powerpc/kvm: Prefer fault_in_pages_readable function

Directly use fault_in_pages_readable instead of manual __get_user code. Fix
warning treated as error with W=1:

  arch/powerpc/kernel/kvm.c:675:6: error: variable ‘tmp’ set but not used [-Werror=unused-but-set-variable]

Suggested-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Mathieu Malaterre 2018-03-28 21:58:11 +02:00 committed by Michael Ellerman
parent 0078778a86
commit 9f9eae5ce7

View File

@ -25,6 +25,7 @@
#include <linux/kvm_para.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/pagemap.h>
#include <asm/reg.h>
#include <asm/sections.h>
@ -672,14 +673,13 @@ static void kvm_use_magic_page(void)
{
u32 *p;
u32 *start, *end;
u32 tmp;
u32 features;
/* Tell the host to map the magic page to -4096 on all CPUs */
on_each_cpu(kvm_map_magic_page, &features, 1);
/* Quick self-test to see if the mapping works */
if (__get_user(tmp, (u32*)KVM_MAGIC_PAGE)) {
if (!fault_in_pages_readable((const char *)KVM_MAGIC_PAGE, sizeof(u32))) {
kvm_patching_worked = false;
return;
}