2 * VGIC MMIO handling functions
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
14 #include <linux/bitops.h>
15 #include <linux/bsearch.h>
16 #include <linux/kvm.h>
17 #include <linux/kvm_host.h>
18 #include <kvm/iodev.h>
19 #include <kvm/arm_vgic.h>
22 #include "vgic-mmio.h"
24 unsigned long vgic_mmio_read_raz(struct kvm_vcpu *vcpu,
25 gpa_t addr, unsigned int len)
30 unsigned long vgic_mmio_read_rao(struct kvm_vcpu *vcpu,
31 gpa_t addr, unsigned int len)
36 void vgic_mmio_write_wi(struct kvm_vcpu *vcpu, gpa_t addr,
37 unsigned int len, unsigned long val)
42 static int match_region(const void *key, const void *elt)
44 const unsigned int offset = (unsigned long)key;
45 const struct vgic_register_region *region = elt;
47 if (offset < region->reg_offset)
50 if (offset >= region->reg_offset + region->len)
56 /* Find the proper register handler entry given a certain address offset. */
57 static const struct vgic_register_region *
58 vgic_find_mmio_region(const struct vgic_register_region *region, int nr_regions,
61 return bsearch((void *)(uintptr_t)offset, region, nr_regions,
62 sizeof(region[0]), match_region);
66 * kvm_mmio_read_buf() returns a value in a format where it can be converted
67 * to a byte array and be directly observed as the guest wanted it to appear
68 * in memory if it had done the store itself, which is LE for the GIC, as the
69 * guest knows the GIC is always LE.
71 * We convert this value to the CPUs native format to deal with it as a data
74 unsigned long vgic_data_mmio_bus_to_host(const void *val, unsigned int len)
76 unsigned long data = kvm_mmio_read_buf(val, len);
82 return le16_to_cpu(data);
84 return le32_to_cpu(data);
86 return le64_to_cpu(data);
91 * kvm_mmio_write_buf() expects a value in a format such that if converted to
92 * a byte array it is observed as the guest would see it if it could perform
93 * the load directly. Since the GIC is LE, and the guest knows this, the
94 * guest expects a value in little endian format.
96 * We convert the data value from the CPUs native format to LE so that the
97 * value is returned in the proper format.
99 void vgic_data_host_to_mmio_bus(void *buf, unsigned int len,
106 data = cpu_to_le16(data);
109 data = cpu_to_le32(data);
112 data = cpu_to_le64(data);
115 kvm_mmio_write_buf(buf, len, data);
119 struct vgic_io_device *kvm_to_vgic_iodev(const struct kvm_io_device *dev)
121 return container_of(dev, struct vgic_io_device, dev);
124 static bool check_region(const struct vgic_register_region *region,
127 if ((region->access_flags & VGIC_ACCESS_8bit) && len == 1)
129 if ((region->access_flags & VGIC_ACCESS_32bit) &&
130 len == sizeof(u32) && !(addr & 3))
132 if ((region->access_flags & VGIC_ACCESS_64bit) &&
133 len == sizeof(u64) && !(addr & 7))
139 static int dispatch_mmio_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
140 gpa_t addr, int len, void *val)
142 struct vgic_io_device *iodev = kvm_to_vgic_iodev(dev);
143 const struct vgic_register_region *region;
144 struct kvm_vcpu *r_vcpu;
147 region = vgic_find_mmio_region(iodev->regions, iodev->nr_regions,
148 addr - iodev->base_addr);
149 if (!region || !check_region(region, addr, len)) {
154 r_vcpu = iodev->redist_vcpu ? iodev->redist_vcpu : vcpu;
155 data = region->read(r_vcpu, addr, len);
156 vgic_data_host_to_mmio_bus(val, len, data);
160 static int dispatch_mmio_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
161 gpa_t addr, int len, const void *val)
163 struct vgic_io_device *iodev = kvm_to_vgic_iodev(dev);
164 const struct vgic_register_region *region;
165 struct kvm_vcpu *r_vcpu;
166 unsigned long data = vgic_data_mmio_bus_to_host(val, len);
168 region = vgic_find_mmio_region(iodev->regions, iodev->nr_regions,
169 addr - iodev->base_addr);
173 if (!check_region(region, addr, len))
176 r_vcpu = iodev->redist_vcpu ? iodev->redist_vcpu : vcpu;
177 region->write(r_vcpu, addr, len, data);
181 struct kvm_io_device_ops kvm_io_gic_ops = {
182 .read = dispatch_mmio_read,
183 .write = dispatch_mmio_write,
186 int vgic_register_dist_iodev(struct kvm *kvm, gpa_t dist_base_address,
189 struct vgic_io_device *io_device = &kvm->arch.vgic.dist_iodev;
195 len = vgic_v2_init_dist_iodev(io_device);
201 io_device->base_addr = dist_base_address;
202 io_device->redist_vcpu = NULL;
204 mutex_lock(&kvm->slots_lock);
205 ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, dist_base_address,
206 len, &io_device->dev);
207 mutex_unlock(&kvm->slots_lock);