accel/mshv: reserve ioapic routes on s->irq_routes

We reserve 24 ioapic routes using the new functions that operate on the
mshv apic state.

commit/add_msi_routing() fn's can be removed now.

Signed-off-by: Magnus Kulke <magnuskulke@linux.microsoft.com>
Link: https://lore.kernel.org/r/20260417105618.3621-13-magnuskulke@linux.microsoft.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

accel/mshv/irq.c

@@ -36,93 +36,6 @@ void mshv_init_msicontrol(void)
     msi_control->updated = false;
 }
 
-static int add_msi_routing(uint64_t addr, uint32_t data)
-{
-    struct mshv_user_irq_entry *route_entry;
-    uint32_t high_addr = addr >> 32;
-    uint32_t low_addr = addr & 0xFFFFFFFF;
-    int gsi;
-    GHashTable *gsi_routes;
-
-    trace_mshv_add_msi_routing(addr, data);
-
-    assert(msi_control);
-
-    WITH_QEMU_LOCK_GUARD(&msi_control_mutex) {
-        /* find an empty slot */
-        gsi = 0;
-        gsi_routes = msi_control->gsi_routes;
-        while (gsi < MSHV_MAX_MSI_ROUTES) {
-            route_entry = g_hash_table_lookup(gsi_routes, GINT_TO_POINTER(gsi));
-            if (!route_entry) {
-                break;
-            }
-            gsi++;
-        }
-        if (gsi >= MSHV_MAX_MSI_ROUTES) {
-            error_report("No empty gsi slot available");
-            return -1;
-        }
-
-        /* create new entry */
-        route_entry = g_new0(struct mshv_user_irq_entry, 1);
-        route_entry->gsi = gsi;
-        route_entry->address_hi = high_addr;
-        route_entry->address_lo = low_addr;
-        route_entry->data = data;
-
-        g_hash_table_insert(gsi_routes, GINT_TO_POINTER(gsi), route_entry);
-        msi_control->updated = true;
-    }
-
-    return gsi;
-}
-
-static int commit_msi_routing_table(int vm_fd)
-{
-    guint len;
-    int i, ret;
-    size_t table_size;
-    struct mshv_user_irq_table *table;
-    GHashTableIter iter;
-    gpointer key, value;
-
-    assert(msi_control);
-
-    WITH_QEMU_LOCK_GUARD(&msi_control_mutex) {
-        if (!msi_control->updated) {
-            /* nothing to update */
-            return 0;
-        }
-
-        /* Calculate the size of the table */
-        len = g_hash_table_size(msi_control->gsi_routes);
-        table_size = sizeof(struct mshv_user_irq_table)
-                     + len * sizeof(struct mshv_user_irq_entry);
-        table = g_malloc0(table_size);
-
-        g_hash_table_iter_init(&iter, msi_control->gsi_routes);
-        i = 0;
-        while (g_hash_table_iter_next(&iter, &key, &value)) {
-            struct mshv_user_irq_entry *entry = value;
-            table->entries[i] = *entry;
-            i++;
-        }
-        table->nr = i;
-
-        trace_mshv_commit_msi_routing_table(vm_fd, len);
-
-        ret = ioctl(vm_fd, MSHV_SET_MSI_ROUTING, table);
-        g_free(table);
-        if (ret < 0) {
-            error_report("Failed to commit msi routing table");
-            return -1;
-        }
-        msi_control->updated = false;
-    }
-    return 0;
-}
-
 /* Pass an eventfd which is to be used for injecting interrupts from userland */
 static int irqfd(int vm_fd, int fd, int resample_fd, uint32_t gsi,
                  uint32_t flags)
@@ -420,37 +333,45 @@ int mshv_irqchip_remove_irqfd_notifier_gsi(const EventNotifier *event,
     return irqchip_update_irqfd_notifier_gsi(event, NULL, virq, false);
 }
 
-int mshv_reserve_ioapic_msi_routes(int vm_fd)
+static int mshv_reserve_ioapic_msi_routes(MshvState *s)
 {
-    int ret, gsi;
+    int ret, i;
+    int gsi = 0;
+    struct mshv_user_irq_entry blank_entry = { 0 };
 
     /*
      * Reserve GSI 0-23 for IOAPIC pins, to avoid conflicts of legacy
      * peripherals with MSI-X devices
      */
-    for (gsi = 0; gsi < IOAPIC_NUM_PINS; gsi++) {
-        ret = add_msi_routing(0, 0);
+    for (i = 0; i < IOAPIC_NUM_PINS; i++) {
+        /* ret = add_msi_routing(0, 0); */
+        ret = irqchip_allocate_gsi(s, &gsi);
         if (ret < 0) {
-            error_report("Failed to reserve GSI %d", gsi);
+            error_report("Failed to reserve GSI %d: %s", gsi, strerror(-ret));
             return -1;
         }
+        blank_entry.gsi = gsi;
+        add_routing_entry(s, &blank_entry);
     }
 
-    ret = commit_msi_routing_table(vm_fd);
-    if (ret < 0) {
-        error_report("Failed to commit reserved IOAPIC MSI routes");
-        return -1;
-    }
+    mshv_irqchip_commit_routes(s);
 
     return 0;
 }
 
 void mshv_init_irq_routing(MshvState *s)
 {
+    int ret;
     int gsi_count = MSHV_MAX_MSI_ROUTES;
 
     s->irq_routes = g_malloc0(sizeof(*s->irq_routes));
     s->nr_allocated_irq_routes = 0;
     s->gsi_count = gsi_count;
     s->used_gsi_bitmap = bitmap_new(gsi_count);
+
+    ret = mshv_reserve_ioapic_msi_routes(s);
+    if (ret < 0) {
+        error_report("Failed to reserve IOAPIC MSI routes");
+        abort();
+    }
 }

accel/mshv/mshv-all.c

@@ -264,11 +264,6 @@ static int create_vm(int mshv_fd, int *vm_fd)
         return -1;
     }
 
-    ret = mshv_reserve_ioapic_msi_routes(*vm_fd);
-    if (ret < 0) {
-        return -1;
-    }
-
     ret = mshv_arch_post_init_vm(*vm_fd);
     if (ret < 0) {
         return -1;

include/system/mshv_int.h

@@ -122,6 +122,5 @@ int mshv_configure_msr(const CPUState *cpu, const MshvMsrEntry *msrs,
 
 /* interrupt */
 void mshv_init_msicontrol(void);
-int mshv_reserve_ioapic_msi_routes(int vm_fd);
 
 #endif