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| author | James Hogan <james.hogan@imgtec.com> | 2013-07-12 10:26:11 +0000 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2013-07-19 10:41:17 +0200 |
| commit | f2a5b1d78c076c525d20176d227faf2e6a20257c (patch) | |
| tree | f837a60fda719084884b28c054614fa9bd594403 | |
| parent | 38a997a70e6cf0ee9fc26de146601ba10fa552a4 (diff) | |
| download | linux-f2a5b1d78c076c525d20176d227faf2e6a20257c.tar.bz2 | |
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>
| -rw-r--r-- | arch/mips/Kconfig | 1 |
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 |