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qga: ignore non present cpus when handling qmp_guest_get_vcpus() 

If VM has VCPUs plugged sparselly (for example a VM started with
3 VCPUs (cpu0, cpu1 and cpu2) and then cpu1 was hotunplugged so
only cpu0 and cpu2 are present), QGA will rise a error
  error: internal error: unable to execute QEMU agent command 'guest-get-vcpus':
  open("/sys/devices/system/cpu/cpu1/"): No such file or directory
when
  virsh vcpucount FOO --guest
is executed.
Fix it by ignoring non present CPUs when fetching CPUs status from sysfs.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
This commit is contained in:
Igor Mammedov 2018-09-06 14:51:54 +02:00 committed by Michael Roth
parent 0692b03ee1
commit b4bf912a6c
1 changed files with 57 additions and 54 deletions
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111
qga/commands-posix.c
View File

@ -2035,61 +2035,56 @@ static long sysconf_exact(int name, const char *name_str, Error **errp)
* Written members remain unmodified on error.
*/
static void transfer_vcpu(GuestLogicalProcessor *vcpu, bool sys2vcpu,
Error **errp)
char *dirpath, Error **errp)
{
char *dirpath;
int fd;
int res;
int dirfd;
static const char fn[] = "online";
dirpath = g_strdup_printf("/sys/devices/system/cpu/cpu%" PRId64 "/",
vcpu->logical_id);
dirfd = open(dirpath, O_RDONLY | O_DIRECTORY);
if (dirfd == -1) {
error_setg_errno(errp, errno, "open(\"%s\")", dirpath);
return;
}
fd = openat(dirfd, fn, sys2vcpu ? O_RDONLY : O_RDWR);
if (fd == -1) {
if (errno != ENOENT) {
error_setg_errno(errp, errno, "open(\"%s/%s\")", dirpath, fn);
} else if (sys2vcpu) {
vcpu->online = true;
vcpu->can_offline = false;
} else if (!vcpu->online) {
error_setg(errp, "logical processor #%" PRId64 " can't be "
"offlined", vcpu->logical_id);
} /* otherwise pretend successful re-onlining */
} else {
static const char fn[] = "online";
int fd;
int res;
unsigned char status;
fd = openat(dirfd, fn, sys2vcpu ? O_RDONLY : O_RDWR);
if (fd == -1) {
if (errno != ENOENT) {
error_setg_errno(errp, errno, "open(\"%s/%s\")", dirpath, fn);
} else if (sys2vcpu) {
vcpu->online = true;
vcpu->can_offline = false;
} else if (!vcpu->online) {
error_setg(errp, "logical processor #%" PRId64 " can't be "
"offlined", vcpu->logical_id);
} /* otherwise pretend successful re-onlining */
} else {
unsigned char status;
res = pread(fd, &status, 1, 0);
if (res == -1) {
error_setg_errno(errp, errno, "pread(\"%s/%s\")", dirpath, fn);
} else if (res == 0) {
error_setg(errp, "pread(\"%s/%s\"): unexpected EOF", dirpath,
fn);
} else if (sys2vcpu) {
vcpu->online = (status != '0');
vcpu->can_offline = true;
} else if (vcpu->online != (status != '0')) {
status = '0' + vcpu->online;
if (pwrite(fd, &status, 1, 0) == -1) {
error_setg_errno(errp, errno, "pwrite(\"%s/%s\")", dirpath,
fn);
}
} /* otherwise pretend successful re-(on|off)-lining */
res = pread(fd, &status, 1, 0);
if (res == -1) {
error_setg_errno(errp, errno, "pread(\"%s/%s\")", dirpath, fn);
} else if (res == 0) {
error_setg(errp, "pread(\"%s/%s\"): unexpected EOF", dirpath,
fn);
} else if (sys2vcpu) {
vcpu->online = (status != '0');
vcpu->can_offline = true;
} else if (vcpu->online != (status != '0')) {
status = '0' + vcpu->online;
if (pwrite(fd, &status, 1, 0) == -1) {
error_setg_errno(errp, errno, "pwrite(\"%s/%s\")", dirpath,
fn);
}
} /* otherwise pretend successful re-(on|off)-lining */
res = close(fd);
g_assert(res == 0);
}
res = close(dirfd);
res = close(fd);
g_assert(res == 0);
}
g_free(dirpath);
res = close(dirfd);
g_assert(res == 0);
}
GuestLogicalProcessorList *qmp_guest_get_vcpus(Error **errp)
@ -2107,17 +2102,21 @@ GuestLogicalProcessorList *qmp_guest_get_vcpus(Error **errp)
while (local_err == NULL && current < sc_max) {
GuestLogicalProcessor *vcpu;
GuestLogicalProcessorList *entry;
int64_t id = current++;
char *path = g_strdup_printf("/sys/devices/system/cpu/cpu%" PRId64 "/",
id);
vcpu = g_malloc0(sizeof *vcpu);
vcpu->logical_id = current++;
vcpu->has_can_offline = true; /* lolspeak ftw */
transfer_vcpu(vcpu, true, &local_err);
entry = g_malloc0(sizeof *entry);
entry->value = vcpu;
*link = entry;
link = &entry->next;
if (g_file_test(path, G_FILE_TEST_EXISTS)) {
vcpu = g_malloc0(sizeof *vcpu);
vcpu->logical_id = id;
vcpu->has_can_offline = true; /* lolspeak ftw */
transfer_vcpu(vcpu, true, path, &local_err);
entry = g_malloc0(sizeof *entry);
entry->value = vcpu;
*link = entry;
link = &entry->next;
}
g_free(path);
}
if (local_err == NULL) {
@ -2138,7 +2137,11 @@ int64_t qmp_guest_set_vcpus(GuestLogicalProcessorList *vcpus, Error **errp)
processed = 0;
while (vcpus != NULL) {
transfer_vcpu(vcpus->value, false, &local_err);
char *path = g_strdup_printf("/sys/devices/system/cpu/cpu%" PRId64 "/",
vcpus->value->logical_id);
transfer_vcpu(vcpus->value, false, path, &local_err);
g_free(path);
if (local_err != NULL) {
break;
}