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9b4ed67d2528bc9c1d2a6b94de7678920437a18e
xen/tools/libxc/ia64/xc_ia64_linux_restore.c
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/******************************************************************************
* xc_ia64_linux_restore.c
*
* Restore the state of a Linux session.
*
* Copyright (c) 2003, K A Fraser.
* Rewritten for ia64 by Tristan Gingold <tristan.gingold@bull.net>
*/
#include <stdlib.h>
#include <unistd.h>
#include "xg_private.h"
#define PFN_TO_KB(_pfn) ((_pfn) << (PAGE_SHIFT - 10))
/* total number of pages used by the current guest */
static unsigned long max_pfn;
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) ? 1 : 0;
}
static int
read_page(int xc_handle, int io_fd, uint32_t dom, unsigned long pfn)
{
void *mem;
mem = xc_map_foreign_range(xc_handle, dom, PAGE_SIZE,
PROT_READ|PROT_WRITE, pfn);
if (mem == NULL) {
ERROR("cannot map page");
return -1;
}
if (!read_exact(io_fd, mem, PAGE_SIZE)) {
ERROR("Error when reading from state file (5)");
return -1;
}
munmap(mem, PAGE_SIZE);
return 0;
}
int
xc_linux_restore(int xc_handle, int io_fd, uint32_t dom,
unsigned long nr_pfns, unsigned int store_evtchn,
unsigned long *store_mfn, unsigned int console_evtchn,
unsigned long *console_mfn)
{
DECLARE_DOMCTL;
int rc = 1, i;
unsigned long mfn, pfn;
unsigned long ver;
/* 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_t *shared_info = (shared_info_t *)shared_info_page;
/* A copy of the CPU context of the guest. */
vcpu_guest_context_t ctxt;
unsigned long *page_array = NULL;
/* A temporary mapping of the guest's start_info page. */
start_info_t *start_info;
max_pfn = nr_pfns;
DPRINTF("xc_linux_restore start: max_pfn = %ld\n", max_pfn);
if (!read_exact(io_fd, &ver, sizeof(unsigned long))) {
ERROR("Error when reading version");
goto out;
}
if (ver != 1) {
ERROR("version of save doesn't match");
goto out;
}
if (mlock(&ctxt, sizeof(ctxt))) {
/* needed for build domctl, but might as well do early */
ERROR("Unable to mlock ctxt");
return 1;
}
/* 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;
if (xc_domain_setmaxmem(xc_handle, dom, PFN_TO_KB(max_pfn)) != 0) {
errno = ENOMEM;
goto out;
}
if (xc_domain_memory_increase_reservation(xc_handle, dom, max_pfn,
0, 0, NULL) != 0) {
ERROR("Failed to increase reservation by %ld KB", PFN_TO_KB(max_pfn));
errno = ENOMEM;
goto out;
}
DPRINTF("Increased domain reservation by %ld KB\n", PFN_TO_KB(max_pfn));
if (!read_exact(io_fd, &domctl.u.arch_setup, sizeof(domctl.u.arch_setup))) {
ERROR("read: domain setup");
goto out;
}
/* Build firmware (will be overwritten). */
domctl.domain = (domid_t)dom;
domctl.u.arch_setup.flags &= ~XEN_DOMAINSETUP_query;
domctl.u.arch_setup.bp = ((nr_pfns - 3) << PAGE_SHIFT)
+ sizeof (start_info_t);
domctl.u.arch_setup.maxmem = (nr_pfns - 3) << PAGE_SHIFT;
domctl.cmd = XEN_DOMCTL_arch_setup;
if (xc_domctl(xc_handle, &domctl))
goto out;
/* Get pages. */
page_array = malloc(max_pfn * sizeof(unsigned long));
if (page_array == NULL ) {
ERROR("Could not allocate memory");
goto out;
}
if (xc_ia64_get_pfn_list(xc_handle, dom, page_array,
0, max_pfn) != max_pfn) {
ERROR("Could not get the page frame list");
goto out;
}
DPRINTF("Reloading memory pages: 0%%\n");
while (1) {
if (!read_exact(io_fd, &mfn, sizeof(unsigned long))) {
ERROR("Error when reading batch size");
goto out;
}
if (mfn == INVALID_MFN)
break;
pfn = page_array[mfn];
//DPRINTF("xc_linux_restore: page %lu/%lu at %lx\n", mfn, max_pfn, pfn);
if (read_page(xc_handle, io_fd, dom, page_array[mfn]) < 0)
goto out;
}
DPRINTF("Received all pages\n");
/* Get the list of PFNs that are not in the psuedo-phys map */
{
unsigned int count;
unsigned long *pfntab;
int rc;
if (!read_exact(io_fd, &count, sizeof(count))) {
ERROR("Error when reading pfn count");
goto out;
}
pfntab = malloc(sizeof(unsigned long) * count);
if (!pfntab) {
ERROR("Out of memory");
goto out;
}
if (!read_exact(io_fd, pfntab, sizeof(unsigned long)*count)) {
ERROR("Error when reading pfntab");
goto out;
}
DPRINTF ("Try to free %u pages\n", count);
for (i = 0; i < count; i++) {
volatile unsigned long pfn;
struct xen_memory_reservation reservation = {
.nr_extents = 1,
.extent_order = 0,
.domid = dom
};
set_xen_guest_handle(reservation.extent_start,
(unsigned long *)&pfn);
pfn = pfntab[i];
rc = xc_memory_op(xc_handle, XENMEM_decrease_reservation,
&reservation);
if (rc != 1) {
ERROR("Could not decrease reservation : %d", rc);
goto out;
}
}
DPRINTF("Decreased reservation by %d pages\n", count);
}
if (!read_exact(io_fd, &ctxt, sizeof(ctxt))) {
ERROR("Error when reading ctxt");
goto out;
}
fprintf(stderr, "ip=%016lx, b0=%016lx\n", ctxt.user_regs.cr_iip,
ctxt.user_regs.b0);
/* First to initialize. */
domctl.cmd = XEN_DOMCTL_setvcpucontext;
domctl.domain = (domid_t)dom;
domctl.u.vcpucontext.vcpu = 0;
set_xen_guest_handle(domctl.u.vcpucontext.ctxt, &ctxt);
if (xc_domctl(xc_handle, &domctl) != 0) {
ERROR("Couldn't set vcpu context");
goto out;
}
/* Second to set registers... */
ctxt.flags = VGCF_EXTRA_REGS;
domctl.cmd = XEN_DOMCTL_setvcpucontext;
domctl.domain = (domid_t)dom;
domctl.u.vcpucontext.vcpu = 0;
set_xen_guest_handle(domctl.u.vcpucontext.ctxt, &ctxt);
if (xc_domctl(xc_handle, &domctl) != 0) {
ERROR("Couldn't set vcpu context");
goto out;
}
/* Just a check. */
if (xc_vcpu_getcontext(xc_handle, dom, 0 /* XXX */, &ctxt)) {
ERROR("Could not get vcpu context");
goto out;
}
/* Then get privreg page. */
if (read_page(xc_handle, io_fd, dom, ctxt.privregs_pfn) < 0) {
ERROR("Could not read vcpu privregs");
goto out;
}
/* Read shared info. */
shared_info = xc_map_foreign_range(xc_handle, dom, PAGE_SIZE,
PROT_READ|PROT_WRITE, shared_info_frame);
if (shared_info == NULL) {
ERROR("cannot map page");
goto out;
}
if (!read_exact(io_fd, shared_info, PAGE_SIZE)) {
ERROR("Error when reading shared_info page");
goto out;
}
/* clear any pending events and the selector */
memset(&(shared_info->evtchn_pending[0]), 0,
sizeof (shared_info->evtchn_pending));
for (i = 0; i < MAX_VIRT_CPUS; i++)
shared_info->vcpu_info[i].evtchn_pending_sel = 0;
mfn = page_array[shared_info->arch.start_info_pfn];
munmap (shared_info, PAGE_SIZE);
/* Uncanonicalise the suspend-record frame number and poke resume rec. */
start_info = xc_map_foreign_range(xc_handle, dom, PAGE_SIZE,
PROT_READ | PROT_WRITE, mfn);
start_info->nr_pages = max_pfn;
start_info->shared_info = shared_info_frame << PAGE_SHIFT;
start_info->flags = 0;
*store_mfn = page_array[start_info->store_mfn];
start_info->store_evtchn = store_evtchn;
*console_mfn = page_array[start_info->console.domU.mfn];
start_info->console.domU.evtchn = console_evtchn;
munmap(start_info, PAGE_SIZE);
/*
* Safety checking of saved context:
* 1. user_regs is fine, as Xen checks that on context switch.
* 2. fpu_ctxt is fine, as it can't hurt Xen.
* 3. trap_ctxt needs the code selectors checked.
* 4. ldt base must be page-aligned, no more than 8192 ents, ...
* 5. gdt already done, and further checking is done by Xen.
* 6. check that kernel_ss is safe.
* 7. pt_base is already done.
* 8. debugregs are checked by Xen.
* 9. callback code selectors need checking.
*/
DPRINTF("Domain ready to be built.\n");
rc = 0;
out:
if ((rc != 0) && (dom != 0))
xc_domain_destroy(xc_handle, dom);
free (page_array);
DPRINTF("Restore exit with rc=%d\n", rc);
return rc;
}
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