drivers: virt_ivshmem: Allow multiple instances of ivShMem devices.

- Supporting multiple instances of ivShMem virtual devices.
- Introduces DT based configuration for ivShMem devices.
- Add DTS overlay file to test new multiple ivshmem instance capability.
- Enable BDF unspecified device initialization.
  (limited to one instance. An improved version of pcie_bdf_lookup()
  will come soon that fixes this limitation)
- Make PCIE DTS file macros available for a proper ivshmem device
  properties parsing.

Sample for dts file:
pcie0 {
	label = "PCIE_0";
	#address-cells = <1>;
	#size-cells = <1>;
	compatible = "intel,pcie";
	ranges;
    ivshmem0: ivshmem@800 {
	    compatible = "qemu,ivshmem";
	    reg = <PCIE_BDF_NONE PCIE_ID(0x1af4,0x1110)>;
	    label = "IVSHMEM";
	    status = "okay";
    };
};

Signed-off-by: Michael Schmidt <michael1.schmidt@intel.com>

drivers/virtualization/virt_ivshmem.c

@@ -4,6 +4,8 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+#define DT_DRV_COMPAT qemu_ivshmem
+
 #define LOG_LEVEL CONFIG_IVSHMEM_LOG_LEVEL
 #include <logging/log.h>
 LOG_MODULE_REGISTER(ivshmem);
@@ -223,25 +225,42 @@ static const struct ivshmem_driver_api ivshmem_api = {
 static int ivshmem_init(const struct device *dev)
 {
 	struct ivshmem *data = dev->data;
+	static bool bdf_lookup_done;
 
-	data->bdf = pcie_bdf_lookup(PCIE_ID(IVSHMEM_VENDOR_ID,
-					    IVSHMEM_DEVICE_ID));
-	if (data->bdf == PCIE_BDF_NONE) {
-		LOG_WRN("ivshmem device not found");
+	if ((data->bdf == PCIE_BDF_NONE) && bdf_lookup_done) {
+		LOG_ERR("One instance of ivshmem with pcie_bdf_lookup() already initialized.\n"
+			"Using more than one with PCIE_BDF_NONE parameter might conflict\n"
+			"with already initialized instances.");
 		return -ENOTSUP;
 	}
-
+	if ((data->bdf == PCIE_BDF_NONE) && !bdf_lookup_done) {
+		if (data->dev_ven_id) {
+			data->bdf = pcie_bdf_lookup(data->dev_ven_id);
+		} else {
+			data->bdf = pcie_bdf_lookup(PCIE_ID(IVSHMEM_VENDOR_ID, IVSHMEM_DEVICE_ID));
+		}
+		if (data->bdf == PCIE_BDF_NONE) {
+			LOG_WRN("ivshmem device not found");
+			return -ENOTSUP;
+		}
+	}
 	LOG_DBG("ivshmem found at bdf 0x%x", data->bdf);
+	bdf_lookup_done = true;
 
 	if (!ivshmem_configure(dev)) {
 		return -EIO;
 	}
-
 	return 0;
 }
 
-static struct ivshmem ivshmem_data;
+#define IVSHMEM_DEVICE_INIT(n) \
+	static struct ivshmem ivshmem_data_##n = { \
+		.bdf = DT_INST_REG_ADDR_BY_IDX(n, 0), \
+		.dev_ven_id = DT_INST_REG_SIZE_BY_IDX(n, 0) \
+	}; \
+	DEVICE_DT_INST_DEFINE(n, &ivshmem_init, NULL, \
+			      &ivshmem_data_##n, NULL, \
+			      POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE, \
+			      &ivshmem_api);
 
-DEVICE_DEFINE(ivshmem, CONFIG_IVSHMEM_DEV_NAME,
-	      ivshmem_init, NULL, &ivshmem_data, NULL,
-	      POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &ivshmem_api);
+DT_INST_FOREACH_STATUS_OKAY(IVSHMEM_DEVICE_INIT)

drivers/virtualization/virt_ivshmem.h

@@ -25,6 +25,7 @@ struct ivshmem_param {
 struct ivshmem {
 	DEVICE_MMIO_RAM;
 	pcie_bdf_t bdf;
+	uint32_t dev_ven_id;
 	uintptr_t shmem;
 	size_t size;
 #ifdef CONFIG_IVSHMEM_DOORBELL

dts/bindings/virtualization/qemu,ivshmem.yaml

@@ -0,0 +1,8 @@
+# Copyright (c) 2021 Intel Corporation
+# SPDX-License-Identifier: Apache-2.0
+
+description: ivShMem device properties
+
+compatible: "qemu,ivshmem"
+
+include: base.yaml

tests/drivers/virtualization/ivshmem/app.overlay

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2021 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#include <dt-bindings/pcie/pcie.h>
+
+/ {
+	pcie0 {
+		label = "PCIE_0";
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "intel,pcie";
+		ranges;
+
+		ivshmem0: ivshmem@800 {
+			compatible = "qemu,ivshmem";
+
+			reg = <PCIE_BDF_NONE PCIE_ID(0x1af4,0x1110)>;
+			label = "IVSHMEM";
+			status = "okay";
+		};
+	};
+};