DM: virtio-i2c: add support for virtio i2c adapter

Add virtio i2c adapter BE driver.

Tracked-On: #3357
Signed-off-by: Conghui Chen <conghui.chen@intel.com>
Reviewed-by: Yuan Liu <yuan1.liu@intel.com>
Reviewed-by: Shuo A Liu <shuo.a.liu@intel.com>
Acked-by: Wang Yu <yu1.wang@intel.com>

devicemodel/Makefile

@@ -105,6 +105,7 @@ SRCS += hw/pci/core.c
 SRCS += hw/pci/virtio/virtio_console.c
 SRCS += hw/pci/virtio/virtio_block.c
 SRCS += hw/pci/virtio/virtio_input.c
+SRCS += hw/pci/virtio/virtio_i2c.c
 SRCS += hw/pci/ahci.c
 SRCS += hw/pci/hostbridge.c
 SRCS += hw/pci/platform_gsi_info.c

devicemodel/hw/pci/virtio/virtio_i2c.c

@@ -0,0 +1,197 @@
+/*
+ * Copyright (C) 2019 Intel Corporation. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+
+#include <sys/param.h>
+#include <sys/uio.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <pthread.h>
+#include <openssl/md5.h>
+#include <linux/i2c.h>
+#include <linux/i2c-dev.h>
+#include <sys/ioctl.h>
+
+#include "dm.h"
+#include "pci_core.h"
+#include "virtio.h"
+
+/* I2c adapter virtualization architecture
+ *
+ *                +-----------------------------+
+ *                | ACRN DM                     |
+ *                |  +----------------------+   |  virtqueue
+ *                |  |                      |<--+-----------+
+ *                |  | virtio i2c mediator  |   |           |
+ *                |  |                      |   |           |
+ *                |  +--+-----+-----+-------+   |           |
+ *                +-----+-----+-----+-----------+           |
+ * User space   +-------+     |     +-----------+           |
+ *              v             v                 v           |
+ *    +---------+----+  +-----+--------+  +-----+------+    |  +-----------+
+ * ---+ /dev/i2c-0   +--+ /dev/i2c-1   +--+ /dev/i2c-n +----+--+UOS:       |
+ *    |              |                 |  |            |    |  |/dev/i2c-n |
+ *    +----------+---+  +-------+------+  +-----+------+    |  +-----+-----+
+ * Kernel space  v              v               v           |        v
+ *         +-----+-------+ +----+--------+ +----+--------+  |  +-----+------------+
+ *         |i2c adapter 0| |i2c adapter 1| |i2c adapter n|  +->|UOS:              |
+ *         |             | |             |               |     |virtio i2c adapter|
+ *         +-----+-------+ +-------------+ +-------------+     +------------------+
+ * --------------+-----------------------------------------
+ * Hardware      +----------+
+ *               |          |
+ *          bus 0v          v      ....
+ *         +-----+---+ +----+----+
+ *         |i2c slave| |i2c slave| ....
+ *         +---------+ +---------+
+ */
+
+static int virtio_i2c_debug=0;
+#define VIRTIO_I2C_PREF "virtio_i2c: "
+#define DPRINTF(fmt, args...) \
+	do { if (virtio_i2c_debug) printf(VIRTIO_I2C_PREF fmt, ##args); } while (0)
+#define WPRINTF(fmt, args...) printf(VIRTIO_I2C_PREF fmt, ##args)
+
+/*
+ * Per-device struct
+ */
+struct virtio_i2c {
+	struct virtio_base base;
+	pthread_mutex_t mtx;
+	struct virtio_vq_info vq;
+	char ident[256];
+};
+
+static void virtio_i2c_reset(void *);
+static void virtio_i2c_notify(void *, struct virtio_vq_info *);
+
+static struct virtio_ops virtio_i2c_ops = {
+	"virtio_i2c",		/* our name */
+	1,			/* we support 1 virtqueue */
+	0, /* config reg size */
+	virtio_i2c_reset,	/* reset */
+	virtio_i2c_notify,	/* device-wide qnotify */
+	NULL,	/* read PCI config */
+	NULL,	/* write PCI config */
+	NULL,			/* apply negotiated features */
+	NULL,			/* called on guest set status */
+};
+
+static void
+virtio_i2c_reset(void *vdev)
+{
+	struct virtio_i2c *vi2c = vdev;
+
+	DPRINTF("device reset requested !\n");
+	virtio_reset_dev(&vi2c->base);
+}
+
+static void
+virtio_i2c_notify(void *vdev, struct virtio_vq_info *vq)
+{
+	/* TODO: Add notify logic */
+}
+
+static int
+virtio_i2c_init(struct vmctx *ctx, struct pci_vdev *dev, char *opts)
+{
+	MD5_CTX mdctx;
+	u_char digest[16];
+	struct virtio_i2c *vi2c;
+	pthread_mutexattr_t attr;
+	int rc;
+
+	vi2c = calloc(1, sizeof(struct virtio_i2c));
+	if (!vi2c) {
+		WPRINTF("calloc returns NULL\n");
+		return -ENOMEM;
+	}
+
+	/* init mutex attribute properly to avoid deadlock */
+	rc = pthread_mutexattr_init(&attr);
+	if (rc) {
+		WPRINTF("mutexattr init failed with erro %d!\n", rc);
+		goto mtx_fail;
+	}
+	rc = pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
+	if (rc) {
+		WPRINTF("mutexattr_settype failed with "
+					"error %d!\n", rc);
+		goto mtx_fail;
+	}
+
+	rc = pthread_mutex_init(&vi2c->mtx, &attr);
+	if (rc) {
+		WPRINTF("pthread_mutex_init failed with "
+					"error %d!\n", rc);
+		goto mtx_fail;
+	}
+
+	/* init virtio struct and virtqueues */
+	virtio_linkup(&vi2c->base, &virtio_i2c_ops, vi2c, dev, &vi2c->vq, BACKEND_VBSU);
+	vi2c->base.mtx = &vi2c->mtx;
+	vi2c->vq.qsize = 64;
+
+	MD5_Init(&mdctx);
+	MD5_Update(&mdctx, "vi2c", strlen("vi2c"));
+	MD5_Final(digest, &mdctx);
+	rc = snprintf(vi2c->ident, sizeof(vi2c->ident),
+		"ACRN--%02X%02X-%02X%02X-%02X%02X", digest[0],
+		digest[1], digest[2], digest[3], digest[4],
+		digest[5]);
+	if (rc < 0) {
+		WPRINTF("create ident failed");
+		goto fail;
+	}
+	if (rc >= sizeof(vi2c->ident)) {
+		WPRINTF("ident too long\n");
+	}
+
+	pci_set_cfgdata16(dev, PCIR_DEVICE, VIRTIO_DEV_I2C);
+	pci_set_cfgdata16(dev, PCIR_VENDOR, INTEL_VENDOR_ID);
+	pci_set_cfgdata8(dev, PCIR_CLASS, PCIC_SERIALBUS);
+	pci_set_cfgdata16(dev, PCIR_SUBDEV_0, VIRTIO_TYPE_I2C);
+	pci_set_cfgdata16(dev, PCIR_SUBVEND_0, INTEL_VENDOR_ID);
+
+	if (virtio_interrupt_init(&vi2c->base, virtio_uses_msix())) {
+		WPRINTF("failed to init interrupt");
+		rc = -1;
+		goto fail;
+	}
+	virtio_set_io_bar(&vi2c->base, 0);
+	return 0;
+
+fail:
+	pthread_mutex_destroy(&vi2c->mtx);
+mtx_fail:
+	free(vi2c);
+	return rc;
+}
+
+static void
+virtio_i2c_deinit(struct vmctx *ctx, struct pci_vdev *dev, char *opts)
+{
+	struct virtio_i2c *vi2c;
+
+	if (dev->arg) {
+		DPRINTF("deinit\n");
+		vi2c = (struct virtio_i2c *) dev->arg;
+		pthread_mutex_destroy(&vi2c->mtx);
+		free(vi2c);
+		dev->arg = NULL;
+	}
+}
+
+struct pci_vdev_ops pci_ops_virtio_i2c = {
+	.class_name		= "virtio-i2c",
+	.vdev_init		= virtio_i2c_init,
+	.vdev_deinit		= virtio_i2c_deinit,
+	.vdev_barwrite		= virtio_pci_write,
+	.vdev_barread		= virtio_pci_read,
+};
+DEFINE_PCI_DEVTYPE(pci_ops_virtio_i2c);

devicemodel/include/virtio.h

@@ -207,6 +207,7 @@ enum {
 #define	VIRTIO_TYPE_HDCP	0xFFF9
 #define	VIRTIO_TYPE_COREU	0xFFF8
 #define	VIRTIO_TYPE_GPIO	0xFFF7
+#define	VIRTIO_TYPE_I2C		0xFFF6
 
 /*
  * PCI vendor/device IDs
@@ -230,6 +231,7 @@ enum {
 #define	VIRTIO_DEV_HDCP		0x8607
 #define	VIRTIO_DEV_COREU	0x8608
 #define	VIRTIO_DEV_GPIO		0x8609
+#define VIRTIO_DEV_I2C		0x860a
 
 /*
  * VIRTIO_CONFIG_S_NEEDS_RESET is not defined