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libvirt/tests/virnumamock.c
Michal Privoznik 32c887e4b7 virnumamock: Allow CPU-less NUMA nodes
The original virNumaGetNodeCPUs() returns an empty virBitmap if
given NUMA node has no CPUs. But that's not how our mock behaves
- it looks under $fakesysfs/node/node$N/cpulist only to find an
empty file which is then passed to virBitmapParseUnlimited()
which threats such input as error.

Fortunately, we don't have any fake sysfs data where this path is
hit, but we might soon.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-05-17 15:54:20 +02:00

189 lines
4.6 KiB
C

/*
* virnumamock.c: Mock some virNuma functions using sysfs
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include "internal.h"
#include "virmock.h"
#include "virnuma.h"
#include "virfile.h"
#include "viralloc.h"
#include "virstring.h"
#define VIR_FROM_THIS VIR_FROM_NONE
#define SYSFS_SYSTEM_PATH "/sys/devices/system"
static int numa_avail = -1;
/*
* Poor man's mocked NUMA guesser. We basically check if
* /sys/devices/system/node (where /sys/devices/system can already be mocked or
* changed in the tests) exists and cache the result.
*/
bool
virNumaIsAvailable(void)
{
if (numa_avail < 0) {
char *sysfs_node_path = NULL;
sysfs_node_path = g_strdup_printf("%s/node", SYSFS_SYSTEM_PATH);
numa_avail = virFileExists(sysfs_node_path);
VIR_FREE(sysfs_node_path);
}
/*
* Quite a few more things need to be mocked if NUMA is not available and
* you are using this file. Do not remove the abort() call below unless you
* make sure all under virCapabilitiesInitNUMAFake() is mocked (and whatever
* might have changed since this comment was added. You are welcome.
*/
if (!numa_avail)
abort();
return numa_avail;
}
int
virNumaGetMaxNode(void)
{
int ret = -1;
virBitmap *map = NULL;
if (virFileReadValueBitmap(&map, "%s/node/online", SYSFS_SYSTEM_PATH) < 0)
return -1;
ret = virBitmapLastSetBit(map);
virBitmapFree(map);
return ret;
}
bool
virNumaNodeIsAvailable(int node)
{
bool ret = false;
virBitmap *map = NULL;
if (virFileReadValueBitmap(&map, "%s/node/online", SYSFS_SYSTEM_PATH) < 0)
return false;
ret = virBitmapIsBitSet(map, node);
virBitmapFree(map);
return ret;
}
int
virNumaGetNodeMemory(int node,
unsigned long long *memsize,
unsigned long long *memfree)
{
const unsigned long long base = 1 << 30;
if (memsize)
*memsize = base * (node + 1);
if (memfree)
*memfree = base;
return 0;
}
int
virNumaGetDistances(int node G_GNUC_UNUSED,
int **distances,
int *ndistances)
{
*distances = NULL;
*ndistances = 0;
return 0;
}
/*
* TODO: Adapt virNumaGetHugePageInfo{Path,Dir} to use sysfs so that the
* paths can be modified and this function can be thrown away and instead we'd
* have copied info from /sys (as we do with /sys/devices/system).
*/
int
virNumaGetPages(int node,
unsigned int **pages_size,
unsigned long long **pages_avail,
unsigned long long **pages_free,
size_t *npages)
{
const int pages_def[] = { 4, 2 * 1024, 1 * 1024 * 1024};
const int npages_def = G_N_ELEMENTS(pages_def);
size_t i = 0;
if (pages_size)
*pages_size = g_new0(unsigned int, npages_def);
if (pages_avail)
*pages_avail = g_new0(unsigned long long, npages_def);
if (pages_free)
*pages_free = g_new0(unsigned long long, npages_def);
*npages = npages_def;
if (pages_size)
memcpy(*pages_size, pages_def, sizeof(pages_def));
node++;
if (node <= 0)
node = 32;
if (pages_avail || pages_free) {
for (i = 0; i < *npages; i++) {
if (pages_avail)
(*pages_avail)[i] = (node + i) * 2 << 10;
if (pages_free)
(*pages_free)[i] = (node + i) * 1 << 10;
}
}
return 0;
}
int
virNumaGetNodeCPUs(int node, virBitmap **cpus)
{
int ret = -1;
char *cpulist = NULL;
if (virFileReadValueString(&cpulist,
"%s/node/node%u/cpulist",
SYSFS_SYSTEM_PATH, node) < 0)
return -1;
if (STREQ(cpulist, "")) {
unsigned int max_n_cpus = virNumaGetMaxCPUs();
*cpus = virBitmapNew(max_n_cpus);
} else {
*cpus = virBitmapParseUnlimited(cpulist);
}
if (!*cpus)
goto cleanup;
ret = virBitmapCountBits(*cpus);
cleanup:
VIR_FREE(cpulist);
return ret;
}