From: Peter Maydell <peter.maydell@linaro.org>
To: qemu-devel@nongnu.org
Cc: Igor Mammedov <imammedo@redhat.com>
Subject: [PATCH v2] docs/system/cpu-hotplug: Update example's socket-id/core-id
Date: Thu, 10 Oct 2024 14:18:00 +0100 [thread overview]
Message-ID: <20241010131800.3210161-1-peter.maydell@linaro.org> (raw)
The example of how to do vCPU hotplug and hot-unlpug in the
cpu-hotplug documentation no longer works, because the way we
allocate socket-id and core-id to CPUs by default has changed at some
point. The output also no longer matches what current QEMU produces
in some more cosmetic ways.
Update the example to match current QEMU. The differences are:
* the second CPU is now socket-id=0 core-id=1,
not socket-id=1 core-id=0
* the order of fields in QMP responses is now in alphabetical order
* the "arch" member is no longer present in the query-cpus-fast
output (it was removed in QEMU 6.0)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Igor Mammedov <imammedo@redhat.com>
Message-id: 20240819144303.37852-1-peter.maydell@linaro.org
---
v1->v2:
* update device_add command line to use right socket-id/core-id
* expand commit message to mention that "arch" field has gone
---
docs/system/cpu-hotplug.rst | 56 ++++++++++++++++++-------------------
1 file changed, 27 insertions(+), 29 deletions(-)
diff --git a/docs/system/cpu-hotplug.rst b/docs/system/cpu-hotplug.rst
index 015ce2b6ec3..cc50937c36c 100644
--- a/docs/system/cpu-hotplug.rst
+++ b/docs/system/cpu-hotplug.rst
@@ -33,23 +33,23 @@ vCPU hotplug
{
"return": [
{
- "type": "IvyBridge-IBRS-x86_64-cpu",
- "vcpus-count": 1,
"props": {
- "socket-id": 1,
- "core-id": 0,
+ "core-id": 1,
+ "socket-id": 0,
"thread-id": 0
- }
+ },
+ "type": "IvyBridge-IBRS-x86_64-cpu",
+ "vcpus-count": 1
},
{
+ "props": {
+ "core-id": 0,
+ "socket-id": 0,
+ "thread-id": 0
+ },
"qom-path": "/machine/unattached/device[0]",
"type": "IvyBridge-IBRS-x86_64-cpu",
- "vcpus-count": 1,
- "props": {
- "socket-id": 0,
- "core-id": 0,
- "thread-id": 0
- }
+ "vcpus-count": 1
}
]
}
@@ -58,18 +58,18 @@ vCPU hotplug
(4) The ``query-hotpluggable-cpus`` command returns an object for CPUs
that are present (containing a "qom-path" member) or which may be
hot-plugged (no "qom-path" member). From its output in step (3), we
- can see that ``IvyBridge-IBRS-x86_64-cpu`` is present in socket 0,
- while hot-plugging a CPU into socket 1 requires passing the listed
+ can see that ``IvyBridge-IBRS-x86_64-cpu`` is present in socket 0 core 0,
+ while hot-plugging a CPU into socket 0 core 1 requires passing the listed
properties to QMP ``device_add``::
- (QEMU) device_add id=cpu-2 driver=IvyBridge-IBRS-x86_64-cpu socket-id=1 core-id=0 thread-id=0
+ (QEMU) device_add id=cpu-2 driver=IvyBridge-IBRS-x86_64-cpu socket-id=0 core-id=1 thread-id=0
{
"execute": "device_add",
"arguments": {
- "socket-id": 1,
+ "core-id": 1,
"driver": "IvyBridge-IBRS-x86_64-cpu",
"id": "cpu-2",
- "core-id": 0,
+ "socket-id": 0,
"thread-id": 0
}
}
@@ -83,34 +83,32 @@ vCPU hotplug
(QEMU) query-cpus-fast
{
- "execute": "query-cpus-fast",
"arguments": {}
+ "execute": "query-cpus-fast",
}
{
"return": [
{
- "qom-path": "/machine/unattached/device[0]",
- "target": "x86_64",
- "thread-id": 11534,
"cpu-index": 0,
"props": {
- "socket-id": 0,
"core-id": 0,
+ "socket-id": 0,
"thread-id": 0
},
- "arch": "x86"
+ "qom-path": "/machine/unattached/device[0]",
+ "target": "x86_64",
+ "thread-id": 28957
},
{
- "qom-path": "/machine/peripheral/cpu-2",
- "target": "x86_64",
- "thread-id": 12106,
"cpu-index": 1,
"props": {
- "socket-id": 1,
- "core-id": 0,
+ "core-id": 1,
+ "socket-id": 0,
"thread-id": 0
},
- "arch": "x86"
+ "qom-path": "/machine/peripheral/cpu-2",
+ "target": "x86_64",
+ "thread-id": 29095
}
]
}
@@ -123,10 +121,10 @@ From the 'qmp-shell', invoke the QMP ``device_del`` command::
(QEMU) device_del id=cpu-2
{
- "execute": "device_del",
"arguments": {
"id": "cpu-2"
}
+ "execute": "device_del",
}
{
"return": {}
--
2.34.1
next reply other threads:[~2024-10-10 13:18 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-10 13:18 Peter Maydell [this message]
2024-10-18 15:52 ` [PATCH v2] docs/system/cpu-hotplug: Update example's socket-id/core-id Peter Maydell
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20241010131800.3210161-1-peter.maydell@linaro.org \
--to=peter.maydell@linaro.org \
--cc=imammedo@redhat.com \
--cc=qemu-devel@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).