[Qemu-devel] [PATCH v2 9/9] Do GSI routing

[Glauber Costa <glommer@redhat.com>]

To follow correctly what our bios ACPI tables say, we have to be able to program
our irqchips with GSI routing mappings. This support is already in qemu-kvm

Signed-off-by: Glauber Costa <glommer@redhat.com>
---
 kvm-all.c         |    6 ++-
 kvm.h             |    3 +
 target-i386/kvm.c |  118 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 125 insertions(+), 2 deletions(-)

diff --git a/kvm-all.c b/kvm-all.c
index 7a3671f..cf10abe 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -66,6 +66,8 @@ struct KVMState
 #endif
     int irqchip_in_kernel;
     int pit_in_kernel;
+
+    KVMArchState *arch_state;
 };
 
 static KVMState *kvm_state;
@@ -539,12 +541,12 @@ int kvm_init(int smp_cpus)
     if (ret < 0)
         goto err;
 
+    kvm_state = s;
+
     ret = kvm_arch_init(s, smp_cpus);
     if (ret < 0)
         goto err;
 
-    kvm_state = s;
-
     return 0;
 
 err:
diff --git a/kvm.h b/kvm.h
index c5a0915..15df381 100644
--- a/kvm.h
+++ b/kvm.h
@@ -72,7 +72,10 @@ int kvm_set_irq(int irq, int level, int *status);
 /* internal API */
 
 struct KVMState;
+struct KVMArchState;
+
 typedef struct KVMState KVMState;
+typedef struct KVMArchState KVMArchState;
 
 int kvm_ioctl(KVMState *s, int type, ...);
 
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 0224818..8439f2f 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -36,6 +36,16 @@
 
 #ifdef KVM_CAP_EXT_CPUID
 
+struct KVMArchState
+{
+    struct kvm_irq_routing *irq_routes;
+    int nr_allocated_irq_routes;
+    void *used_gsi_bitmap;
+    int max_gsi;
+};
+
+static KVMArchState *kvm_arch_state;
+
 static struct kvm_cpuid2 *try_get_cpuid(KVMState *s, int max)
 {
     struct kvm_cpuid2 *cpuid;
@@ -266,10 +276,118 @@ static int kvm_has_msr_star(CPUState *env)
     return 0;
 }
 
+/*
+ * Setup x86 specific IRQ routing
+ */
+static inline void set_gsi(KVMArchState *s, unsigned int gsi)
+{
+    uint32_t *bitmap = s->used_gsi_bitmap;
+
+    if (gsi < s->max_gsi)
+        bitmap[gsi / 32] |= 1U << (gsi % 32);
+    else
+        fprintf(stderr, "Invalid GSI %d\n", gsi);
+}
+
+static int kvm_add_routing_entry(KVMArchState *s, struct kvm_irq_routing_entry *entry)
+{
+    struct kvm_irq_routing *z;
+    struct kvm_irq_routing_entry *new;
+    int n, size;
+
+    if (s->irq_routes->nr == s->nr_allocated_irq_routes) {
+        n = s->nr_allocated_irq_routes * 2;
+        if (n < 64)
+            n = 64;
+        size = sizeof(struct kvm_irq_routing);
+        size += n * sizeof(*new);
+        z = realloc(s->irq_routes, size);
+        if (!z)
+            return -ENOMEM;
+        s->nr_allocated_irq_routes = n;
+        s->irq_routes = z;
+    }
+    n = s->irq_routes->nr++;
+    new = &s->irq_routes->entries[n];
+    memset(new, 0, sizeof(*new));
+    new->gsi = entry->gsi;
+    new->type = entry->type;
+    new->flags = entry->flags;
+    new->u = entry->u;
+
+    set_gsi(s, entry->gsi);
+
+    return 0;
+}
+
+static int kvm_add_irq_route(KVMArchState *s, int gsi, int irqchip, int pin)
+{
+    struct kvm_irq_routing_entry e;
+
+    e.gsi = gsi;
+    e.type = KVM_IRQ_ROUTING_IRQCHIP;
+    e.flags = 0;
+    e.u.irqchip.irqchip = irqchip;
+    e.u.irqchip.pin = pin;
+    return kvm_add_routing_entry(s, &e);
+}
+
+static int kvm_init_irq_routing(KVMState *s)
+{
+    int i, r;
+    int gsi_count, gsi_bits;
+
+    gsi_count = kvm_check_extension(s, KVM_CAP_IRQ_ROUTING);
+    if (!kvm_irqchip_in_kernel() && (gsi_count > 0)) {
+        return 0;
+    }
+
+        /* Round up so we can search ints using ffs */
+    gsi_bits = ((gsi_count - 31) & ~31);
+    kvm_arch_state->used_gsi_bitmap = qemu_mallocz(gsi_bits / 8);
+    kvm_arch_state->max_gsi = gsi_bits;
+
+    /* Mark any over-allocated bits as already in use */
+    for (i = gsi_count; i < gsi_bits; i++) {
+        set_gsi(kvm_arch_state, i);
+    }
+
+    kvm_arch_state->irq_routes->nr = 0;
+
+    for (i = 0; i < 8; ++i) {
+        if (i == 2)
+            continue;
+        r = kvm_add_irq_route(kvm_arch_state, i, KVM_IRQCHIP_PIC_MASTER, i);
+        if (r < 0)
+            return r;
+    }
+    for (i = 8; i < 16; ++i) {
+        r = kvm_add_irq_route(kvm_arch_state, i, KVM_IRQCHIP_PIC_SLAVE, i - 8);
+        if (r < 0)
+            return r;
+    }
+    for (i = 0; i < 24; ++i) {
+        if (i == 0) {
+            r = kvm_add_irq_route(kvm_arch_state, i, KVM_IRQCHIP_IOAPIC, 2);
+        } else if (i != 2) {
+            r = kvm_add_irq_route(kvm_arch_state, i, KVM_IRQCHIP_IOAPIC, i);
+        }
+        if (r < 0)
+            return r;
+    }
+
+    kvm_arch_state->irq_routes->flags = 0;
+    return kvm_vm_ioctl(s, KVM_SET_GSI_ROUTING, kvm_arch_state->irq_routes);
+}
 int kvm_arch_init(KVMState *s, int smp_cpus)
 {
     int ret;
 
+    kvm_arch_state = qemu_mallocz(sizeof(*kvm_arch_state));
+    kvm_arch_state->irq_routes = qemu_mallocz(sizeof(*kvm_arch_state->irq_routes));
+
+    kvm_init_irq_routing(s);
+
     /* create vm86 tss.  KVM uses vm86 mode to emulate 16-bit code
      * directly.  In order to use vm86 mode, a TSS is needed.  Since this
      * must be part of guest physical memory, we need to allocate it.  Older
-- 
1.6.2.5