xen: balloon: allow PVMMU interfaces to be compiled out

The ARM platform has no concept of PVMMU and therefor no
HYPERVISOR_update_va_mapping et al. Allow this code to be compiled out
when not required.

In some similar situations (e.g. P2M) we have defined dummy functions
to avoid this, however I think we can/should draw the line at dummying
out actual hypercalls.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Ian Campbell 2012-10-03 12:17:50 +01:00
parent d71f513985
commit c2374bf57e
3 changed files with 8 additions and 1 deletions

View file

@ -6,6 +6,7 @@ config XEN
bool "Xen guest support"
select PARAVIRT
select PARAVIRT_CLOCK
select XEN_HAVE_PVMMU
depends on X86_64 || (X86_32 && X86_PAE && !X86_VISWS)
depends on X86_CMPXCHG && X86_TSC
help

View file

@ -206,4 +206,7 @@ config XEN_MCE_LOG
Allow kernel fetching MCE error from Xen platform and
converting it into Linux mcelog format for mcelog tools
config XEN_HAVE_PVMMU
bool
endmenu

View file

@ -359,6 +359,7 @@ static enum bp_state increase_reservation(unsigned long nr_pages)
set_phys_to_machine(pfn, frame_list[i]);
#ifdef CONFIG_XEN_HAVE_PVMMU
/* Link back into the page tables if not highmem. */
if (xen_pv_domain() && !PageHighMem(page)) {
int ret;
@ -368,6 +369,7 @@ static enum bp_state increase_reservation(unsigned long nr_pages)
0);
BUG_ON(ret);
}
#endif
/* Relinquish the page back to the allocator. */
ClearPageReserved(page);
@ -416,13 +418,14 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
scrub_page(page);
#ifdef CONFIG_XEN_HAVE_PVMMU
if (xen_pv_domain() && !PageHighMem(page)) {
ret = HYPERVISOR_update_va_mapping(
(unsigned long)__va(pfn << PAGE_SHIFT),
__pte_ma(0), 0);
BUG_ON(ret);
}
#endif
}
/* Ensure that ballooned highmem pages don't have kmaps. */