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MIPS: KVM: Mark KVM_GUEST (T&E KVM) as BROKEN_ON_SMP

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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>
This commit is contained in:
James Hogan 2013-07-12 10:26:11 +00:00 committed by Ralf Baechle
parent 38a997a70e
commit f2a5b1d78c
1 changed files with 1 additions and 0 deletions
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arch/mips/Kconfig
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@ -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