qdev: Introduce DEFINE_PROP_RESERVED_REGION

Introduce a new property defining a reserved region:
<low address>:<high address>:<type>.

This will be used to encode reserved IOVA regions.

For instance, in virtio-iommu use case, reserved IOVA regions
will be passed by the machine code to the virtio-iommu-pci
device (an array of those). The type of the reserved region
will match the virtio_iommu_probe_resv_mem subtype value:
- VIRTIO_IOMMU_RESV_MEM_T_RESERVED (0)
- VIRTIO_IOMMU_RESV_MEM_T_MSI (1)

on PC/Q35 machine, this will be used to inform the
virtio-iommu-pci device it should bypass the MSI region.
The reserved region will be: 0xfee00000:0xfeefffff:1.

On ARM, we can declare the ITS MSI doorbell as an MSI
region to prevent MSIs from being mapped on guest side.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-id: 20200629070404.10969-2-eric.auger@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 89 insertions, 0 deletions

diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
index 71f8aca..ca7771f 100644
--- a/hw/core/qdev-properties.c
+++ b/hw/core/qdev-properties.c
@@ -15,6 +15,7 @@
 #include "chardev/char.h"
 #include "qemu/uuid.h"
 #include "qemu/units.h"
+#include "qemu/cutils.h"
 
 void qdev_prop_set_after_realize(DeviceState *dev, const char *name,
                                   Error **errp)
@@ -578,6 +579,94 @@ const PropertyInfo qdev_prop_macaddr = {
     .set   = set_mac,
 };
 
+/* --- Reserved Region --- */
+
+/*
+ * Accepted syntax:
+ *   <low address>:<high address>:<type>
+ *   where low/high addresses are uint64_t in hexadecimal
+ *   and type is a non-negative decimal integer
+ */
+static void get_reserved_region(Object *obj, Visitor *v, const char *name,
+                                void *opaque, Error **errp)
+{
+    DeviceState *dev = DEVICE(obj);
+    Property *prop = opaque;
+    ReservedRegion *rr = qdev_get_prop_ptr(dev, prop);
+    char buffer[64];
+    char *p = buffer;
+    int rc;
+
+    rc = snprintf(buffer, sizeof(buffer), "0x%"PRIx64":0x%"PRIx64":%u",
+                  rr->low, rr->high, rr->type);
+    assert(rc < sizeof(buffer));
+
+    visit_type_str(v, name, &p, errp);
+}
+
+static void set_reserved_region(Object *obj, Visitor *v, const char *name,
+                                void *opaque, Error **errp)
+{
+    DeviceState *dev = DEVICE(obj);
+    Property *prop = opaque;
+    ReservedRegion *rr = qdev_get_prop_ptr(dev, prop);
+    Error *local_err = NULL;
+    const char *endptr;
+    char *str;
+    int ret;
+
+    if (dev->realized) {
+        qdev_prop_set_after_realize(dev, name, errp);
+        return;
+    }
+
+    visit_type_str(v, name, &str, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
+    ret = qemu_strtou64(str, &endptr, 16, &rr->low);
+    if (ret) {
+        error_setg(errp, "start address of '%s'"
+                   " must be a hexadecimal integer", name);
+        goto out;
+    }
+    if (*endptr != ':') {
+        goto separator_error;
+    }
+
+    ret = qemu_strtou64(endptr + 1, &endptr, 16, &rr->high);
+    if (ret) {
+        error_setg(errp, "end address of '%s'"
+                   " must be a hexadecimal integer", name);
+        goto out;
+    }
+    if (*endptr != ':') {
+        goto separator_error;
+    }
+
+    ret = qemu_strtoui(endptr + 1, &endptr, 10, &rr->type);
+    if (ret) {
+        error_setg(errp, "type of '%s'"
+                   " must be a non-negative decimal integer", name);
+    }
+    goto out;
+
+separator_error:
+    error_setg(errp, "reserved region fields must be separated with ':'");
+out:
+    g_free(str);
+    return;
+}
+
+const PropertyInfo qdev_prop_reserved_region = {
+    .name  = "reserved_region",
+    .description = "Reserved Region, example: 0xFEE00000:0xFEEFFFFF:0",
+    .get   = get_reserved_region,
+    .set   = set_reserved_region,
+};
+
 /* --- on/off/auto --- */
 
 const PropertyInfo qdev_prop_on_off_auto = {