[RFC 03/13] KVM: arm64: ITS: KVM_DEV_ARM_VGIC_GRP_ITS_REGS group

[Eric Auger]

The ITS KVM device exposes a new KVM_DEV_ARM_VGIC_GRP_ITS_REGS
group which allows the userspace to save/restore ITS registers.

At this stage the get/set/has operations are not yet implemented.

Signed-off-by: Eric Auger <eric.au...@redhat.com>
---
 arch/arm/include/uapi/asm/kvm.h   |  1 +
 arch/arm64/include/uapi/asm/kvm.h |  1 +
 virt/kvm/arm/vgic/vgic-its.c      | 36 +++++++++++++++++++++++++++++++++++-
 3 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h
index f347779..f6a167c 100644
--- a/arch/arm/include/uapi/asm/kvm.h
+++ b/arch/arm/include/uapi/asm/kvm.h
@@ -192,6 +192,7 @@ struct kvm_arch_memory_slot {
 #define KVM_DEV_ARM_VGIC_GRP_REDIST_REGS 5
 #define KVM_DEV_ARM_VGIC_CPU_SYSREGS    6
 #define KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO 7
+#define KVM_DEV_ARM_VGIC_GRP_ITS_REGS  8
 #define KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_SHIFT 10
 #define KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_MASK \
                        (0x3fffffULL << KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_SHIFT)
diff --git a/arch/arm64/include/uapi/asm/kvm.h 
b/arch/arm64/include/uapi/asm/kvm.h
index 4100f8c..8850e9b 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -212,6 +212,7 @@ struct kvm_arch_memory_slot {
 #define KVM_DEV_ARM_VGIC_GRP_REDIST_REGS 5
 #define KVM_DEV_ARM_VGIC_CPU_SYSREGS    6
 #define KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO 7
+#define KVM_DEV_ARM_VGIC_GRP_ITS_REGS 8
 #define KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_SHIFT 10
 #define KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_MASK \
                        (0x3fffffULL << KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_SHIFT)
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 8c2b3cd..058034d 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -1445,6 +1445,19 @@ static void vgic_its_destroy(struct kvm_device *kvm_dev)
        kfree(its);
 }
 
+int vgic_its_has_attr_regs(struct kvm_device *dev,
+                          struct kvm_device_attr *attr)
+{
+       return -ENXIO;
+}
+
+int vgic_its_attr_regs_access(struct kvm_device *dev,
+                             struct kvm_device_attr *attr,
+                             u64 *reg, bool is_write)
+{
+       return -ENXIO;
+}
+
 static int vgic_its_has_attr(struct kvm_device *dev,
                             struct kvm_device_attr *attr)
 {
@@ -1461,6 +1474,8 @@ static int vgic_its_has_attr(struct kvm_device *dev,
                        return 0;
                }
                break;
+       case KVM_DEV_ARM_VGIC_GRP_ITS_REGS:
+               return vgic_its_has_attr_regs(dev, attr);
        }
        return -ENXIO;
 }
@@ -1500,6 +1515,15 @@ static int vgic_its_set_attr(struct kvm_device *dev,
                        return 0;
                }
                break;
+       case KVM_DEV_ARM_VGIC_GRP_ITS_REGS: {
+               u64 __user *uaddr = (u64 __user *)(long)attr->addr;
+               u64 reg;
+
+               if (get_user(reg, uaddr))
+                       return -EFAULT;
+
+               return vgic_its_attr_regs_access(dev, attr, &reg, true);
+       }
        }
        return -ENXIO;
 }
@@ -1520,10 +1544,20 @@ static int vgic_its_get_attr(struct kvm_device *dev,
                if (copy_to_user(uaddr, &addr, sizeof(addr)))
                        return -EFAULT;
                break;
+       }
+       case KVM_DEV_ARM_VGIC_GRP_ITS_REGS: {
+               u64 __user *uaddr = (u64 __user *)(long)attr->addr;
+               u64 reg;
+               int ret;
+
+               ret = vgic_its_attr_regs_access(dev, attr, &reg, false);
+               if (ret)
+                       return ret;
+               return put_user(reg, uaddr);
+       }
        default:
                return -ENXIO;
        }
-       }
 
        return 0;
 }
-- 
2.5.5

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