qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Bin Meng <bmeng.cn@gmail.com>
To: David Hildenbrand <david@redhat.com>,
	Paolo Bonzini <pbonzini@redhat.com>, Peter Xu <peterx@redhat.com>
Cc: "Peter Maydell" <peter.maydell@linaro.org>,
	"Philippe Mathieu-Daudé" <f4bug@amsat.org>,
	qemu-devel@nongnu.org
Subject: [PATCH] docs/devel: memory: Document MemoryRegionOps requirement
Date: Mon,  6 Sep 2021 20:20:20 +0800	[thread overview]
Message-ID: <20210906122020.5793-1-bmeng.cn@gmail.com> (raw)

It's been a requirement that at least one function pointer for read
and one for write are provided ever since the MemoryRegion APIs were
introduced in 2012.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
---

 docs/devel/memory.rst | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/docs/devel/memory.rst b/docs/devel/memory.rst
index 5dc8a12682..7b589b21d2 100644
--- a/docs/devel/memory.rst
+++ b/docs/devel/memory.rst
@@ -344,6 +344,11 @@ based on the attributes used for the memory transaction, or need
 to be able to respond that the access should provoke a bus error
 rather than completing successfully; those devices can use the
 ->read_with_attrs() and ->write_with_attrs() callbacks instead.
+The requirement for a device's MemoryRegionOps is that at least
+one callback for read and one for write are provided. If both
+->read() and ->read_with_attrs() are provided, the plain ->read()
+version takes precedence over the with_attrs() version. So does
+the write callback.
 
 In addition various constraints can be supplied to control how these
 callbacks are called:
-- 
2.25.1



             reply	other threads:[~2021-09-06 12:21 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-06 12:20 Bin Meng [this message]
2021-09-06 12:25 ` [PATCH] docs/devel: memory: Document MemoryRegionOps requirement David Hildenbrand
2021-09-06 13:01 ` Philippe Mathieu-Daudé
2021-09-08 18:50   ` Peter Xu
2021-09-08 20:17     ` Philippe Mathieu-Daudé
2021-10-02 14:37       ` Bin Meng

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=20210906122020.5793-1-bmeng.cn@gmail.com \
    --to=bmeng.cn@gmail.com \
    --cc=david@redhat.com \
    --cc=f4bug@amsat.org \
    --cc=pbonzini@redhat.com \
    --cc=peter.maydell@linaro.org \
    --cc=peterx@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).