virtio-iommu: Add a granule property

This allows to choose which granule will be used by
default by the virtio-iommu. Current page size mask
default is qemu_target_page_mask so this translates
into a 4k granule on ARM and x86_64 where virtio-iommu
is supported.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>

Message-Id: <20240307134445.92296-3-eric.auger@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/virtio/virtio-iommu.c

@@ -29,6 +29,7 @@
 #include "sysemu/reset.h"
 #include "sysemu/sysemu.h"
 #include "qemu/reserved-region.h"
+#include "qemu/units.h"
 #include "qapi/error.h"
 #include "qemu/error-report.h"
 #include "trace.h"
@@ -1115,8 +1116,8 @@ static int virtio_iommu_notify_flag_changed(IOMMUMemoryRegion *iommu_mr,
 }
 
 /*
- * The default mask (TARGET_PAGE_MASK) is the smallest supported guest granule,
+ * The default mask depends on the "granule" property. For example, with
- * for example 0xfffffffffffff000. When an assigned device has page size
+ * 4k granule, it is -(4 * KiB). When an assigned device has page size
  * restrictions due to the hardware IOMMU configuration, apply this restriction
  * to the mask.
  */
@@ -1313,8 +1314,27 @@ static void virtio_iommu_device_realize(DeviceState *dev, Error **errp)
      * in vfio realize
      */
     s->config.bypass = s->boot_bypass;
-    s->config.page_size_mask = qemu_target_page_mask();
     s->config.input_range.end = UINT64_MAX;
+
+    switch (s->granule_mode) {
+    case GRANULE_MODE_4K:
+        s->config.page_size_mask = -(4 * KiB);
+        break;
+    case GRANULE_MODE_8K:
+        s->config.page_size_mask = -(8 * KiB);
+        break;
+    case GRANULE_MODE_16K:
+        s->config.page_size_mask = -(16 * KiB);
+        break;
+    case GRANULE_MODE_64K:
+        s->config.page_size_mask = -(64 * KiB);
+        break;
+    case GRANULE_MODE_HOST:
+        s->config.page_size_mask = qemu_real_host_page_mask();
+        break;
+    default:
+        error_setg(errp, "Unsupported granule mode");
+    }
     s->config.domain_range.end = UINT32_MAX;
     s->config.probe_size = VIOMMU_PROBE_SIZE;
 
@@ -1522,6 +1542,8 @@ static Property virtio_iommu_properties[] = {
     DEFINE_PROP_LINK("primary-bus", VirtIOIOMMU, primary_bus,
                      TYPE_PCI_BUS, PCIBus *),
     DEFINE_PROP_BOOL("boot-bypass", VirtIOIOMMU, boot_bypass, true),
+    DEFINE_PROP_GRANULE_MODE("granule", VirtIOIOMMU, granule_mode,
+                             GRANULE_MODE_4K),
     DEFINE_PROP_END_OF_LIST(),
 };
 

include/hw/virtio/virtio-iommu.h

@@ -24,6 +24,7 @@
 #include "hw/virtio/virtio.h"
 #include "hw/pci/pci.h"
 #include "qom/object.h"
+#include "qapi/qapi-types-virtio.h"
 
 #define TYPE_VIRTIO_IOMMU "virtio-iommu-device"
 #define TYPE_VIRTIO_IOMMU_PCI "virtio-iommu-pci"
@@ -66,6 +67,7 @@ struct VirtIOIOMMU {
     bool boot_bypass;
     Notifier machine_done;
     bool granule_frozen;
+    GranuleMode granule_mode;
 };
 
 #endif