From f2a5b1d78c076c525d20176d227faf2e6a20257c Mon Sep 17 00:00:00 2001
From: James Hogan <james.hogan@imgtec.com>
Date: Fri, 12 Jul 2013 10:26:11 +0000
Subject: MIPS: KVM: Mark KVM_GUEST (T&E KVM) as BROKEN_ON_SMP

Make KVM_GUEST depend on BROKEN_ON_SMP so that it cannot be enabled with
SMP.

SMP kernels use ll/sc instructions for an atomic section in the tlb fill
handler, with a tlbp instruction contained in the middle. This cannot be
emulated with trap & emulate KVM because the tlbp instruction traps and
the eret to return to the guest code clears the LLbit which makes the sc
instruction always fail.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/5588/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/Kconfig | 1 +
 1 file changed, 1 insertion(+)

(limited to 'arch')

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 4758a8fd3e99..c3abed332301 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1702,6 +1702,7 @@ endchoice
 
 config KVM_GUEST
 	bool "KVM Guest Kernel"
+	depends on BROKEN_ON_SMP
 	help
 	  Select this option if building a guest kernel for KVM (Trap & Emulate) mode
 
-- 
cgit v1.2.3