KVM/MIPS32: Binary patching of select privileged instructions.

Currently, the following instructions are translated:
- CACHE (indexed)
- CACHE (va based): translated to a SYNCI, overkill on D-CACHE operations,
  but still much faster than a trap.
- mfc0/mtc0: the virtual COP0 registers for the guest are implemented as
  2-D array.
  [COP#][SEL] and this is mapped into the guest kernel address space @ VA 0x0.
  mfc0/mtc0 operations are transformed to load/stores.

Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kvm/kvm_mips_comm.h

@@ -0,0 +1,23 @@
+/*
+* This file is subject to the terms and conditions of the GNU General Public
+* License.  See the file "COPYING" in the main directory of this archive
+* for more details.
+*
+* KVM/MIPS: commpage: mapped into get kernel space
+*
+* Copyright (C) 2012  MIPS Technologies, Inc.  All rights reserved.
+* Authors: Sanjay Lal <sanjayl@kymasys.com>
+*/
+
+#ifndef __KVM_MIPS_COMMPAGE_H__
+#define __KVM_MIPS_COMMPAGE_H__
+
+struct kvm_mips_commpage {
+	struct mips_coproc cop0;	/* COP0 state is mapped into Guest kernel via commpage */
+};
+
+#define KVM_MIPS_COMM_EIDI_OFFSET       0x0
+
+extern void kvm_mips_commpage_init(struct kvm_vcpu *vcpu);
+
+#endif /* __KVM_MIPS_COMMPAGE_H__ */