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a47cb321e9a8311cf400d3cb44d8e9f255cd3139
xen/tools/libxc/xc_tmem.c
T
Keir Fraser 734a7f6677 tmem: save/restore/migrate/livemigrate and shared pool authentication 
Attached patch implements save/restore/migration/livemigration
for transcendent memory ("tmem").  Without this patch, domains
using tmem may in some cases lose data when doing save/restore
or migrate/livemigrate.  Also included in this patch is
support for a new (privileged) hypercall for authorizing
domains to share pools; this provides the foundation to
accomodate upstream linux requests for security for shared
pools.

Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
2009-08-06 09:19:55 +01:00

456 lines
14 KiB
C
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/******************************************************************************
* xc_tmem.c
*
* Copyright (C) 2008 Oracle Corp.
*/
#include "xc_private.h"
#include <xen/tmem.h>
static int do_tmem_op(int xc, tmem_op_t *op)
{
int ret;
DECLARE_HYPERCALL;
hypercall.op = __HYPERVISOR_tmem_op;
hypercall.arg[0] = (unsigned long)op;
if (lock_pages(op, sizeof(*op)) != 0)
{
PERROR("Could not lock memory for Xen hypercall");
return -EFAULT;
}
if ((ret = do_xen_hypercall(xc, &hypercall)) < 0)
{
if ( errno == EACCES )
DPRINTF("tmem operation failed -- need to"
" rebuild the user-space tool set?\n");
}
unlock_pages(op, sizeof(*op));
return ret;
}
int xc_tmem_control(int xc,
int32_t pool_id,
uint32_t subop,
uint32_t cli_id,
uint32_t arg1,
uint32_t arg2,
uint64_t arg3,
void *buf)
{
tmem_op_t op;
int rc;
op.cmd = TMEM_CONTROL;
op.pool_id = pool_id;
op.u.ctrl.subop = subop;
op.u.ctrl.cli_id = cli_id;
set_xen_guest_handle(op.u.ctrl.buf,buf);
op.u.ctrl.arg1 = arg1;
op.u.ctrl.arg2 = arg2;
op.u.ctrl.arg3 = arg3;
if (subop == TMEMC_LIST) {
if ((arg1 != 0) && (lock_pages(buf, arg1) != 0))
{
PERROR("Could not lock memory for Xen hypercall");
return -ENOMEM;
}
}
#ifdef VALGRIND
if (arg1 != 0)
memset(buf, 0, arg1);
#endif
rc = do_tmem_op(xc, &op);
if (subop == TMEMC_LIST) {
if (arg1 != 0)
unlock_pages(buf, arg1);
}
return rc;
}
static int xc_tmem_uuid_parse(char *uuid_str, uint64_t *uuid_lo, uint64_t *uuid_hi)
{
char *p = uuid_str;
uint64_t *x = uuid_hi;
int i = 0, digit;
*uuid_lo = 0; *uuid_hi = 0;
for ( p = uuid_str, i = 0; i != 36 && *p != '\0'; p++, i++ )
{
if ( (i == 8 || i == 13 || i == 18 || i == 23) )
{
if ( *p != '-' )
return -1;
if ( i == 18 )
x = uuid_lo;
continue;
}
else if ( *p >= '0' && *p <= '9' )
digit = *p - '0';
else if ( *p >= 'A' && *p <= 'F' )
digit = *p - 'A';
else if ( *p >= 'a' && *p <= 'f' )
digit = *p - 'a';
else
return -1;
*x = (*x << 4) | digit;
}
if ( (i != 1 && i != 36) || *p != '\0' )
return -1;
return 0;
}
int xc_tmem_auth(int xc,
int cli_id,
char *uuid_str,
int arg1)
{
tmem_op_t op;
op.cmd = TMEM_AUTH;
op.pool_id = 0;
op.u.new.arg1 = cli_id;
op.u.new.flags = arg1;
if ( xc_tmem_uuid_parse(uuid_str, &op.u.new.uuid[0],
&op.u.new.uuid[1]) < 0 )
{
PERROR("Can't parse uuid, use xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx");
return -1;
}
return do_tmem_op(xc, &op);
}
/* Save/restore/live migrate */
/*
Note that live migration complicates the save/restore format in
multiple ways: Though saving/migration can only occur when all
tmem pools belonging to the domain-being-saved are frozen and
this ensures that new pools can't be created or existing pools
grown (in number of pages), it is possible during a live migration
that pools may be destroyed and pages invalidated while the migration
is in process. As a result, (1) it is not safe to pre-specify counts
for these values precisely, but only as a "max", and (2) a "invalidation"
list (of pools, objects, pages) must be appended when the domain is truly
suspended.
*/
/* returns 0 if nothing to save, -1 if error saving, 1 if saved successfully */
int xc_tmem_save(int xc, int dom, int io_fd, int live, int field_marker)
{
int marker = field_marker;
int i, j;
uint32_t max_pools, version;
uint32_t weight, cap, flags;
uint32_t pool_id;
uint32_t minusone = -1;
struct tmem_handle *h;
if ( xc_tmem_control(xc,0,TMEMC_SAVE_BEGIN,dom,live,0,0,NULL) <= 0 )
return 0;
if ( write_exact(io_fd, &marker, sizeof(marker)) )
return -1;
version = xc_tmem_control(xc,0,TMEMC_SAVE_GET_VERSION,0,0,0,0,NULL);
if ( write_exact(io_fd, &version, sizeof(version)) )
return -1;
max_pools = xc_tmem_control(xc,0,TMEMC_SAVE_GET_MAXPOOLS,0,0,0,0,NULL);
if ( write_exact(io_fd, &max_pools, sizeof(max_pools)) )
return -1;
if ( version == -1 || max_pools == -1 )
return -1;
if ( write_exact(io_fd, &minusone, sizeof(minusone)) )
return -1;
flags = xc_tmem_control(xc,0,TMEMC_SAVE_GET_CLIENT_FLAGS,dom,0,0,0,NULL);
if ( write_exact(io_fd, &flags, sizeof(flags)) )
return -1;
weight = xc_tmem_control(xc,0,TMEMC_SAVE_GET_CLIENT_WEIGHT,dom,0,0,0,NULL);
if ( write_exact(io_fd, &weight, sizeof(weight)) )
return -1;
cap = xc_tmem_control(xc,0,TMEMC_SAVE_GET_CLIENT_CAP,dom,0,0,0,NULL);
if ( write_exact(io_fd, &cap, sizeof(cap)) )
return -1;
if ( flags == -1 || weight == -1 || cap == -1 )
return -1;
if ( write_exact(io_fd, &minusone, sizeof(minusone)) )
return -1;
for ( i = 0; i < max_pools; i++ )
{
uint64_t uuid[2];
uint32_t n_pages;
uint32_t pagesize;
char *buf = NULL;
int bufsize = 0;
int checksum = 0;
/* get pool id, flags, pagesize, n_pages, uuid */
flags = xc_tmem_control(xc,i,TMEMC_SAVE_GET_POOL_FLAGS,dom,0,0,0,NULL);
if ( flags != -1 )
{
pool_id = i;
n_pages = xc_tmem_control(xc,i,TMEMC_SAVE_GET_POOL_NPAGES,dom,0,0,0,NULL);
if ( !(flags & TMEM_POOL_PERSIST) )
n_pages = 0;
(void)xc_tmem_control(xc,i,TMEMC_SAVE_GET_POOL_UUID,dom,sizeof(uuid),0,0,&uuid);
if ( write_exact(io_fd, &pool_id, sizeof(pool_id)) )
return -1;
if ( write_exact(io_fd, &flags, sizeof(flags)) )
return -1;
if ( write_exact(io_fd, &n_pages, sizeof(n_pages)) )
return -1;
if ( write_exact(io_fd, &uuid, sizeof(uuid)) )
return -1;
if ( n_pages == 0 )
continue;
pagesize = 1 << (((flags >> TMEM_POOL_PAGESIZE_SHIFT) &
TMEM_POOL_PAGESIZE_MASK) + 12);
if ( pagesize > bufsize )
{
bufsize = pagesize + sizeof(struct tmem_handle);
if ( (buf = realloc(buf,bufsize)) == NULL )
return -1;
}
for ( j = n_pages; j > 0; j-- )
{
int ret;
if ( (ret = xc_tmem_control(xc, pool_id,
TMEMC_SAVE_GET_NEXT_PAGE, dom,
bufsize, 0, 0, buf)) > 0 )
{
h = (struct tmem_handle *)buf;
if ( write_exact(io_fd, &h->oid, sizeof(h->oid)) )
return -1;
if ( write_exact(io_fd, &h->index, sizeof(h->index)) )
return -1;
h++;
checksum += *(char *)h;
if ( write_exact(io_fd, h, pagesize) )
return -1;
} else if ( ret == 0 ) {
continue;
} else {
/* page list terminator */
h = (struct tmem_handle *)buf;
h->oid = -1;
if ( write_exact(io_fd, &h->oid, sizeof(h->oid)) )
return -1;
break;
}
}
DPRINTF("saved %d tmem pages for dom=%d pool=%d, checksum=%x\n",
n_pages-j,dom,pool_id,checksum);
}
}
/* pool list terminator */
minusone = -1;
if ( write_exact(io_fd, &minusone, sizeof(minusone)) )
return -1;
return 1;
}
/* only called for live migration */
int xc_tmem_save_extra(int xc, int dom, int io_fd, int field_marker)
{
struct tmem_handle handle;
int marker = field_marker;
uint32_t minusone;
int count = 0, checksum = 0;
if ( write_exact(io_fd, &marker, sizeof(marker)) )
return -1;
while ( xc_tmem_control(xc, 0, TMEMC_SAVE_GET_NEXT_INV, dom,
sizeof(handle),0,0,&handle) > 0 ) {
if ( write_exact(io_fd, &handle.pool_id, sizeof(handle.pool_id)) )
return -1;
if ( write_exact(io_fd, &handle.oid, sizeof(handle.oid)) )
return -1;
if ( write_exact(io_fd, &handle.index, sizeof(handle.index)) )
return -1;
count++;
checksum += handle.pool_id + handle.oid + handle.index;
}
if ( count )
DPRINTF("needed %d tmem invalidates, check=%d\n",count,checksum);
minusone = -1;
if ( write_exact(io_fd, &minusone, sizeof(minusone)) )
return -1;
return 0;
}
/* only called for live migration */
void xc_tmem_save_done(int xc, int dom)
{
xc_tmem_control(xc,0,TMEMC_SAVE_END,dom,0,0,0,NULL);
}
/* restore routines */
static int xc_tmem_restore_new_pool(
int xc,
int cli_id,
uint32_t pool_id,
uint32_t flags,
uint64_t uuid_lo,
uint64_t uuid_hi)
{
tmem_op_t op;
op.cmd = TMEM_RESTORE_NEW;
op.pool_id = pool_id;
op.u.new.arg1 = cli_id;
op.u.new.flags = flags;
op.u.new.uuid[0] = uuid_lo;
op.u.new.uuid[1] = uuid_hi;
return do_tmem_op(xc, &op);
}
int xc_tmem_restore(int xc, int dom, int io_fd)
{
uint32_t save_max_pools, save_version;
uint32_t this_max_pools, this_version;
uint32_t pool_id;
uint32_t minusone;
uint32_t weight, cap, flags;
int checksum = 0;
save_version = xc_tmem_control(xc,0,TMEMC_SAVE_GET_VERSION,dom,0,0,0,NULL);
if ( save_version == -1 )
return -1; /* domain doesn't exist */
save_max_pools = xc_tmem_control(xc,0,TMEMC_SAVE_GET_MAXPOOLS,0,0,0,0,NULL);
if ( read_exact(io_fd, &this_version, sizeof(this_version)) )
return -1;
if ( read_exact(io_fd, &this_max_pools, sizeof(this_max_pools)) )
return -1;
/* FIXME check here to ensure no version mismatch or maxpools mismatch */
if ( read_exact(io_fd, &minusone, sizeof(minusone)) )
return -1;
if ( minusone != -1 )
return -1;
if ( xc_tmem_control(xc,0,TMEMC_RESTORE_BEGIN,dom,0,0,0,NULL) < 0 )
return -1;
if ( read_exact(io_fd, &flags, sizeof(flags)) )
return -1;
if ( flags & TMEM_CLIENT_COMPRESS )
if ( xc_tmem_control(xc,0,TMEMC_SET_COMPRESS,dom,1,0,0,NULL) < 0 )
return -1;
if ( flags & TMEM_CLIENT_FROZEN )
if ( xc_tmem_control(xc,0,TMEMC_FREEZE,dom,0,0,0,NULL) < 0 )
return -1;
if ( read_exact(io_fd, &weight, sizeof(weight)) )
return -1;
if ( xc_tmem_control(xc,0,TMEMC_SET_WEIGHT,dom,0,0,0,NULL) < 0 )
return -1;
if ( read_exact(io_fd, &cap, sizeof(cap)) )
return -1;
if ( xc_tmem_control(xc,0,TMEMC_SET_CAP,dom,0,0,0,NULL) < 0 )
return -1;
if ( read_exact(io_fd, &minusone, sizeof(minusone)) )
return -1;
while ( read_exact(io_fd, &pool_id, sizeof(pool_id)) == 0 && pool_id != -1 )
{
uint64_t uuid[2];
uint32_t n_pages;
char *buf = NULL;
int bufsize = 0, pagesize;
int j;
if ( read_exact(io_fd, &flags, sizeof(flags)) )
return -1;
if ( read_exact(io_fd, &n_pages, sizeof(n_pages)) )
return -1;
if ( read_exact(io_fd, &uuid, sizeof(uuid)) )
return -1;
if ( xc_tmem_restore_new_pool(xc, dom, pool_id,
flags, uuid[0], uuid[1]) < 0)
return -1;
if ( n_pages <= 0 )
continue;
pagesize = 1 << (((flags >> TMEM_POOL_PAGESIZE_SHIFT) &
TMEM_POOL_PAGESIZE_MASK) + 12);
if ( pagesize > bufsize )
{
bufsize = pagesize;
if ( (buf = realloc(buf,bufsize)) == NULL )
return -1;
}
for ( j = n_pages; j > 0; j-- )
{
uint64_t oid;
uint32_t index;
int rc;
if ( read_exact(io_fd, &oid, sizeof(oid)) )
return -1;
if ( oid == -1 )
break;
if ( read_exact(io_fd, &index, sizeof(index)) )
return -1;
if ( read_exact(io_fd, buf, pagesize) )
return -1;
checksum += *buf;
if ( (rc = xc_tmem_control(xc, pool_id, TMEMC_RESTORE_PUT_PAGE,
dom, bufsize, index, oid, buf)) <= 0 )
{
DPRINTF("xc_tmem_restore: putting page failed, rc=%d\n",rc);
return -1;
}
}
if ( n_pages )
DPRINTF("restored %d tmem pages for dom=%d pool=%d, check=%x\n",
n_pages-j,dom,pool_id,checksum);
}
if ( pool_id != -1 )
return -1;
return 0;
}
/* only called for live migration, must be called after suspend */
int xc_tmem_restore_extra(int xc, int dom, int io_fd)
{
uint32_t pool_id;
uint64_t oid;
uint32_t index;
int count = 0;
int checksum = 0;
while ( read_exact(io_fd, &pool_id, sizeof(pool_id)) == 0 && pool_id != -1 )
{
if ( read_exact(io_fd, &oid, sizeof(oid)) )
return -1;
if ( read_exact(io_fd, &index, sizeof(index)) )
return -1;
if ( xc_tmem_control(xc, pool_id, TMEMC_RESTORE_FLUSH_PAGE, dom,
0,index,oid,NULL) <= 0 )
return -1;
count++;
checksum += pool_id + oid + index;
}
if ( pool_id != -1 )
return -1;
if ( count )
DPRINTF("invalidated %d tmem pages, check=%d\n",count,checksum);
return 0;
}
/*
* Local variables:
* mode: C
* c-set-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/
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