virtio/s390: make legacy support configurable
We may want to remove legacy virtio support in the future. In order
to prepare virtio-ccw for that, add an option to disable legacy
support there. This means raising the minimum transport revision
to 1.
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index a0e2130..787c237 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -938,6 +938,17 @@
Select this option if you want to run the kernel as a guest under
the KVM hypervisor.
+config VIRTIO_CCW_LEGACY
+ def_bool y
+ prompt "Support for legacy virtio-ccw devices"
+ depends on S390_GUEST
+ select VIRTIO_LEGACY
+ help
+ Enabling this option adds support for virtio-ccw paravirtual device
+ drivers with legacy support, i.e. it enables transitional a
+ transitional virtio-ccw driver.
+
+ If unsure, say Y.
endmenu
menu "Selftests"
diff --git a/drivers/s390/virtio/Makefile b/drivers/s390/virtio/Makefile
index 2dc4d9a..96dd684 100644
--- a/drivers/s390/virtio/Makefile
+++ b/drivers/s390/virtio/Makefile
@@ -4,3 +4,4 @@
# Copyright IBM Corp. 2008
obj-$(CONFIG_S390_GUEST) += virtio_ccw.o
+obj-$(CONFIG_VIRTIO_CCW_LEGACY) += virtio_ccw_legacy.o
diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c
index 06c57a3..b3ef176 100644
--- a/drivers/s390/virtio/virtio_ccw.c
+++ b/drivers/s390/virtio/virtio_ccw.c
@@ -11,11 +11,8 @@
#include <linux/init.h>
#include <linux/memblock.h>
#include <linux/err.h>
-#include <linux/virtio.h>
-#include <linux/virtio_config.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
-#include <linux/virtio_ring.h>
#include <linux/pfn.h>
#include <linux/async.h>
#include <linux/wait.h>
@@ -30,16 +27,16 @@
#include <asm/irq.h>
#include <asm/cio.h>
#include <asm/ccwdev.h>
-#include <asm/virtio-ccw.h>
#include <asm/isc.h>
#include <asm/airq.h>
+#include "virtio_ccw_common.h"
/*
* Provide a knob to turn off support for older revisions. This is useful
* if we want to act as a non-transitional virtio device driver: requiring
* a minimum revision of 1 turns off support for legacy devices.
*/
-static int min_revision;
+int min_revision = VIRTIO_CCW_REV_MIN;
module_param(min_revision, int, 0444);
MODULE_PARM_DESC(min_revision, "minimum transport revision to accept");
@@ -53,9 +50,6 @@
__u16 num;
} __packed;
-#define VIRTIO_CCW_CONFIG_SIZE 0x100
-/* same as PCI config space size, should be enough for all drivers */
-
struct vcdev_dma_area {
unsigned long indicators;
unsigned long indicators2;
@@ -63,25 +57,6 @@
__u8 status;
};
-struct virtio_ccw_device {
- struct virtio_device vdev;
- __u8 config[VIRTIO_CCW_CONFIG_SIZE];
- struct ccw_device *cdev;
- __u32 curr_io;
- int err;
- unsigned int revision; /* Transport revision */
- wait_queue_head_t wait_q;
- spinlock_t lock;
- struct mutex io_lock; /* Serializes I/O requests */
- struct list_head virtqueues;
- bool is_thinint;
- bool going_away;
- bool device_lost;
- unsigned int config_ready;
- void *airq_info;
- struct vcdev_dma_area *dma_area;
-};
-
static inline unsigned long *indicators(struct virtio_ccw_device *vcdev)
{
return &vcdev->dma_area->indicators;
@@ -92,13 +67,6 @@
return &vcdev->dma_area->indicators2;
}
-struct vq_info_block_legacy {
- __u64 queue;
- __u32 align;
- __u16 index;
- __u16 num;
-} __packed;
-
struct vq_info_block {
__u64 desc;
__u32 res0;
@@ -129,18 +97,6 @@
/* the highest virtio-ccw revision we support */
#define VIRTIO_CCW_REV_MAX 2
-struct virtio_ccw_vq_info {
- struct virtqueue *vq;
- int num;
- union {
- struct vq_info_block s;
- struct vq_info_block_legacy l;
- } *info_block;
- int bit_nr;
- struct list_head node;
- long cookie;
-};
-
#define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
#define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
@@ -164,40 +120,6 @@
return summary_indicators + info->summary_indicator_idx;
}
-#define CCW_CMD_SET_VQ 0x13
-#define CCW_CMD_VDEV_RESET 0x33
-#define CCW_CMD_SET_IND 0x43
-#define CCW_CMD_SET_CONF_IND 0x53
-#define CCW_CMD_READ_FEAT 0x12
-#define CCW_CMD_WRITE_FEAT 0x11
-#define CCW_CMD_READ_CONF 0x22
-#define CCW_CMD_WRITE_CONF 0x21
-#define CCW_CMD_WRITE_STATUS 0x31
-#define CCW_CMD_READ_VQ_CONF 0x32
-#define CCW_CMD_READ_STATUS 0x72
-#define CCW_CMD_SET_IND_ADAPTER 0x73
-#define CCW_CMD_SET_VIRTIO_REV 0x83
-
-#define VIRTIO_CCW_DOING_SET_VQ 0x00010000
-#define VIRTIO_CCW_DOING_RESET 0x00040000
-#define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
-#define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
-#define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
-#define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
-#define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
-#define VIRTIO_CCW_DOING_SET_IND 0x01000000
-#define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
-#define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
-#define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
-#define VIRTIO_CCW_DOING_SET_VIRTIO_REV 0x10000000
-#define VIRTIO_CCW_DOING_READ_STATUS 0x20000000
-#define VIRTIO_CCW_INTPARM_MASK 0xffff0000
-
-static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
-{
- return container_of(vdev, struct virtio_ccw_device, vdev);
-}
-
static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
{
unsigned long i, flags;
@@ -327,8 +249,8 @@
return ret;
}
-static int ccw_io_helper(struct virtio_ccw_device *vcdev,
- struct ccw1 *ccw, __u32 intparm)
+int ccw_io_helper(struct virtio_ccw_device *vcdev,
+ struct ccw1 *ccw, __u32 intparm)
{
int ret;
unsigned long flags;
@@ -398,7 +320,7 @@
ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
}
-static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
+bool virtio_ccw_kvm_notify(struct virtqueue *vq)
{
struct virtio_ccw_vq_info *info = vq->priv;
struct virtio_ccw_device *vcdev;
@@ -415,8 +337,8 @@
return true;
}
-static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
- struct ccw1 *ccw, int index)
+int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
+ struct ccw1 *ccw, int index)
{
int ret;
@@ -435,30 +357,29 @@
{
struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
struct virtio_ccw_vq_info *info = vq->priv;
+ struct vq_info_block *info_block;
unsigned long flags;
int ret;
unsigned int index = vq->index;
+ if (vcdev->revision == 0) {
+ virtio_ccw_del_vq_legacy(vq, ccw);
+ return;
+ }
+
/* Remove from our list. */
spin_lock_irqsave(&vcdev->lock, flags);
list_del(&info->node);
spin_unlock_irqrestore(&vcdev->lock, flags);
/* Release from host. */
- if (vcdev->revision == 0) {
- info->info_block->l.queue = 0;
- info->info_block->l.align = 0;
- info->info_block->l.index = index;
- info->info_block->l.num = 0;
- ccw->count = sizeof(info->info_block->l);
- } else {
- info->info_block->s.desc = 0;
- info->info_block->s.index = index;
- info->info_block->s.num = 0;
- info->info_block->s.avail = 0;
- info->info_block->s.used = 0;
- ccw->count = sizeof(info->info_block->s);
- }
+ info_block = info->info_block;
+ info_block->desc = 0;
+ info_block->index = index;
+ info_block->num = 0;
+ info_block->avail = 0;
+ info_block->used = 0;
+ ccw->count = sizeof(*info_block);
ccw->cmd_code = CCW_CMD_SET_VQ;
ccw->flags = 0;
ccw->cda = (__u32)(unsigned long)(info->info_block);
@@ -474,7 +395,7 @@
vring_del_virtqueue(vq);
ccw_device_dma_free(vcdev->cdev, info->info_block,
- sizeof(*info->info_block));
+ sizeof(*info_block));
kfree(info);
}
@@ -505,9 +426,13 @@
int err;
struct virtqueue *vq = NULL;
struct virtio_ccw_vq_info *info;
+ struct vq_info_block *info_block;
u64 queue;
unsigned long flags;
- bool may_reduce;
+
+ if (vcdev->revision == 0)
+ return virtio_ccw_setup_vq_legacy(vdev, i, callback, name,
+ ctx, ccw);
/* Allocate queue. */
info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
@@ -517,7 +442,7 @@
goto out_err;
}
info->info_block = ccw_device_dma_zalloc(vcdev->cdev,
- sizeof(*info->info_block));
+ sizeof(struct vq_info_block));
if (!info->info_block) {
dev_warn(&vcdev->cdev->dev, "no info block\n");
err = -ENOMEM;
@@ -528,9 +453,8 @@
err = info->num;
goto out_err;
}
- may_reduce = vcdev->revision > 0;
vq = vring_create_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN,
- vdev, true, may_reduce, ctx,
+ vdev, true, true, ctx,
virtio_ccw_kvm_notify, callback, name);
if (!vq) {
@@ -544,20 +468,13 @@
/* Register it with the host. */
queue = virtqueue_get_desc_addr(vq);
- if (vcdev->revision == 0) {
- info->info_block->l.queue = queue;
- info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
- info->info_block->l.index = i;
- info->info_block->l.num = info->num;
- ccw->count = sizeof(info->info_block->l);
- } else {
- info->info_block->s.desc = queue;
- info->info_block->s.index = i;
- info->info_block->s.num = info->num;
- info->info_block->s.avail = (__u64)virtqueue_get_avail_addr(vq);
- info->info_block->s.used = (__u64)virtqueue_get_used_addr(vq);
- ccw->count = sizeof(info->info_block->s);
- }
+ info_block = info->info_block;
+ info_block->desc = queue;
+ info_block->index = i;
+ info_block->num = info->num;
+ info_block->avail = (__u64)virtqueue_get_avail_addr(vq);
+ info_block->used = (__u64)virtqueue_get_used_addr(vq);
+ ccw->count = sizeof(*info_block);
ccw->cmd_code = CCW_CMD_SET_VQ;
ccw->flags = 0;
ccw->cda = (__u32)(unsigned long)(info->info_block);
@@ -582,7 +499,7 @@
vring_del_virtqueue(vq);
if (info) {
ccw_device_dma_free(vcdev->cdev, info->info_block,
- sizeof(*info->info_block));
+ sizeof(*info_block));
}
kfree(info);
return ERR_PTR(err);
@@ -1249,6 +1166,7 @@
ret = ccw_io_helper(vcdev, ccw,
VIRTIO_CCW_DOING_SET_VIRTIO_REV);
if (ret == -EOPNOTSUPP) {
+#ifdef CONFIG_VIRTIO_CCW_LEGACY
if (vcdev->revision == 0)
/*
* The host device does not support setting
@@ -1257,6 +1175,7 @@
*/
ret = 0;
else
+#endif
vcdev->revision--;
}
} while (vcdev->revision >= min_revision && ret == -EOPNOTSUPP);
@@ -1475,6 +1394,9 @@
{
int rc;
+ if (min_revision < VIRTIO_CCW_REV_MIN)
+ min_revision = VIRTIO_CCW_REV_MIN;
+
/* parse no_auto string before we do anything further */
no_auto_parse();
diff --git a/drivers/s390/virtio/virtio_ccw_common.h b/drivers/s390/virtio/virtio_ccw_common.h
new file mode 100644
index 0000000..6c6c9e9a
--- /dev/null
+++ b/drivers/s390/virtio/virtio_ccw_common.h
@@ -0,0 +1,113 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * common definitions for the ccw based virtio transport
+ *
+ * Copyright IBM Corp. 2012, 2014
+ * Copyright Red Hat, Inc. 2021
+ *
+ * Author(s): Cornelia Huck <cohuck@redhat.com>
+ */
+
+#include <linux/virtio.h>
+#include <linux/virtio_config.h>
+#include <linux/virtio_ring.h>
+#include <asm/cio.h>
+#include <asm/virtio-ccw.h>
+
+#ifdef CONFIG_VIRTIO_CCW_LEGACY
+#define VIRTIO_CCW_REV_MIN 0
+void virtio_ccw_del_vq_legacy(struct virtqueue *vq, struct ccw1 *ccw);
+struct virtqueue *virtio_ccw_setup_vq_legacy(struct virtio_device *vdev,
+ int i, vq_callback_t *callback,
+ const char *name, bool ctx,
+ struct ccw1 *ccw);
+#else
+#define VIRTIO_CCW_REV_MIN 1
+static inline void virtio_ccw_del_vq_legacy(struct virtqueue *vq,
+ struct ccw1 *ccw)
+{
+}
+static inline struct virtqueue *
+virtio_ccw_setup_vq_legacy(struct virtio_device *vdev,
+ int i, vq_callback_t *callback,
+ const char *name, bool ctx,
+ struct ccw1 *ccw)
+{
+ return ERR_PTR(-EINVAL);
+}
+#endif
+
+extern int min_revision;
+
+struct virtio_ccw_vq_info {
+ struct virtqueue *vq;
+ int num;
+ void *info_block;
+ int bit_nr;
+ struct list_head node;
+ long cookie;
+};
+
+#define CCW_CMD_SET_VQ 0x13
+#define CCW_CMD_VDEV_RESET 0x33
+#define CCW_CMD_SET_IND 0x43
+#define CCW_CMD_SET_CONF_IND 0x53
+#define CCW_CMD_READ_FEAT 0x12
+#define CCW_CMD_WRITE_FEAT 0x11
+#define CCW_CMD_READ_CONF 0x22
+#define CCW_CMD_WRITE_CONF 0x21
+#define CCW_CMD_WRITE_STATUS 0x31
+#define CCW_CMD_READ_VQ_CONF 0x32
+#define CCW_CMD_READ_STATUS 0x72
+#define CCW_CMD_SET_IND_ADAPTER 0x73
+#define CCW_CMD_SET_VIRTIO_REV 0x83
+
+#define VIRTIO_CCW_DOING_SET_VQ 0x00010000
+#define VIRTIO_CCW_DOING_RESET 0x00040000
+#define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
+#define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
+#define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
+#define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
+#define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
+#define VIRTIO_CCW_DOING_SET_IND 0x01000000
+#define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
+#define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
+#define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
+#define VIRTIO_CCW_DOING_SET_VIRTIO_REV 0x10000000
+#define VIRTIO_CCW_DOING_READ_STATUS 0x20000000
+#define VIRTIO_CCW_INTPARM_MASK 0xffff0000
+
+#define VIRTIO_CCW_CONFIG_SIZE 0x100
+/* same as PCI config space size, should be enough for all drivers */
+
+struct virtio_ccw_device {
+ struct virtio_device vdev;
+ __u8 config[VIRTIO_CCW_CONFIG_SIZE];
+ struct ccw_device *cdev;
+ __u32 curr_io;
+ int err;
+ unsigned int revision; /* Transport revision */
+ wait_queue_head_t wait_q;
+ spinlock_t lock;
+ struct mutex io_lock; /* Serializes I/O requests */
+ struct list_head virtqueues;
+ bool is_thinint;
+ bool going_away;
+ bool device_lost;
+ unsigned int config_ready;
+ void *airq_info;
+ struct vcdev_dma_area *dma_area;
+};
+
+static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
+{
+ return container_of(vdev, struct virtio_ccw_device, vdev);
+}
+
+int ccw_io_helper(struct virtio_ccw_device *vcdev,
+ struct ccw1 *ccw, __u32 intparm);
+
+int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
+ struct ccw1 *ccw, int index);
+
+bool virtio_ccw_kvm_notify(struct virtqueue *vq);
diff --git a/drivers/s390/virtio/virtio_ccw_legacy.c b/drivers/s390/virtio/virtio_ccw_legacy.c
new file mode 100644
index 0000000..bc9ae10
--- /dev/null
+++ b/drivers/s390/virtio/virtio_ccw_legacy.c
@@ -0,0 +1,139 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ccw based virtio transport -- legacy support
+ *
+ * Copyright IBM Corp. 2012, 2014
+ * Copyright Red Hat, Inc. 2021
+ *
+ * Author(s): Cornelia Huck <cohuck@redhat.com>
+ */
+
+#include <linux/slab.h>
+#include <asm/ccwdev.h>
+#include "virtio_ccw_common.h"
+
+struct vq_info_block_legacy {
+ __u64 queue;
+ __u32 align;
+ __u16 index;
+ __u16 num;
+} __packed;
+
+
+void virtio_ccw_del_vq_legacy(struct virtqueue *vq, struct ccw1 *ccw)
+{
+ struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
+ struct virtio_ccw_vq_info *info = vq->priv;
+ struct vq_info_block_legacy *info_block;
+ unsigned long flags;
+ int ret;
+ unsigned int index = vq->index;
+
+ /* Remove from our list. */
+ spin_lock_irqsave(&vcdev->lock, flags);
+ list_del(&info->node);
+ spin_unlock_irqrestore(&vcdev->lock, flags);
+
+ /* Release from host. */
+ info_block = info->info_block;
+ info_block->queue = 0;
+ info_block->align = 0;
+ info_block->index = index;
+ info_block->num = 0;
+ ccw->count = sizeof(*info_block);
+ ccw->cmd_code = CCW_CMD_SET_VQ;
+ ccw->flags = 0;
+ ccw->cda = (__u32)(unsigned long)(info->info_block);
+ ret = ccw_io_helper(vcdev, ccw,
+ VIRTIO_CCW_DOING_SET_VQ | index);
+ /*
+ * -ENODEV isn't considered an error: The device is gone anyway.
+ * This may happen on device detach.
+ */
+ if (ret && (ret != -ENODEV))
+ dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d\n",
+ ret, index);
+
+ vring_del_virtqueue(vq);
+ ccw_device_dma_free(vcdev->cdev, info->info_block,
+ sizeof(*info_block));
+ kfree(info);
+}
+
+struct virtqueue *virtio_ccw_setup_vq_legacy(struct virtio_device *vdev,
+ int i, vq_callback_t *callback,
+ const char *name, bool ctx,
+ struct ccw1 *ccw)
+{
+ struct virtio_ccw_device *vcdev = to_vc_device(vdev);
+ int err;
+ struct virtqueue *vq = NULL;
+ struct virtio_ccw_vq_info *info;
+ struct vq_info_block_legacy *info_block;
+ u64 queue;
+ unsigned long flags;
+
+ /* Allocate queue. */
+ info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
+ if (!info) {
+ err = -ENOMEM;
+ goto out_err;
+ }
+ info->info_block = ccw_device_dma_zalloc(vcdev->cdev,
+ sizeof(struct vq_info_block_legacy));
+ if (!info->info_block) {
+ dev_warn(&vcdev->cdev->dev, "no info block\n");
+ err = -ENOMEM;
+ goto out_err;
+ }
+ info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
+ if (info->num < 0) {
+ err = info->num;
+ goto out_err;
+ }
+ vq = vring_create_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN,
+ vdev, true, false, ctx,
+ virtio_ccw_kvm_notify, callback, name);
+
+ if (!vq) {
+ dev_warn(&vcdev->cdev->dev, "no vq\n");
+ err = -ENOMEM;
+ goto out_err;
+ }
+
+ /* Register it with the host. */
+ queue = virtqueue_get_desc_addr(vq);
+ info_block->queue = queue;
+ info_block->align = KVM_VIRTIO_CCW_RING_ALIGN;
+ info_block->index = i;
+ info_block->num = info->num;
+ ccw->count = sizeof(*info_block);
+ ccw->cmd_code = CCW_CMD_SET_VQ;
+ ccw->flags = 0;
+ ccw->cda = (__u32)(unsigned long)(info->info_block);
+ err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
+ if (err) {
+ dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
+ goto out_err;
+ }
+
+ info->vq = vq;
+ vq->priv = info;
+
+ /* Save it to our list. */
+ spin_lock_irqsave(&vcdev->lock, flags);
+ list_add(&info->node, &vcdev->virtqueues);
+ spin_unlock_irqrestore(&vcdev->lock, flags);
+
+ return vq;
+
+out_err:
+ if (vq)
+ vring_del_virtqueue(vq);
+ if (info) {
+ ccw_device_dma_free(vcdev->cdev, info->info_block,
+ sizeof(*info_block));
+ }
+ kfree(info);
+ return ERR_PTR(err);
+}
diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index ce1b3f6..481ec3a 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -26,6 +26,13 @@
if VIRTIO_MENU
+config VIRTIO_LEGACY
+ def_bool y
+ help
+ This option selects base support for legacy virtio devices prior
+ to the virtio standard, such as those in the Virtio PCI Card
+ 0.9.X Draft and older.
+
config VIRTIO_PCI
tristate "PCI driver for virtio devices"
depends on PCI
@@ -43,6 +50,7 @@
bool "Support for legacy virtio draft 0.9.X and older devices"
default y
depends on VIRTIO_PCI
+ select VIRTIO_LEGACY
help
Virtio PCI Card 0.9.X Draft (circa 2014) and older device support.
