[PATCH v2 1/5] qdev: Introduce DEFINE_PROP_RESERVED_REGION

[Eric Auger <eric.auger@redhat.com>]

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>

---

v11 -> v12:
- rename into DEFINE_PROP_RESERVED_REGION
- do not use g_strsplit anymore, use endptr instead
- remove 0x references
---
 include/exec/memory.h        |  6 +++
 include/hw/qdev-properties.h |  3 ++
 include/qemu/typedefs.h      |  1 +
 hw/core/qdev-properties.c    | 89 ++++++++++++++++++++++++++++++++++++
 4 files changed, 99 insertions(+)

diff --git a/include/exec/memory.h b/include/exec/memory.h
index e000bd2f97..7e47afabe8 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -57,6 +57,12 @@ struct MemoryRegionMmio {
     CPUWriteMemoryFunc *write[3];
 };
 
+struct ReservedRegion {
+    hwaddr low;
+    hwaddr high;
+    unsigned int type;
+};
+
 typedef struct IOMMUTLBEntry IOMMUTLBEntry;
 
 /* See address_space_translate: bit 0 is read, bit 1 is write.  */
diff --git a/include/hw/qdev-properties.h b/include/hw/qdev-properties.h
index f161604fb6..03bf850a7e 100644
--- a/include/hw/qdev-properties.h
+++ b/include/hw/qdev-properties.h
@@ -19,6 +19,7 @@ extern const PropertyInfo qdev_prop_string;
 extern const PropertyInfo qdev_prop_chr;
 extern const PropertyInfo qdev_prop_tpm;
 extern const PropertyInfo qdev_prop_macaddr;
+extern const PropertyInfo qdev_prop_reserved_region;
 extern const PropertyInfo qdev_prop_on_off_auto;
 extern const PropertyInfo qdev_prop_multifd_compression;
 extern const PropertyInfo qdev_prop_losttickpolicy;
@@ -183,6 +184,8 @@ extern const PropertyInfo qdev_prop_pcie_link_width;
     DEFINE_PROP(_n, _s, _f, qdev_prop_drive_iothread, BlockBackend *)
 #define DEFINE_PROP_MACADDR(_n, _s, _f)         \
     DEFINE_PROP(_n, _s, _f, qdev_prop_macaddr, MACAddr)
+#define DEFINE_PROP_RESERVED_REGION(_n, _s, _f)         \
+    DEFINE_PROP(_n, _s, _f, qdev_prop_reserved_region, ReservedRegion)
 #define DEFINE_PROP_ON_OFF_AUTO(_n, _s, _f, _d) \
     DEFINE_PROP_SIGNED(_n, _s, _f, _d, qdev_prop_on_off_auto, OnOffAuto)
 #define DEFINE_PROP_MULTIFD_COMPRESSION(_n, _s, _f, _d) \
diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
index ecf3cde26c..85c4f891f4 100644
--- a/include/qemu/typedefs.h
+++ b/include/qemu/typedefs.h
@@ -59,6 +59,7 @@ typedef struct ISABus ISABus;
 typedef struct ISADevice ISADevice;
 typedef struct IsaDma IsaDma;
 typedef struct MACAddr MACAddr;
+typedef struct ReservedRegion ReservedRegion;
 typedef struct MachineClass MachineClass;
 typedef struct MachineState MachineState;
 typedef struct MemoryListener MemoryListener;
diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
index 2047114fca..c2e0cc7cda 100644
--- a/hw/core/qdev-properties.c
+++ b/hw/core/qdev-properties.c
@@ -14,6 +14,7 @@
 #include "qapi/visitor.h"
 #include "chardev/char.h"
 #include "qemu/uuid.h"
+#include "qemu/cutils.h"
 
 void qdev_prop_set_after_realize(DeviceState *dev, const char *name,
                                   Error **errp)
@@ -577,6 +578,94 @@ const PropertyInfo qdev_prop_macaddr = {
     .set   = set_mac,
 };
 
+/* --- Reserved Region --- */
+
+/*
+ * accepted syntax version:
+ *   <low address>,<high address>,<type>
+ *   where low/high addresses are uint64_t in hexadecimal
+ *   and type is an unsigned integer in decimal
+ */
+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;
+
+    snprintf(buffer, sizeof(buffer), "0x%"PRIx64",0x%"PRIx64",%u",
+             rr->low, rr->high, rr->type);
+
+    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, "Failed to decode reserved region low addr");
+        error_append_hint(errp,
+                          "should be an address in hexadecimal\n");
+        goto out;
+    }
+    if (*endptr != ',') {
+        goto separator_error;
+    }
+
+    ret = qemu_strtou64(endptr + 1, &endptr, 16, &rr->high);
+    if (ret) {
+        error_setg(errp, "Failed to decode reserved region high addr");
+        error_append_hint(errp,
+                          "should be an address in hexadecimal\n");
+        goto out;
+    }
+    if (*endptr != ',') {
+        goto separator_error;
+    }
+
+    ret = qemu_strtoui(endptr + 1, &endptr, 10, &rr->type);
+    if (ret) {
+        error_setg(errp, "Failed to decode reserved region type");
+        error_append_hint(errp, "should be an unsigned integer in decimal\n");
+    }
+    goto out;
+
+separator_error:
+    error_setg(errp, "reserved region fields must be separated with commas");
+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 = {
-- 
2.20.1