[RFC PATCH v2 1/4] arm/arm64: vgic-new: Introduce 64-bit reg access support

[vijay.kilari@gmail.com (vijay.kilari at gmail.com)]

From: Vijaya Kumar K <Vijaya.Kumar@cavium.com>

vgic_attr_regs_access() handles only 32-bit register
value. Pass u64 as parameter and locally handle 32-bit
reads and writes depending on attribute group.

Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@cavium.com>
---
 virt/kvm/arm/vgic/vgic-kvm-device.c | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c b/virt/kvm/arm/vgic/vgic-kvm-device.c
index 0130c4b..06de322 100644
--- a/virt/kvm/arm/vgic/vgic-kvm-device.c
+++ b/virt/kvm/arm/vgic/vgic-kvm-device.c
@@ -236,12 +236,13 @@ void kvm_register_vgic_device(unsigned long type)
  */
 static int vgic_attr_regs_access(struct kvm_device *dev,
 				 struct kvm_device_attr *attr,
-				 u32 *reg, bool is_write)
+				 u64 *reg, bool is_write)
 {
 	gpa_t addr;
 	int cpuid, ret, c;
 	struct kvm_vcpu *vcpu, *tmp_vcpu;
 	int vcpu_lock_idx = -1;
+	u32 tmp32;
 
 	cpuid = (attr->attr & KVM_DEV_ARM_VGIC_CPUID_MASK) >>
 		 KVM_DEV_ARM_VGIC_CPUID_SHIFT;
@@ -272,12 +273,19 @@ static int vgic_attr_regs_access(struct kvm_device *dev,
 		vcpu_lock_idx = c;
 	}
 
+	if (is_write)
+		tmp32 = *reg;
+
 	switch (attr->group) {
 	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
-		ret = vgic_v2_cpuif_uaccess(vcpu, is_write, addr, reg);
+		ret = vgic_v2_cpuif_uaccess(vcpu, is_write, addr, &tmp32);
+		if (!is_write)
+			*reg = tmp32;
 		break;
 	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
-		ret = vgic_v2_dist_uaccess(vcpu, is_write, addr, reg);
+		ret = vgic_v2_dist_uaccess(vcpu, is_write, addr, &tmp32);
+		if (!is_write)
+			*reg = tmp32;
 		break;
 	default:
 		ret = -EINVAL;
@@ -309,11 +317,13 @@ static int vgic_v2_set_attr(struct kvm_device *dev,
 	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
 	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: {
 		u32 __user *uaddr = (u32 __user *)(long)attr->addr;
-		u32 reg;
+		u32 tmp32;
+		u64 reg;
 
-		if (get_user(reg, uaddr))
+		if (get_user(tmp32, uaddr))
 			return -EFAULT;
 
+		reg = tmp32;
 		return vgic_attr_regs_access(dev, attr, &reg, true);
 	}
 	}
@@ -334,12 +344,14 @@ static int vgic_v2_get_attr(struct kvm_device *dev,
 	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
 	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: {
 		u32 __user *uaddr = (u32 __user *)(long)attr->addr;
-		u32 reg = 0;
+		u32 tmp32;
+		u64 reg;
 
 		ret = vgic_attr_regs_access(dev, attr, &reg, false);
 		if (ret)
 			return ret;
-		return put_user(reg, uaddr);
+		tmp32 = reg;
+		return put_user(tmp32, uaddr);
 	}
 	}
 
-- 
1.9.1