[RFC 21/55] KVM: arm64: Forward HVC instruction to the guest hypervisor

[Jintack Lim <jintack@cs.columbia.edu>]

Forward exceptions due to hvc instruction to the guest hypervisor.

Signed-off-by: Jintack Lim <jintack@cs.columbia.edu>
---
 arch/arm64/include/asm/kvm_nested.h |  5 +++++
 arch/arm64/kvm/Makefile             |  1 +
 arch/arm64/kvm/handle_exit.c        | 11 +++++++++++
 arch/arm64/kvm/handle_exit_nested.c | 27 +++++++++++++++++++++++++++
 4 files changed, 44 insertions(+)
 create mode 100644 arch/arm64/include/asm/kvm_nested.h
 create mode 100644 arch/arm64/kvm/handle_exit_nested.c

diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h
new file mode 100644
index 0000000..620b4d3
--- /dev/null
+++ b/arch/arm64/include/asm/kvm_nested.h
@@ -0,0 +1,5 @@
+#ifndef __ARM64_KVM_NESTED_H__
+#define __ARM64_KVM_NESTED_H__
+
+int handle_hvc_nested(struct kvm_vcpu *vcpu);
+#endif
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index b342bdd..9c35e9a 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -35,4 +35,5 @@ kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/irqchip.o
 kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/arch_timer.o
 kvm-$(CONFIG_KVM_ARM_PMU) += $(KVM)/arm/pmu.o
 
+kvm-$(CONFIG_KVM_ARM_NESTED_HYP) += handle_exit_nested.o
 kvm-$(CONFIG_KVM_ARM_NESTED_HYP) += emulate-nested.o
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index a891684..208be16 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -29,6 +29,10 @@
 #include <asm/kvm_mmu.h>
 #include <asm/kvm_psci.h>
 
+#ifdef CONFIG_KVM_ARM_NESTED_HYP
+#include <asm/kvm_nested.h>
+#endif
+
 #define CREATE_TRACE_POINTS
 #include "trace.h"
 
@@ -42,6 +46,13 @@ static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
 			    kvm_vcpu_hvc_get_imm(vcpu));
 	vcpu->stat.hvc_exit_stat++;
 
+#ifdef CONFIG_KVM_ARM_NESTED_HYP
+	ret = handle_hvc_nested(vcpu);
+	if (ret < 0 && ret != -EINVAL)
+		return ret;
+	else if (ret >= 0)
+		return ret;
+#endif
 	ret = kvm_psci_call(vcpu);
 	if (ret < 0) {
 		kvm_inject_undefined(vcpu);
diff --git a/arch/arm64/kvm/handle_exit_nested.c b/arch/arm64/kvm/handle_exit_nested.c
new file mode 100644
index 0000000..a6ce23b
--- /dev/null
+++ b/arch/arm64/kvm/handle_exit_nested.c
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2016 - Columbia University
+ * Author: Jintack Lim <jintack@cs.columbia.edu>
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+
+#include <asm/kvm_emulate.h>
+
+/* We forward all hvc instruction to the guest hypervisor. */
+int handle_hvc_nested(struct kvm_vcpu *vcpu)
+{
+	return kvm_inject_nested_sync(vcpu, kvm_vcpu_get_hsr(vcpu));
+}
-- 
1.9.1