From a0a846a5d721046003374bafb9ae7857ceff506a Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Thu, 4 Oct 2018 04:46:23 -0400 Subject: [PATCH] docs/devel/memory.txt: Document _with_attrs accessors When we added the _with_attrs accessors we forgot to mention them in the documentation. Backports commit 687ac05d71bbb3172e0546248e40483ef43a4813 from qemu --- qemu/docs/memory.txt | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/qemu/docs/memory.txt b/qemu/docs/memory.txt index 3dd7d7ca..22006254 100644 --- a/qemu/docs/memory.txt +++ b/qemu/docs/memory.txt @@ -273,8 +273,15 @@ is made visible (which can be immediately, later, or never). MMIO Operations --------------- -MMIO regions are provided with ->read() and ->write() callbacks; in addition -various constraints can be supplied to control how these callbacks are called: +MMIO regions are provided with ->read() and ->write() callbacks, +which are sufficient for most devices. Some devices change behaviour +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. + +In addition various constraints can be supplied to control how these +callbacks are called: - .valid.min_access_size, .valid.max_access_size define the access sizes (in bytes) which the device accepts; accesses outside this range will