From: "Philippe Mathieu-Daudé" <philmd@redhat.com>
To: Markus Armbruster <armbru@redhat.com>, qemu-devel@nongnu.org
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
"Philippe Mathieu-Daudé" <philmd@redhat.com>
Subject: [PATCH v5 2/8] qapi: Correct balloon documentation
Date: Sun, 13 Sep 2020 21:53:42 +0200 [thread overview]
Message-ID: <20200913195348.1064154-3-philmd@redhat.com> (raw)
In-Reply-To: <20200913195348.1064154-1-philmd@redhat.com>
The documentation incorrectly uses the "size of the balloon"
description when it should be "logical size of the VM". Fix it.
The relation between both values is:
logical_vm_size = vm_ram_size - balloon_size
Reported-by: David Hildenbrand <david@redhat.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
qapi/misc.json | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/qapi/misc.json b/qapi/misc.json
index b21963a176d..a667fdf03e5 100644
--- a/qapi/misc.json
+++ b/qapi/misc.json
@@ -192,7 +192,8 @@
#
# Information about the guest balloon device.
#
-# @actual: the number of bytes the balloon currently contains
+# @actual: the logical size of the VM in bytes
+# Formula used: logical_vm_size = vm_ram_size - balloon_size
#
# Since: 0.14.0
#
@@ -228,7 +229,8 @@
# Emitted when the guest changes the actual BALLOON level. This value is
# equivalent to the @actual field return by the 'query-balloon' command
#
-# @actual: actual level of the guest memory balloon in bytes
+# @actual: the logical size of the VM in bytes
+# Formula used: logical_vm_size = vm_ram_size - balloon_size
#
# Note: this event is rate-limited.
#
@@ -759,7 +761,10 @@
#
# Request the balloon driver to change its balloon size.
#
-# @value: the target size of the balloon in bytes
+# @value: the target logical size of the VM in bytes
+# We can deduce the size of the balloon using this formula:
+# logical_vm_size = vm_ram_size - balloon_size
+# From it we have: balloon_size = vm_ram_size - @value
#
# Returns: - Nothing on success
# - If the balloon driver is enabled but not functional because the KVM
@@ -777,6 +782,8 @@
# -> { "execute": "balloon", "arguments": { "value": 536870912 } }
# <- { "return": {} }
#
+# With a 2.5GiB guest this command inflated the balloon to 3GiB.
+#
##
{ 'command': 'balloon', 'data': {'value': 'int'} }
--
2.26.2
next prev parent reply other threads:[~2020-09-13 19:55 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-13 19:53 [PATCH v5 0/8] user-mode: Prune build dependencies (part 2) Philippe Mathieu-Daudé
2020-09-13 19:53 ` [PATCH v5 1/8] qapi: Restrict LostTickPolicy enum to machine code Philippe Mathieu-Daudé
2020-09-14 9:14 ` Markus Armbruster
2020-09-14 9:37 ` Philippe Mathieu-Daudé
2020-09-15 6:27 ` Markus Armbruster
2020-09-13 19:53 ` Philippe Mathieu-Daudé [this message]
2020-09-13 19:53 ` [PATCH v5 3/8] qapi: Restrict balloon-related commands " Philippe Mathieu-Daudé
2020-09-14 9:16 ` Markus Armbruster
2020-09-14 9:42 ` Philippe Mathieu-Daudé
2020-09-14 9:48 ` David Hildenbrand
2020-09-14 11:21 ` Markus Armbruster
2020-09-14 12:15 ` Philippe Mathieu-Daudé
2020-09-15 6:24 ` Markus Armbruster
2020-09-13 19:53 ` [PATCH v5 4/8] qapi: Restrict query-vm-generation-id command " Philippe Mathieu-Daudé
2020-09-13 19:53 ` [PATCH v5 5/8] qapi: Restrict query-uuid " Philippe Mathieu-Daudé
2020-09-13 19:53 ` [PATCH v5 6/8] qapi: Restrict device memory commands " Philippe Mathieu-Daudé
2020-09-13 19:53 ` [PATCH v5 7/8] qapi: Extract ACPI commands to 'acpi.json' Philippe Mathieu-Daudé
2020-09-13 19:53 ` [PATCH v5 8/8] qapi: Extract PCI commands to 'pci.json' Philippe Mathieu-Daudé
2020-09-15 6:29 ` [PATCH v5 0/8] user-mode: Prune build dependencies (part 2) Markus Armbruster
2020-09-15 7:09 ` Philippe Mathieu-Daudé
2020-09-15 8:52 ` Markus Armbruster
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=20200913195348.1064154-3-philmd@redhat.com \
--to=philmd@redhat.com \
--cc=armbru@redhat.com \
--cc=pbonzini@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).