openrisc_sim_net_init() attempts to connect the IRQ line from the
ethernet device to both CPUs in an SMP configuration by simply caling
sysbus_connect_irq() for it twice.  This doesn't work, because the
second connection simply overrides the first.

Fix this by creating a TYPE_SPLIT_IRQ to split the IRQ in the SMP
case.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Stafford Horne <shorne@gmail.com>
Message-id: 20201127225127.14770-2-peter.maydell@linaro.org
---
 hw/openrisc/openrisc_sim.c | 13 +++++++++++--
 hw/openrisc/Kconfig        |  1 +
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/hw/openrisc/openrisc_sim.c b/hw/openrisc/openrisc_sim.c
index d752282e675..a8adf6b70d7 100644
--- a/hw/openrisc/openrisc_sim.c
+++ b/hw/openrisc/openrisc_sim.c
@@ -34,6 +34,7 @@
 #include "hw/sysbus.h"
 #include "sysemu/qtest.h"
 #include "sysemu/reset.h"
+#include "hw/core/split-irq.h"
 
 #define KERNEL_LOAD_ADDR 0x100
 
@@ -64,8 +65,16 @@ static void openrisc_sim_net_init(hwaddr base, hwaddr descriptors,
 
     s = SYS_BUS_DEVICE(dev);
     sysbus_realize_and_unref(s, &error_fatal);
-    for (i = 0; i < num_cpus; i++) {
-        sysbus_connect_irq(s, 0, cpu_irqs[i][irq_pin]);
+    if (num_cpus > 1) {
+        DeviceState *splitter = qdev_new(TYPE_SPLIT_IRQ);
+        qdev_prop_set_uint32(splitter, "num-lines", num_cpus);
+        qdev_realize_and_unref(splitter, NULL, &error_fatal);
+        for (i = 0; i < num_cpus; i++) {
+            qdev_connect_gpio_out(splitter, i, cpu_irqs[i][irq_pin]);
+        }
+        sysbus_connect_irq(s, 0, qdev_get_gpio_in(splitter, 0));
+    } else {
+        sysbus_connect_irq(s, 0, cpu_irqs[0][irq_pin]);
     }
     sysbus_mmio_map(s, 0, base);
     sysbus_mmio_map(s, 1, descriptors);
diff --git a/hw/openrisc/Kconfig b/hw/openrisc/Kconfig
index 6c1e86884e2..8f284f3ba04 100644
--- a/hw/openrisc/Kconfig
+++ b/hw/openrisc/Kconfig
@@ -3,3 +3,4 @@ config OR1K_SIM
     select SERIAL
     select OPENCORES_ETH
     select OMPIC
+    select SPLIT_IRQ
-- 
2.20.1