kernel/virt/kvm/arm/vgic-v3.c

   1 /*
   2  * Copyright (C) 2013 ARM Limited, All Rights Reserved.
   3  * Author: Marc Zyngier <marc.zyngier@arm.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <linux/cpu.h>
  19 #include <linux/kvm.h>
  20 #include <linux/kvm_host.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/io.h>
  23 #include <linux/of.h>
  24 #include <linux/of_address.h>
  25 #include <linux/of_irq.h>
  26
  27 #include <linux/irqchip/arm-gic-v3.h>
  28
  29 #include <asm/kvm_emulate.h>
  30 #include <asm/kvm_arm.h>
  31 #include <asm/kvm_mmu.h>
  32
  33 /* These are for GICv2 emulation only */
  34 #define GICH_LR_VIRTUALID               (0x3ffUL << 0)
  35 #define GICH_LR_PHYSID_CPUID_SHIFT      (10)
  36 #define GICH_LR_PHYSID_CPUID            (7UL << GICH_LR_PHYSID_CPUID_SHIFT)
  37 #define ICH_LR_VIRTUALID_MASK           (BIT_ULL(32) - 1)
  38
  39 /*
  40  * LRs are stored in reverse order in memory. make sure we index them
  41  * correctly.
  42  */
  43 #define LR_INDEX(lr)                    (VGIC_V3_MAX_LRS - 1 - lr)
  44
  45 static u32 ich_vtr_el2;
  46
  47 static struct vgic_lr vgic_v3_get_lr(const struct kvm_vcpu *vcpu, int lr)
  48 {
  49         struct vgic_lr lr_desc;
  50         u64 val = vcpu->arch.vgic_cpu.vgic_v3.vgic_lr[LR_INDEX(lr)];
  51
  52         if (vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3)
  53                 lr_desc.irq = val & ICH_LR_VIRTUALID_MASK;
  54         else
  55                 lr_desc.irq = val & GICH_LR_VIRTUALID;
  56
  57         lr_desc.source = 0;
  58         if (lr_desc.irq <= 15 &&
  59             vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2)
  60                 lr_desc.source = (val >> GICH_LR_PHYSID_CPUID_SHIFT) & 0x7;
  61
  62         lr_desc.state = 0;
  63
  64         if (val & ICH_LR_PENDING_BIT)
  65                 lr_desc.state |= LR_STATE_PENDING;
  66         if (val & ICH_LR_ACTIVE_BIT)
  67                 lr_desc.state |= LR_STATE_ACTIVE;
  68         if (val & ICH_LR_EOI)
  69                 lr_desc.state |= LR_EOI_INT;
  70
  71         return lr_desc;
  72 }
  73
  74 static void vgic_v3_set_lr(struct kvm_vcpu *vcpu, int lr,
  75                            struct vgic_lr lr_desc)
  76 {
  77         u64 lr_val;
  78
  79         lr_val = lr_desc.irq;
  80
  81         /*
  82          * Currently all guest IRQs are Group1, as Group0 would result
  83          * in a FIQ in the guest, which it wouldn't expect.
  84          * Eventually we want to make this configurable, so we may revisit
  85          * this in the future.
  86          */
  87         if (vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3)
  88                 lr_val |= ICH_LR_GROUP;
  89         else
  90                 lr_val |= (u32)lr_desc.source << GICH_LR_PHYSID_CPUID_SHIFT;
  91
  92         if (lr_desc.state & LR_STATE_PENDING)
  93                 lr_val |= ICH_LR_PENDING_BIT;
  94         if (lr_desc.state & LR_STATE_ACTIVE)
  95                 lr_val |= ICH_LR_ACTIVE_BIT;
  96         if (lr_desc.state & LR_EOI_INT)
  97                 lr_val |= ICH_LR_EOI;
  98
  99         vcpu->arch.vgic_cpu.vgic_v3.vgic_lr[LR_INDEX(lr)] = lr_val;
 100 }
 101
 102 static void vgic_v3_sync_lr_elrsr(struct kvm_vcpu *vcpu, int lr,
 103                                   struct vgic_lr lr_desc)
 104 {
 105         if (!(lr_desc.state & LR_STATE_MASK))
 106                 vcpu->arch.vgic_cpu.vgic_v3.vgic_elrsr |= (1U << lr);
 107         else
 108                 vcpu->arch.vgic_cpu.vgic_v3.vgic_elrsr &= ~(1U << lr);
 109 }
 110
 111 static u64 vgic_v3_get_elrsr(const struct kvm_vcpu *vcpu)
 112 {
 113         return vcpu->arch.vgic_cpu.vgic_v3.vgic_elrsr;
 114 }
 115
 116 static u64 vgic_v3_get_eisr(const struct kvm_vcpu *vcpu)
 117 {
 118         return vcpu->arch.vgic_cpu.vgic_v3.vgic_eisr;
 119 }
 120
 121 static void vgic_v3_clear_eisr(struct kvm_vcpu *vcpu)
 122 {
 123         vcpu->arch.vgic_cpu.vgic_v3.vgic_eisr = 0;
 124 }
 125
 126 static u32 vgic_v3_get_interrupt_status(const struct kvm_vcpu *vcpu)
 127 {
 128         u32 misr = vcpu->arch.vgic_cpu.vgic_v3.vgic_misr;
 129         u32 ret = 0;
 130
 131         if (misr & ICH_MISR_EOI)
 132                 ret |= INT_STATUS_EOI;
 133         if (misr & ICH_MISR_U)
 134                 ret |= INT_STATUS_UNDERFLOW;
 135
 136         return ret;
 137 }
 138
 139 static void vgic_v3_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
 140 {
 141         u32 vmcr = vcpu->arch.vgic_cpu.vgic_v3.vgic_vmcr;
 142
 143         vmcrp->ctlr = (vmcr & ICH_VMCR_CTLR_MASK) >> ICH_VMCR_CTLR_SHIFT;
 144         vmcrp->abpr = (vmcr & ICH_VMCR_BPR1_MASK) >> ICH_VMCR_BPR1_SHIFT;
 145         vmcrp->bpr  = (vmcr & ICH_VMCR_BPR0_MASK) >> ICH_VMCR_BPR0_SHIFT;
 146         vmcrp->pmr  = (vmcr & ICH_VMCR_PMR_MASK) >> ICH_VMCR_PMR_SHIFT;
 147 }
 148
 149 static void vgic_v3_enable_underflow(struct kvm_vcpu *vcpu)
 150 {
 151         vcpu->arch.vgic_cpu.vgic_v3.vgic_hcr |= ICH_HCR_UIE;
 152 }
 153
 154 static void vgic_v3_disable_underflow(struct kvm_vcpu *vcpu)
 155 {
 156         vcpu->arch.vgic_cpu.vgic_v3.vgic_hcr &= ~ICH_HCR_UIE;
 157 }
 158
 159 static void vgic_v3_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
 160 {
 161         u32 vmcr;
 162
 163         vmcr  = (vmcrp->ctlr << ICH_VMCR_CTLR_SHIFT) & ICH_VMCR_CTLR_MASK;
 164         vmcr |= (vmcrp->abpr << ICH_VMCR_BPR1_SHIFT) & ICH_VMCR_BPR1_MASK;
 165         vmcr |= (vmcrp->bpr << ICH_VMCR_BPR0_SHIFT) & ICH_VMCR_BPR0_MASK;
 166         vmcr |= (vmcrp->pmr << ICH_VMCR_PMR_SHIFT) & ICH_VMCR_PMR_MASK;
 167
 168         vcpu->arch.vgic_cpu.vgic_v3.vgic_vmcr = vmcr;
 169 }
 170
 171 static void vgic_v3_enable(struct kvm_vcpu *vcpu)
 172 {
 173         struct vgic_v3_cpu_if *vgic_v3 = &vcpu->arch.vgic_cpu.vgic_v3;
 174
 175         /*
 176          * By forcing VMCR to zero, the GIC will restore the binary
 177          * points to their reset values. Anything else resets to zero
 178          * anyway.
 179          */
 180         vgic_v3->vgic_vmcr = 0;
 181
 182         /*
 183          * If we are emulating a GICv3, we do it in an non-GICv2-compatible
 184          * way, so we force SRE to 1 to demonstrate this to the guest.
 185          * This goes with the spec allowing the value to be RAO/WI.
 186          */
 187         if (vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3)
 188                 vgic_v3->vgic_sre = ICC_SRE_EL1_SRE;
 189         else
 190                 vgic_v3->vgic_sre = 0;
 191
 192         /* Get the show on the road... */
 193         vgic_v3->vgic_hcr = ICH_HCR_EN;
 194 }
 195
 196 static const struct vgic_ops vgic_v3_ops = {
 197         .get_lr                 = vgic_v3_get_lr,
 198         .set_lr                 = vgic_v3_set_lr,
 199         .sync_lr_elrsr          = vgic_v3_sync_lr_elrsr,
 200         .get_elrsr              = vgic_v3_get_elrsr,
 201         .get_eisr               = vgic_v3_get_eisr,
 202         .clear_eisr             = vgic_v3_clear_eisr,
 203         .get_interrupt_status   = vgic_v3_get_interrupt_status,
 204         .enable_underflow       = vgic_v3_enable_underflow,
 205         .disable_underflow      = vgic_v3_disable_underflow,
 206         .get_vmcr               = vgic_v3_get_vmcr,
 207         .set_vmcr               = vgic_v3_set_vmcr,
 208         .enable                 = vgic_v3_enable,
 209 };
 210
 211 static struct vgic_params vgic_v3_params;
 212
 213 /**
 214  * vgic_v3_probe - probe for a GICv3 compatible interrupt controller in DT
 215  * @node:       pointer to the DT node
 216  * @ops:        address of a pointer to the GICv3 operations
 217  * @params:     address of a pointer to HW-specific parameters
 218  *
 219  * Returns 0 if a GICv3 has been found, with the low level operations
 220  * in *ops and the HW parameters in *params. Returns an error code
 221  * otherwise.
 222  */
 223 int vgic_v3_probe(struct device_node *vgic_node,
 224                   const struct vgic_ops **ops,
 225                   const struct vgic_params **params)
 226 {
 227         int ret = 0;
 228         u32 gicv_idx;
 229         struct resource vcpu_res;
 230         struct vgic_params *vgic = &vgic_v3_params;
 231
 232         vgic->maint_irq = irq_of_parse_and_map(vgic_node, 0);
 233         if (!vgic->maint_irq) {
 234                 kvm_err("error getting vgic maintenance irq from DT\n");
 235                 ret = -ENXIO;
 236                 goto out;
 237         }
 238
 239         ich_vtr_el2 = kvm_call_hyp(__vgic_v3_get_ich_vtr_el2);
 240
 241         /*
 242          * The ListRegs field is 5 bits, but there is a architectural
 243          * maximum of 16 list registers. Just ignore bit 4...
 244          */
 245         vgic->nr_lr = (ich_vtr_el2 & 0xf) + 1;
 246         vgic->can_emulate_gicv2 = false;
 247
 248         if (of_property_read_u32(vgic_node, "#redistributor-regions", &gicv_idx))
 249                 gicv_idx = 1;
 250
 251         gicv_idx += 3; /* Also skip GICD, GICC, GICH */
 252         if (of_address_to_resource(vgic_node, gicv_idx, &vcpu_res)) {
 253                 kvm_info("GICv3: no GICV resource entry\n");
 254                 vgic->vcpu_base = 0;
 255         } else if (!PAGE_ALIGNED(vcpu_res.start)) {
 256                 pr_warn("GICV physical address 0x%llx not page aligned\n",
 257                         (unsigned long long)vcpu_res.start);
 258                 vgic->vcpu_base = 0;
 259         } else if (!PAGE_ALIGNED(resource_size(&vcpu_res))) {
 260                 pr_warn("GICV size 0x%llx not a multiple of page size 0x%lx\n",
 261                         (unsigned long long)resource_size(&vcpu_res),
 262                         PAGE_SIZE);
 263                 vgic->vcpu_base = 0;
 264         } else {
 265                 vgic->vcpu_base = vcpu_res.start;
 266                 vgic->can_emulate_gicv2 = true;
 267                 kvm_register_device_ops(&kvm_arm_vgic_v2_ops,
 268                                         KVM_DEV_TYPE_ARM_VGIC_V2);
 269         }
 270         if (vgic->vcpu_base == 0)
 271                 kvm_info("disabling GICv2 emulation\n");
 272         kvm_register_device_ops(&kvm_arm_vgic_v3_ops, KVM_DEV_TYPE_ARM_VGIC_V3);
 273
 274         vgic->vctrl_base = NULL;
 275         vgic->type = VGIC_V3;
 276         vgic->max_gic_vcpus = KVM_MAX_VCPUS;
 277
 278         kvm_info("%s@%llx IRQ%d\n", vgic_node->name,
 279                  vcpu_res.start, vgic->maint_irq);
 280
 281         *ops = &vgic_v3_ops;
 282         *params = vgic;
 283
 284 out:
 285         of_node_put(vgic_node);
 286         return ret;
 287 }