tools/kvm/irq.c

   1 #include "kvm/irq.h"
   2 #include "kvm/kvm.h"
   3 #include "kvm/util.h"
   4
   5 #include <linux/types.h>
   6 #include <linux/rbtree.h>
   7 #include <linux/list.h>
   8 #include <linux/kvm.h>
   9 #include <sys/ioctl.h>
  10
  11 #include <stddef.h>
  12 #include <stdlib.h>
  13
  14 #define IRQ_MAX_GSI                     64
  15 #define IRQCHIP_MASTER                  0
  16 #define IRQCHIP_SLAVE                   1
  17 #define IRQCHIP_IOAPIC                  2
  18
  19 static u8               next_line       = 3;
  20 static u8               next_dev        = 1;
  21 static struct rb_root   pci_tree        = RB_ROOT;
  22
  23 /* First 24 GSIs are routed between IRQCHIPs and IOAPICs */
  24 static u32 gsi = 24;
  25
  26 struct kvm_irq_routing *irq_routing;
  27
  28 static int irq__add_routing(u32 gsi, u32 type, u32 irqchip, u32 pin)
  29 {
  30         if (gsi >= IRQ_MAX_GSI)
  31                 return -ENOSPC;
  32
  33         irq_routing->entries[irq_routing->nr++] =
  34                 (struct kvm_irq_routing_entry) {
  35                         .gsi = gsi,
  36                         .type = type,
  37                         .u.irqchip.irqchip = irqchip,
  38                         .u.irqchip.pin = pin,
  39                 };
  40
  41         return 0;
  42 }
  43
  44 static struct pci_dev *search(struct rb_root *root, u32 id)
  45 {
  46         struct rb_node *node = root->rb_node;
  47
  48         while (node) {
  49                 struct pci_dev *data = container_of(node, struct pci_dev, node);
  50                 int result;
  51
  52                 result = id - data->id;
  53
  54                 if (result < 0)
  55                         node = node->rb_left;
  56                 else if (result > 0)
  57                         node = node->rb_right;
  58                 else
  59                         return data;
  60         }
  61         return NULL;
  62 }
  63
  64 static int insert(struct rb_root *root, struct pci_dev *data)
  65 {
  66         struct rb_node **new = &(root->rb_node), *parent = NULL;
  67
  68         /* Figure out where to put new node */
  69         while (*new) {
  70                 struct pci_dev *this    = container_of(*new, struct pci_dev, node);
  71                 int result              = data->id - this->id;
  72
  73                 parent = *new;
  74                 if (result < 0)
  75                         new = &((*new)->rb_left);
  76                 else if (result > 0)
  77                         new = &((*new)->rb_right);
  78                 else
  79                         return 0;
  80         }
  81
  82         /* Add new node and rebalance tree. */
  83         rb_link_node(&data->node, parent, new);
  84         rb_insert_color(&data->node, root);
  85
  86         return 1;
  87 }
  88
  89 int irq__register_device(u32 dev, u8 *num, u8 *pin, u8 *line)
  90 {
  91         struct pci_dev *node;
  92
  93         node = search(&pci_tree, dev);
  94
  95         if (!node) {
  96                 /* We haven't found a node - First device of it's kind */
  97                 node = malloc(sizeof(*node));
  98                 if (node == NULL)
  99                         return -1;
 100
 101                 *node = (struct pci_dev) {
 102                         .id     = dev,
 103                         /*
 104                          * PCI supports only INTA#,B#,C#,D# per device.
 105                          * A#,B#,C#,D# are allowed for multifunctional
 106                          * devices so stick with A# for our single
 107                          * function devices.
 108                          */
 109                         .pin    = 1,
 110                 };
 111
 112                 INIT_LIST_HEAD(&node->lines);
 113
 114                 if (insert(&pci_tree, node) != 1) {
 115                         free(node);
 116                         return -1;
 117                 }
 118         }
 119
 120         if (node) {
 121                 /* This device already has a pin assigned, give out a new line and device id */
 122                 struct irq_line *new = malloc(sizeof(*new));
 123                 if (new == NULL)
 124                         return -1;
 125
 126                 new->line       = next_line++;
 127                 *line           = new->line;
 128                 *pin            = node->pin;
 129                 *num            = next_dev++;
 130
 131                 list_add(&new->node, &node->lines);
 132
 133                 return 0;
 134         }
 135
 136         return -1;
 137 }
 138
 139 void irq__init(struct kvm *kvm)
 140 {
 141         int i, r;
 142
 143         irq_routing = malloc(sizeof(struct kvm_irq_routing) +
 144                         IRQ_MAX_GSI * sizeof(struct kvm_irq_routing_entry));
 145         if (irq_routing == NULL)
 146                 die("Failed allocating space for GSI table");
 147
 148         /* Hook first 8 GSIs to master IRQCHIP */
 149         for (i = 0; i < 8; i++)
 150                 if (i != 2)
 151                         irq__add_routing(i, KVM_IRQ_ROUTING_IRQCHIP, IRQCHIP_MASTER, i);
 152
 153         /* Hook next 8 GSIs to slave IRQCHIP */
 154         for (i = 8; i < 16; i++)
 155                 irq__add_routing(i, KVM_IRQ_ROUTING_IRQCHIP, IRQCHIP_SLAVE, i - 8);
 156
 157         /* Last but not least, IOAPIC */
 158         for (i = 0; i < 24; i++) {
 159                 if (i == 0)
 160                         irq__add_routing(i, KVM_IRQ_ROUTING_IRQCHIP, IRQCHIP_IOAPIC, 2);
 161                 else if (i != 2)
 162                         irq__add_routing(i, KVM_IRQ_ROUTING_IRQCHIP, IRQCHIP_IOAPIC, i);
 163         }
 164
 165         r = ioctl(kvm->vm_fd, KVM_SET_GSI_ROUTING, irq_routing);
 166         if (r)
 167                 die("Failed setting GSI routes");
 168 }
 169
 170 int irq__add_msix_route(struct kvm *kvm, u32 low, u32 high, u32 data)
 171 {
 172         int r;
 173
 174         irq_routing->entries[irq_routing->nr++] =
 175                 (struct kvm_irq_routing_entry) {
 176                         .gsi = gsi,
 177                         .type = KVM_IRQ_ROUTING_MSI,
 178                         .u.msi.address_lo = low,
 179                         .u.msi.address_hi = high,
 180                         .u.msi.data = data,
 181                 };
 182
 183         r = ioctl(kvm->vm_fd, KVM_SET_GSI_ROUTING, irq_routing);
 184         if (r)
 185                 return r;
 186
 187         return gsi++;
 188 }
 189
 190 struct rb_node *irq__get_pci_tree(void)
 191 {
 192         return rb_first(&pci_tree);
 193 }