virtio — archive

[PATCH 1/1] split-ring: clarify the field len in the used ring

From: Cornelia Huck <[email protected]>
To: [email protected]
Date: Mon, 29 Nov 2021 16:33:00 -0000

On Fri, Nov 26 2021, Halil Pasic <[email protected]> wrote: > The current descriptor is misleading: "the descriptor chain which was > used" generally includes both the descriptors that map the device read > only, and descriptors that map the device write only portions of the > buffer described by the descriptor chain. The argument that "used" means > "written to" does not stand because one has to "use" the descriptor > chain even when the whole buffer is device read only. > > One can argue, that the most straightforward way to interpret the phrase > "total length of that descriptor chain" (without context) like the > length of the list is usually defined: i.e. like the number of > descriptors that constitute the chain. This is clearly not what we want > here. Another intuitive way to interpret "total length of that > descriptor chain" is size of the buffer mapped by the descriptor chain. > This is not what we want either. In fact such wrongful interpretations > have caused bugs in the wild. > > On the other hand, the text below the listing that gets modified here > clearly describes the semantics of \field{len}. So let us replace > the ambiguous explanation in the listing, with a hopefully non-ambiguous > one. > > Signed-off-by: Halil Pasic <[email protected]> > --- > split-ring.tex | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) Thanks, pushed as an editorial update.