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 <[email protected]>
Signed-off-by: Konrad Rzeszutek Wilk <[email protected]>
diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
index fdce49c..c31ee77 100644
--- a/arch/x86/xen/Kconfig
+++ b/arch/x86/xen/Kconfig
@@ -6,6 +6,7 @@
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
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index 126d8ce..cabfa97 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -206,4 +206,7 @@
Allow kernel fetching MCE error from Xen platform and
converting it into Linux mcelog format for mcelog tools
+config XEN_HAVE_PVMMU
+ bool
+
endmenu
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index d6886d9..a56776d 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -359,6 +359,7 @@
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 @@
0);
BUG_ON(ret);
}
+#endif
/* Relinquish the page back to the allocator. */
ClearPageReserved(page);
@@ -416,13 +418,14 @@
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. */
