From: Lin Ma <lma@suse.com>
To: qemu-devel@nongnu.org
Cc: mdroth@linux.vnet.ibm.com, marcandre.lureau@gmail.com,
Lin Ma <lma@suse.com>
Subject: [PATCH v5] qga: Correct loop count in qmp_guest_get_vcpus()
Date: Tue, 1 Dec 2020 17:56:07 +0800 [thread overview]
Message-ID: <20201201095607.23389-1-lma@suse.com> (raw)
The guest-get-vcpus returns incorrect vcpu info in case we hotunplug vcpus(not
the last one).
e.g.:
A VM has 4 VCPUs: cpu0 + 3 hotunpluggable online vcpus(cpu1, cpu2 and cpu3).
Hotunplug cpu2, Now only cpu0, cpu1 and cpu3 are present & online.
./qmp-shell /tmp/qmp-monitor.sock
(QEMU) query-hotpluggable-cpus
{"return": [
{"props": {"core-id": 0, "thread-id": 0, "socket-id": 3}, "vcpus-count": 1,
"qom-path": "/machine/peripheral/cpu3", "type": "host-x86_64-cpu"},
{"props": {"core-id": 0, "thread-id": 0, "socket-id": 2}, "vcpus-count": 1,
"qom-path": "/machine/peripheral/cpu2", "type": "host-x86_64-cpu"},
{"props": {"core-id": 0, "thread-id": 0, "socket-id": 1}, "vcpus-count": 1,
"qom-path": "/machine/peripheral/cpu1", "type": "host-x86_64-cpu"},
{"props": {"core-id": 0, "thread-id": 0, "socket-id": 0}, "vcpus-count": 1,
"qom-path": "/machine/unattached/device[0]", "type": "host-x86_64-cpu"}
]}
(QEMU) device_del id=cpu2
{"return": {}}
(QEMU) query-hotpluggable-cpus
{"return": [
{"props": {"core-id": 0, "thread-id": 0, "socket-id": 3}, "vcpus-count": 1,
"qom-path": "/machine/peripheral/cpu3", "type": "host-x86_64-cpu"},
{"props": {"core-id": 0, "thread-id": 0, "socket-id": 2}, "vcpus-count": 1,
"type": "host-x86_64-cpu"},
{"props": {"core-id": 0, "thread-id": 0, "socket-id": 1}, "vcpus-count": 1,
"qom-path": "/machine/peripheral/cpu1", "type": "host-x86_64-cpu"},
{"props": {"core-id": 0, "thread-id": 0, "socket-id": 0}, "vcpus-count": 1,
"qom-path": "/machine/unattached/device[0]", "type": "host-x86_64-cpu"}
]}
Before:
./qmp-shell -N /tmp/qmp-ga.sock
Welcome to the QMP low-level shell!
Connected
(QEMU) guest-get-vcpus
{"return": [
{"online": true, "can-offline": false, "logical-id": 0},
{"online": true, "can-offline": true, "logical-id": 1}]}
After:
./qmp-shell -N /tmp/qmp-ga.sock
Welcome to the QMP low-level shell!
Connected
(QEMU) guest-get-vcpus
{"return": [
{"online": true, "can-offline": false, "logical-id": 0},
{"online": true, "can-offline": true, "logical-id": 1},
{"online": true, "can-offline": true, "logical-id": 3}]}
Signed-off-by: Lin Ma <lma@suse.com>
---
qga/commands-posix.c | 43 ++++++++++++++-----------------------------
1 file changed, 14 insertions(+), 29 deletions(-)
diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index c089e38120..f66bf84126 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -2376,24 +2376,6 @@ error:
return NULL;
}
-#define SYSCONF_EXACT(name, errp) sysconf_exact((name), #name, (errp))
-
-static long sysconf_exact(int name, const char *name_str, Error **errp)
-{
- long ret;
-
- errno = 0;
- ret = sysconf(name);
- if (ret == -1) {
- if (errno == 0) {
- error_setg(errp, "sysconf(%s): value indefinite", name_str);
- } else {
- error_setg_errno(errp, errno, "sysconf(%s)", name_str);
- }
- }
- return ret;
-}
-
/* Transfer online/offline status between @vcpu and the guest system.
*
* On input either @errp or *@errp must be NULL.
@@ -2464,24 +2446,28 @@ static void transfer_vcpu(GuestLogicalProcessor *vcpu, bool sys2vcpu,
GuestLogicalProcessorList *qmp_guest_get_vcpus(Error **errp)
{
- int64_t current;
GuestLogicalProcessorList *head, **link;
- long sc_max;
+ const char *cpu_dir = "/sys/devices/system/cpu";
+ const gchar *line;
+ g_autoptr(GDir) cpu_gdir = NULL;
Error *local_err = NULL;
- current = 0;
head = NULL;
link = &head;
- sc_max = SYSCONF_EXACT(_SC_NPROCESSORS_CONF, &local_err);
+ cpu_gdir = g_dir_open(cpu_dir, 0, NULL);
+
+ if (cpu_gdir == NULL) {
+ error_setg_errno(errp, errno, "failed to list entries: %s", cpu_dir);
+ return NULL;
+ }
- while (local_err == NULL && current < sc_max) {
+ while (local_err == NULL && (line = g_dir_read_name(cpu_gdir)) != NULL) {
GuestLogicalProcessor *vcpu;
GuestLogicalProcessorList *entry;
- int64_t id = current++;
- char *path = g_strdup_printf("/sys/devices/system/cpu/cpu%" PRId64 "/",
- id);
-
- if (g_file_test(path, G_FILE_TEST_EXISTS)) {
+ int64_t id;
+ if (sscanf(line, "cpu%ld", &id)) {
+ g_autofree char *path = g_strdup_printf("/sys/devices/system/cpu/"
+ "cpu%" PRId64 "/", id);
vcpu = g_malloc0(sizeof *vcpu);
vcpu->logical_id = id;
vcpu->has_can_offline = true; /* lolspeak ftw */
@@ -2491,7 +2477,6 @@ GuestLogicalProcessorList *qmp_guest_get_vcpus(Error **errp)
*link = entry;
link = &entry->next;
}
- g_free(path);
}
if (local_err == NULL) {
--
2.26.0
next reply other threads:[~2020-12-01 9:57 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-01 9:56 Lin Ma [this message]
2020-12-01 10:23 ` [PATCH v5] qga: Correct loop count in qmp_guest_get_vcpus() Marc-André Lureau
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