virt/kvm/arm/vgic/vgic-its.c

   1 /*
   2  * GICv3 ITS emulation
   3  *
   4  * Copyright (C) 2015,2016 ARM Ltd.
   5  * Author: Andre Przywara <andre.przywara@arm.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <linux/cpu.h>
  21 #include <linux/kvm.h>
  22 #include <linux/kvm_host.h>
  23 #include <linux/interrupt.h>
  24
  25 #include <linux/irqchip/arm-gic-v3.h>
  26
  27 #include <asm/kvm_emulate.h>
  28 #include <asm/kvm_arm.h>
  29 #include <asm/kvm_mmu.h>
  30
  31 #include "vgic.h"
  32 #include "vgic-mmio.h"
  33
  34 #define REGISTER_ITS_DESC(off, rd, wr, length, acc)             \
  35 {                                                               \
  36         .reg_offset = off,                                      \
  37         .len = length,                                          \
  38         .access_flags = acc,                                    \
  39         .its_read = rd,                                         \
  40         .its_write = wr,                                        \
  41 }
  42
  43 static unsigned long its_mmio_read_raz(struct kvm *kvm, struct vgic_its *its,
  44                                        gpa_t addr, unsigned int len)
  45 {
  46         return 0;
  47 }
  48
  49 static void its_mmio_write_wi(struct kvm *kvm, struct vgic_its *its,
  50                               gpa_t addr, unsigned int len, unsigned long val)
  51 {
  52         /* Ignore */
  53 }
  54
  55 static struct vgic_register_region its_registers[] = {
  56         REGISTER_ITS_DESC(GITS_CTLR,
  57                 its_mmio_read_raz, its_mmio_write_wi, 4,
  58                 VGIC_ACCESS_32bit),
  59         REGISTER_ITS_DESC(GITS_IIDR,
  60                 its_mmio_read_raz, its_mmio_write_wi, 4,
  61                 VGIC_ACCESS_32bit),
  62         REGISTER_ITS_DESC(GITS_TYPER,
  63                 its_mmio_read_raz, its_mmio_write_wi, 8,
  64                 VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
  65         REGISTER_ITS_DESC(GITS_CBASER,
  66                 its_mmio_read_raz, its_mmio_write_wi, 8,
  67                 VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
  68         REGISTER_ITS_DESC(GITS_CWRITER,
  69                 its_mmio_read_raz, its_mmio_write_wi, 8,
  70                 VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
  71         REGISTER_ITS_DESC(GITS_CREADR,
  72                 its_mmio_read_raz, its_mmio_write_wi, 8,
  73                 VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
  74         REGISTER_ITS_DESC(GITS_BASER,
  75                 its_mmio_read_raz, its_mmio_write_wi, 0x40,
  76                 VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
  77         REGISTER_ITS_DESC(GITS_IDREGS_BASE,
  78                 its_mmio_read_raz, its_mmio_write_wi, 0x30,
  79                 VGIC_ACCESS_32bit),
  80 };
  81
  82 static int vgic_its_init_its(struct kvm *kvm, struct vgic_its *its)
  83 {
  84         struct vgic_io_device *iodev = &its->iodev;
  85         int ret;
  86
  87         if (IS_VGIC_ADDR_UNDEF(its->vgic_its_base))
  88                 return -ENXIO;
  89
  90         iodev->regions = its_registers;
  91         iodev->nr_regions = ARRAY_SIZE(its_registers);
  92         kvm_iodevice_init(&iodev->dev, &kvm_io_gic_ops);
  93
  94         iodev->base_addr = its->vgic_its_base;
  95         iodev->iodev_type = IODEV_ITS;
  96         iodev->its = its;
  97         mutex_lock(&kvm->slots_lock);
  98         ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, iodev->base_addr,
  99                                       KVM_VGIC_V3_ITS_SIZE, &iodev->dev);
 100         mutex_unlock(&kvm->slots_lock);
 101
 102         return ret;
 103 }