From: Peter Xu <peterx@redhat.com>
To: qemu-devel@nongnu.org
Cc: "Marc-André Lureau" <marcandre.lureau@redhat.com>,
"Daniel P . Berrange" <berrange@redhat.com>,
"Christian Borntraeger" <borntraeger@de.ibm.com>,
"Fam Zheng" <famz@redhat.com>, "Kevin Wolf" <kwolf@redhat.com>,
"Max Reitz" <mreitz@redhat.com>,
peterx@redhat.com, "Eric Auger" <eric.auger@redhat.com>,
"Eric Blake" <eblake@redhat.com>, "John Snow" <jsnow@redhat.com>,
"Markus Armbruster" <armbru@redhat.com>,
"Peter Maydell" <peter.maydell@linaro.org>,
"Dr . David Alan Gilbert" <dgilbert@redhat.com>
Subject: [Qemu-devel] [PATCH v3 4/6] docs: mention shared state protect for OOB
Date: Fri, 15 Jun 2018 09:42:47 +0800 [thread overview]
Message-ID: <20180615014249.22730-5-peterx@redhat.com> (raw)
In-Reply-To: <20180615014249.22730-1-peterx@redhat.com>
Out-Of-Band handlers need to protect shared state if there is any.
Mention it in the document.
Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
docs/devel/qapi-code-gen.txt | 3 +++
1 file changed, 3 insertions(+)
diff --git a/docs/devel/qapi-code-gen.txt b/docs/devel/qapi-code-gen.txt
index 1366228b2a..bee9de35df 100644
--- a/docs/devel/qapi-code-gen.txt
+++ b/docs/devel/qapi-code-gen.txt
@@ -680,6 +680,9 @@ OOB command handlers must satisfy the following conditions:
- It does not invoke system calls that may block,
- It does not access guest RAM that may block when userfaultfd is
enabled for postcopy live migration.
+- It needs to protect any shared state, since as long as a command
+ supports Out-Of-Band it means the handler can be run in parallel
+ with the same handler running in the other thread.
If in doubt, do not implement OOB execution support.
--
2.17.1
next prev parent reply other threads:[~2018-06-15 1:43 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-15 1:42 [Qemu-devel] [PATCH v3 0/6] monitor: enable OOB by default Peter Xu
2018-06-15 1:42 ` [Qemu-devel] [PATCH v3 1/6] chardev: comment details for CLOSED event Peter Xu
2018-06-15 12:49 ` Markus Armbruster
2018-06-18 15:55 ` Stefan Hajnoczi
2018-06-15 1:42 ` [Qemu-devel] [PATCH v3 2/6] monitor: flush qmp responses when CLOSED Peter Xu
2018-06-15 8:11 ` Markus Armbruster
2018-06-19 4:35 ` Peter Xu
2018-06-19 13:40 ` Markus Armbruster
2018-06-15 1:42 ` [Qemu-devel] [PATCH v3 3/6] tests: iotests: drop some stderr line Peter Xu
2018-06-15 8:13 ` Markus Armbruster
2018-06-19 4:41 ` Peter Xu
2018-06-15 1:42 ` Peter Xu [this message]
2018-06-15 12:37 ` [Qemu-devel] [PATCH v3 4/6] docs: mention shared state protect for OOB Markus Armbruster
2018-06-19 4:49 ` Peter Xu
2018-06-15 1:42 ` [Qemu-devel] [PATCH v3 5/6] monitor: remove "x-oob", turn oob on by default Peter Xu
2018-06-15 1:42 ` [Qemu-devel] [PATCH v3 6/6] Revert "tests: Add parameter to qtest_init_without_qmp_handshake" Peter Xu
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