Re: [PATCH 3/5] tools/libs/foreignmemory: Fix PAGE_SIZE redefinition error

[Julien Grall <julien@xxxxxxx>]

On 28/04/2021 19:27, Costin Lupu wrote:
> Hi Julien,
Hi Costin,

> On 4/28/21 12:03 PM, Julien Grall wrote:
> > Hi Costin,
> >
> > On 27/04/2021 13:05, Costin Lupu wrote:
> > >    tools/libs/foreignmemory/private.h | 6 ++++--
> > >    1 file changed, 4 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/tools/libs/foreignmemory/private.h
> > > b/tools/libs/foreignmemory/private.h
> > > index 1ee3626dd2..f3c1ba2867 100644
> > > --- a/tools/libs/foreignmemory/private.h
> > > +++ b/tools/libs/foreignmemory/private.h
> > > @@ -10,11 +10,13 @@
> > >    #include <xen/xen.h>
> > >    #include <xen/sys/privcmd.h>
> > >    -#ifndef PAGE_SHIFT /* Mini-os, Yukk */
> > > +#ifndef PAGE_SHIFT
> > >    #define PAGE_SHIFT           12
> > >    #endif
> > > -#ifndef __MINIOS__ /* Yukk */
> > > +#ifndef PAGE_SIZE
> > >    #define PAGE_SIZE            (1UL << PAGE_SHIFT)
> > > +#endif
> > > +#ifndef PAGE_MASK
> > >    #define PAGE_MASK            (~(PAGE_SIZE-1))
> > >    #endif
> > Looking at the usage, I believe PAGE_* are referring to the page
> > granularity of Xen rather than the page granularity of the control
> > domain itself.
> >
> > So it would be incorrect to use the domain's page granularity here and
> > would break dom0 using 64KB page granularity on Arm.
> >
> > Instead, we should replace PAGE_* with XC_PAGE_*. If some of them are
> > still referring to the control domain granularity, then we should use
> > getpageshift() (Or equivalent) because the userspace shouldn't rely on a
> > specific page granularity.
> Yes, this makes sense. One thing I need to clarify: what does XC stand
> for? I thought for some time it stands for Xen Control.
I think it is Xen Control, which is a bit confusing for that specific 
define.
Cheers,

--
Julien Grall