On Wed, Jul 16, 2008 at 10:16:56AM +0900, Isaku Yamahata wrote:
> Some comments below
>
> On Tue, Jul 15, 2008 at 04:25:45PM +1000, Simon Horman wrote:
> [snip]
> > Index: xen-unstable.hg/xen/include/asm-ia64/linux-xen/linux/efi.h
> > ===================================================================
> > --- xen-unstable.hg.orig/xen/include/asm-ia64/linux-xen/linux/efi.h
> > 2008-07-15 16:11:00.000000000 +1000
> > +++ xen-unstable.hg/xen/include/asm-ia64/linux-xen/linux/efi.h
> > 2008-07-15 16:16:56.000000000 +1000
> > @@ -24,10 +24,6 @@
> > #include <asm/page.h>
> > #include <asm/system.h>
> >
> > -#ifdef XEN
> > -extern void * pal_vaddr;
> > -#endif
> > -
> > #define EFI_SUCCESS 0
> > #define EFI_LOAD_ERROR ( 1 | (1UL << (BITS_PER_LONG-1)))
> > #define EFI_INVALID_PARAMETER ( 2 | (1UL << (BITS_PER_LONG-1)))
> > @@ -302,6 +298,9 @@ efi_guid_unparse(efi_guid_t *guid, char
> > extern void efi_init (void);
> > extern void *efi_get_pal_addr (void);
> > extern void efi_map_pal_code (void);
> > +#ifdef XEN
> > +extern void efi_unmap_pal_code (void);
> > +#endif
> > extern void efi_map_memmap(void);
> > extern void efi_memmap_walk (efi_freemem_callback_t callback, void *arg);
> > extern void efi_gettimeofday (struct timespec *ts);
> > @@ -469,13 +468,19 @@ struct efi_generic_dev_path {
> > #define XEN_EFI_RR_ENTER(rr6, rr7) do { \
> > rr6 = ia64_get_rr(6UL << 61); \
> > rr7 = ia64_get_rr(7UL << 61); \
> > - set_one_rr_efi(6UL << 61, XEN_EFI_RR); \
> > - set_one_rr_efi(7UL << 61, XEN_EFI_RR); \
> > + if (rr7 != XEN_EFI_RR) { \
> > + set_one_rr_efi(6UL << 61, XEN_EFI_RR); \
> > + set_one_rr_efi(7UL << 61, XEN_EFI_RR); \
> > + efi_map_pal_code(); \
> > + } \
> > } while (0)
> >
> > #define XEN_EFI_RR_LEAVE(rr6, rr7) do { \
> > - set_one_rr_efi(6UL << 61, rr6); \
> > - set_one_rr_efi(7UL << 61, rr7); \
> > + if (rr7 != XEN_EFI_RR) { \
> > + efi_unmap_pal_code(); \
> > + set_one_rr_efi(6UL << 61, rr6); \
> > + set_one_rr_efi(7UL << 61, rr7); \
> > + } \
> > } while (0)
> >
> > #else
>
> I think that rr7 check in XEN_EFI_RR_LEAVE is necessary.
> On the other hand, the rr7 check in XEN_EFI_RR_ENTRY might cause
> problems because there is a window between setting rr[7] = XEN_EFI_RR
> and itr[IA64_TR_PALCODE].
> The window can be closed by always setting rr's and calling
> efi_unmap_pal_code() and efi_map_pal_code() in XEN_EFI_RR_ENTRY().
>
> I may be too paranoiac, though.
Better to be paranoid than broken. I will incoporate
your idea of unpining before pinning in efi_map_pal_code()
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