[dpdk-dev] [PATCH v4 08/12] virtio, qtest: Add functionality to handle interrupt

[Tetsuya Mukawa]

The patch adds functionality to handle interrupt from pci device of
QEMU guest. To handle the interrupts, the patch adds to initialize piix3
pci device.

Signed-off-by: Tetsuya Mukawa <mukawa at igel.co.jp>
---
 drivers/net/virtio/qtest_utils.c | 225 ++++++++++++++++++++++++++++++++++++++-
 drivers/net/virtio/qtest_utils.h |  68 +++++++++++-
 2 files changed, 287 insertions(+), 6 deletions(-)

diff --git a/drivers/net/virtio/qtest_utils.c b/drivers/net/virtio/qtest_utils.c
index 338224a..337546a 100644
--- a/drivers/net/virtio/qtest_utils.c
+++ b/drivers/net/virtio/qtest_utils.c
@@ -36,6 +36,7 @@
 #include <sys/un.h>
 #include <pthread.h>
 #include <fcntl.h>
+#include <sys/eventfd.h>
 
 #include <rte_malloc.h>
 
@@ -43,6 +44,12 @@
 #include "virtio_ethdev.h"
 #include "qtest_utils.h"
 
+/* PIIX3 configuration registers */
+#define PIIX3_REG_ADDR_PIRQA            0x60
+#define PIIX3_REG_ADDR_PIRQB            0x61
+#define PIIX3_REG_ADDR_PIRQC            0x62
+#define PIIX3_REG_ADDR_PIRQD            0x63
+
 /* ivshmem configuration */
 #define IVSHMEM_PROTOCOL_VERSION        0
 
@@ -74,6 +81,14 @@ struct qtest_session {
 	size_t evq_total_len;
 
 	union qtest_pipefds msgfds;
+
+	int irqno;
+	pthread_t intr_th;
+	int intr_th_started;
+	int eventfd;
+	rte_atomic16_t enable_intr;
+	rte_intr_callback_fn cb;
+	void *cb_arg;
 };
 
 static int
@@ -230,6 +245,29 @@ qtest_pci_inb(struct qtest_session *s, uint8_t bus, uint8_t device,
 	return (tmp >> ((offset & 0x3) * 8)) & 0xff;
 }
 
+static void
+qtest_pci_outb(struct qtest_session *s, uint8_t bus, uint8_t device,
+		uint8_t function, uint8_t offset, uint8_t value)
+{
+	uint32_t addr, tmp, pos;
+
+	addr = PCI_CONFIG_ADDR(bus, device, function, offset);
+	pos = (offset % 4) * 8;
+
+	if (pthread_mutex_lock(&s->qtest_session_lock) < 0)
+		rte_panic("Cannot lock mutex\n");
+
+	qtest_raw_out(s, 0xcf8, addr, 'l');
+	tmp = qtest_raw_in(s, 0xcfc, 'l');
+	tmp = (tmp & ~(0xff << pos)) | (value << pos);
+
+	qtest_raw_out(s, 0xcf8, addr, 'l');
+	qtest_raw_out(s, 0xcfc, tmp, 'l');
+
+	if (pthread_mutex_unlock(&s->qtest_session_lock) < 0)
+		rte_panic("Cannot unlock mutex\n");
+}
+
 static uint32_t
 qtest_pci_inl(struct qtest_session *s, uint8_t bus, uint8_t device,
 		uint8_t function, uint8_t offset)
@@ -389,15 +427,112 @@ qtest_find_device(struct qtest_session *s, const char *name)
 	return NULL;
 }
 
+int
+qtest_intr_enable(struct qtest_session *s)
+{
+	rte_atomic16_set(&s->enable_intr, 1);
+
+	return 0;
+}
+
+int
+qtest_intr_disable(struct qtest_session *s)
+{
+	rte_atomic16_set(&s->enable_intr, 0);
+
+	return 0;
+}
+
+void
+qtest_intr_callback_register(struct qtest_session *s,
+		rte_intr_callback_fn cb, void *cb_arg)
+{
+	s->cb = cb;
+	s->cb_arg = cb_arg;
+	rte_atomic16_set(&s->enable_intr, 1);
+}
+
+void
+qtest_intr_callback_unregister(struct qtest_session *s,
+		rte_intr_callback_fn cb __rte_unused,
+		void *cb_arg __rte_unused)
+{
+	rte_atomic16_set(&s->enable_intr, 0);
+	s->cb = NULL;
+	s->cb_arg = NULL;
+}
+
+static void *
+qtest_intr_handler(void *data) {
+	struct qtest_session *s = (struct qtest_session *)data;
+	eventfd_t value;
+	int ret;
+
+	for (;;) {
+		ret = eventfd_read(s->eventfd, &value);
+		if (ret < 0)
+			return NULL;
+		s->cb(NULL, s->cb_arg);
+	}
+	return NULL;
+}
+
+static int
+qtest_intr_initialize(struct qtest_session *s)
+{
+	char buf[64];
+	int ret;
+
+	snprintf(buf, sizeof(buf), "irq_intercept_in ioapic\n");
+
+	if (pthread_mutex_lock(&s->qtest_session_lock) < 0)
+		rte_panic("Cannot lock mutex\n");
+
+	/* To enable interrupt, send "irq_intercept_in" message to QEMU */
+	ret = qtest_raw_send(s->qtest_socket, buf, strlen(buf));
+	if (ret < 0) {
+		pthread_mutex_unlock(&s->qtest_session_lock);
+		return -1;
+	}
+
+	/* just ignore QEMU response */
+	ret = qtest_raw_recv(s->msgfds.readfd, buf, sizeof(buf));
+	if (ret < 0) {
+		pthread_mutex_unlock(&s->qtest_session_lock);
+		return -1;
+	}
+
+	if (pthread_mutex_unlock(&s->qtest_session_lock) < 0)
+		rte_panic("Cannot lock mutex\n");
+
+	return 0;
+}
+
 static void
 qtest_event_send(struct qtest_session *s, char *buf)
 {
+	char interrupt_message[32];
 	int ret;
 
-	/* relay normal message to pipe */
-	ret = qtest_raw_send(s->msgfds.writefd, buf, strlen(buf));
-	if (ret < 0)
-		rte_panic("cannot relay normal message\n");
+	/* This message will come when interrupt occurs */
+	snprintf(interrupt_message, sizeof(interrupt_message),
+			"IRQ raise %d", s->irqno);
+
+	if (strncmp(buf, interrupt_message,
+				strlen(interrupt_message)) == 0) {
+		if (rte_atomic16_read(&s->enable_intr) == 0)
+			return;
+
+		/* relay interrupt to eventfd */
+		ret = eventfd_write(s->eventfd, 1);
+		if (ret < 0)
+			rte_panic("cannot relay interrupt\n");
+	} else {
+		/* relay normal message to pipe */
+		ret = qtest_raw_send(s->msgfds.writefd, buf, strlen(buf));
+		if (ret < 0)
+			rte_panic("cannot relay normal message\n");
+	}
 }
 
 static void
@@ -415,6 +550,7 @@ qtest_close_sockets(struct qtest_session *s)
 	qtest_close_one_socket(&s->qtest_socket);
 	qtest_close_one_socket(&s->msgfds.readfd);
 	qtest_close_one_socket(&s->msgfds.writefd);
+	qtest_close_one_socket(&s->eventfd);
 	qtest_close_one_socket(&s->ivshmem_socket);
 }
 
@@ -518,6 +654,57 @@ qtest_event_handler(void *data) {
 	return NULL;
 }
 
+/* This function should be fixed when multiple target devices are supported */
+int
+qtest_init_piix3_device(struct qtest_session *s, struct qtest_pci_device *dev)
+{
+	uint8_t bus, device, slot = 0;
+	struct qtest_pci_device *tmpdev;
+	uint8_t pcislot2regaddr[] = {	0xff,
+					0xff,
+					0xff,
+					PIIX3_REG_ADDR_PIRQC,
+					PIIX3_REG_ADDR_PIRQD,
+					PIIX3_REG_ADDR_PIRQA,
+					PIIX3_REG_ADDR_PIRQB};
+
+	bus = dev->bus_addr;
+	device = dev->device_addr;
+
+	PMD_DRV_LOG(INFO,
+		"Find %s on virtual PCI bus: %04x:%02x:00.0\n",
+		dev->name, bus, device);
+
+	/* Get slot id that is connected to target device(virtio-net device) */
+	TAILQ_FOREACH(tmpdev, &s->head, next) {
+		if (strcmp(tmpdev->name, "piix3") != 0 &&
+				strcmp(tmpdev->name, "ivshmem") != 0) {
+			slot = tmpdev->device_addr;
+			break;
+		}
+	}
+
+	if (slot == 0)
+		return -1;
+
+	/*
+	 * Set interrupt routing for target device.
+	 * Here is i440fx/piix3 connection settings
+	 * ---------------------------------------
+	 * PCI Slot3 -> PIRQC
+	 * PCI Slot4 -> PIRQD
+	 * PCI Slot5 -> PIRQA
+	 * PCI Slot6 -> PIRQB
+	 */
+	if (pcislot2regaddr[slot] != 0xff) {
+		qtest_pci_outb(s, bus, device, 0,
+				pcislot2regaddr[slot],
+				s->irqno);
+	}
+
+	return 0;
+}
+
 /*
  * Common initialization of PCI device.
  * To know detail, see pci specification.
@@ -855,6 +1042,12 @@ qtest_vdev_uninit(struct qtest_session *s)
 		s->event_th_started = 0;
 	}
 
+	if (s->intr_th_started) {
+		pthread_cancel(s->intr_th);
+		pthread_join(s->intr_th, NULL);
+		s->intr_th_started = 0;
+	}
+
 	pthread_mutex_destroy(&s->qtest_session_lock);
 	qtest_remove_target_devices(s);
 	rte_free(s);
@@ -862,7 +1055,7 @@ qtest_vdev_uninit(struct qtest_session *s)
 
 struct qtest_session *
 qtest_vdev_init(char *qtest_path, char *ivshmem_path,
-		struct qtest_pci_device *devices, int devnum)
+		int irqno, struct qtest_pci_device *devices, int devnum)
 {
 	struct qtest_session *s;
 	int ret;
@@ -886,12 +1079,21 @@ qtest_vdev_init(char *qtest_path, char *ivshmem_path,
 		goto error;
 	}
 
+	s->eventfd = eventfd(0, 0);
+	if (s->eventfd < 0) {
+		PMD_DRV_LOG(ERR, "Failed to open eventfd\n");
+		goto error;
+	}
+
 	ret = qtest_register_target_devices(s, devices, devnum);
 	if (ret != 0) {
 		PMD_DRV_LOG(ERR, "Failed to initialize qtest session\n");
 		goto error;
 	}
 
+	rte_atomic16_set(&s->enable_intr, 0);
+	s->irqno = irqno;
+
 	s->ivshmem_socket = qtest_open_socket(ivshmem_path);
 	if (s->ivshmem_socket < 0) {
 		PMD_DRV_LOG(ERR, "Failed to open %s\n", ivshmem_path);
@@ -911,6 +1113,19 @@ qtest_vdev_init(char *qtest_path, char *ivshmem_path,
 	}
 	s->event_th_started = 1;
 
+	ret = pthread_create(&s->intr_th, NULL, qtest_intr_handler, s);
+	if (ret != 0) {
+		PMD_DRV_LOG(ERR, "Failed to create interrupt handler\n");
+		goto error;
+	}
+	s->intr_th_started = 1;
+
+	ret = qtest_intr_initialize(s);
+	if (ret != 0) {
+		PMD_DRV_LOG(ERR, "Failed to initialize interrupt\n");
+		goto error;
+	}
+
 	ret = qtest_setup_shared_memory(s);
 	if (ret != 0) {
 		PMD_DRV_LOG(ERR, "Failed to setup shared memory\n");
diff --git a/drivers/net/virtio/qtest_utils.h b/drivers/net/virtio/qtest_utils.h
index 26994b1..0717ee9 100644
--- a/drivers/net/virtio/qtest_utils.h
+++ b/drivers/net/virtio/qtest_utils.h
@@ -134,6 +134,8 @@ struct qtest_pci_device {
  *   Path of qtest socket.
  * @param ivshmem_path
  *   Path of ivshmem socket.
+ * @param irqno
+ *   Interrupt number of the target device(virtio-net device).
  * @param devices
  *   Array of device information. It should contain piix3, ivshmem and target
  *   device(virtio-net device).
@@ -143,7 +145,7 @@ struct qtest_pci_device {
  *   The pointer to qtest session structure.
  */
 struct qtest_session *qtest_vdev_init(char *qtest_path, char *ivshmem_path,
-		struct qtest_pci_device *devices, int devnum);
+		int irqno, struct qtest_pci_device *devices, int devnum);
 
 /**
  * @internal
@@ -156,6 +158,56 @@ void qtest_vdev_uninit(struct qtest_session *s);
 
 /**
  * @internal
+ * Register interrupt callback.
+ *
+ * @param s
+ *   The pointer to qtest session structure.
+ * @param cb
+ *   The pointer to callback.
+ * @param cb_arg
+ *   The pointer to callback argument.
+ */
+void qtest_intr_callback_register(struct qtest_session *s,
+		rte_intr_callback_fn cb, void *cb_arg);
+
+/**
+ * @internal
+ * Unregister interrupt callback.
+ *
+ * @param s
+ *   The pointer to qtest session structure.
+ * @param cb
+ *   The pointer to callback.
+ * @param cb_arg
+ *   The pointer to callback argument.
+ */
+void qtest_intr_callback_unregister(struct qtest_session *s,
+		rte_intr_callback_fn cb, void *cb_arg);
+
+/**
+ * @internal
+ * Enable interrupt callback.
+ *
+ * @param s
+ *   The pointer to qtest session structure.
+ * @return
+ *   0 on success, negative on error
+ */
+int qtest_intr_enable(struct qtest_session *s);
+
+/**
+ * @internal
+ * Disable interrupt callback.
+ *
+ * @param s
+ *   The pointer to qtest session structure.
+ * @return
+ *   0 on success, negative on error
+ */
+int qtest_intr_disable(struct qtest_session *s);
+
+/**
+ * @internal
  * Read a port of QEMU guest.
  *
  * @param s
@@ -218,6 +270,20 @@ void qtest_write(struct qtest_session *s, uint64_t addr,
 
 /**
  * @internal
+ * Initialization function of piix3 device.
+ *
+ * @param s
+ *   The pointer to qtest session structure.
+ * @param dev
+ *   The pointer of pci device.
+ * @return
+ *   0 on success, negative on error
+ */
+int qtest_init_piix3_device(struct qtest_session *s,
+			struct qtest_pci_device *dev);
+
+/**
+ * @internal
  * Initialization function of general device.
  *
  * @param s
-- 
2.1.4