Re: [PATCH] plugins: Expose physical addresses instead of device offsets

From: Aaron Lindsay via <qemu-devel@nongnu.org>
To: "Alex Bennée" <alex.bennee@linaro.org>
Cc: Peter Maydell <peter.maydell@linaro.org>,
	QEMU Developers <qemu-devel@nongnu.org>,
	"Emilio G. Cota" <cota@braap.org>,
	Richard Henderson <richard.henderson@linaro.org>
Subject: Re: [PATCH] plugins: Expose physical addresses instead of device offsets
Date: Tue, 9 Mar 2021 15:30:07 -0500	[thread overview]
Message-ID: <YEfaz7QnmcjCmliz@strawberry.localdomain> (raw)
In-Reply-To: <87lfaw8bcc.fsf@linaro.org>

On Mar 09 17:45, Alex Bennée wrote:
> Aaron Lindsay <aaron@os.amperecomputing.com> writes:
> > On Mar 09 10:08, Peter Maydell wrote:
> >> On Mon, 8 Mar 2021 at 20:14, Aaron Lindsay <aaron@os.amperecomputing.com> wrote:
> >> >
> >> > This allows plugins to query for full virtual-to-physical address
> >> > translation for a given `qemu_plugin_hwaddr` and stops exposing the
> >> > offset within the device itself. As this change breaks the API,
> >> > QEMU_PLUGIN_VERSION is incremented.
> >> >
> >> > Signed-off-by: Aaron Lindsay <aaron@os.amperecomputing.com>
> >> > ---
> >> 
> >> 
> >> > diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h
> >> > index c66507fe8f..2252ecf2f0 100644
> >> > --- a/include/qemu/qemu-plugin.h
> >> > +++ b/include/qemu/qemu-plugin.h
> >> > @@ -47,7 +47,7 @@ typedef uint64_t qemu_plugin_id_t;
> >> >
> >> >  extern QEMU_PLUGIN_EXPORT int qemu_plugin_version;
> >> >
> >> > -#define QEMU_PLUGIN_VERSION 0
> >> > +#define QEMU_PLUGIN_VERSION 1
> >> >
> >> >  typedef struct {
> >> >      /* string describing architecture */
> >> > @@ -328,7 +328,7 @@ struct qemu_plugin_hwaddr *qemu_plugin_get_hwaddr(qemu_plugin_meminfo_t info,
> >> >   * offset will be into the appropriate block of RAM.
> >> >   */
> >> >  bool qemu_plugin_hwaddr_is_io(const struct qemu_plugin_hwaddr *haddr);
> >> > -uint64_t qemu_plugin_hwaddr_device_offset(const struct qemu_plugin_hwaddr *haddr);
> >> > +uint64_t qemu_plugin_hwaddr_phys_addr(const struct qemu_plugin_hwaddr *haddr);
> >> 
> >> 
> >> This should have a documentation comment, since this is the public-facing API.
> >
> > I now see I neglected to update the comment right here the function
> > declaration, and will do so for v2.
> >
> > But are you asking for additional documentation beyond that change? If
> > so, where is the right place to add this? docs/devel/tcg-plugins.rst
> > doesn't seem to have much in the way of documentation for the actual
> > calls.
> 
> The calls should be documented in @kerneldoc style comments in the main
> plugin header. Which reminds me I should be able to extract them into
> the tcg-plugins.rst document via sphinx.

I just sent out v2, in which I took a pass at updating this
documentation. Let me know what you think.

-Aaron