Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / virt / kvm / arm / vgic-v2-emul.c
diff --git a/kernel/virt/kvm/arm/vgic-v2-emul.c b/kernel/virt/kvm/arm/vgic-v2-emul.c
new file mode 100644 (file)
index 0000000..1390797
--- /dev/null
@@ -0,0 +1,856 @@
+/*
+ * Contains GICv2 specific emulation code, was in vgic.c before.
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ *
+ * 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/cpu.h>
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+
+#include <linux/irqchip/arm-gic.h>
+
+#include <asm/kvm_emulate.h>
+#include <asm/kvm_arm.h>
+#include <asm/kvm_mmu.h>
+
+#include "vgic.h"
+
+#define GICC_ARCH_VERSION_V2           0x2
+
+static void vgic_dispatch_sgi(struct kvm_vcpu *vcpu, u32 reg);
+static u8 *vgic_get_sgi_sources(struct vgic_dist *dist, int vcpu_id, int sgi)
+{
+       return dist->irq_sgi_sources + vcpu_id * VGIC_NR_SGIS + sgi;
+}
+
+static bool handle_mmio_misc(struct kvm_vcpu *vcpu,
+                            struct kvm_exit_mmio *mmio, phys_addr_t offset)
+{
+       u32 reg;
+       u32 word_offset = offset & 3;
+
+       switch (offset & ~3) {
+       case 0:                 /* GICD_CTLR */
+               reg = vcpu->kvm->arch.vgic.enabled;
+               vgic_reg_access(mmio, &reg, word_offset,
+                               ACCESS_READ_VALUE | ACCESS_WRITE_VALUE);
+               if (mmio->is_write) {
+                       vcpu->kvm->arch.vgic.enabled = reg & 1;
+                       vgic_update_state(vcpu->kvm);
+                       return true;
+               }
+               break;
+
+       case 4:                 /* GICD_TYPER */
+               reg  = (atomic_read(&vcpu->kvm->online_vcpus) - 1) << 5;
+               reg |= (vcpu->kvm->arch.vgic.nr_irqs >> 5) - 1;
+               vgic_reg_access(mmio, &reg, word_offset,
+                               ACCESS_READ_VALUE | ACCESS_WRITE_IGNORED);
+               break;
+
+       case 8:                 /* GICD_IIDR */
+               reg = (PRODUCT_ID_KVM << 24) | (IMPLEMENTER_ARM << 0);
+               vgic_reg_access(mmio, &reg, word_offset,
+                               ACCESS_READ_VALUE | ACCESS_WRITE_IGNORED);
+               break;
+       }
+
+       return false;
+}
+
+static bool handle_mmio_set_enable_reg(struct kvm_vcpu *vcpu,
+                                      struct kvm_exit_mmio *mmio,
+                                      phys_addr_t offset)
+{
+       return vgic_handle_enable_reg(vcpu->kvm, mmio, offset,
+                                     vcpu->vcpu_id, ACCESS_WRITE_SETBIT);
+}
+
+static bool handle_mmio_clear_enable_reg(struct kvm_vcpu *vcpu,
+                                        struct kvm_exit_mmio *mmio,
+                                        phys_addr_t offset)
+{
+       return vgic_handle_enable_reg(vcpu->kvm, mmio, offset,
+                                     vcpu->vcpu_id, ACCESS_WRITE_CLEARBIT);
+}
+
+static bool handle_mmio_set_pending_reg(struct kvm_vcpu *vcpu,
+                                       struct kvm_exit_mmio *mmio,
+                                       phys_addr_t offset)
+{
+       return vgic_handle_set_pending_reg(vcpu->kvm, mmio, offset,
+                                          vcpu->vcpu_id);
+}
+
+static bool handle_mmio_clear_pending_reg(struct kvm_vcpu *vcpu,
+                                         struct kvm_exit_mmio *mmio,
+                                         phys_addr_t offset)
+{
+       return vgic_handle_clear_pending_reg(vcpu->kvm, mmio, offset,
+                                            vcpu->vcpu_id);
+}
+
+static bool handle_mmio_set_active_reg(struct kvm_vcpu *vcpu,
+                                      struct kvm_exit_mmio *mmio,
+                                      phys_addr_t offset)
+{
+       return vgic_handle_set_active_reg(vcpu->kvm, mmio, offset,
+                                         vcpu->vcpu_id);
+}
+
+static bool handle_mmio_clear_active_reg(struct kvm_vcpu *vcpu,
+                                        struct kvm_exit_mmio *mmio,
+                                        phys_addr_t offset)
+{
+       return vgic_handle_clear_active_reg(vcpu->kvm, mmio, offset,
+                                           vcpu->vcpu_id);
+}
+
+static bool handle_mmio_priority_reg(struct kvm_vcpu *vcpu,
+                                    struct kvm_exit_mmio *mmio,
+                                    phys_addr_t offset)
+{
+       u32 *reg = vgic_bytemap_get_reg(&vcpu->kvm->arch.vgic.irq_priority,
+                                       vcpu->vcpu_id, offset);
+       vgic_reg_access(mmio, reg, offset,
+                       ACCESS_READ_VALUE | ACCESS_WRITE_VALUE);
+       return false;
+}
+
+#define GICD_ITARGETSR_SIZE    32
+#define GICD_CPUTARGETS_BITS   8
+#define GICD_IRQS_PER_ITARGETSR        (GICD_ITARGETSR_SIZE / GICD_CPUTARGETS_BITS)
+static u32 vgic_get_target_reg(struct kvm *kvm, int irq)
+{
+       struct vgic_dist *dist = &kvm->arch.vgic;
+       int i;
+       u32 val = 0;
+
+       irq -= VGIC_NR_PRIVATE_IRQS;
+
+       for (i = 0; i < GICD_IRQS_PER_ITARGETSR; i++)
+               val |= 1 << (dist->irq_spi_cpu[irq + i] + i * 8);
+
+       return val;
+}
+
+static void vgic_set_target_reg(struct kvm *kvm, u32 val, int irq)
+{
+       struct vgic_dist *dist = &kvm->arch.vgic;
+       struct kvm_vcpu *vcpu;
+       int i, c;
+       unsigned long *bmap;
+       u32 target;
+
+       irq -= VGIC_NR_PRIVATE_IRQS;
+
+       /*
+        * Pick the LSB in each byte. This ensures we target exactly
+        * one vcpu per IRQ. If the byte is null, assume we target
+        * CPU0.
+        */
+       for (i = 0; i < GICD_IRQS_PER_ITARGETSR; i++) {
+               int shift = i * GICD_CPUTARGETS_BITS;
+
+               target = ffs((val >> shift) & 0xffU);
+               target = target ? (target - 1) : 0;
+               dist->irq_spi_cpu[irq + i] = target;
+               kvm_for_each_vcpu(c, vcpu, kvm) {
+                       bmap = vgic_bitmap_get_shared_map(&dist->irq_spi_target[c]);
+                       if (c == target)
+                               set_bit(irq + i, bmap);
+                       else
+                               clear_bit(irq + i, bmap);
+               }
+       }
+}
+
+static bool handle_mmio_target_reg(struct kvm_vcpu *vcpu,
+                                  struct kvm_exit_mmio *mmio,
+                                  phys_addr_t offset)
+{
+       u32 reg;
+
+       /* We treat the banked interrupts targets as read-only */
+       if (offset < 32) {
+               u32 roreg;
+
+               roreg = 1 << vcpu->vcpu_id;
+               roreg |= roreg << 8;
+               roreg |= roreg << 16;
+
+               vgic_reg_access(mmio, &roreg, offset,
+                               ACCESS_READ_VALUE | ACCESS_WRITE_IGNORED);
+               return false;
+       }
+
+       reg = vgic_get_target_reg(vcpu->kvm, offset & ~3U);
+       vgic_reg_access(mmio, &reg, offset,
+                       ACCESS_READ_VALUE | ACCESS_WRITE_VALUE);
+       if (mmio->is_write) {
+               vgic_set_target_reg(vcpu->kvm, reg, offset & ~3U);
+               vgic_update_state(vcpu->kvm);
+               return true;
+       }
+
+       return false;
+}
+
+static bool handle_mmio_cfg_reg(struct kvm_vcpu *vcpu,
+                               struct kvm_exit_mmio *mmio, phys_addr_t offset)
+{
+       u32 *reg;
+
+       reg = vgic_bitmap_get_reg(&vcpu->kvm->arch.vgic.irq_cfg,
+                                 vcpu->vcpu_id, offset >> 1);
+
+       return vgic_handle_cfg_reg(reg, mmio, offset);
+}
+
+static bool handle_mmio_sgi_reg(struct kvm_vcpu *vcpu,
+                               struct kvm_exit_mmio *mmio, phys_addr_t offset)
+{
+       u32 reg;
+
+       vgic_reg_access(mmio, &reg, offset,
+                       ACCESS_READ_RAZ | ACCESS_WRITE_VALUE);
+       if (mmio->is_write) {
+               vgic_dispatch_sgi(vcpu, reg);
+               vgic_update_state(vcpu->kvm);
+               return true;
+       }
+
+       return false;
+}
+
+/* Handle reads of GICD_CPENDSGIRn and GICD_SPENDSGIRn */
+static bool read_set_clear_sgi_pend_reg(struct kvm_vcpu *vcpu,
+                                       struct kvm_exit_mmio *mmio,
+                                       phys_addr_t offset)
+{
+       struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+       int sgi;
+       int min_sgi = (offset & ~0x3);
+       int max_sgi = min_sgi + 3;
+       int vcpu_id = vcpu->vcpu_id;
+       u32 reg = 0;
+
+       /* Copy source SGIs from distributor side */
+       for (sgi = min_sgi; sgi <= max_sgi; sgi++) {
+               u8 sources = *vgic_get_sgi_sources(dist, vcpu_id, sgi);
+
+               reg |= ((u32)sources) << (8 * (sgi - min_sgi));
+       }
+
+       mmio_data_write(mmio, ~0, reg);
+       return false;
+}
+
+static bool write_set_clear_sgi_pend_reg(struct kvm_vcpu *vcpu,
+                                        struct kvm_exit_mmio *mmio,
+                                        phys_addr_t offset, bool set)
+{
+       struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+       int sgi;
+       int min_sgi = (offset & ~0x3);
+       int max_sgi = min_sgi + 3;
+       int vcpu_id = vcpu->vcpu_id;
+       u32 reg;
+       bool updated = false;
+
+       reg = mmio_data_read(mmio, ~0);
+
+       /* Clear pending SGIs on the distributor */
+       for (sgi = min_sgi; sgi <= max_sgi; sgi++) {
+               u8 mask = reg >> (8 * (sgi - min_sgi));
+               u8 *src = vgic_get_sgi_sources(dist, vcpu_id, sgi);
+
+               if (set) {
+                       if ((*src & mask) != mask)
+                               updated = true;
+                       *src |= mask;
+               } else {
+                       if (*src & mask)
+                               updated = true;
+                       *src &= ~mask;
+               }
+       }
+
+       if (updated)
+               vgic_update_state(vcpu->kvm);
+
+       return updated;
+}
+
+static bool handle_mmio_sgi_set(struct kvm_vcpu *vcpu,
+                               struct kvm_exit_mmio *mmio,
+                               phys_addr_t offset)
+{
+       if (!mmio->is_write)
+               return read_set_clear_sgi_pend_reg(vcpu, mmio, offset);
+       else
+               return write_set_clear_sgi_pend_reg(vcpu, mmio, offset, true);
+}
+
+static bool handle_mmio_sgi_clear(struct kvm_vcpu *vcpu,
+                                 struct kvm_exit_mmio *mmio,
+                                 phys_addr_t offset)
+{
+       if (!mmio->is_write)
+               return read_set_clear_sgi_pend_reg(vcpu, mmio, offset);
+       else
+               return write_set_clear_sgi_pend_reg(vcpu, mmio, offset, false);
+}
+
+static const struct vgic_io_range vgic_dist_ranges[] = {
+       {
+               .base           = GIC_DIST_CTRL,
+               .len            = 12,
+               .bits_per_irq   = 0,
+               .handle_mmio    = handle_mmio_misc,
+       },
+       {
+               .base           = GIC_DIST_IGROUP,
+               .len            = VGIC_MAX_IRQS / 8,
+               .bits_per_irq   = 1,
+               .handle_mmio    = handle_mmio_raz_wi,
+       },
+       {
+               .base           = GIC_DIST_ENABLE_SET,
+               .len            = VGIC_MAX_IRQS / 8,
+               .bits_per_irq   = 1,
+               .handle_mmio    = handle_mmio_set_enable_reg,
+       },
+       {
+               .base           = GIC_DIST_ENABLE_CLEAR,
+               .len            = VGIC_MAX_IRQS / 8,
+               .bits_per_irq   = 1,
+               .handle_mmio    = handle_mmio_clear_enable_reg,
+       },
+       {
+               .base           = GIC_DIST_PENDING_SET,
+               .len            = VGIC_MAX_IRQS / 8,
+               .bits_per_irq   = 1,
+               .handle_mmio    = handle_mmio_set_pending_reg,
+       },
+       {
+               .base           = GIC_DIST_PENDING_CLEAR,
+               .len            = VGIC_MAX_IRQS / 8,
+               .bits_per_irq   = 1,
+               .handle_mmio    = handle_mmio_clear_pending_reg,
+       },
+       {
+               .base           = GIC_DIST_ACTIVE_SET,
+               .len            = VGIC_MAX_IRQS / 8,
+               .bits_per_irq   = 1,
+               .handle_mmio    = handle_mmio_set_active_reg,
+       },
+       {
+               .base           = GIC_DIST_ACTIVE_CLEAR,
+               .len            = VGIC_MAX_IRQS / 8,
+               .bits_per_irq   = 1,
+               .handle_mmio    = handle_mmio_clear_active_reg,
+       },
+       {
+               .base           = GIC_DIST_PRI,
+               .len            = VGIC_MAX_IRQS,
+               .bits_per_irq   = 8,
+               .handle_mmio    = handle_mmio_priority_reg,
+       },
+       {
+               .base           = GIC_DIST_TARGET,
+               .len            = VGIC_MAX_IRQS,
+               .bits_per_irq   = 8,
+               .handle_mmio    = handle_mmio_target_reg,
+       },
+       {
+               .base           = GIC_DIST_CONFIG,
+               .len            = VGIC_MAX_IRQS / 4,
+               .bits_per_irq   = 2,
+               .handle_mmio    = handle_mmio_cfg_reg,
+       },
+       {
+               .base           = GIC_DIST_SOFTINT,
+               .len            = 4,
+               .handle_mmio    = handle_mmio_sgi_reg,
+       },
+       {
+               .base           = GIC_DIST_SGI_PENDING_CLEAR,
+               .len            = VGIC_NR_SGIS,
+               .handle_mmio    = handle_mmio_sgi_clear,
+       },
+       {
+               .base           = GIC_DIST_SGI_PENDING_SET,
+               .len            = VGIC_NR_SGIS,
+               .handle_mmio    = handle_mmio_sgi_set,
+       },
+       {}
+};
+
+static void vgic_dispatch_sgi(struct kvm_vcpu *vcpu, u32 reg)
+{
+       struct kvm *kvm = vcpu->kvm;
+       struct vgic_dist *dist = &kvm->arch.vgic;
+       int nrcpus = atomic_read(&kvm->online_vcpus);
+       u8 target_cpus;
+       int sgi, mode, c, vcpu_id;
+
+       vcpu_id = vcpu->vcpu_id;
+
+       sgi = reg & 0xf;
+       target_cpus = (reg >> 16) & 0xff;
+       mode = (reg >> 24) & 3;
+
+       switch (mode) {
+       case 0:
+               if (!target_cpus)
+                       return;
+               break;
+
+       case 1:
+               target_cpus = ((1 << nrcpus) - 1) & ~(1 << vcpu_id) & 0xff;
+               break;
+
+       case 2:
+               target_cpus = 1 << vcpu_id;
+               break;
+       }
+
+       kvm_for_each_vcpu(c, vcpu, kvm) {
+               if (target_cpus & 1) {
+                       /* Flag the SGI as pending */
+                       vgic_dist_irq_set_pending(vcpu, sgi);
+                       *vgic_get_sgi_sources(dist, c, sgi) |= 1 << vcpu_id;
+                       kvm_debug("SGI%d from CPU%d to CPU%d\n",
+                                 sgi, vcpu_id, c);
+               }
+
+               target_cpus >>= 1;
+       }
+}
+
+static bool vgic_v2_queue_sgi(struct kvm_vcpu *vcpu, int irq)
+{
+       struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+       unsigned long sources;
+       int vcpu_id = vcpu->vcpu_id;
+       int c;
+
+       sources = *vgic_get_sgi_sources(dist, vcpu_id, irq);
+
+       for_each_set_bit(c, &sources, dist->nr_cpus) {
+               if (vgic_queue_irq(vcpu, c, irq))
+                       clear_bit(c, &sources);
+       }
+
+       *vgic_get_sgi_sources(dist, vcpu_id, irq) = sources;
+
+       /*
+        * If the sources bitmap has been cleared it means that we
+        * could queue all the SGIs onto link registers (see the
+        * clear_bit above), and therefore we are done with them in
+        * our emulated gic and can get rid of them.
+        */
+       if (!sources) {
+               vgic_dist_irq_clear_pending(vcpu, irq);
+               vgic_cpu_irq_clear(vcpu, irq);
+               return true;
+       }
+
+       return false;
+}
+
+/**
+ * kvm_vgic_map_resources - Configure global VGIC state before running any VCPUs
+ * @kvm: pointer to the kvm struct
+ *
+ * Map the virtual CPU interface into the VM before running any VCPUs.  We
+ * can't do this at creation time, because user space must first set the
+ * virtual CPU interface address in the guest physical address space.
+ */
+static int vgic_v2_map_resources(struct kvm *kvm,
+                                const struct vgic_params *params)
+{
+       struct vgic_dist *dist = &kvm->arch.vgic;
+       int ret = 0;
+
+       if (!irqchip_in_kernel(kvm))
+               return 0;
+
+       mutex_lock(&kvm->lock);
+
+       if (vgic_ready(kvm))
+               goto out;
+
+       if (IS_VGIC_ADDR_UNDEF(dist->vgic_dist_base) ||
+           IS_VGIC_ADDR_UNDEF(dist->vgic_cpu_base)) {
+               kvm_err("Need to set vgic cpu and dist addresses first\n");
+               ret = -ENXIO;
+               goto out;
+       }
+
+       vgic_register_kvm_io_dev(kvm, dist->vgic_dist_base,
+                                KVM_VGIC_V2_DIST_SIZE,
+                                vgic_dist_ranges, -1, &dist->dist_iodev);
+
+       /*
+        * Initialize the vgic if this hasn't already been done on demand by
+        * accessing the vgic state from userspace.
+        */
+       ret = vgic_init(kvm);
+       if (ret) {
+               kvm_err("Unable to allocate maps\n");
+               goto out_unregister;
+       }
+
+       ret = kvm_phys_addr_ioremap(kvm, dist->vgic_cpu_base,
+                                   params->vcpu_base, KVM_VGIC_V2_CPU_SIZE,
+                                   true);
+       if (ret) {
+               kvm_err("Unable to remap VGIC CPU to VCPU\n");
+               goto out_unregister;
+       }
+
+       dist->ready = true;
+       goto out;
+
+out_unregister:
+       kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &dist->dist_iodev.dev);
+
+out:
+       if (ret)
+               kvm_vgic_destroy(kvm);
+       mutex_unlock(&kvm->lock);
+       return ret;
+}
+
+static void vgic_v2_add_sgi_source(struct kvm_vcpu *vcpu, int irq, int source)
+{
+       struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+
+       *vgic_get_sgi_sources(dist, vcpu->vcpu_id, irq) |= 1 << source;
+}
+
+static int vgic_v2_init_model(struct kvm *kvm)
+{
+       int i;
+
+       for (i = VGIC_NR_PRIVATE_IRQS; i < kvm->arch.vgic.nr_irqs; i += 4)
+               vgic_set_target_reg(kvm, 0, i);
+
+       return 0;
+}
+
+void vgic_v2_init_emulation(struct kvm *kvm)
+{
+       struct vgic_dist *dist = &kvm->arch.vgic;
+
+       dist->vm_ops.queue_sgi = vgic_v2_queue_sgi;
+       dist->vm_ops.add_sgi_source = vgic_v2_add_sgi_source;
+       dist->vm_ops.init_model = vgic_v2_init_model;
+       dist->vm_ops.map_resources = vgic_v2_map_resources;
+
+       kvm->arch.max_vcpus = VGIC_V2_MAX_CPUS;
+}
+
+static bool handle_cpu_mmio_misc(struct kvm_vcpu *vcpu,
+                                struct kvm_exit_mmio *mmio, phys_addr_t offset)
+{
+       bool updated = false;
+       struct vgic_vmcr vmcr;
+       u32 *vmcr_field;
+       u32 reg;
+
+       vgic_get_vmcr(vcpu, &vmcr);
+
+       switch (offset & ~0x3) {
+       case GIC_CPU_CTRL:
+               vmcr_field = &vmcr.ctlr;
+               break;
+       case GIC_CPU_PRIMASK:
+               vmcr_field = &vmcr.pmr;
+               break;
+       case GIC_CPU_BINPOINT:
+               vmcr_field = &vmcr.bpr;
+               break;
+       case GIC_CPU_ALIAS_BINPOINT:
+               vmcr_field = &vmcr.abpr;
+               break;
+       default:
+               BUG();
+       }
+
+       if (!mmio->is_write) {
+               reg = *vmcr_field;
+               mmio_data_write(mmio, ~0, reg);
+       } else {
+               reg = mmio_data_read(mmio, ~0);
+               if (reg != *vmcr_field) {
+                       *vmcr_field = reg;
+                       vgic_set_vmcr(vcpu, &vmcr);
+                       updated = true;
+               }
+       }
+       return updated;
+}
+
+static bool handle_mmio_abpr(struct kvm_vcpu *vcpu,
+                            struct kvm_exit_mmio *mmio, phys_addr_t offset)
+{
+       return handle_cpu_mmio_misc(vcpu, mmio, GIC_CPU_ALIAS_BINPOINT);
+}
+
+static bool handle_cpu_mmio_ident(struct kvm_vcpu *vcpu,
+                                 struct kvm_exit_mmio *mmio,
+                                 phys_addr_t offset)
+{
+       u32 reg;
+
+       if (mmio->is_write)
+               return false;
+
+       /* GICC_IIDR */
+       reg = (PRODUCT_ID_KVM << 20) |
+             (GICC_ARCH_VERSION_V2 << 16) |
+             (IMPLEMENTER_ARM << 0);
+       mmio_data_write(mmio, ~0, reg);
+       return false;
+}
+
+/*
+ * CPU Interface Register accesses - these are not accessed by the VM, but by
+ * user space for saving and restoring VGIC state.
+ */
+static const struct vgic_io_range vgic_cpu_ranges[] = {
+       {
+               .base           = GIC_CPU_CTRL,
+               .len            = 12,
+               .handle_mmio    = handle_cpu_mmio_misc,
+       },
+       {
+               .base           = GIC_CPU_ALIAS_BINPOINT,
+               .len            = 4,
+               .handle_mmio    = handle_mmio_abpr,
+       },
+       {
+               .base           = GIC_CPU_ACTIVEPRIO,
+               .len            = 16,
+               .handle_mmio    = handle_mmio_raz_wi,
+       },
+       {
+               .base           = GIC_CPU_IDENT,
+               .len            = 4,
+               .handle_mmio    = handle_cpu_mmio_ident,
+       },
+};
+
+static int vgic_attr_regs_access(struct kvm_device *dev,
+                                struct kvm_device_attr *attr,
+                                u32 *reg, bool is_write)
+{
+       const struct vgic_io_range *r = NULL, *ranges;
+       phys_addr_t offset;
+       int ret, cpuid, c;
+       struct kvm_vcpu *vcpu, *tmp_vcpu;
+       struct vgic_dist *vgic;
+       struct kvm_exit_mmio mmio;
+       u32 data;
+
+       offset = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK;
+       cpuid = (attr->attr & KVM_DEV_ARM_VGIC_CPUID_MASK) >>
+               KVM_DEV_ARM_VGIC_CPUID_SHIFT;
+
+       mutex_lock(&dev->kvm->lock);
+
+       ret = vgic_init(dev->kvm);
+       if (ret)
+               goto out;
+
+       if (cpuid >= atomic_read(&dev->kvm->online_vcpus)) {
+               ret = -EINVAL;
+               goto out;
+       }
+
+       vcpu = kvm_get_vcpu(dev->kvm, cpuid);
+       vgic = &dev->kvm->arch.vgic;
+
+       mmio.len = 4;
+       mmio.is_write = is_write;
+       mmio.data = &data;
+       if (is_write)
+               mmio_data_write(&mmio, ~0, *reg);
+       switch (attr->group) {
+       case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
+               mmio.phys_addr = vgic->vgic_dist_base + offset;
+               ranges = vgic_dist_ranges;
+               break;
+       case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
+               mmio.phys_addr = vgic->vgic_cpu_base + offset;
+               ranges = vgic_cpu_ranges;
+               break;
+       default:
+               BUG();
+       }
+       r = vgic_find_range(ranges, 4, offset);
+
+       if (unlikely(!r || !r->handle_mmio)) {
+               ret = -ENXIO;
+               goto out;
+       }
+
+
+       spin_lock(&vgic->lock);
+
+       /*
+        * Ensure that no other VCPU is running by checking the vcpu->cpu
+        * field.  If no other VPCUs are running we can safely access the VGIC
+        * state, because even if another VPU is run after this point, that
+        * VCPU will not touch the vgic state, because it will block on
+        * getting the vgic->lock in kvm_vgic_sync_hwstate().
+        */
+       kvm_for_each_vcpu(c, tmp_vcpu, dev->kvm) {
+               if (unlikely(tmp_vcpu->cpu != -1)) {
+                       ret = -EBUSY;
+                       goto out_vgic_unlock;
+               }
+       }
+
+       /*
+        * Move all pending IRQs from the LRs on all VCPUs so the pending
+        * state can be properly represented in the register state accessible
+        * through this API.
+        */
+       kvm_for_each_vcpu(c, tmp_vcpu, dev->kvm)
+               vgic_unqueue_irqs(tmp_vcpu);
+
+       offset -= r->base;
+       r->handle_mmio(vcpu, &mmio, offset);
+
+       if (!is_write)
+               *reg = mmio_data_read(&mmio, ~0);
+
+       ret = 0;
+out_vgic_unlock:
+       spin_unlock(&vgic->lock);
+out:
+       mutex_unlock(&dev->kvm->lock);
+       return ret;
+}
+
+static int vgic_v2_create(struct kvm_device *dev, u32 type)
+{
+       return kvm_vgic_create(dev->kvm, type);
+}
+
+static void vgic_v2_destroy(struct kvm_device *dev)
+{
+       kfree(dev);
+}
+
+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: {
+               u32 __user *uaddr = (u32 __user *)(long)attr->addr;
+               u32 reg;
+
+               if (get_user(reg, uaddr))
+                       return -EFAULT;
+
+               return vgic_attr_regs_access(dev, attr, &reg, true);
+       }
+
+       }
+
+       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: {
+               u32 __user *uaddr = (u32 __user *)(long)attr->addr;
+               u32 reg = 0;
+
+               ret = vgic_attr_regs_access(dev, attr, &reg, false);
+               if (ret)
+                       return ret;
+               return put_user(reg, uaddr);
+       }
+
+       }
+
+       return -ENXIO;
+}
+
+static int vgic_v2_has_attr(struct kvm_device *dev,
+                           struct kvm_device_attr *attr)
+{
+       phys_addr_t offset;
+
+       switch (attr->group) {
+       case KVM_DEV_ARM_VGIC_GRP_ADDR:
+               switch (attr->attr) {
+               case KVM_VGIC_V2_ADDR_TYPE_DIST:
+               case KVM_VGIC_V2_ADDR_TYPE_CPU:
+                       return 0;
+               }
+               break;
+       case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
+               offset = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK;
+               return vgic_has_attr_regs(vgic_dist_ranges, offset);
+       case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
+               offset = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK;
+               return vgic_has_attr_regs(vgic_cpu_ranges, offset);
+       case KVM_DEV_ARM_VGIC_GRP_NR_IRQS:
+               return 0;
+       case KVM_DEV_ARM_VGIC_GRP_CTRL:
+               switch (attr->attr) {
+               case KVM_DEV_ARM_VGIC_CTRL_INIT:
+                       return 0;
+               }
+       }
+       return -ENXIO;
+}
+
+struct kvm_device_ops kvm_arm_vgic_v2_ops = {
+       .name = "kvm-arm-vgic-v2",
+       .create = vgic_v2_create,
+       .destroy = vgic_v2_destroy,
+       .set_attr = vgic_v2_set_attr,
+       .get_attr = vgic_v2_get_attr,
+       .has_attr = vgic_v2_has_attr,
+};