[PATCH 4.18 195/197] x86: kvm: avoid unused variable warning

From: Greg Kroah-Hartman
Date: Thu Sep 13 2018 - 10:06:32 EST

4.18-stable review patch. If anyone has any objections, please let me know.


From: Arnd Bergmann <arnd@xxxxxxxx>

commit 7288bde1f9df6c1475675419bdd7725ce84dec56 upstream.

Removing one of the two accesses of the maxphyaddr variable led to
a harmless warning:

arch/x86/kvm/x86.c: In function 'kvm_set_mmio_spte_mask':
arch/x86/kvm/x86.c:6563:6: error: unused variable 'maxphyaddr' [-Werror=unused-variable]

Removing the #ifdef seems to be the nicest workaround, as it
makes the code look cleaner than adding another #ifdef.

Fixes: 28a1f3ac1d0c ("kvm: x86: Set highest physical address bits in non-present/reserved SPTEs")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # L1TF
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

arch/x86/kvm/x86.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6516,14 +6516,12 @@ static void kvm_set_mmio_spte_mask(void)
/* Set the present bit. */
mask |= 1ull;

-#ifdef CONFIG_X86_64
* If reserved bit is not supported, clear the present bit to disable
* mmio page fault.
- if (maxphyaddr == 52)
+ if (IS_ENABLED(CONFIG_X86_64) && maxphyaddr == 52)
mask &= ~1ull;

kvm_mmu_set_mmio_spte_mask(mask, mask);