, p2m) != p2m_missing)
		if (cmpxchg(&mid[mididx], p2m_orig, p2m) != p2m_orig)
		free_p2m_page(p2m);
		else
		mid_mfn[mididx] = virt_to_mfn(p2m);
		@@ -354,11 +497,91 @@ static bool alloc_p2m(unsigned long pfn)
		return true;
		}

		bool __early_alloc_p2m(unsigned long pfn)
		{
		unsigned topidx, mididx, idx;

		topidx = p2m_top_index(pfn);
		mididx = p2m_mid_index(pfn);
		idx = p2m_index(pfn);

		/* Pfff.. No boundary cross-over, lets get out. */
		if (!idx)
		return false;

		WARN(p2m_top[topidx][mididx] == p2m_identity,
		"P2M[%d][%d] == IDENTITY, should be MISSING (or alloced)!\n",
		topidx, mididx);

		/*
		* Could be done by xen_build_dynamic_phys_to_machine..
		*/
		if (p2m_top[topidx][mididx] != p2m_missing)
		return false;

		/* Boundary cross-over for the edges: */
		if (idx) {
		unsigned long *p2m = extend_brk(PAGE_SIZE, PAGE_SIZE);

		p2m_init(p2m);

		p2m_top[topidx][mididx] = p2m;

		}
		return idx != 0;
		}
		unsigned long set_phys_range_identity(unsigned long pfn_s,
		unsigned long pfn_e)
		{
		unsigned long pfn;

		if (unlikely(pfn_s >= MAX_P2M_PFN \|\| pfn_e >= MAX_P2M_PFN))
		return 0;

		if (unlikely(xen_feature(XENFEAT_auto_translated_physmap)))
		return pfn_e - pfn_s;

		if (pfn_s > pfn_e)
		return 0;

		for (pfn = (pfn_s & ~(P2M_MID_PER_PAGE * P2M_PER_PAGE - 1));
		pfn < ALIGN(pfn_e, (P2M_MID_PER_PAGE * P2M_PER_PAGE));
		pfn += P2M_MID_PER_PAGE * P2M_PER_PAGE)
		{
		unsigned topidx = p2m_top_index(pfn);
		if (p2m_top[topidx] == p2m_mid_missing) {
		unsigned long **mid = extend_brk(PAGE_SIZE, PAGE_SIZE);

		p2m_mid_init(mid);

		p2m_top[topidx] = mid;
		}
		}

		__early_alloc_p2m(pfn_s);
		__early_alloc_p2m(pfn_e);

		for (pfn = pfn_s; pfn < pfn_e; pfn++)
		if (!__set_phys_to_machine(pfn, IDENTITY_FRAME(pfn)))
		break;

		if (!WARN((pfn - pfn_s) != (pfn_e - pfn_s),
		"Identity mapping failed. We are %ld short of 1-1 mappings!\n",
		(pfn_e - pfn_s) - (pfn - pfn_s)))
		printk(KERN_DEBUG "1-1 mapping on %lx->%lx\n", pfn_s, pfn);

		return pfn - pfn_s;
		}

		/* Try to install p2m mapping; fail if intermediate bits missing */
		bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
		{
		unsigned topidx, mididx, idx;

		if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) {
		BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);
		return true;
		}
		if (unlikely(pfn >= MAX_P2M_PFN)) {
		BUG_ON(mfn != INVALID_P2M_ENTRY);
		return true;
		@@ -368,6 +591,21 @@ bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
		mididx = p2m_mid_index(pfn);
		idx = p2m_index(pfn);

		/* For sparse holes were the p2m leaf has real PFN along with
		* PCI holes, stick in the PFN as the MFN value.
		*/
		if (mfn != INVALID_P2M_ENTRY && (mfn & IDENTITY_FRAME_BIT)) {
		if (p2m_top[topidx][mididx] == p2m_identity)
		return true;

		/* Swap over from MISSING to IDENTITY if needed. */
		if (p2m_top[topidx][mididx] == p2m_missing) {
		WARN_ON(cmpxchg(&p2m_top[topidx][mididx], p2m_missing,
		p2m_identity) != p2m_missing);
		return true;
		}
		}

		if (p2m_top[topidx][mididx] == p2m_missing)
		return mfn == INVALID_P2M_ENTRY;

		@@ -378,11 +616,6 @@ bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)

		bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
		{
		if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) {
		BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);
		return true;
		}

		if (unlikely(!__set_phys_to_machine(pfn, mfn))) {
		if (!alloc_p2m(pfn))
		return false;
		@@ -520,3 +753,80 @@ 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

arch/x86/xen/setup.c

+67 −1

Original line number	Diff line number	Diff line
		@@ -52,6 +52,8 @@ phys_addr_t xen_extra_mem_start, xen_extra_mem_size;

		static __init void xen_add_extra_mem(unsigned long pages)
		{
		unsigned long pfn;

		u64 size = (u64)pages * PAGE_SIZE;
		u64 extra_start = xen_extra_mem_start + xen_extra_mem_size;

		@@ -66,6 +68,9 @@ static __init void xen_add_extra_mem(unsigned long pages)
		xen_extra_mem_size += size;

		xen_max_p2m_pfn = PFN_DOWN(extra_start + size);

		for (pfn = PFN_DOWN(extra_start); pfn <= xen_max_p2m_pfn; pfn++)
		__set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
		}

		static unsigned long __init xen_release_chunk(phys_addr_t start_addr,
		@@ -104,7 +109,7 @@ static unsigned long __init xen_release_chunk(phys_addr_t start_addr,
		WARN(ret != 1, "Failed to release memory %lx-%lx err=%d\n",
		start, end, ret);
		if (ret == 1) {
		set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
		__set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
		len++;
		}
		}
		@@ -138,12 +143,55 @@ static unsigned long __init xen_return_unused_memory(unsigned long max_pfn,
		return released;
		}

		static unsigned long __init xen_set_identity(const struct e820entry *list,
		ssize_t map_size)
		{
		phys_addr_t last = xen_initial_domain() ? 0 : ISA_END_ADDRESS;
		phys_addr_t start_pci = last;
		const struct e820entry *entry;
		unsigned long identity = 0;
		int i;

		for (i = 0, entry = list; i < map_size; i++, entry++) {
		phys_addr_t start = entry->addr;
		phys_addr_t end = start + entry->size;

		if (start < last)
		start = last;

		if (end <= start)
		continue;

		/* Skip over the 1MB region. */
		if (last > end)
		continue;

		if (entry->type == E820_RAM) {
		if (start > start_pci)
		identity += set_phys_range_identity(
		PFN_UP(start_pci), PFN_DOWN(start));

		/* Without saving 'last' we would gooble RAM too
		* at the end of the loop. */
		last = end;
		start_pci = end;
		continue;
		}
		start_pci = min(start, start_pci);
		last = end;
		}
		if (last > start_pci)
		identity += set_phys_range_identity(
		PFN_UP(start_pci), PFN_DOWN(last));
		return identity;
		}
		/**
		* machine_specific_memory_setup - Hook for machine specific memory setup.
		**/
		char * __init xen_memory_setup(void)
		{
		static struct e820entry map[E820MAX] __initdata;
		static struct e820entry map_raw[E820MAX] __initdata;

		unsigned long max_pfn = xen_start_info->nr_pages;
		unsigned long long mem_end;
		@@ -151,6 +199,7 @@ char * __init xen_memory_setup(void)
		struct xen_memory_map memmap;
		unsigned long extra_pages = 0;
		unsigned long extra_limit;
		unsigned long identity_pages = 0;
		int i;
		int op;

		@@ -176,6 +225,7 @@ char * __init xen_memory_setup(void)
		}
		BUG_ON(rc);

		memcpy(map_raw, map, sizeof(map));
		e820.nr_map = 0;
		xen_extra_mem_start = mem_end;
		for (i = 0; i < memmap.nr_entries; i++) {
		@@ -194,6 +244,15 @@ char * __init xen_memory_setup(void)
		end -= delta;

		extra_pages += PFN_DOWN(delta);
		/*
		* Set RAM below 4GB that is not for us to be unusable.
		* This prevents "System RAM" address space from being
		* used as potential resource for I/O address (happens
		* when 'allocate_resource' is called).
		*/
		if (delta &&
		(xen_initial_domain() && end < 0x100000000ULL))
		e820_add_region(end, delta, E820_UNUSABLE);
		}

		if (map[i].size > 0 && end > xen_extra_mem_start)
		@@ -251,6 +310,13 @@ char * __init xen_memory_setup(void)

		xen_add_extra_mem(extra_pages);

		/*
		* Set P2M for all non-RAM pages and E820 gaps to be identity
		* type PFNs. We supply it with the non-sanitized version
		* of the E820.
		*/
		identity_pages = xen_set_identity(map_raw, memmap.nr_entries);
		printk(KERN_INFO "Set %ld page(s) to 1-1 mapping.\n", identity_pages);
		return "Xen";
		}

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