1298 lines
37 KiB
C
1298 lines
37 KiB
C
/*
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* Xen leaves the responsibility for maintaining p2m mappings to the
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* guests themselves, but it must also access and update the p2m array
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* during suspend/resume when all the pages are reallocated.
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*
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* The p2m table is logically a flat array, but we implement it as a
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* three-level tree to allow the address space to be sparse.
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*
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* Xen
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* |
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* p2m_top p2m_top_mfn
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* / \ / \
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* p2m_mid p2m_mid p2m_mid_mfn p2m_mid_mfn
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* / \ / \ / /
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* p2m p2m p2m p2m p2m p2m p2m ...
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*
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* The p2m_mid_mfn pages are mapped by p2m_top_mfn_p.
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*
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* The p2m_top and p2m_top_mfn levels are limited to 1 page, so the
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* maximum representable pseudo-physical address space is:
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* P2M_TOP_PER_PAGE * P2M_MID_PER_PAGE * P2M_PER_PAGE pages
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*
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* P2M_PER_PAGE depends on the architecture, as a mfn is always
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* unsigned long (8 bytes on 64-bit, 4 bytes on 32), leading to
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* 512 and 1024 entries respectively.
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*
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* In short, these structures contain the Machine Frame Number (MFN) of the PFN.
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*
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* However not all entries are filled with MFNs. Specifically for all other
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* leaf entries, or for the top root, or middle one, for which there is a void
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* entry, we assume it is "missing". So (for example)
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* pfn_to_mfn(0x90909090)=INVALID_P2M_ENTRY.
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*
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* We also have the possibility of setting 1-1 mappings on certain regions, so
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* that:
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* pfn_to_mfn(0xc0000)=0xc0000
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*
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* The benefit of this is, that we can assume for non-RAM regions (think
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* PCI BARs, or ACPI spaces), we can create mappings easily because we
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* get the PFN value to match the MFN.
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*
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* For this to work efficiently we have one new page p2m_identity and
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* allocate (via reserved_brk) any other pages we need to cover the sides
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* (1GB or 4MB boundary violations). All entries in p2m_identity are set to
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* INVALID_P2M_ENTRY type (Xen toolstack only recognizes that and MFNs,
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* no other fancy value).
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*
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* On lookup we spot that the entry points to p2m_identity and return the
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* identity value instead of dereferencing and returning INVALID_P2M_ENTRY.
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* If the entry points to an allocated page, we just proceed as before and
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* return the PFN. If the PFN has IDENTITY_FRAME_BIT set we unmask that in
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* appropriate functions (pfn_to_mfn).
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*
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* The reason for having the IDENTITY_FRAME_BIT instead of just returning the
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* PFN is that we could find ourselves where pfn_to_mfn(pfn)==pfn for a
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* non-identity pfn. To protect ourselves against we elect to set (and get) the
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* IDENTITY_FRAME_BIT on all identity mapped PFNs.
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*
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* This simplistic diagram is used to explain the more subtle piece of code.
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* There is also a digram of the P2M at the end that can help.
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* Imagine your E820 looking as so:
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*
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* 1GB 2GB 4GB
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* /-------------------+---------\/----\ /----------\ /---+-----\
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* | System RAM | Sys RAM ||ACPI| | reserved | | Sys RAM |
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* \-------------------+---------/\----/ \----------/ \---+-----/
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* ^- 1029MB ^- 2001MB
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*
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* [1029MB = 263424 (0x40500), 2001MB = 512256 (0x7D100),
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* 2048MB = 524288 (0x80000)]
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*
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* And dom0_mem=max:3GB,1GB is passed in to the guest, meaning memory past 1GB
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* is actually not present (would have to kick the balloon driver to put it in).
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*
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* When we are told to set the PFNs for identity mapping (see patch: "xen/setup:
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* Set identity mapping for non-RAM E820 and E820 gaps.") we pass in the start
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* of the PFN and the end PFN (263424 and 512256 respectively). The first step
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* is to reserve_brk a top leaf page if the p2m[1] is missing. The top leaf page
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* covers 512^2 of page estate (1GB) and in case the start or end PFN is not
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* aligned on 512^2*PAGE_SIZE (1GB) we reserve_brk new middle and leaf pages as
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* required to split any existing p2m_mid_missing middle pages.
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*
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* With the E820 example above, 263424 is not 1GB aligned so we allocate a
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* reserve_brk page which will cover the PFNs estate from 0x40000 to 0x80000.
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* Each entry in the allocate page is "missing" (points to p2m_missing).
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*
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* Next stage is to determine if we need to do a more granular boundary check
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* on the 4MB (or 2MB depending on architecture) off the start and end pfn's.
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* We check if the start pfn and end pfn violate that boundary check, and if
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* so reserve_brk a (p2m[x][y]) leaf page. This way we have a much finer
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* granularity of setting which PFNs are missing and which ones are identity.
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* In our example 263424 and 512256 both fail the check so we reserve_brk two
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* pages. Populate them with INVALID_P2M_ENTRY (so they both have "missing"
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* values) and assign them to p2m[1][2] and p2m[1][488] respectively.
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*
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* At this point we would at minimum reserve_brk one page, but could be up to
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* three. Each call to set_phys_range_identity has at maximum a three page
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* cost. If we were to query the P2M at this stage, all those entries from
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* start PFN through end PFN (so 1029MB -> 2001MB) would return
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* INVALID_P2M_ENTRY ("missing").
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*
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* The next step is to walk from the start pfn to the end pfn setting
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* the IDENTITY_FRAME_BIT on each PFN. This is done in set_phys_range_identity.
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* If we find that the middle entry is pointing to p2m_missing we can swap it
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* over to p2m_identity - this way covering 4MB (or 2MB) PFN space (and
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* similarly swapping p2m_mid_missing for p2m_mid_identity for larger regions).
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* At this point we do not need to worry about boundary aligment (so no need to
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* reserve_brk a middle page, figure out which PFNs are "missing" and which
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* ones are identity), as that has been done earlier. If we find that the
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* middle leaf is not occupied by p2m_identity or p2m_missing, we dereference
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* that page (which covers 512 PFNs) and set the appropriate PFN with
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* IDENTITY_FRAME_BIT. In our example 263424 and 512256 end up there, and we
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* set from p2m[1][2][256->511] and p2m[1][488][0->256] with
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* IDENTITY_FRAME_BIT set.
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*
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* All other regions that are void (or not filled) either point to p2m_missing
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* (considered missing) or have the default value of INVALID_P2M_ENTRY (also
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* considered missing). In our case, p2m[1][2][0->255] and p2m[1][488][257->511]
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* contain the INVALID_P2M_ENTRY value and are considered "missing."
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*
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* Finally, the region beyond the end of of the E820 (4 GB in this example)
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* is set to be identity (in case there are MMIO regions placed here).
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*
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* This is what the p2m ends up looking (for the E820 above) with this
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* fabulous drawing:
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*
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* p2m /--------------\
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* /-----\ | &mfn_list[0],| /-----------------\
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* | 0 |------>| &mfn_list[1],| /---------------\ | ~0, ~0, .. |
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* |-----| | ..., ~0, ~0 | | ~0, ~0, [x]---+----->| IDENTITY [@256] |
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* | 1 |---\ \--------------/ | [p2m_identity]+\ | IDENTITY [@257] |
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* |-----| \ | [p2m_identity]+\\ | .... |
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* | 2 |--\ \-------------------->| ... | \\ \----------------/
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* |-----| \ \---------------/ \\
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* | 3 |-\ \ \\ p2m_identity [1]
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* |-----| \ \-------------------->/---------------\ /-----------------\
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* | .. |\ | | [p2m_identity]+-->| ~0, ~0, ~0, ... |
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* \-----/ | | | [p2m_identity]+-->| ..., ~0 |
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* | | | .... | \-----------------/
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* | | +-[x], ~0, ~0.. +\
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* | | \---------------/ \
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* | | \-> /---------------\
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* | V p2m_mid_missing p2m_missing | IDENTITY[@0] |
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* | /-----------------\ /------------\ | IDENTITY[@256]|
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* | | [p2m_missing] +---->| ~0, ~0, ...| | ~0, ~0, .... |
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* | | [p2m_missing] +---->| ..., ~0 | \---------------/
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* | | ... | \------------/
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* | \-----------------/
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* |
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* | p2m_mid_identity
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* | /-----------------\
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* \-->| [p2m_identity] +---->[1]
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* | [p2m_identity] +---->[1]
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* | ... |
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* \-----------------/
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*
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* where ~0 is INVALID_P2M_ENTRY. IDENTITY is (PFN | IDENTITY_BIT)
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/list.h>
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#include <linux/hash.h>
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#include <linux/sched.h>
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#include <linux/seq_file.h>
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#include <linux/bootmem.h>
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#include <asm/cache.h>
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#include <asm/setup.h>
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#include <asm/xen/page.h>
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#include <asm/xen/hypercall.h>
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#include <asm/xen/hypervisor.h>
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#include <xen/balloon.h>
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#include <xen/grant_table.h>
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#include "p2m.h"
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#include "multicalls.h"
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#include "xen-ops.h"
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static void __init m2p_override_init(void);
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unsigned long xen_max_p2m_pfn __read_mostly;
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static unsigned long *p2m_mid_missing_mfn;
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static unsigned long *p2m_top_mfn;
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static unsigned long **p2m_top_mfn_p;
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/* Placeholders for holes in the address space */
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static RESERVE_BRK_ARRAY(unsigned long, p2m_missing, P2M_PER_PAGE);
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static RESERVE_BRK_ARRAY(unsigned long *, p2m_mid_missing, P2M_MID_PER_PAGE);
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static RESERVE_BRK_ARRAY(unsigned long **, p2m_top, P2M_TOP_PER_PAGE);
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static RESERVE_BRK_ARRAY(unsigned long, p2m_identity, P2M_PER_PAGE);
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static RESERVE_BRK_ARRAY(unsigned long *, p2m_mid_identity, P2M_MID_PER_PAGE);
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RESERVE_BRK(p2m_mid, PAGE_SIZE * (MAX_DOMAIN_PAGES / (P2M_PER_PAGE * P2M_MID_PER_PAGE)));
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/* For each I/O range remapped we may lose up to two leaf pages for the boundary
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* violations and three mid pages to cover up to 3GB. With
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* early_can_reuse_p2m_middle() most of the leaf pages will be reused by the
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* remapped region.
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*/
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RESERVE_BRK(p2m_identity_remap, PAGE_SIZE * 2 * 3 * MAX_REMAP_RANGES);
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static inline unsigned p2m_top_index(unsigned long pfn)
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{
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BUG_ON(pfn >= MAX_P2M_PFN);
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return pfn / (P2M_MID_PER_PAGE * P2M_PER_PAGE);
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}
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static inline unsigned p2m_mid_index(unsigned long pfn)
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{
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return (pfn / P2M_PER_PAGE) % P2M_MID_PER_PAGE;
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}
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static inline unsigned p2m_index(unsigned long pfn)
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{
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return pfn % P2M_PER_PAGE;
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}
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static void p2m_top_init(unsigned long ***top)
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{
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unsigned i;
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for (i = 0; i < P2M_TOP_PER_PAGE; i++)
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top[i] = p2m_mid_missing;
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}
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static void p2m_top_mfn_init(unsigned long *top)
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{
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unsigned i;
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for (i = 0; i < P2M_TOP_PER_PAGE; i++)
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top[i] = virt_to_mfn(p2m_mid_missing_mfn);
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}
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static void p2m_top_mfn_p_init(unsigned long **top)
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{
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unsigned i;
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for (i = 0; i < P2M_TOP_PER_PAGE; i++)
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top[i] = p2m_mid_missing_mfn;
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}
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static void p2m_mid_init(unsigned long **mid, unsigned long *leaf)
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{
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unsigned i;
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for (i = 0; i < P2M_MID_PER_PAGE; i++)
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mid[i] = leaf;
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}
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static void p2m_mid_mfn_init(unsigned long *mid, unsigned long *leaf)
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{
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unsigned i;
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for (i = 0; i < P2M_MID_PER_PAGE; i++)
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mid[i] = virt_to_mfn(leaf);
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}
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static void p2m_init(unsigned long *p2m)
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{
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unsigned i;
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for (i = 0; i < P2M_MID_PER_PAGE; i++)
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p2m[i] = INVALID_P2M_ENTRY;
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}
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/*
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* Build the parallel p2m_top_mfn and p2m_mid_mfn structures
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*
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* This is called both at boot time, and after resuming from suspend:
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* - At boot time we're called rather early, and must use alloc_bootmem*()
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* to allocate memory.
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*
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* - After resume we're called from within stop_machine, but the mfn
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* tree should already be completely allocated.
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*/
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void __ref xen_build_mfn_list_list(void)
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{
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unsigned long pfn;
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if (xen_feature(XENFEAT_auto_translated_physmap))
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return;
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/* Pre-initialize p2m_top_mfn to be completely missing */
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if (p2m_top_mfn == NULL) {
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p2m_mid_missing_mfn = alloc_bootmem_align(PAGE_SIZE, PAGE_SIZE);
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p2m_mid_mfn_init(p2m_mid_missing_mfn, p2m_missing);
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p2m_top_mfn_p = alloc_bootmem_align(PAGE_SIZE, PAGE_SIZE);
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p2m_top_mfn_p_init(p2m_top_mfn_p);
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p2m_top_mfn = alloc_bootmem_align(PAGE_SIZE, PAGE_SIZE);
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p2m_top_mfn_init(p2m_top_mfn);
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} else {
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/* Reinitialise, mfn's all change after migration */
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p2m_mid_mfn_init(p2m_mid_missing_mfn, p2m_missing);
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}
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for (pfn = 0; pfn < xen_max_p2m_pfn; pfn += P2M_PER_PAGE) {
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unsigned topidx = p2m_top_index(pfn);
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unsigned mididx = p2m_mid_index(pfn);
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unsigned long **mid;
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unsigned long *mid_mfn_p;
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mid = p2m_top[topidx];
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mid_mfn_p = p2m_top_mfn_p[topidx];
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/* Don't bother allocating any mfn mid levels if
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* they're just missing, just update the stored mfn,
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* since all could have changed over a migrate.
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*/
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if (mid == p2m_mid_missing) {
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BUG_ON(mididx);
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BUG_ON(mid_mfn_p != p2m_mid_missing_mfn);
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p2m_top_mfn[topidx] = virt_to_mfn(p2m_mid_missing_mfn);
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pfn += (P2M_MID_PER_PAGE - 1) * P2M_PER_PAGE;
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continue;
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}
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if (mid_mfn_p == p2m_mid_missing_mfn) {
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/*
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* XXX boot-time only! We should never find
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* missing parts of the mfn tree after
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* runtime.
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*/
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mid_mfn_p = alloc_bootmem_align(PAGE_SIZE, PAGE_SIZE);
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p2m_mid_mfn_init(mid_mfn_p, p2m_missing);
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p2m_top_mfn_p[topidx] = mid_mfn_p;
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}
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p2m_top_mfn[topidx] = virt_to_mfn(mid_mfn_p);
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mid_mfn_p[mididx] = virt_to_mfn(mid[mididx]);
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}
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}
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void xen_setup_mfn_list_list(void)
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{
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if (xen_feature(XENFEAT_auto_translated_physmap))
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return;
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BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
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HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list =
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virt_to_mfn(p2m_top_mfn);
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HYPERVISOR_shared_info->arch.max_pfn = xen_max_p2m_pfn;
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}
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/* Set up p2m_top to point to the domain-builder provided p2m pages */
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void __init xen_build_dynamic_phys_to_machine(void)
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{
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unsigned long *mfn_list;
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unsigned long max_pfn;
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unsigned long pfn;
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if (xen_feature(XENFEAT_auto_translated_physmap))
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return;
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mfn_list = (unsigned long *)xen_start_info->mfn_list;
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max_pfn = min(MAX_DOMAIN_PAGES, xen_start_info->nr_pages);
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xen_max_p2m_pfn = max_pfn;
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p2m_missing = extend_brk(PAGE_SIZE, PAGE_SIZE);
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p2m_init(p2m_missing);
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p2m_identity = extend_brk(PAGE_SIZE, PAGE_SIZE);
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p2m_init(p2m_identity);
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p2m_mid_missing = extend_brk(PAGE_SIZE, PAGE_SIZE);
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p2m_mid_init(p2m_mid_missing, p2m_missing);
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p2m_mid_identity = extend_brk(PAGE_SIZE, PAGE_SIZE);
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p2m_mid_init(p2m_mid_identity, p2m_identity);
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p2m_top = extend_brk(PAGE_SIZE, PAGE_SIZE);
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p2m_top_init(p2m_top);
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/*
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* The domain builder gives us a pre-constructed p2m array in
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* mfn_list for all the pages initially given to us, so we just
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* need to graft that into our tree structure.
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*/
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for (pfn = 0; pfn < max_pfn; pfn += P2M_PER_PAGE) {
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unsigned topidx = p2m_top_index(pfn);
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unsigned mididx = p2m_mid_index(pfn);
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if (p2m_top[topidx] == p2m_mid_missing) {
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unsigned long **mid = extend_brk(PAGE_SIZE, PAGE_SIZE);
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p2m_mid_init(mid, p2m_missing);
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p2m_top[topidx] = mid;
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}
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/*
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* As long as the mfn_list has enough entries to completely
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* fill a p2m page, pointing into the array is ok. But if
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* not the entries beyond the last pfn will be undefined.
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*/
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if (unlikely(pfn + P2M_PER_PAGE > max_pfn)) {
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unsigned long p2midx;
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p2midx = max_pfn % P2M_PER_PAGE;
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for ( ; p2midx < P2M_PER_PAGE; p2midx++)
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mfn_list[pfn + p2midx] = INVALID_P2M_ENTRY;
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}
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p2m_top[topidx][mididx] = &mfn_list[pfn];
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}
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m2p_override_init();
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}
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#ifdef CONFIG_X86_64
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unsigned long __init xen_revector_p2m_tree(void)
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{
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unsigned long va_start;
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unsigned long va_end;
|
|
unsigned long pfn;
|
|
unsigned long pfn_free = 0;
|
|
unsigned long *mfn_list = NULL;
|
|
unsigned long size;
|
|
|
|
va_start = xen_start_info->mfn_list;
|
|
/*We copy in increments of P2M_PER_PAGE * sizeof(unsigned long),
|
|
* so make sure it is rounded up to that */
|
|
size = PAGE_ALIGN(xen_start_info->nr_pages * sizeof(unsigned long));
|
|
va_end = va_start + size;
|
|
|
|
/* If we were revectored already, don't do it again. */
|
|
if (va_start <= __START_KERNEL_map && va_start >= __PAGE_OFFSET)
|
|
return 0;
|
|
|
|
mfn_list = alloc_bootmem_align(size, PAGE_SIZE);
|
|
if (!mfn_list) {
|
|
pr_warn("Could not allocate space for a new P2M tree!\n");
|
|
return xen_start_info->mfn_list;
|
|
}
|
|
/* Fill it out with INVALID_P2M_ENTRY value */
|
|
memset(mfn_list, 0xFF, size);
|
|
|
|
for (pfn = 0; pfn < ALIGN(MAX_DOMAIN_PAGES, P2M_PER_PAGE); pfn += P2M_PER_PAGE) {
|
|
unsigned topidx = p2m_top_index(pfn);
|
|
unsigned mididx;
|
|
unsigned long *mid_p;
|
|
|
|
if (!p2m_top[topidx])
|
|
continue;
|
|
|
|
if (p2m_top[topidx] == p2m_mid_missing)
|
|
continue;
|
|
|
|
mididx = p2m_mid_index(pfn);
|
|
mid_p = p2m_top[topidx][mididx];
|
|
if (!mid_p)
|
|
continue;
|
|
if ((mid_p == p2m_missing) || (mid_p == p2m_identity))
|
|
continue;
|
|
|
|
if ((unsigned long)mid_p == INVALID_P2M_ENTRY)
|
|
continue;
|
|
|
|
/* The old va. Rebase it on mfn_list */
|
|
if (mid_p >= (unsigned long *)va_start && mid_p <= (unsigned long *)va_end) {
|
|
unsigned long *new;
|
|
|
|
if (pfn_free > (size / sizeof(unsigned long))) {
|
|
WARN(1, "Only allocated for %ld pages, but we want %ld!\n",
|
|
size / sizeof(unsigned long), pfn_free);
|
|
return 0;
|
|
}
|
|
new = &mfn_list[pfn_free];
|
|
|
|
copy_page(new, mid_p);
|
|
p2m_top[topidx][mididx] = &mfn_list[pfn_free];
|
|
|
|
pfn_free += P2M_PER_PAGE;
|
|
|
|
}
|
|
/* This should be the leafs allocated for identity from _brk. */
|
|
}
|
|
return (unsigned long)mfn_list;
|
|
|
|
}
|
|
#else
|
|
unsigned long __init xen_revector_p2m_tree(void)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
unsigned long get_phys_to_machine(unsigned long pfn)
|
|
{
|
|
unsigned topidx, mididx, idx;
|
|
|
|
if (unlikely(pfn >= MAX_P2M_PFN))
|
|
return IDENTITY_FRAME(pfn);
|
|
|
|
topidx = p2m_top_index(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);
|
|
|
|
static void *alloc_p2m_page(void)
|
|
{
|
|
return (void *)__get_free_page(GFP_KERNEL | __GFP_REPEAT);
|
|
}
|
|
|
|
static void free_p2m_page(void *p)
|
|
{
|
|
free_page((unsigned long)p);
|
|
}
|
|
|
|
/*
|
|
* Fully allocate the p2m structure for a given pfn. We need to check
|
|
* that both the top and mid levels are allocated, and make sure the
|
|
* parallel mfn tree is kept in sync. We may race with other cpus, so
|
|
* the new pages are installed with cmpxchg; if we lose the race then
|
|
* simply free the page we allocated and use the one that's there.
|
|
*/
|
|
static bool alloc_p2m(unsigned long pfn)
|
|
{
|
|
unsigned topidx, mididx;
|
|
unsigned long ***top_p, **mid;
|
|
unsigned long *top_mfn_p, *mid_mfn;
|
|
unsigned long *p2m_orig;
|
|
|
|
topidx = p2m_top_index(pfn);
|
|
mididx = p2m_mid_index(pfn);
|
|
|
|
top_p = &p2m_top[topidx];
|
|
mid = ACCESS_ONCE(*top_p);
|
|
|
|
if (mid == p2m_mid_missing) {
|
|
/* Mid level is missing, allocate a new one */
|
|
mid = alloc_p2m_page();
|
|
if (!mid)
|
|
return false;
|
|
|
|
p2m_mid_init(mid, p2m_missing);
|
|
|
|
if (cmpxchg(top_p, p2m_mid_missing, mid) != p2m_mid_missing)
|
|
free_p2m_page(mid);
|
|
}
|
|
|
|
top_mfn_p = &p2m_top_mfn[topidx];
|
|
mid_mfn = ACCESS_ONCE(p2m_top_mfn_p[topidx]);
|
|
|
|
BUG_ON(virt_to_mfn(mid_mfn) != *top_mfn_p);
|
|
|
|
if (mid_mfn == p2m_mid_missing_mfn) {
|
|
/* Separately check the mid mfn level */
|
|
unsigned long missing_mfn;
|
|
unsigned long mid_mfn_mfn;
|
|
unsigned long old_mfn;
|
|
|
|
mid_mfn = alloc_p2m_page();
|
|
if (!mid_mfn)
|
|
return false;
|
|
|
|
p2m_mid_mfn_init(mid_mfn, p2m_missing);
|
|
|
|
missing_mfn = virt_to_mfn(p2m_mid_missing_mfn);
|
|
mid_mfn_mfn = virt_to_mfn(mid_mfn);
|
|
old_mfn = cmpxchg(top_mfn_p, missing_mfn, mid_mfn_mfn);
|
|
if (old_mfn != missing_mfn) {
|
|
free_p2m_page(mid_mfn);
|
|
mid_mfn = mfn_to_virt(old_mfn);
|
|
} else {
|
|
p2m_top_mfn_p[topidx] = mid_mfn;
|
|
}
|
|
}
|
|
|
|
p2m_orig = ACCESS_ONCE(p2m_top[topidx][mididx]);
|
|
if (p2m_orig == p2m_identity || p2m_orig == p2m_missing) {
|
|
/* p2m leaf page is missing */
|
|
unsigned long *p2m;
|
|
|
|
p2m = alloc_p2m_page();
|
|
if (!p2m)
|
|
return false;
|
|
|
|
p2m_init(p2m);
|
|
|
|
if (cmpxchg(&mid[mididx], p2m_orig, p2m) != p2m_orig)
|
|
free_p2m_page(p2m);
|
|
else
|
|
mid_mfn[mididx] = virt_to_mfn(p2m);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static bool __init early_alloc_p2m(unsigned long pfn, bool check_boundary)
|
|
{
|
|
unsigned topidx, mididx, idx;
|
|
unsigned long *p2m;
|
|
|
|
topidx = p2m_top_index(pfn);
|
|
mididx = p2m_mid_index(pfn);
|
|
idx = p2m_index(pfn);
|
|
|
|
/* Pfff.. No boundary cross-over, lets get out. */
|
|
if (!idx && check_boundary)
|
|
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: */
|
|
p2m = extend_brk(PAGE_SIZE, PAGE_SIZE);
|
|
|
|
p2m_init(p2m);
|
|
|
|
p2m_top[topidx][mididx] = p2m;
|
|
|
|
return true;
|
|
}
|
|
|
|
static bool __init early_alloc_p2m_middle(unsigned long pfn)
|
|
{
|
|
unsigned topidx = p2m_top_index(pfn);
|
|
unsigned long **mid;
|
|
|
|
mid = p2m_top[topidx];
|
|
if (mid == p2m_mid_missing) {
|
|
mid = extend_brk(PAGE_SIZE, PAGE_SIZE);
|
|
|
|
p2m_mid_init(mid, p2m_missing);
|
|
|
|
p2m_top[topidx] = mid;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Skim over the P2M tree looking at pages that are either filled with
|
|
* INVALID_P2M_ENTRY or with 1:1 PFNs. If found, re-use that page and
|
|
* replace the P2M leaf with a p2m_missing or p2m_identity.
|
|
* Stick the old page in the new P2M tree location.
|
|
*/
|
|
static bool __init early_can_reuse_p2m_middle(unsigned long set_pfn)
|
|
{
|
|
unsigned topidx;
|
|
unsigned mididx;
|
|
unsigned ident_pfns;
|
|
unsigned inv_pfns;
|
|
unsigned long *p2m;
|
|
unsigned idx;
|
|
unsigned long pfn;
|
|
|
|
/* We only look when this entails a P2M middle layer */
|
|
if (p2m_index(set_pfn))
|
|
return false;
|
|
|
|
for (pfn = 0; pfn < MAX_DOMAIN_PAGES; pfn += P2M_PER_PAGE) {
|
|
topidx = p2m_top_index(pfn);
|
|
|
|
if (!p2m_top[topidx])
|
|
continue;
|
|
|
|
if (p2m_top[topidx] == p2m_mid_missing)
|
|
continue;
|
|
|
|
mididx = p2m_mid_index(pfn);
|
|
p2m = p2m_top[topidx][mididx];
|
|
if (!p2m)
|
|
continue;
|
|
|
|
if ((p2m == p2m_missing) || (p2m == p2m_identity))
|
|
continue;
|
|
|
|
if ((unsigned long)p2m == INVALID_P2M_ENTRY)
|
|
continue;
|
|
|
|
ident_pfns = 0;
|
|
inv_pfns = 0;
|
|
for (idx = 0; idx < P2M_PER_PAGE; idx++) {
|
|
/* IDENTITY_PFNs are 1:1 */
|
|
if (p2m[idx] == IDENTITY_FRAME(pfn + idx))
|
|
ident_pfns++;
|
|
else if (p2m[idx] == INVALID_P2M_ENTRY)
|
|
inv_pfns++;
|
|
else
|
|
break;
|
|
}
|
|
if ((ident_pfns == P2M_PER_PAGE) || (inv_pfns == P2M_PER_PAGE))
|
|
goto found;
|
|
}
|
|
return false;
|
|
found:
|
|
/* Found one, replace old with p2m_identity or p2m_missing */
|
|
p2m_top[topidx][mididx] = (ident_pfns ? p2m_identity : p2m_missing);
|
|
|
|
/* Reset where we want to stick the old page in. */
|
|
topidx = p2m_top_index(set_pfn);
|
|
mididx = p2m_mid_index(set_pfn);
|
|
|
|
/* This shouldn't happen */
|
|
if (WARN_ON(p2m_top[topidx] == p2m_mid_missing))
|
|
early_alloc_p2m_middle(set_pfn);
|
|
|
|
if (WARN_ON(p2m_top[topidx][mididx] != p2m_missing))
|
|
return false;
|
|
|
|
p2m_init(p2m);
|
|
p2m_top[topidx][mididx] = p2m;
|
|
|
|
return true;
|
|
}
|
|
bool __init early_set_phys_to_machine(unsigned long pfn, unsigned long mfn)
|
|
{
|
|
if (unlikely(!__set_phys_to_machine(pfn, mfn))) {
|
|
if (!early_alloc_p2m_middle(pfn))
|
|
return false;
|
|
|
|
if (early_can_reuse_p2m_middle(pfn))
|
|
return __set_phys_to_machine(pfn, mfn);
|
|
|
|
if (!early_alloc_p2m(pfn, false /* boundary crossover OK!*/))
|
|
return false;
|
|
|
|
if (!__set_phys_to_machine(pfn, mfn))
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static void __init early_split_p2m(unsigned long pfn)
|
|
{
|
|
unsigned long mididx, idx;
|
|
|
|
mididx = p2m_mid_index(pfn);
|
|
idx = p2m_index(pfn);
|
|
|
|
/*
|
|
* Allocate new middle and leaf pages if this pfn lies in the
|
|
* middle of one.
|
|
*/
|
|
if (mididx || idx)
|
|
early_alloc_p2m_middle(pfn);
|
|
if (idx)
|
|
early_alloc_p2m(pfn, false);
|
|
}
|
|
|
|
unsigned long __init set_phys_range_identity(unsigned long pfn_s,
|
|
unsigned long pfn_e)
|
|
{
|
|
unsigned long pfn;
|
|
|
|
if (unlikely(pfn_s >= 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;
|
|
|
|
if (pfn_e > MAX_P2M_PFN)
|
|
pfn_e = MAX_P2M_PFN;
|
|
|
|
early_split_p2m(pfn_s);
|
|
early_split_p2m(pfn_e);
|
|
|
|
for (pfn = pfn_s; pfn < pfn_e;) {
|
|
unsigned topidx = p2m_top_index(pfn);
|
|
unsigned mididx = p2m_mid_index(pfn);
|
|
|
|
if (!__set_phys_to_machine(pfn, IDENTITY_FRAME(pfn)))
|
|
break;
|
|
pfn++;
|
|
|
|
/*
|
|
* If the PFN was set to a middle or leaf identity
|
|
* page the remainder must also be identity, so skip
|
|
* ahead to the next middle or leaf entry.
|
|
*/
|
|
if (p2m_top[topidx] == p2m_mid_identity)
|
|
pfn = ALIGN(pfn, P2M_MID_PER_PAGE * P2M_PER_PAGE);
|
|
else if (p2m_top[topidx][mididx] == p2m_identity)
|
|
pfn = ALIGN(pfn, P2M_PER_PAGE);
|
|
}
|
|
|
|
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));
|
|
|
|
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;
|
|
|
|
/* don't track P2M changes in autotranslate guests */
|
|
if (unlikely(xen_feature(XENFEAT_auto_translated_physmap)))
|
|
return true;
|
|
|
|
if (unlikely(pfn >= MAX_P2M_PFN)) {
|
|
BUG_ON(mfn != INVALID_P2M_ENTRY);
|
|
return true;
|
|
}
|
|
|
|
topidx = p2m_top_index(pfn);
|
|
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.
|
|
*
|
|
* set_phys_range_identity() will have allocated new middle
|
|
* and leaf pages as required so an existing p2m_mid_missing
|
|
* or p2m_missing mean that whole range will be identity so
|
|
* these can be switched to p2m_mid_identity or p2m_identity.
|
|
*/
|
|
if (mfn != INVALID_P2M_ENTRY && (mfn & IDENTITY_FRAME_BIT)) {
|
|
if (p2m_top[topidx] == p2m_mid_identity)
|
|
return true;
|
|
|
|
if (p2m_top[topidx] == p2m_mid_missing) {
|
|
WARN_ON(cmpxchg(&p2m_top[topidx], p2m_mid_missing,
|
|
p2m_mid_identity) != p2m_mid_missing);
|
|
return true;
|
|
}
|
|
|
|
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;
|
|
|
|
p2m_top[topidx][mididx][idx] = mfn;
|
|
|
|
return true;
|
|
}
|
|
|
|
bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
|
|
{
|
|
if (unlikely(!__set_phys_to_machine(pfn, mfn))) {
|
|
if (!alloc_p2m(pfn))
|
|
return false;
|
|
|
|
if (!__set_phys_to_machine(pfn, mfn))
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
#define M2P_OVERRIDE_HASH_SHIFT 10
|
|
#define M2P_OVERRIDE_HASH (1 << M2P_OVERRIDE_HASH_SHIFT)
|
|
|
|
static RESERVE_BRK_ARRAY(struct list_head, m2p_overrides, M2P_OVERRIDE_HASH);
|
|
static DEFINE_SPINLOCK(m2p_override_lock);
|
|
|
|
static void __init m2p_override_init(void)
|
|
{
|
|
unsigned i;
|
|
|
|
m2p_overrides = extend_brk(sizeof(*m2p_overrides) * M2P_OVERRIDE_HASH,
|
|
sizeof(unsigned long));
|
|
|
|
for (i = 0; i < M2P_OVERRIDE_HASH; i++)
|
|
INIT_LIST_HEAD(&m2p_overrides[i]);
|
|
}
|
|
|
|
static unsigned long mfn_hash(unsigned long mfn)
|
|
{
|
|
return hash_long(mfn, M2P_OVERRIDE_HASH_SHIFT);
|
|
}
|
|
|
|
int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
|
|
struct gnttab_map_grant_ref *kmap_ops,
|
|
struct page **pages, unsigned int count)
|
|
{
|
|
int i, ret = 0;
|
|
bool lazy = false;
|
|
pte_t *pte;
|
|
|
|
if (xen_feature(XENFEAT_auto_translated_physmap))
|
|
return 0;
|
|
|
|
if (kmap_ops &&
|
|
!in_interrupt() &&
|
|
paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) {
|
|
arch_enter_lazy_mmu_mode();
|
|
lazy = true;
|
|
}
|
|
|
|
for (i = 0; i < count; i++) {
|
|
unsigned long mfn, pfn;
|
|
|
|
/* Do not add to override if the map failed. */
|
|
if (map_ops[i].status)
|
|
continue;
|
|
|
|
if (map_ops[i].flags & GNTMAP_contains_pte) {
|
|
pte = (pte_t *) (mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) +
|
|
(map_ops[i].host_addr & ~PAGE_MASK));
|
|
mfn = pte_mfn(*pte);
|
|
} else {
|
|
mfn = PFN_DOWN(map_ops[i].dev_bus_addr);
|
|
}
|
|
pfn = page_to_pfn(pages[i]);
|
|
|
|
WARN_ON(PagePrivate(pages[i]));
|
|
SetPagePrivate(pages[i]);
|
|
set_page_private(pages[i], mfn);
|
|
pages[i]->index = pfn_to_mfn(pfn);
|
|
|
|
if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
if (kmap_ops) {
|
|
ret = m2p_add_override(mfn, pages[i], &kmap_ops[i]);
|
|
if (ret)
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
out:
|
|
if (lazy)
|
|
arch_leave_lazy_mmu_mode();
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(set_foreign_p2m_mapping);
|
|
|
|
/* Add an MFN override for a particular page */
|
|
int m2p_add_override(unsigned long mfn, struct page *page,
|
|
struct gnttab_map_grant_ref *kmap_op)
|
|
{
|
|
unsigned long flags;
|
|
unsigned long pfn;
|
|
unsigned long uninitialized_var(address);
|
|
unsigned level;
|
|
pte_t *ptep = NULL;
|
|
|
|
pfn = page_to_pfn(page);
|
|
if (!PageHighMem(page)) {
|
|
address = (unsigned long)__va(pfn << PAGE_SHIFT);
|
|
ptep = lookup_address(address, &level);
|
|
if (WARN(ptep == NULL || level != PG_LEVEL_4K,
|
|
"m2p_add_override: pfn %lx not mapped", pfn))
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (kmap_op != NULL) {
|
|
if (!PageHighMem(page)) {
|
|
struct multicall_space mcs =
|
|
xen_mc_entry(sizeof(*kmap_op));
|
|
|
|
MULTI_grant_table_op(mcs.mc,
|
|
GNTTABOP_map_grant_ref, kmap_op, 1);
|
|
|
|
xen_mc_issue(PARAVIRT_LAZY_MMU);
|
|
}
|
|
}
|
|
spin_lock_irqsave(&m2p_override_lock, flags);
|
|
list_add(&page->lru, &m2p_overrides[mfn_hash(mfn)]);
|
|
spin_unlock_irqrestore(&m2p_override_lock, flags);
|
|
|
|
/* p2m(m2p(mfn)) == mfn: the mfn is already present somewhere in
|
|
* this domain. Set the FOREIGN_FRAME_BIT in the p2m for the other
|
|
* pfn so that the following mfn_to_pfn(mfn) calls will return the
|
|
* pfn from the m2p_override (the backend pfn) instead.
|
|
* We need to do this because the pages shared by the frontend
|
|
* (xen-blkfront) can be already locked (lock_page, called by
|
|
* do_read_cache_page); when the userspace backend tries to use them
|
|
* with direct_IO, mfn_to_pfn returns the pfn of the frontend, so
|
|
* do_blockdev_direct_IO is going to try to lock the same pages
|
|
* again resulting in a deadlock.
|
|
* As a side effect get_user_pages_fast might not be safe on the
|
|
* frontend pages while they are being shared with the backend,
|
|
* because mfn_to_pfn (that ends up being called by GUPF) will
|
|
* return the backend pfn rather than the frontend pfn. */
|
|
pfn = mfn_to_pfn_no_overrides(mfn);
|
|
if (get_phys_to_machine(pfn) == mfn)
|
|
set_phys_to_machine(pfn, FOREIGN_FRAME(mfn));
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(m2p_add_override);
|
|
|
|
int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
|
|
struct gnttab_map_grant_ref *kmap_ops,
|
|
struct page **pages, unsigned int count)
|
|
{
|
|
int i, ret = 0;
|
|
bool lazy = false;
|
|
|
|
if (xen_feature(XENFEAT_auto_translated_physmap))
|
|
return 0;
|
|
|
|
if (kmap_ops &&
|
|
!in_interrupt() &&
|
|
paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) {
|
|
arch_enter_lazy_mmu_mode();
|
|
lazy = true;
|
|
}
|
|
|
|
for (i = 0; i < count; i++) {
|
|
unsigned long mfn = get_phys_to_machine(page_to_pfn(pages[i]));
|
|
unsigned long pfn = page_to_pfn(pages[i]);
|
|
|
|
if (mfn == INVALID_P2M_ENTRY || !(mfn & FOREIGN_FRAME_BIT)) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
set_page_private(pages[i], INVALID_P2M_ENTRY);
|
|
WARN_ON(!PagePrivate(pages[i]));
|
|
ClearPagePrivate(pages[i]);
|
|
set_phys_to_machine(pfn, pages[i]->index);
|
|
|
|
if (kmap_ops)
|
|
ret = m2p_remove_override(pages[i], &kmap_ops[i], mfn);
|
|
if (ret)
|
|
goto out;
|
|
}
|
|
|
|
out:
|
|
if (lazy)
|
|
arch_leave_lazy_mmu_mode();
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clear_foreign_p2m_mapping);
|
|
|
|
int m2p_remove_override(struct page *page,
|
|
struct gnttab_map_grant_ref *kmap_op,
|
|
unsigned long mfn)
|
|
{
|
|
unsigned long flags;
|
|
unsigned long pfn;
|
|
unsigned long uninitialized_var(address);
|
|
unsigned level;
|
|
pte_t *ptep = NULL;
|
|
|
|
pfn = page_to_pfn(page);
|
|
|
|
if (!PageHighMem(page)) {
|
|
address = (unsigned long)__va(pfn << PAGE_SHIFT);
|
|
ptep = lookup_address(address, &level);
|
|
|
|
if (WARN(ptep == NULL || level != PG_LEVEL_4K,
|
|
"m2p_remove_override: pfn %lx not mapped", pfn))
|
|
return -EINVAL;
|
|
}
|
|
|
|
spin_lock_irqsave(&m2p_override_lock, flags);
|
|
list_del(&page->lru);
|
|
spin_unlock_irqrestore(&m2p_override_lock, flags);
|
|
|
|
if (kmap_op != NULL) {
|
|
if (!PageHighMem(page)) {
|
|
struct multicall_space mcs;
|
|
struct gnttab_unmap_and_replace *unmap_op;
|
|
struct page *scratch_page = get_balloon_scratch_page();
|
|
unsigned long scratch_page_address = (unsigned long)
|
|
__va(page_to_pfn(scratch_page) << PAGE_SHIFT);
|
|
|
|
/*
|
|
* It might be that we queued all the m2p grant table
|
|
* hypercalls in a multicall, then m2p_remove_override
|
|
* get called before the multicall has actually been
|
|
* issued. In this case handle is going to -1 because
|
|
* it hasn't been modified yet.
|
|
*/
|
|
if (kmap_op->handle == -1)
|
|
xen_mc_flush();
|
|
/*
|
|
* Now if kmap_op->handle is negative it means that the
|
|
* hypercall actually returned an error.
|
|
*/
|
|
if (kmap_op->handle == GNTST_general_error) {
|
|
printk(KERN_WARNING "m2p_remove_override: "
|
|
"pfn %lx mfn %lx, failed to modify kernel mappings",
|
|
pfn, mfn);
|
|
put_balloon_scratch_page();
|
|
return -1;
|
|
}
|
|
|
|
xen_mc_batch();
|
|
|
|
mcs = __xen_mc_entry(
|
|
sizeof(struct gnttab_unmap_and_replace));
|
|
unmap_op = mcs.args;
|
|
unmap_op->host_addr = kmap_op->host_addr;
|
|
unmap_op->new_addr = scratch_page_address;
|
|
unmap_op->handle = kmap_op->handle;
|
|
|
|
MULTI_grant_table_op(mcs.mc,
|
|
GNTTABOP_unmap_and_replace, unmap_op, 1);
|
|
|
|
mcs = __xen_mc_entry(0);
|
|
MULTI_update_va_mapping(mcs.mc, scratch_page_address,
|
|
pfn_pte(page_to_pfn(scratch_page),
|
|
PAGE_KERNEL_RO), 0);
|
|
|
|
xen_mc_issue(PARAVIRT_LAZY_MMU);
|
|
|
|
kmap_op->host_addr = 0;
|
|
put_balloon_scratch_page();
|
|
}
|
|
}
|
|
|
|
/* p2m(m2p(mfn)) == FOREIGN_FRAME(mfn): the mfn is already present
|
|
* somewhere in this domain, even before being added to the
|
|
* m2p_override (see comment above in m2p_add_override).
|
|
* If there are no other entries in the m2p_override corresponding
|
|
* to this mfn, then remove the FOREIGN_FRAME_BIT from the p2m for
|
|
* the original pfn (the one shared by the frontend): the backend
|
|
* cannot do any IO on this page anymore because it has been
|
|
* unshared. Removing the FOREIGN_FRAME_BIT from the p2m entry of
|
|
* the original pfn causes mfn_to_pfn(mfn) to return the frontend
|
|
* pfn again. */
|
|
mfn &= ~FOREIGN_FRAME_BIT;
|
|
pfn = mfn_to_pfn_no_overrides(mfn);
|
|
if (get_phys_to_machine(pfn) == FOREIGN_FRAME(mfn) &&
|
|
m2p_find_override(mfn) == NULL)
|
|
set_phys_to_machine(pfn, mfn);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(m2p_remove_override);
|
|
|
|
struct page *m2p_find_override(unsigned long mfn)
|
|
{
|
|
unsigned long flags;
|
|
struct list_head *bucket = &m2p_overrides[mfn_hash(mfn)];
|
|
struct page *p, *ret;
|
|
|
|
ret = NULL;
|
|
|
|
spin_lock_irqsave(&m2p_override_lock, flags);
|
|
|
|
list_for_each_entry(p, bucket, lru) {
|
|
if (page_private(p) == mfn) {
|
|
ret = p;
|
|
break;
|
|
}
|
|
}
|
|
|
|
spin_unlock_irqrestore(&m2p_override_lock, flags);
|
|
|
|
return ret;
|
|
}
|
|
|
|
unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn)
|
|
{
|
|
struct page *p = m2p_find_override(mfn);
|
|
unsigned long ret = pfn;
|
|
|
|
if (p)
|
|
ret = page_to_pfn(p);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(m2p_find_override_pfn);
|
|
|
|
#ifdef CONFIG_XEN_DEBUG_FS
|
|
#include <linux/debugfs.h>
|
|
#include "debugfs.h"
|
|
static int p2m_dump_show(struct seq_file *m, void *v)
|
|
{
|
|
static const char * const level_name[] = { "top", "middle",
|
|
"entry", "abnormal", "error"};
|
|
#define TYPE_IDENTITY 0
|
|
#define TYPE_MISSING 1
|
|
#define TYPE_PFN 2
|
|
#define TYPE_UNKNOWN 3
|
|
static const char * const type_name[] = {
|
|
[TYPE_IDENTITY] = "identity",
|
|
[TYPE_MISSING] = "missing",
|
|
[TYPE_PFN] = "pfn",
|
|
[TYPE_UNKNOWN] = "abnormal"};
|
|
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
|
|
}
|
|
|
|
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_p2m_debugfs(void)
|
|
{
|
|
struct dentry *d_xen = xen_init_debugfs();
|
|
|
|
if (d_xen == NULL)
|
|
return -ENOMEM;
|
|
|
|
d_mmu_debug = debugfs_create_dir("mmu", d_xen);
|
|
|
|
debugfs_create_file("p2m", 0600, d_mmu_debug, NULL, &p2m_dump_fops);
|
|
return 0;
|
|
}
|
|
fs_initcall(xen_p2m_debugfs);
|
|
#endif /* CONFIG_XEN_DEBUG_FS */
|