On Fri, 17 Sep 2010, Blue Swirl wrote:
> On Fri, Sep 17, 2010 at 11:15 AM, <anthony.perard@xxxxxxxxxx> wrote:
> > From: Anthony PERARD <anthony.perard@xxxxxxxxxx>
> >
> > The mapcache maps chucks of guest memory on demand, unmaps them when
> > they are not needed anymore.
> >
> > Each call to qemu_get_ram_ptr makes a call to qemu_map_cache with the
> > lock option, so mapcache will not unmap these ram_ptr.
> >
> > Signed-off-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
> > ---
> > Makefile.target | 2 +-
> > exec.c | 36 ++++++-
> > hw/xen.h | 4 +
> > xen-all.c | 63 ++++++++++++
> > xen-stub.c | 4 +
> > xen_mapcache.c | 302
> > +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > xen_mapcache.h | 26 +++++
> > 7 files changed, 432 insertions(+), 5 deletions(-)
> > create mode 100644 xen_mapcache.c
> > create mode 100644 xen_mapcache.h
> >
[...]
> > + while (j > 0) {
> > + word = (word << 1) | !err[i + --j];
>
> You are mixing bitwise OR with logical NOT, is this correct?
Yes, this is correct.
> > + }
> > + entry->valid_mapping[i / BITS_PER_LONG] = word;
> > + }
> > +
> > + qemu_free(pfns);
> > + qemu_free(err);
> > +}
> > +
> > +uint8_t *qemu_map_cache(target_phys_addr_t phys_addr, target_phys_addr_t
> > size, uint8_t lock)
> > +{
> > + MapCacheEntry *entry, *pentry = NULL;
> > + unsigned long address_index = phys_addr >> MCACHE_BUCKET_SHIFT;
> > + unsigned long address_offset = phys_addr & (MCACHE_BUCKET_SIZE-1);
>
> unsigned long will not be long enough on 32 bit host (or 32 bit user
> space) for a 64 bit target. I can't remember if this was a supported
> case for Xen anyway.
Xen can do that, so I change unsigned long to target_phys_addr_t.
[...]
> > diff --git a/xen_mapcache.h b/xen_mapcache.h
> > new file mode 100644
> > index 0000000..5a6730f
> > --- /dev/null
> > +++ b/xen_mapcache.h
> > @@ -0,0 +1,26 @@
> > +#ifndef XEN_MAPCACHE_H
> > +#define XEN_MAPCACHE_H
> > +
> > +#if (defined(__i386__) || defined(__x86_64__))
> > +# define MAPCACHE
>
> xen_mapcache.c could be split into two files, xen-mapcache-stub.c and
> xen-mapcache.c. configure could perform the check for i386 or x86_64
> host and define CONFIG_XEN_MAPCACHE=y appropriately. Then
> Makefile.target would compile the correct file based on that.
Ok, I will do that.
--
Anthony PERARD
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
Home