[Qemu-devel] [PATCH v8 14/19] hw/arm/virt: add support for VFIO devices

[Eric Auger <eric.auger@linaro.org>]

VFIO devices are dynamic sysbus devices. They could already be
instantiated. However for them to be functional, IRQ injection must
be programmed and started. This programming must happen after the
sysbus devices are attached to the platform bus and IRQ are bound.
Only at that time the GSI they are connected to are identified and
irqfd can be programmed.

Binding happens in a machine init done notifier registered by the
platform bus init. The IRQ start is done in a reset notifier.

This patchs adds the registration of the IRQ start notifier in machvirt.

Signed-off-by: Eric Auger <eric.auger@linaro.org>

---

v7 -> v8:
- vfio_kick_irqs replaces older vfio_register_irq_starter. The new
function registers a reset notifier while the older registered a
machine init done notifier.
- Given the fact platform_bus_first_irq has become part of a const
struct its handle cannot be passed as a void* to the reset notifier.
We now pass the interrupt DeviceState*.
- create_gic now returns the DeviceState handle of the gic so that it
can be passed to the reset notifier registration
---
 hw/arm/virt.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 37326a9..346b04a 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -44,6 +44,7 @@
 #include "qemu/error-report.h"
 #include "hw/arm/sysbus-fdt.h"
 #include "hw/platform-bus.h"
+#include "hw/vfio/vfio-platform.h"
 
 #define NUM_VIRTIO_TRANSPORTS 32
 
@@ -330,7 +331,7 @@ static void fdt_add_gic_node(const VirtBoardInfo *vbi)
     qemu_fdt_setprop_cell(vbi->fdt, "/intc", "phandle", gic_phandle);
 }
 
-static void create_gic(const VirtBoardInfo *vbi, qemu_irq *pic)
+static DeviceState *create_gic(const VirtBoardInfo *vbi, qemu_irq *pic)
 {
     /* We create a standalone GIC v2 */
     DeviceState *gicdev;
@@ -378,6 +379,7 @@ static void create_gic(const VirtBoardInfo *vbi, qemu_irq *pic)
     }
 
     fdt_add_gic_node(vbi);
+    return gicdev;
 }
 
 static void create_uart(const VirtBoardInfo *vbi, qemu_irq *pic)
@@ -537,7 +539,8 @@ static void create_flash(const VirtBoardInfo *vbi)
 }
 
 static void create_platform_bus(VirtBoardInfo *vbi, qemu_irq *pic,
-                                const ARMPlatformBusSystemParams *system_params)
+                                const ARMPlatformBusSystemParams *system_params,
+                                DeviceState *gic)
 {
     DeviceState *dev;
     SysBusDevice *s;
@@ -571,6 +574,9 @@ static void create_platform_bus(VirtBoardInfo *vbi, qemu_irq *pic,
     memory_region_add_subregion(sysmem,
                                 system_params->platform_bus_base,
                                 sysbus_mmio_get_region(s, 0));
+
+    /* setup VFIO signaling/IRQFD for all VFIO platform sysbus devices */
+    qemu_register_reset(vfio_kick_irqs, gic);
 }
 
 static void *machvirt_dtb(const struct arm_boot_info *binfo, int *fdt_size)
@@ -589,6 +595,7 @@ static void machvirt_init(MachineState *machine)
     MemoryRegion *ram = g_new(MemoryRegion, 1);
     const char *cpu_model = machine->cpu_model;
     VirtBoardInfo *vbi;
+    DeviceState *gic;
 
     if (!cpu_model) {
         cpu_model = "cortex-a15";
@@ -646,7 +653,7 @@ static void machvirt_init(MachineState *machine)
 
     create_flash(vbi);
 
-    create_gic(vbi, pic);
+    gic = create_gic(vbi, pic);
 
     create_uart(vbi, pic);
 
@@ -658,7 +665,7 @@ static void machvirt_init(MachineState *machine)
      */
     create_virtio_devices(vbi, pic);
 
-    create_platform_bus(vbi, pic, &platform_bus_params);
+    create_platform_bus(vbi, pic, &platform_bus_params, gic);
 
     vbi->bootinfo.ram_size = machine->ram_size;
     vbi->bootinfo.kernel_filename = machine->kernel_filename;
-- 
1.8.3.2