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2eaec0bc67baffbabdfd1436cf3f7d3adae435ab
xen/tools/libxc/xc_domain_restore.c
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/******************************************************************************
* xc_domain_restore.c
*
* Restore the state of a guest session.
*
* Copyright (c) 2003, K A Fraser.
* Copyright (c) 2006, Intel Corporation
* Copyright (c) 2007, XenSource Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
* Place - Suite 330, Boston, MA 02111-1307 USA.
*
*/
#include <stdlib.h>
#include <unistd.h>
#include "xg_private.h"
#include "xg_save_restore.h"
#include "xc_dom.h"
#include <xen/hvm/ioreq.h>
#include <xen/hvm/params.h>
/* max mfn of the current host machine */
static unsigned long max_mfn;
/* virtual starting address of the hypervisor */
static unsigned long hvirt_start;
/* #levels of page tables used by the current guest */
static unsigned int pt_levels;
/* number of pfns this guest has (i.e. number of entries in the P2M) */
static unsigned long p2m_size;
/* number of 'in use' pfns in the guest (i.e. #P2M entries with a valid mfn) */
static unsigned long nr_pfns;
/* Live mapping of the table mapping each PFN to its current MFN. */
static xen_pfn_t *live_p2m = NULL;
/* A table mapping each PFN to its new MFN. */
static xen_pfn_t *p2m = NULL;
/* A table of P2M mappings in the current region */
static xen_pfn_t *p2m_batch = NULL;
/* Address size of the guest, in bytes */
unsigned int guest_width;
static ssize_t
read_exact(int fd, void *buf, size_t count)
{
int r = 0, s;
unsigned char *b = buf;
while ( r < count )
{
s = read(fd, &b[r], count - r);
if ( (s == -1) && (errno == EINTR) )
continue;
if ( s <= 0 )
break;
r += s;
}
return (r == count);
}
/*
** In the state file (or during transfer), all page-table pages are
** converted into a 'canonical' form where references to actual mfns
** are replaced with references to the corresponding pfns.
** This function inverts that operation, replacing the pfn values with
** the (now known) appropriate mfn values.
*/
static int uncanonicalize_pagetable(int xc_handle, uint32_t dom,
unsigned long type, void *page)
{
int i, pte_last;
unsigned long pfn;
uint64_t pte;
int nr_mfns = 0;
pte_last = PAGE_SIZE / ((pt_levels == 2)? 4 : 8);
/* First pass: work out how many (if any) MFNs we need to alloc */
for ( i = 0; i < pte_last; i++ )
{
if ( pt_levels == 2 )
pte = ((uint32_t *)page)[i];
else
pte = ((uint64_t *)page)[i];
/* XXX SMH: below needs fixing for PROT_NONE etc */
if ( !(pte & _PAGE_PRESENT) )
continue;
pfn = (pte >> PAGE_SHIFT) & MFN_MASK_X86;
if ( pfn >= p2m_size )
{
/* This "page table page" is probably not one; bail. */
ERROR("Frame number in type %lu page table is out of range: "
"i=%d pfn=0x%lx p2m_size=%lu",
type >> 28, i, pfn, p2m_size);
return 0;
}
if ( p2m[pfn] == INVALID_P2M_ENTRY )
{
/* Have a 'valid' PFN without a matching MFN - need to alloc */
p2m_batch[nr_mfns++] = pfn;
p2m[pfn]--;
}
}
/* Allocate the requisite number of mfns. */
if ( nr_mfns &&
(xc_domain_memory_populate_physmap(xc_handle, dom, nr_mfns, 0, 0,
p2m_batch) != 0) )
{
ERROR("Failed to allocate memory for batch.!\n");
errno = ENOMEM;
return 0;
}
/* Second pass: uncanonicalize each present PTE */
nr_mfns = 0;
for ( i = 0; i < pte_last; i++ )
{
if ( pt_levels == 2 )
pte = ((uint32_t *)page)[i];
else
pte = ((uint64_t *)page)[i];
/* XXX SMH: below needs fixing for PROT_NONE etc */
if ( !(pte & _PAGE_PRESENT) )
continue;
pfn = (pte >> PAGE_SHIFT) & MFN_MASK_X86;
if ( p2m[pfn] == (INVALID_P2M_ENTRY-1) )
p2m[pfn] = p2m_batch[nr_mfns++];
pte &= ~MADDR_MASK_X86;
pte |= (uint64_t)p2m[pfn] << PAGE_SHIFT;
if ( pt_levels == 2 )
((uint32_t *)page)[i] = (uint32_t)pte;
else
((uint64_t *)page)[i] = (uint64_t)pte;
}
return 1;
}
/* Load the p2m frame list, plus potential extended info chunk */
static xen_pfn_t *load_p2m_frame_list(int io_fd, int *pae_extended_cr3)
{
xen_pfn_t *p2m_frame_list;
vcpu_guest_context_either_t ctxt;
xen_pfn_t p2m_fl_zero;
/* Read first entry of P2M list, or extended-info signature (~0UL). */
if ( !read_exact(io_fd, &p2m_fl_zero, sizeof(long)) )
{
ERROR("read extended-info signature failed");
return NULL;
}
if ( p2m_fl_zero == ~0UL )
{
uint32_t tot_bytes;
/* Next 4 bytes: total size of following extended info. */
if ( !read_exact(io_fd, &tot_bytes, sizeof(tot_bytes)) )
{
ERROR("read extended-info size failed");
return NULL;
}
while ( tot_bytes )
{
uint32_t chunk_bytes;
char chunk_sig[4];
/* 4-character chunk signature + 4-byte remaining chunk size. */
if ( !read_exact(io_fd, chunk_sig, sizeof(chunk_sig)) ||
!read_exact(io_fd, &chunk_bytes, sizeof(chunk_bytes)) )
{
ERROR("read extended-info chunk signature failed");
return NULL;
}
tot_bytes -= 8;
/* VCPU context structure? */
if ( !strncmp(chunk_sig, "vcpu", 4) )
{
/* Pick a guest word-size and PT depth from the ctxt size */
if ( chunk_bytes == sizeof (ctxt.x32) )
{
guest_width = 4;
if ( pt_levels > 2 )
pt_levels = 3;
}
else if ( chunk_bytes == sizeof (ctxt.x64) )
{
guest_width = 8;
pt_levels = 4;
}
else
{
ERROR("bad extended-info context size %d", chunk_bytes);
return NULL;
}
if ( !read_exact(io_fd, &ctxt, chunk_bytes) )
{
ERROR("read extended-info vcpu context failed");
return NULL;
}
tot_bytes -= chunk_bytes;
chunk_bytes = 0;
if ( GET_FIELD(&ctxt, vm_assist)
& (1UL << VMASST_TYPE_pae_extended_cr3) )
*pae_extended_cr3 = 1;
}
/* Any remaining bytes of this chunk: read and discard. */
while ( chunk_bytes )
{
unsigned long sz = MIN(chunk_bytes, sizeof(xen_pfn_t));
if ( !read_exact(io_fd, &p2m_fl_zero, sz) )
{
ERROR("read-and-discard extended-info chunk bytes failed");
return NULL;
}
chunk_bytes -= sz;
tot_bytes -= sz;
}
}
/* Now read the real first entry of P2M list. */
if ( !read_exact(io_fd, &p2m_fl_zero, sizeof(xen_pfn_t)) )
{
ERROR("read first entry of p2m_frame_list failed");
return NULL;
}
}
/* Now that we know the guest's word-size, can safely allocate
* the p2m frame list */
if ( (p2m_frame_list = malloc(P2M_FL_SIZE)) == NULL )
{
ERROR("Couldn't allocate p2m_frame_list array");
return NULL;
}
/* First entry has already been read. */
p2m_frame_list[0] = p2m_fl_zero;
if ( !read_exact(io_fd, &p2m_frame_list[1],
(P2M_FL_ENTRIES - 1) * sizeof(xen_pfn_t)) )
{
ERROR("read p2m_frame_list failed");
return NULL;
}
return p2m_frame_list;
}
int xc_domain_restore(int xc_handle, int io_fd, uint32_t dom,
unsigned int store_evtchn, unsigned long *store_mfn,
unsigned int console_evtchn, unsigned long *console_mfn,
unsigned int hvm, unsigned int pae)
{
DECLARE_DOMCTL;
int rc = 1, i, j, n, m, pae_extended_cr3 = 0;
unsigned long mfn, pfn;
unsigned int prev_pc, this_pc;
int verify = 0;
int nraces = 0;
/* The new domain's shared-info frame number. */
unsigned long shared_info_frame;
unsigned char shared_info_page[PAGE_SIZE]; /* saved contents from file */
shared_info_either_t *old_shared_info = (shared_info_either_t *)shared_info_page;
shared_info_either_t *new_shared_info;
/* A copy of the CPU context of the guest. */
vcpu_guest_context_either_t ctxt;
/* A table containing the type of each PFN (/not/ MFN!). */
unsigned long *pfn_type = NULL;
/* A table of MFNs to map in the current region */
xen_pfn_t *region_mfn = NULL;
/* Types of the pfns in the current region */
unsigned long region_pfn_type[MAX_BATCH_SIZE];
/* A copy of the pfn-to-mfn table frame list. */
xen_pfn_t *p2m_frame_list = NULL;
/* A temporary mapping of the guest's start_info page. */
start_info_either_t *start_info;
/* Our mapping of the current region (batch) */
char *region_base;
struct xc_mmu *mmu = NULL;
/* used by debug verify code */
unsigned long buf[PAGE_SIZE/sizeof(unsigned long)];
struct mmuext_op pin[MAX_PIN_BATCH];
unsigned int nr_pins;
uint64_t vcpumap = 1ULL;
unsigned int max_vcpu_id = 0;
int new_ctxt_format = 0;
/* Magic frames in HVM guests: ioreqs and xenstore comms. */
uint64_t magic_pfns[3]; /* ioreq_pfn, bufioreq_pfn, store_pfn */
/* Buffer for holding HVM context */
uint8_t *hvm_buf = NULL;
/* For info only */
nr_pfns = 0;
if ( !read_exact(io_fd, &p2m_size, sizeof(unsigned long)) )
{
ERROR("read: p2m_size");
goto out;
}
DPRINTF("xc_domain_restore start: p2m_size = %lx\n", p2m_size);
if ( !get_platform_info(xc_handle, dom,
&max_mfn, &hvirt_start, &pt_levels, &guest_width) )
{
ERROR("Unable to get platform info.");
return 1;
}
/* The *current* word size of the guest isn't very interesting; for now
* assume the guest will be the same as we are. We'll fix that later
* if we discover otherwise. */
guest_width = sizeof(unsigned long);
pt_levels = (guest_width == 8) ? 4 : (pt_levels == 2) ? 2 : 3;
if ( lock_pages(&ctxt, sizeof(ctxt)) )
{
/* needed for build domctl, but might as well do early */
ERROR("Unable to lock ctxt");
return 1;
}
if ( !hvm )
{
/* Load the p2m frame list, plus potential extended info chunk */
p2m_frame_list = load_p2m_frame_list(io_fd, &pae_extended_cr3);
if ( !p2m_frame_list )
goto out;
/* Now that we know the word size, tell Xen about it */
memset(&domctl, 0, sizeof(domctl));
domctl.domain = dom;
domctl.cmd = XEN_DOMCTL_set_address_size;
domctl.u.address_size.size = guest_width * 8;
rc = do_domctl(xc_handle, &domctl);
if ( rc != 0 )
{
ERROR("Unable to set guest address size.");
goto out;
}
rc = 1;
}
/* We want zeroed memory so use calloc rather than malloc. */
p2m = calloc(p2m_size, MAX(guest_width, sizeof (xen_pfn_t)));
pfn_type = calloc(p2m_size, sizeof(unsigned long));
region_mfn = calloc(MAX_BATCH_SIZE, sizeof(xen_pfn_t));
p2m_batch = calloc(MAX_BATCH_SIZE, sizeof(xen_pfn_t));
if ( (p2m == NULL) || (pfn_type == NULL) ||
(region_mfn == NULL) || (p2m_batch == NULL) )
{
ERROR("memory alloc failed");
errno = ENOMEM;
goto out;
}
if ( lock_pages(region_mfn, sizeof(xen_pfn_t) * MAX_BATCH_SIZE) )
{
ERROR("Could not lock region_mfn");
goto out;
}
if ( lock_pages(p2m_batch, sizeof(xen_pfn_t) * MAX_BATCH_SIZE) )
{
ERROR("Could not lock p2m_batch");
goto out;
}
/* Get the domain's shared-info frame. */
domctl.cmd = XEN_DOMCTL_getdomaininfo;
domctl.domain = (domid_t)dom;
if ( xc_domctl(xc_handle, &domctl) < 0 )
{
ERROR("Could not get information on new domain");
goto out;
}
shared_info_frame = domctl.u.getdomaininfo.shared_info_frame;
/* Mark all PFNs as invalid; we allocate on demand */
for ( pfn = 0; pfn < p2m_size; pfn++ )
p2m[pfn] = INVALID_P2M_ENTRY;
mmu = xc_alloc_mmu_updates(xc_handle, dom);
if ( mmu == NULL )
{
ERROR("Could not initialise for MMU updates");
goto out;
}
DPRINTF("Reloading memory pages: 0%%\n");
/*
* Now simply read each saved frame into its new machine frame.
* We uncanonicalise page tables as we go.
*/
prev_pc = 0;
n = m = 0;
for ( ; ; )
{
int j, nr_mfns = 0;
this_pc = (n * 100) / p2m_size;
if ( (this_pc - prev_pc) >= 5 )
{
PPRINTF("\b\b\b\b%3d%%", this_pc);
prev_pc = this_pc;
}
if ( !read_exact(io_fd, &j, sizeof(int)) )
{
ERROR("Error when reading batch size");
goto out;
}
PPRINTF("batch %d\n",j);
if ( j == -1 )
{
verify = 1;
DPRINTF("Entering page verify mode\n");
continue;
}
if ( j == -2 )
{
new_ctxt_format = 1;
if ( !read_exact(io_fd, &max_vcpu_id, sizeof(int)) ||
(max_vcpu_id >= 64) ||
!read_exact(io_fd, &vcpumap, sizeof(uint64_t)) )
{
ERROR("Error when reading max_vcpu_id");
goto out;
}
continue;
}
if ( j == 0 )
break; /* our work here is done */
if ( (j > MAX_BATCH_SIZE) || (j < 0) )
{
ERROR("Max batch size exceeded. Giving up.");
goto out;
}
if ( !read_exact(io_fd, region_pfn_type, j*sizeof(unsigned long)) )
{
ERROR("Error when reading region pfn types");
goto out;
}
/* First pass for this batch: work out how much memory to alloc */
nr_mfns = 0;
for ( i = 0; i < j; i++ )
{
unsigned long pfn, pagetype;
pfn = region_pfn_type[i] & ~XEN_DOMCTL_PFINFO_LTAB_MASK;
pagetype = region_pfn_type[i] & XEN_DOMCTL_PFINFO_LTAB_MASK;
if ( (pagetype != XEN_DOMCTL_PFINFO_XTAB) &&
(p2m[pfn] == INVALID_P2M_ENTRY) )
{
/* Have a live PFN which hasn't had an MFN allocated */
p2m_batch[nr_mfns++] = pfn;
p2m[pfn]--;
}
}
/* Now allocate a bunch of mfns for this batch */
if ( nr_mfns &&
(xc_domain_memory_populate_physmap(xc_handle, dom, nr_mfns, 0,
0, p2m_batch) != 0) )
{
ERROR("Failed to allocate memory for batch.!\n");
errno = ENOMEM;
goto out;
}
/* Second pass for this batch: update p2m[] and region_mfn[] */
nr_mfns = 0;
for ( i = 0; i < j; i++ )
{
unsigned long pfn, pagetype;
pfn = region_pfn_type[i] & ~XEN_DOMCTL_PFINFO_LTAB_MASK;
pagetype = region_pfn_type[i] & XEN_DOMCTL_PFINFO_LTAB_MASK;
if ( pagetype == XEN_DOMCTL_PFINFO_XTAB )
region_mfn[i] = ~0UL; /* map will fail but we don't care */
else
{
if ( p2m[pfn] == (INVALID_P2M_ENTRY-1) )
{
/* We just allocated a new mfn above; update p2m */
p2m[pfn] = p2m_batch[nr_mfns++];
nr_pfns++;
}
/* setup region_mfn[] for batch map.
* For HVM guests, this interface takes PFNs, not MFNs */
region_mfn[i] = hvm ? pfn : p2m[pfn];
}
}
/* Map relevant mfns */
region_base = xc_map_foreign_batch(
xc_handle, dom, PROT_WRITE, region_mfn, j);
if ( region_base == NULL )
{
ERROR("map batch failed");
goto out;
}
for ( i = 0; i < j; i++ )
{
void *page;
unsigned long pagetype;
pfn = region_pfn_type[i] & ~XEN_DOMCTL_PFINFO_LTAB_MASK;
pagetype = region_pfn_type[i] & XEN_DOMCTL_PFINFO_LTAB_MASK;
if ( pagetype == XEN_DOMCTL_PFINFO_XTAB )
/* a bogus/unmapped page: skip it */
continue;
if ( pfn > p2m_size )
{
ERROR("pfn out of range");
goto out;
}
pfn_type[pfn] = pagetype;
mfn = p2m[pfn];
/* In verify mode, we use a copy; otherwise we work in place */
page = verify ? (void *)buf : (region_base + i*PAGE_SIZE);
if ( !read_exact(io_fd, page, PAGE_SIZE) )
{
ERROR("Error when reading page (type was %lx)", pagetype);
goto out;
}
pagetype &= XEN_DOMCTL_PFINFO_LTABTYPE_MASK;
if ( (pagetype >= XEN_DOMCTL_PFINFO_L1TAB) &&
(pagetype <= XEN_DOMCTL_PFINFO_L4TAB) )
{
/*
** A page table page - need to 'uncanonicalize' it, i.e.
** replace all the references to pfns with the corresponding
** mfns for the new domain.
**
** On PAE we need to ensure that PGDs are in MFNs < 4G, and
** so we may need to update the p2m after the main loop.
** Hence we defer canonicalization of L1s until then.
*/
if ((pt_levels != 3) ||
pae_extended_cr3 ||
(pagetype != XEN_DOMCTL_PFINFO_L1TAB)) {
if (!uncanonicalize_pagetable(xc_handle, dom,
pagetype, page)) {
/*
** Failing to uncanonicalize a page table can be ok
** under live migration since the pages type may have
** changed by now (and we'll get an update later).
*/
DPRINTF("PT L%ld race on pfn=%08lx mfn=%08lx\n",
pagetype >> 28, pfn, mfn);
nraces++;
continue;
}
}
}
else if ( pagetype != XEN_DOMCTL_PFINFO_NOTAB )
{
ERROR("Bogus page type %lx page table is out of range: "
"i=%d p2m_size=%lu", pagetype, i, p2m_size);
goto out;
}
if ( verify )
{
int res = memcmp(buf, (region_base + i*PAGE_SIZE), PAGE_SIZE);
if ( res )
{
int v;
DPRINTF("************** pfn=%lx type=%lx gotcs=%08lx "
"actualcs=%08lx\n", pfn, pfn_type[pfn],
csum_page(region_base + i*PAGE_SIZE),
csum_page(buf));
for ( v = 0; v < 4; v++ )
{
unsigned long *p = (unsigned long *)
(region_base + i*PAGE_SIZE);
if ( buf[v] != p[v] )
DPRINTF(" %d: %08lx %08lx\n", v, buf[v], p[v]);
}
}
}
if ( !hvm &&
xc_add_mmu_update(xc_handle, mmu,
(((unsigned long long)mfn) << PAGE_SHIFT)
| MMU_MACHPHYS_UPDATE, pfn) )
{
ERROR("failed machpys update mfn=%lx pfn=%lx", mfn, pfn);
goto out;
}
} /* end of 'batch' for loop */
munmap(region_base, j*PAGE_SIZE);
n+= j; /* crude stats */
/*
* Discard cache for portion of file read so far up to last
* page boundary every 16MB or so.
*/
m += j;
if ( m > MAX_PAGECACHE_USAGE )
{
discard_file_cache(io_fd, 0 /* no flush */);
m = 0;
}
}
/*
* Ensure we flush all machphys updates before potential PAE-specific
* reallocations below.
*/
if ( !hvm && xc_flush_mmu_updates(xc_handle, mmu) )
{
ERROR("Error doing flush_mmu_updates()");
goto out;
}
DPRINTF("Received all pages (%d races)\n", nraces);
if ( hvm )
{
uint32_t rec_len;
/* Set HVM-specific parameters */
if ( !read_exact(io_fd, magic_pfns, sizeof(magic_pfns)) )
{
ERROR("error reading magic page addresses");
goto out;
}
/* These comms pages need to be zeroed at the start of day */
if ( xc_clear_domain_page(xc_handle, dom, magic_pfns[0]) ||
xc_clear_domain_page(xc_handle, dom, magic_pfns[1]) ||
xc_clear_domain_page(xc_handle, dom, magic_pfns[2]) )
{
ERROR("error zeroing magic pages");
goto out;
}
if ( (rc = xc_set_hvm_param(xc_handle, dom,
HVM_PARAM_IOREQ_PFN, magic_pfns[0]))
|| (rc = xc_set_hvm_param(xc_handle, dom,
HVM_PARAM_BUFIOREQ_PFN, magic_pfns[1]))
|| (rc = xc_set_hvm_param(xc_handle, dom,
HVM_PARAM_STORE_PFN, magic_pfns[2]))
|| (rc = xc_set_hvm_param(xc_handle, dom,
HVM_PARAM_PAE_ENABLED, pae))
|| (rc = xc_set_hvm_param(xc_handle, dom,
HVM_PARAM_STORE_EVTCHN, store_evtchn)) )
{
ERROR("error setting HVM params: %i", rc);
goto out;
}
*store_mfn = magic_pfns[2];
/* Read HVM context */
if ( !read_exact(io_fd, &rec_len, sizeof(uint32_t)) )
{
ERROR("error read hvm context size!\n");
goto out;
}
hvm_buf = malloc(rec_len);
if ( hvm_buf == NULL )
{
ERROR("memory alloc for hvm context buffer failed");
errno = ENOMEM;
goto out;
}
if ( !read_exact(io_fd, hvm_buf, rec_len) )
{
ERROR("error loading the HVM context");
goto out;
}
rc = xc_domain_hvm_setcontext(xc_handle, dom, hvm_buf, rec_len);
if ( rc )
ERROR("error setting the HVM context");
goto out;
}
/* Non-HVM guests only from here on */
if ( (pt_levels == 3) && !pae_extended_cr3 )
{
/*
** XXX SMH on PAE we need to ensure PGDs are in MFNs < 4G. This
** is a little awkward and involves (a) finding all such PGDs and
** replacing them with 'lowmem' versions; (b) upating the p2m[]
** with the new info; and (c) canonicalizing all the L1s using the
** (potentially updated) p2m[].
**
** This is relatively slow (and currently involves two passes through
** the pfn_type[] array), but at least seems to be correct. May wish
** to consider more complex approaches to optimize this later.
*/
int j, k;
/* First pass: find all L3TABs current in > 4G mfns and get new mfns */
for ( i = 0; i < p2m_size; i++ )
{
if ( ((pfn_type[i] & XEN_DOMCTL_PFINFO_LTABTYPE_MASK) ==
XEN_DOMCTL_PFINFO_L3TAB) &&
(p2m[i] > 0xfffffUL) )
{
unsigned long new_mfn;
uint64_t l3ptes[4];
uint64_t *l3tab;
l3tab = (uint64_t *)
xc_map_foreign_range(xc_handle, dom, PAGE_SIZE,
PROT_READ, p2m[i]);
for ( j = 0; j < 4; j++ )
l3ptes[j] = l3tab[j];
munmap(l3tab, PAGE_SIZE);
new_mfn = xc_make_page_below_4G(xc_handle, dom, p2m[i]);
if ( !new_mfn )
{
ERROR("Couldn't get a page below 4GB :-(");
goto out;
}
p2m[i] = new_mfn;
if ( xc_add_mmu_update(xc_handle, mmu,
(((unsigned long long)new_mfn)
<< PAGE_SHIFT) |
MMU_MACHPHYS_UPDATE, i) )
{
ERROR("Couldn't m2p on PAE root pgdir");
goto out;
}
l3tab = (uint64_t *)
xc_map_foreign_range(xc_handle, dom, PAGE_SIZE,
PROT_READ | PROT_WRITE, p2m[i]);
for ( j = 0; j < 4; j++ )
l3tab[j] = l3ptes[j];
munmap(l3tab, PAGE_SIZE);
}
}
/* Second pass: find all L1TABs and uncanonicalize them */
j = 0;
for ( i = 0; i < p2m_size; i++ )
{
if ( ((pfn_type[i] & XEN_DOMCTL_PFINFO_LTABTYPE_MASK) ==
XEN_DOMCTL_PFINFO_L1TAB) )
{
region_mfn[j] = p2m[i];
j++;
}
if ( (i == (p2m_size-1)) || (j == MAX_BATCH_SIZE) )
{
region_base = xc_map_foreign_batch(
xc_handle, dom, PROT_READ | PROT_WRITE, region_mfn, j);
if ( region_base == NULL )
{
ERROR("map batch failed");
goto out;
}
for ( k = 0; k < j; k++ )
{
if ( !uncanonicalize_pagetable(
xc_handle, dom, XEN_DOMCTL_PFINFO_L1TAB,
region_base + k*PAGE_SIZE) )
{
ERROR("failed uncanonicalize pt!");
goto out;
}
}
munmap(region_base, j*PAGE_SIZE);
j = 0;
}
}
if ( xc_flush_mmu_updates(xc_handle, mmu) )
{
ERROR("Error doing xc_flush_mmu_updates()");
goto out;
}
}
/*
* Pin page tables. Do this after writing to them as otherwise Xen
* will barf when doing the type-checking.
*/
nr_pins = 0;
for ( i = 0; i < p2m_size; i++ )
{
if ( (pfn_type[i] & XEN_DOMCTL_PFINFO_LPINTAB) == 0 )
continue;
switch ( pfn_type[i] & XEN_DOMCTL_PFINFO_LTABTYPE_MASK )
{
case XEN_DOMCTL_PFINFO_L1TAB:
pin[nr_pins].cmd = MMUEXT_PIN_L1_TABLE;
break;
case XEN_DOMCTL_PFINFO_L2TAB:
pin[nr_pins].cmd = MMUEXT_PIN_L2_TABLE;
break;
case XEN_DOMCTL_PFINFO_L3TAB:
pin[nr_pins].cmd = MMUEXT_PIN_L3_TABLE;
break;
case XEN_DOMCTL_PFINFO_L4TAB:
pin[nr_pins].cmd = MMUEXT_PIN_L4_TABLE;
break;
default:
continue;
}
pin[nr_pins].arg1.mfn = p2m[i];
nr_pins++;
/* Batch full? Then flush. */
if ( nr_pins == MAX_PIN_BATCH )
{
if ( xc_mmuext_op(xc_handle, pin, nr_pins, dom) < 0 )
{
ERROR("Failed to pin batch of %d page tables", nr_pins);
goto out;
}
nr_pins = 0;
}
}
/* Flush final partial batch. */
if ( (nr_pins != 0) && (xc_mmuext_op(xc_handle, pin, nr_pins, dom) < 0) )
{
ERROR("Failed to pin batch of %d page tables", nr_pins);
goto out;
}
DPRINTF("\b\b\b\b100%%\n");
DPRINTF("Memory reloaded (%ld pages)\n", nr_pfns);
/* Get the list of PFNs that are not in the psuedo-phys map */
{
unsigned int count = 0;
unsigned long *pfntab;
int nr_frees, rc;
if ( !read_exact(io_fd, &count, sizeof(count)) ||
(count > (1U << 28)) ) /* up to 1TB of address space */
{
ERROR("Error when reading pfn count (= %u)", count);
goto out;
}
if ( !(pfntab = malloc(sizeof(unsigned long) * count)) )
{
ERROR("Out of memory");
goto out;
}
if ( !read_exact(io_fd, pfntab, sizeof(unsigned long)*count) )
{
ERROR("Error when reading pfntab");
goto out;
}
nr_frees = 0;
for ( i = 0; i < count; i++ )
{
unsigned long pfn = pfntab[i];
if ( p2m[pfn] != INVALID_P2M_ENTRY )
{
/* pfn is not in physmap now, but was at some point during
the save/migration process - need to free it */
pfntab[nr_frees++] = p2m[pfn];
p2m[pfn] = INVALID_P2M_ENTRY; /* not in pseudo-physical map */
}
}
if ( nr_frees > 0 )
{
struct xen_memory_reservation reservation = {
.nr_extents = nr_frees,
.extent_order = 0,
.domid = dom
};
set_xen_guest_handle(reservation.extent_start, pfntab);
if ( (rc = xc_memory_op(xc_handle, XENMEM_decrease_reservation,
&reservation)) != nr_frees )
{
ERROR("Could not decrease reservation : %d", rc);
goto out;
}
else
DPRINTF("Decreased reservation by %d pages\n", count);
}
}
for ( i = 0; i <= max_vcpu_id; i++ )
{
if ( !(vcpumap & (1ULL << i)) )
continue;
if ( !read_exact(io_fd, &ctxt, ((guest_width == 8)
? sizeof(ctxt.x64)
: sizeof(ctxt.x32))) )
{
ERROR("Error when reading ctxt %d", i);
goto out;
}
if ( !new_ctxt_format )
SET_FIELD(&ctxt, flags, GET_FIELD(&ctxt, flags) | VGCF_online);
if ( i == 0 )
{
/*
* Uncanonicalise the suspend-record frame number and poke
* resume record.
*/
pfn = GET_FIELD(&ctxt, user_regs.edx);
if ( (pfn >= p2m_size) ||
(pfn_type[pfn] != XEN_DOMCTL_PFINFO_NOTAB) )
{
ERROR("Suspend record frame number is bad");
goto out;
}
mfn = p2m[pfn];
SET_FIELD(&ctxt, user_regs.edx, mfn);
start_info = xc_map_foreign_range(
xc_handle, dom, PAGE_SIZE, PROT_READ | PROT_WRITE, mfn);
SET_FIELD(start_info, nr_pages, p2m_size);
SET_FIELD(start_info, shared_info, shared_info_frame<<PAGE_SHIFT);
SET_FIELD(start_info, flags, 0);
*store_mfn = p2m[GET_FIELD(start_info, store_mfn)];
SET_FIELD(start_info, store_mfn, *store_mfn);
SET_FIELD(start_info, store_evtchn, store_evtchn);
*console_mfn = p2m[GET_FIELD(start_info, console.domU.mfn)];
SET_FIELD(start_info, console.domU.mfn, *console_mfn);
SET_FIELD(start_info, console.domU.evtchn, console_evtchn);
munmap(start_info, PAGE_SIZE);
}
/* Uncanonicalise each GDT frame number. */
if ( GET_FIELD(&ctxt, gdt_ents) > 8192 )
{
ERROR("GDT entry count out of range");
goto out;
}
for ( j = 0; (512*j) < GET_FIELD(&ctxt, gdt_ents); j++ )
{
pfn = GET_FIELD(&ctxt, gdt_frames[j]);
if ( (pfn >= p2m_size) ||
(pfn_type[pfn] != XEN_DOMCTL_PFINFO_NOTAB) )
{
ERROR("GDT frame number %i (0x%lx) is bad",
j, (unsigned long)pfn);
goto out;
}
SET_FIELD(&ctxt, gdt_frames[j], p2m[pfn]);
}
/* Uncanonicalise the page table base pointer. */
pfn = xen_cr3_to_pfn(GET_FIELD(&ctxt, ctrlreg[3]));
if ( pfn >= p2m_size )
{
ERROR("PT base is bad: pfn=%lu p2m_size=%lu type=%08lx",
pfn, p2m_size, pfn_type[pfn]);
goto out;
}
if ( (pfn_type[pfn] & XEN_DOMCTL_PFINFO_LTABTYPE_MASK) !=
((unsigned long)pt_levels<<XEN_DOMCTL_PFINFO_LTAB_SHIFT) )
{
ERROR("PT base is bad. pfn=%lu nr=%lu type=%08lx %08lx",
pfn, p2m_size, pfn_type[pfn],
(unsigned long)pt_levels<<XEN_DOMCTL_PFINFO_LTAB_SHIFT);
goto out;
}
SET_FIELD(&ctxt, ctrlreg[3], xen_pfn_to_cr3(p2m[pfn]));
/* Guest pagetable (x86/64) stored in otherwise-unused CR1. */
if ( (pt_levels == 4) && (ctxt.x64.ctrlreg[1] & 1) )
{
pfn = xen_cr3_to_pfn(ctxt.x64.ctrlreg[1] & ~1);
if ( pfn >= p2m_size )
{
ERROR("User PT base is bad: pfn=%lu p2m_size=%lu",
pfn, p2m_size);
goto out;
}
if ( (pfn_type[pfn] & XEN_DOMCTL_PFINFO_LTABTYPE_MASK) !=
((unsigned long)pt_levels<<XEN_DOMCTL_PFINFO_LTAB_SHIFT) )
{
ERROR("User PT base is bad. pfn=%lu nr=%lu type=%08lx %08lx",
pfn, p2m_size, pfn_type[pfn],
(unsigned long)pt_levels<<XEN_DOMCTL_PFINFO_LTAB_SHIFT);
goto out;
}
ctxt.x64.ctrlreg[1] = xen_pfn_to_cr3(p2m[pfn]);
}
domctl.cmd = XEN_DOMCTL_setvcpucontext;
domctl.domain = (domid_t)dom;
domctl.u.vcpucontext.vcpu = i;
set_xen_guest_handle(domctl.u.vcpucontext.ctxt, &ctxt.c);
rc = xc_domctl(xc_handle, &domctl);
if ( rc != 0 )
{
ERROR("Couldn't build vcpu%d", i);
goto out;
}
rc = 1;
}
if ( !read_exact(io_fd, shared_info_page, PAGE_SIZE) )
{
ERROR("Error when reading shared info page");
goto out;
}
/* Restore contents of shared-info page. No checking needed. */
new_shared_info = xc_map_foreign_range(
xc_handle, dom, PAGE_SIZE, PROT_WRITE, shared_info_frame);
/* restore saved vcpu_info and arch specific info */
MEMCPY_FIELD(new_shared_info, old_shared_info, vcpu_info);
MEMCPY_FIELD(new_shared_info, old_shared_info, arch);
/* clear any pending events and the selector */
MEMSET_ARRAY_FIELD(new_shared_info, evtchn_pending, 0);
for ( i = 0; i < MAX_VIRT_CPUS; i++ )
SET_FIELD(new_shared_info, vcpu_info[i].evtchn_pending_sel, 0);
/* mask event channels */
MEMSET_ARRAY_FIELD(new_shared_info, evtchn_mask, 0xff);
/* leave wallclock time. set by hypervisor */
munmap(new_shared_info, PAGE_SIZE);
/* Uncanonicalise the pfn-to-mfn table frame-number list. */
for ( i = 0; i < P2M_FL_ENTRIES; i++ )
{
pfn = p2m_frame_list[i];
if ( (pfn >= p2m_size) || (pfn_type[pfn] != XEN_DOMCTL_PFINFO_NOTAB) )
{
ERROR("PFN-to-MFN frame number %i (%#lx) is bad", i, pfn);
goto out;
}
p2m_frame_list[i] = p2m[pfn];
}
/* Copy the P2M we've constructed to the 'live' P2M */
if ( !(live_p2m = xc_map_foreign_batch(xc_handle, dom, PROT_WRITE,
p2m_frame_list, P2M_FL_ENTRIES)) )
{
ERROR("Couldn't map p2m table");
goto out;
}
/* If the domain we're restoring has a different word size to ours,
* we need to repack the p2m appropriately */
if ( guest_width > sizeof (xen_pfn_t) )
for ( i = p2m_size - 1; i >= 0; i-- )
((uint64_t *)p2m)[i] = p2m[i];
else if ( guest_width > sizeof (xen_pfn_t) )
for ( i = 0; i < p2m_size; i++ )
((uint32_t *)p2m)[i] = p2m[i];
memcpy(live_p2m, p2m, ROUNDUP(p2m_size * guest_width, PAGE_SHIFT));
munmap(live_p2m, ROUNDUP(p2m_size * guest_width, PAGE_SHIFT));
DPRINTF("Domain ready to be built.\n");
rc = 0;
out:
if ( (rc != 0) && (dom != 0) )
xc_domain_destroy(xc_handle, dom);
free(mmu);
free(p2m);
free(pfn_type);
free(hvm_buf);
/* discard cache for save file */
discard_file_cache(io_fd, 1 /*flush*/);
DPRINTF("Restore exit with rc=%d\n", rc);
return rc;
}
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