KVM: arm64: vgic: Tidy-up calls to vgic_{get,set}_common_attr()

The userspace accessors have an early call to vgic_{get,set}_common_attr()
that makes the code hard to follow. Move it to the default: clause of
the decoding switch statement, which results in a nice cleanup.

This requires us to move the handling of the pending table into the
common handling, even if it is strictly a GICv3 feature (it has the
benefit of keeping the whole control group handling in the same
function).

Also cleanup vgic_v3_{get,set}_attr() while we're at it, deduplicating
the calls to vgic_v3_attr_regs_access().

Suggested-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

diff --git a/arch/arm64/kvm/vgic/vgic-kvm-device.c b/arch/arm64/kvm/vgic/vgic-kvm-device.c
index 011171d..edeac23 100644 (file)
--- a/arch/arm64/kvm/vgic/vgic-kvm-device.c
+++ b/arch/arm64/kvm/vgic/vgic-kvm-device.c
@@ -246,6 +246,24 @@ static int vgic_set_common_attr(struct kvm_device *dev,
                        r = vgic_init(dev->kvm);
                        mutex_unlock(&dev->kvm->lock);
                        return r;
+               case KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES:
+                       /*
+                        * OK, this one isn't common at all, but we
+                        * want to handle all control group attributes
+                        * in a single place.
+                        */
+                       if (vgic_check_type(dev->kvm, KVM_DEV_TYPE_ARM_VGIC_V3))
+                               return -ENXIO;
+                       mutex_lock(&dev->kvm->lock);
+
+                       if (!lock_all_vcpus(dev->kvm)) {
+                               mutex_unlock(&dev->kvm->lock);
+                               return -EBUSY;
+                       }
+                       r = vgic_v3_save_pending_tables(dev->kvm);
+                       unlock_all_vcpus(dev->kvm);
+                       mutex_unlock(&dev->kvm->lock);
+                       return r;
                }
                break;
        }
@@ -427,37 +445,25 @@ out:
 static int vgic_v2_set_attr(struct kvm_device *dev,
                            struct kvm_device_attr *attr)
 {
-       int ret;
-
-       ret = vgic_set_common_attr(dev, attr);
-       if (ret != -ENXIO)
-               return ret;
-
        switch (attr->group) {
        case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
        case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
                return vgic_v2_attr_regs_access(dev, attr, true);
+       default:
+               return vgic_set_common_attr(dev, attr);
        }
-
-       return -ENXIO;
 }
 
 static int vgic_v2_get_attr(struct kvm_device *dev,
                            struct kvm_device_attr *attr)
 {
-       int ret;
-
-       ret = vgic_get_common_attr(dev, attr);
-       if (ret != -ENXIO)
-               return ret;
-
        switch (attr->group) {
        case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
        case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
                return vgic_v2_attr_regs_access(dev, attr, false);
+       default:
+               return vgic_get_common_attr(dev, attr);
        }
-
-       return -ENXIO;
 }
 
 static int vgic_v2_has_attr(struct kvm_device *dev,
@@ -618,61 +624,29 @@ out:
 static int vgic_v3_set_attr(struct kvm_device *dev,
                            struct kvm_device_attr *attr)
 {
-       int ret;
-
-       ret = vgic_set_common_attr(dev, attr);
-       if (ret != -ENXIO)
-               return ret;
-
        switch (attr->group) {
        case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
        case KVM_DEV_ARM_VGIC_GRP_REDIST_REGS:
-               return vgic_v3_attr_regs_access(dev, attr, true);
        case KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS:
-               return vgic_v3_attr_regs_access(dev, attr, true);
        case KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO:
                return vgic_v3_attr_regs_access(dev, attr, true);
-       case KVM_DEV_ARM_VGIC_GRP_CTRL: {
-               int ret;
-
-               switch (attr->attr) {
-               case KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES:
-                       mutex_lock(&dev->kvm->lock);
-
-                       if (!lock_all_vcpus(dev->kvm)) {
-                               mutex_unlock(&dev->kvm->lock);
-                               return -EBUSY;
-                       }
-                       ret = vgic_v3_save_pending_tables(dev->kvm);
-                       unlock_all_vcpus(dev->kvm);
-                       mutex_unlock(&dev->kvm->lock);
-                       return ret;
-               }
-               break;
-       }
+       default:
+               return vgic_set_common_attr(dev, attr);
        }
-       return -ENXIO;
 }
 
 static int vgic_v3_get_attr(struct kvm_device *dev,
                            struct kvm_device_attr *attr)
 {
-       int ret;
-
-       ret = vgic_get_common_attr(dev, attr);
-       if (ret != -ENXIO)
-               return ret;
-
        switch (attr->group) {
        case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
        case KVM_DEV_ARM_VGIC_GRP_REDIST_REGS:
-               return vgic_v3_attr_regs_access(dev, attr, false);
        case KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS:
-               return vgic_v3_attr_regs_access(dev, attr, false);
        case KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO:
                return vgic_v3_attr_regs_access(dev, attr, false);
+       default:
+               return vgic_get_common_attr(dev, attr);
        }
-       return -ENXIO;
 }
 
 static int vgic_v3_has_attr(struct kvm_device *dev,