KVM: ARM: Initial skeleton to compile KVM support

Targets KVM support for Cortex A-15 processors.

Contains all the framework components, make files, header files, some
tracing functionality, and basic user space API.

Only supported core is Cortex-A15 for now.

Most functionality is in arch/arm/kvm/* or arch/arm/include/asm/kvm_*.h.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
diff --git a/arch/arm/kvm/reset.c b/arch/arm/kvm/reset.c
new file mode 100644
index 0000000..b80256b
--- /dev/null
+++ b/arch/arm/kvm/reset.c
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2012 - Virtual Open Systems and Columbia University
+ * Author: Christoffer Dall <c.dall@virtualopensystems.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include <linux/compiler.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kvm_host.h>
+#include <linux/kvm.h>
+
+#include <asm/unified.h>
+#include <asm/ptrace.h>
+#include <asm/cputype.h>
+#include <asm/kvm_arm.h>
+#include <asm/kvm_coproc.h>
+
+/******************************************************************************
+ * Cortex-A15 Reset Values
+ */
+
+static const int a15_max_cpu_idx = 3;
+
+static struct kvm_regs a15_regs_reset = {
+	.usr_regs.ARM_cpsr = SVC_MODE | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT,
+};
+
+
+/*******************************************************************************
+ * Exported reset function
+ */
+
+/**
+ * kvm_reset_vcpu - sets core registers and cp15 registers to reset value
+ * @vcpu: The VCPU pointer
+ *
+ * This function finds the right table above and sets the registers on the
+ * virtual CPU struct to their architectually defined reset values.
+ */
+int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
+{
+	struct kvm_regs *cpu_reset;
+
+	switch (vcpu->arch.target) {
+	case KVM_ARM_TARGET_CORTEX_A15:
+		if (vcpu->vcpu_id > a15_max_cpu_idx)
+			return -EINVAL;
+		cpu_reset = &a15_regs_reset;
+		vcpu->arch.midr = read_cpuid_id();
+		break;
+	default:
+		return -ENODEV;
+	}
+
+	/* Reset core registers */
+	memcpy(&vcpu->arch.regs, cpu_reset, sizeof(vcpu->arch.regs));
+
+	/* Reset CP15 registers */
+	kvm_reset_coprocs(vcpu);
+
+	return 0;
+}