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authorJames Hogan <james.hogan@imgtec.com>2013-07-12 10:26:11 +0000
committerRalf Baechle <ralf@linux-mips.org>2013-07-19 10:41:17 +0200
commitf2a5b1d78c076c525d20176d227faf2e6a20257c (patch)
treef837a60fda719084884b28c054614fa9bd594403 /arch
parent38a997a70e6cf0ee9fc26de146601ba10fa552a4 (diff)
downloadlinux-linaro-stable-f2a5b1d78c076c525d20176d227faf2e6a20257c.tar.gz
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>
Diffstat (limited to 'arch')
-rw-r--r--arch/mips/Kconfig1
1 files changed, 1 insertions, 0 deletions
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