KVM: arm/arm64: vgic: Implement VGICv3 CPU interface access

VGICv3 CPU interface registers are accessed using
KVM_DEV_ARM_VGIC_CPU_SYSREGS ioctl. These registers are accessed
as 64-bit. The cpu MPIDR value is passed along with register id.
It is used to identify the cpu for registers access.

The VM that supports SEIs expect it on destination machine to handle
guest aborts and hence checked for ICC_CTLR_EL1.SEIS compatibility.
Similarly, VM that supports Affinity Level 3 that is required for AArch64
mode, is required to be supported on destination machine. Hence checked
for ICC_CTLR_EL1.A3V compatibility.

The arch/arm64/kvm/vgic-sys-reg-v3.c handles read and write of VGIC
CPU registers for AArch64.

For AArch32 mode, arch/arm/kvm/vgic-v3-coproc.c file is created but
APIs are not implemented.

Updated arch/arm/include/uapi/asm/kvm.h with new definitions
required to compile for AArch32.

The version of VGIC v3 specification is defined here
Documentation/virtual/kvm/devices/arm-vgic-v3.txt

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@cavium.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

4 files changed, 66 insertions, 0 deletions

diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c b/virt/kvm/arm/vgic/vgic-kvm-device.c
index 227337fd5156..b30372b59dc2 100644
--- a/virt/kvm/arm/vgic/vgic-kvm-device.c
+++ b/virt/kvm/arm/vgic/vgic-kvm-device.c
@@ -504,6 +504,14 @@ static int vgic_v3_attr_regs_access(struct kvm_device *dev,
                 if (!is_write)
                         *reg = tmp32;
                 break;
+        case KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS: {
+                u64 regid;
+
+                regid = (attr->attr & KVM_DEV_ARM_VGIC_SYSREG_INSTR_MASK);
+                ret = vgic_v3_cpu_sysregs_uaccess(vcpu, is_write,
+                                                  regid, reg);
+                break;
+        }
         default:
                 ret = -EINVAL;
                 break;
@@ -537,6 +545,15 @@ static int vgic_v3_set_attr(struct kvm_device *dev,
                 reg = tmp32;
                 return vgic_v3_attr_regs_access(dev, attr, &reg, true);
         }
+        case KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS: {
+                u64 __user *uaddr = (u64 __user *)(long)attr->addr;
+                u64 reg;
+
+                if (get_user(reg, uaddr))
+                        return -EFAULT;
+
+                return vgic_v3_attr_regs_access(dev, attr, &reg, true);
+        }
         }
         return -ENXIO;
 }
@@ -563,6 +580,15 @@ static int vgic_v3_get_attr(struct kvm_device *dev,
                 tmp32 = reg;
                 return put_user(tmp32, uaddr);
         }
+        case KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS: {
+                u64 __user *uaddr = (u64 __user *)(long)attr->addr;
+                u64 reg;
+
+                ret = vgic_v3_attr_regs_access(dev, attr, &reg, false);
+                if (ret)
+                        return ret;
+                return put_user(reg, uaddr);
+        }
         }
 
         return -ENXIO;
@@ -581,6 +607,7 @@ static int vgic_v3_has_attr(struct kvm_device *dev,
                 break;
         case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
         case KVM_DEV_ARM_VGIC_GRP_REDIST_REGS:
+        case KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS:
                 return vgic_v3_has_attr_regs(dev, attr);
         case KVM_DEV_ARM_VGIC_GRP_NR_IRQS:
                 return 0;
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index 2031138cfcf4..549ae459ca0e 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -645,6 +645,12 @@ int vgic_v3_has_attr_regs(struct kvm_device *dev, struct kvm_device_attr *attr)
                 iodev.base_addr = 0;
                 break;
         }
+        case KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS: {
+                u64 reg, id;
+
+                id = (attr->attr & KVM_DEV_ARM_VGIC_SYSREG_INSTR_MASK);
+                return vgic_v3_has_cpu_sysregs_attr(vcpu, 0, id, &reg);
+        }
         default:
                 return -ENXIO;
         }
diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index 42ff9c9826d3..edc6ee2dc852 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -238,6 +238,13 @@ void vgic_v3_enable(struct kvm_vcpu *vcpu)
                 vgic_v3->vgic_sre = 0;
         }
 
+        vcpu->arch.vgic_cpu.num_id_bits = (kvm_vgic_global_state.ich_vtr_el2 &
+                                           ICH_VTR_ID_BITS_MASK) >>
+                                           ICH_VTR_ID_BITS_SHIFT;
+        vcpu->arch.vgic_cpu.num_pri_bits = ((kvm_vgic_global_state.ich_vtr_el2 &
+                                            ICH_VTR_PRI_BITS_MASK) >>
+                                            ICH_VTR_PRI_BITS_SHIFT) + 1;
+
         /* Get the show on the road... */
         vgic_v3->vgic_hcr = ICH_HCR_EN;
 }
@@ -336,6 +343,7 @@ int vgic_v3_probe(const struct gic_kvm_info *info)
          */
         kvm_vgic_global_state.nr_lr = (ich_vtr_el2 & 0xf) + 1;
         kvm_vgic_global_state.can_emulate_gicv2 = false;
+        kvm_vgic_global_state.ich_vtr_el2 = ich_vtr_el2;
 
         if (!info->vcpu.start) {
                 kvm_info("GICv3: no GICV resource entry\n");
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index ecfe1a6c841a..a5a45f66c058 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -52,6 +52,27 @@
                             VGIC_AFFINITY_LEVEL(val, 2) | \
                             VGIC_AFFINITY_LEVEL(val, 3))
 
+/*
+ * As per Documentation/virtual/kvm/devices/arm-vgic-v3.txt,
+ * below macros are defined for CPUREG encoding.
+ */
+#define KVM_REG_ARM_VGIC_SYSREG_OP0_MASK   0x000000000000c000
+#define KVM_REG_ARM_VGIC_SYSREG_OP0_SHIFT  14
+#define KVM_REG_ARM_VGIC_SYSREG_OP1_MASK   0x0000000000003800
+#define KVM_REG_ARM_VGIC_SYSREG_OP1_SHIFT  11
+#define KVM_REG_ARM_VGIC_SYSREG_CRN_MASK   0x0000000000000780
+#define KVM_REG_ARM_VGIC_SYSREG_CRN_SHIFT  7
+#define KVM_REG_ARM_VGIC_SYSREG_CRM_MASK   0x0000000000000078
+#define KVM_REG_ARM_VGIC_SYSREG_CRM_SHIFT  3
+#define KVM_REG_ARM_VGIC_SYSREG_OP2_MASK   0x0000000000000007
+#define KVM_REG_ARM_VGIC_SYSREG_OP2_SHIFT  0
+
+#define KVM_DEV_ARM_VGIC_SYSREG_MASK (KVM_REG_ARM_VGIC_SYSREG_OP0_MASK | \
+                                      KVM_REG_ARM_VGIC_SYSREG_OP1_MASK | \
+                                      KVM_REG_ARM_VGIC_SYSREG_CRN_MASK | \
+                                      KVM_REG_ARM_VGIC_SYSREG_CRM_MASK | \
+                                      KVM_REG_ARM_VGIC_SYSREG_OP2_MASK)
+
 static inline bool irq_is_pending(struct vgic_irq *irq)
 {
         if (irq->config == VGIC_CONFIG_EDGE)
@@ -139,6 +160,10 @@ int vgic_v3_dist_uaccess(struct kvm_vcpu *vcpu, bool is_write,
                          int offset, u32 *val);
 int vgic_v3_redist_uaccess(struct kvm_vcpu *vcpu, bool is_write,
                          int offset, u32 *val);
+int vgic_v3_cpu_sysregs_uaccess(struct kvm_vcpu *vcpu, bool is_write,
+                         u64 id, u64 *val);
+int vgic_v3_has_cpu_sysregs_attr(struct kvm_vcpu *vcpu, bool is_write, u64 id,
+                                u64 *reg);
 int kvm_register_vgic_device(unsigned long type);
 void vgic_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr);
 void vgic_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr);