The patch below was submitted to be applied to the 4.18-stable tree.
I fail to see how this patch meets the stable kernel rules as found at Documentation/process/stable-kernel-rules.rst.
I could be totally wrong, and if so, please respond to stable@vger.kernel.org and let me know why this patch should be applied. Otherwise, it is now dropped from my patch queues, never to be seen again.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 7288bde1f9df6c1475675419bdd7725ce84dec56 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann arnd@arndb.de Date: Mon, 20 Aug 2018 23:37:50 +0200 Subject: [PATCH] x86: kvm: avoid unused variable warning
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@arndb.de Cc: stable@vger.kernel.org # L1TF Signed-off-by: Paolo Bonzini pbonzini@redhat.com
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index f7dff0457846..14ee9a814888 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6576,14 +6576,12 @@ 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; -#endif
kvm_mmu_set_mmio_spte_mask(mask, mask); }