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kaf24@firebug.cl.cam.ac.uk
2928514138
Thus all can be disabled at compile time. It would be easy to make enabling/disabling a run-time option too. Signed-off-by: Keir Fraser <keir@xensource.com>
117 lines
3.6 KiB
C
117 lines
3.6 KiB
C
/*
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** xg_save_restore.h
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**
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** Defintions and utilities for save / restore.
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*/
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#include "xc_private.h"
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/*
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** We process save/restore/migrate in batches of pages; the below
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** determines how many pages we (at maximum) deal with in each batch.
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*/
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#define MAX_BATCH_SIZE 1024 /* up to 1024 pages (4MB) at a time */
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/* When pinning page tables at the end of restore, we also use batching. */
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#define MAX_PIN_BATCH 1024
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/*
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** Determine various platform information required for save/restore, in
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** particular:
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**
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** - the maximum MFN on this machine, used to compute the size of
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** the M2P table;
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**
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** - the starting virtual address of the the hypervisor; we use this
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** to determine which parts of guest address space(s) do and don't
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** require canonicalization during save/restore; and
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**
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** - the number of page-table levels for save/ restore. This should
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** be a property of the domain, but for the moment we just read it
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** from the hypervisor.
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**
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** Returns 1 on success, 0 on failure.
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*/
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static int get_platform_info(int xc_handle, uint32_t dom,
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/* OUT */ unsigned long *max_mfn,
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/* OUT */ unsigned long *hvirt_start,
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/* OUT */ unsigned int *pt_levels)
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{
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xen_capabilities_info_t xen_caps = "";
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xen_platform_parameters_t xen_params;
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if (xc_version(xc_handle, XENVER_platform_parameters, &xen_params) != 0)
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return 0;
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if (xc_version(xc_handle, XENVER_capabilities, &xen_caps) != 0)
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return 0;
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*max_mfn = xc_memory_op(xc_handle, XENMEM_maximum_ram_page, NULL);
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*hvirt_start = xen_params.virt_start;
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if (strstr(xen_caps, "xen-3.0-x86_64"))
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*pt_levels = 4;
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else if (strstr(xen_caps, "xen-3.0-x86_32p"))
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*pt_levels = 3;
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else if (strstr(xen_caps, "xen-3.0-x86_32"))
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*pt_levels = 2;
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else
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return 0;
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return 1;
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}
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/*
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** Save/restore deal with the mfn_to_pfn (M2P) and pfn_to_mfn (P2M) tables.
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** The M2P simply holds the corresponding PFN, while the top bit of a P2M
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** entry tell us whether or not the the PFN is currently mapped.
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*/
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#define PFN_TO_KB(_pfn) ((_pfn) << (PAGE_SHIFT - 10))
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#define ROUNDUP(_x,_w) (((unsigned long)(_x)+(1UL<<(_w))-1) & ~((1UL<<(_w))-1))
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/*
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** The M2P is made up of some number of 'chunks' of at least 2MB in size.
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** The below definitions and utility function(s) deal with mapping the M2P
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** regarldess of the underlying machine memory size or architecture.
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*/
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#define M2P_SHIFT L2_PAGETABLE_SHIFT_PAE
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#define M2P_CHUNK_SIZE (1 << M2P_SHIFT)
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#define M2P_SIZE(_m) ROUNDUP(((_m) * sizeof(xen_pfn_t)), M2P_SHIFT)
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#define M2P_CHUNKS(_m) (M2P_SIZE((_m)) >> M2P_SHIFT)
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/* Size in bytes of the P2M (rounded up to the nearest PAGE_SIZE bytes) */
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#define P2M_SIZE ROUNDUP((max_pfn * sizeof(xen_pfn_t)), PAGE_SHIFT)
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/* Number of xen_pfn_t in a page */
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#define fpp (PAGE_SIZE/sizeof(xen_pfn_t))
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/* Number of entries in the pfn_to_mfn_frame_list */
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#define P2M_FL_ENTRIES (((max_pfn)+fpp-1)/fpp)
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/* Size in bytes of the pfn_to_mfn_frame_list */
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#define P2M_FL_SIZE ((P2M_FL_ENTRIES)*sizeof(unsigned long))
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/* Number of entries in the pfn_to_mfn_frame_list_list */
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#define P2M_FLL_ENTRIES (((max_pfn)+(fpp*fpp)-1)/(fpp*fpp))
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/* Current guests allow 8MB 'slack' in their P2M */
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#define NR_SLACK_ENTRIES ((8 * 1024 * 1024) / PAGE_SIZE)
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/* Is the given PFN within the 'slack' region at the top of the P2M? */
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#define IS_REAL_PFN(_pfn) ((max_pfn - (_pfn)) > NR_SLACK_ENTRIES)
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/* Returns TRUE if the PFN is currently mapped */
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#define is_mapped(pfn_type) (!((pfn_type) & 0x80000000UL))
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#define INVALID_P2M_ENTRY (~0UL)
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