[4/5] KVM: s390: Add a channel I/O based virtio transport driver.

Message ID	1351516046-30037-5-git-send-email-cornelia.huck@de.ibm.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <kvm-owner@vger.kernel.org> Gateway: Authorized Use Only! Violators will be prosecuted for <kvm@vger.kernel.org> from <cornelia.huck@de.ibm.com>; Mon, 29 Oct 2012 13:07:32 -0000 Gateway: Authorized Use Only! Violators will be prosecuted; Mon, 29 Oct 2012 13:07:30 -0000 From: Cornelia Huck <cornelia.huck@de.ibm.com> To: Avi Kivity <avi@redhat.com>, Marcelo Tosatti <mtosatti@redhat.com> Cc: KVM <kvm@vger.kernel.org>, linux-s390 <linux-s390@vger.kernel.org>, Christian Borntraeger <borntraeger@de.ibm.com>, Carsten Otte <cotte@de.ibm.com>, Alexander Graf <agraf@suse.de>, Heiko Carstens <heiko.carstens@de.ibm.com>, Martin Schwidefsky <schwidefsky@de.ibm.com>, Sebastian Ott <sebott@linux.vnet.ibm.com> Subject: [PATCH 4/5] KVM: s390: Add a channel I/O based virtio transport driver. Date: Mon, 29 Oct 2012 14:07:25 +0100 Message-Id: <1351516046-30037-5-git-send-email-cornelia.huck@de.ibm.com> In-Reply-To: <1351516046-30037-1-git-send-email-cornelia.huck@de.ibm.com> References: <1351516046-30037-1-git-send-email-cornelia.huck@de.ibm.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk

On 29.10.2012, at 14:07, Cornelia Huck wrote: > Add a driver for kvm guests that matches virtual ccw devices provided > by the host as virtio bridge devices. > > These virtio-ccw devices use a special set of channel commands in order > to perform virtio functions. > > Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> > --- > arch/s390/include/asm/irq.h | 1 + > arch/s390/kernel/irq.c | 1 + > drivers/s390/kvm/Makefile | 2 +- > drivers/s390/kvm/virtio_ccw.c | 842 ++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 845 insertions(+), 1 deletion(-) > create mode 100644 drivers/s390/kvm/virtio_ccw.c > > diff --git a/arch/s390/include/asm/irq.h b/arch/s390/include/asm/irq.h > index 6703dd9..ad2ad6b 100644 > --- a/arch/s390/include/asm/irq.h > +++ b/arch/s390/include/asm/irq.h > @@ -33,6 +33,7 @@ enum interruption_class { > IOINT_APB, > IOINT_ADM, > IOINT_CSC, > + IOINT_VIR, > NMI_NMI, > NR_IRQS, > }; > diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c > index 6cdc55b..97c171a 100644 > --- a/arch/s390/kernel/irq.c > +++ b/arch/s390/kernel/irq.c > @@ -58,6 +58,7 @@ static const struct irq_class intrclass_names[] = { > [IOINT_APB] = {.name = "APB", .desc = "[I/O] AP Bus"}, > [IOINT_ADM] = {.name = "ADM", .desc = "[I/O] EADM Subchannel"}, > [IOINT_CSC] = {.name = "CSC", .desc = "[I/O] CHSC Subchannel"}, > + [IOINT_VIR] = {.name = "VIR", .desc = "[I/O] Virtual I/O Devices"}, > [NMI_NMI] = {.name = "NMI", .desc = "[NMI] Machine Check"}, > }; > > diff --git a/drivers/s390/kvm/Makefile b/drivers/s390/kvm/Makefile > index 0815690..241891a 100644 > --- a/drivers/s390/kvm/Makefile > +++ b/drivers/s390/kvm/Makefile > @@ -6,4 +6,4 @@ > # it under the terms of the GNU General Public License (version 2 only) > # as published by the Free Software Foundation. > > -obj-$(CONFIG_S390_GUEST) += kvm_virtio.o > +obj-$(CONFIG_S390_GUEST) += kvm_virtio.o virtio_ccw.o > diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c > new file mode 100644 > index 0000000..4be878f > --- /dev/null > +++ b/drivers/s390/kvm/virtio_ccw.c > @@ -0,0 +1,842 @@ > +/* > + * ccw based virtio transport > + * > + * Copyright IBM Corp. 2012 > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License (version 2 only) > + * as published by the Free Software Foundation. > + * > + * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com> > + */ > + > +#include <linux/kernel_stat.h> > +#include <linux/init.h> > +#include <linux/bootmem.h> > +#include <linux/err.h> > +#include <linux/virtio.h> > +#include <linux/virtio_config.h> > +#include <linux/slab.h> > +#include <linux/virtio_console.h> > +#include <linux/interrupt.h> > +#include <linux/virtio_ring.h> > +#include <linux/pfn.h> > +#include <linux/async.h> > +#include <linux/wait.h> > +#include <linux/list.h> > +#include <linux/bitops.h> > +#include <linux/module.h> > +#include <asm/io.h> > +#include <asm/kvm_para.h> > +#include <asm/setup.h> > +#include <asm/irq.h> > +#include <asm/cio.h> > +#include <asm/ccwdev.h> > +#include <asm/schid.h> > + > +/* > + * virtio related functions > + */ > + > +struct vq_config_block { > + __u16 index; > + __u16 num; > +} __attribute__ ((packed)); > + > +#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 status; > + __u8 config[VIRTIO_CCW_CONFIG_SIZE]; > + struct ccw_device *cdev; > + struct ccw1 *ccw; > + __u32 area; > + __u32 curr_io; > + int err; > + wait_queue_head_t wait_q; > + spinlock_t lock; > + struct list_head virtqueues; > + unsigned long indicators; > + unsigned long indicators2; > + struct vq_config_block *config_block; > +}; > + > +struct vq_info_block { > + __u64 queue; > + __u32 align; > + __u16 index; > + __u16 num; > +} __attribute__ ((packed)); > + > +struct virtio_feature_desc { > + __u32 features; > + __u8 index; > +} __attribute__ ((packed)); > + > +struct virtio_ccw_vq_info { > + struct virtqueue *vq; > + int num; > + int queue_index; > + void *queue; > + struct vq_info_block *info_block; > + struct list_head node; > +}; > + > +#define KVM_VIRTIO_CCW_RING_ALIGN 4096 > + > +#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 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_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 int doing_io(struct virtio_ccw_device *vcdev, __u32 flag) > +{ > + unsigned long flags; > + __u32 ret; > + > + spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags); > + if (vcdev->err) > + ret = 0; > + else > + ret = vcdev->curr_io & flag; > + spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags); > + return ret; > +} > + > +static int ccw_io_helper(struct virtio_ccw_device *vcdev, __u32 intparm) > +{ > + int ret; > + unsigned long flags; > + int flag = intparm & VIRTIO_CCW_INTPARM_MASK; > + > + spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags); > + ret = ccw_device_start(vcdev->cdev, vcdev->ccw, intparm, 0, 0); > + if (!ret) > + vcdev->curr_io |= flag; > + spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags); > + wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0); > + return ret ? ret : vcdev->err; > +} > + > +static void virtio_ccw_kvm_notify(struct virtqueue *vq) > +{ > + struct virtio_ccw_vq_info *info = vq->priv; > + struct virtio_ccw_device *vcdev; > + struct subchannel_id schid; > + __u32 reg2; > + > + vcdev = to_vc_device(info->vq->vdev); > + ccw_device_get_schid(vcdev->cdev, &schid); > + reg2 = *(__u32 *)&schid; That cast looks quite ugly. Can't you just access the field in there you need? Or if it's multiple fields do a union over them? Or assemble them by hand in C? > + kvm_hypercall2(3 /* CCW_NOTIFY */, reg2, info->queue_index); This wants to be a #define :) > +} > + > +static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev, int index) > +{ > + vcdev->config_block->index = index; > + vcdev->ccw->cmd_code = CCW_CMD_READ_VQ_CONF; > + vcdev->ccw->flags = 0; > + vcdev->ccw->count = sizeof(struct vq_config_block); > + vcdev->ccw->cda = (__u32)(unsigned long)(vcdev->config_block); Is this casting a pointer to a u32? What if this is in highmem? Ah, I just saw the comment that ccw memory needs to be <2GB. Phew. Any plans to get rid of that limitation? Alex -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html

diff --git a/arch/s390/include/asm/irq.h b/arch/s390/include/asm/irq.h index 6703dd9..ad2ad6b 100644 --- a/arch/s390/include/asm/irq.h +++ b/arch/s390/include/asm/irq.h @@ -33,6 +33,7 @@ enum interruption_class { IOINT_APB, IOINT_ADM, IOINT_CSC, + IOINT_VIR, NMI_NMI, NR_IRQS, }; diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c index 6cdc55b..97c171a 100644 --- a/arch/s390/kernel/irq.c +++ b/arch/s390/kernel/irq.c @@ -58,6 +58,7 @@ static const struct irq_class intrclass_names[] = { [IOINT_APB] = {.name = "APB", .desc = "[I/O] AP Bus"}, [IOINT_ADM] = {.name = "ADM", .desc = "[I/O] EADM Subchannel"}, [IOINT_CSC] = {.name = "CSC", .desc = "[I/O] CHSC Subchannel"}, + [IOINT_VIR] = {.name = "VIR", .desc = "[I/O] Virtual I/O Devices"}, [NMI_NMI] = {.name = "NMI", .desc = "[NMI] Machine Check"}, }; diff --git a/drivers/s390/kvm/Makefile b/drivers/s390/kvm/Makefile index 0815690..241891a 100644 --- a/drivers/s390/kvm/Makefile +++ b/drivers/s390/kvm/Makefile @@ -6,4 +6,4 @@ # it under the terms of the GNU General Public License (version 2 only) # as published by the Free Software Foundation. -obj-$(CONFIG_S390_GUEST) += kvm_virtio.o +obj-$(CONFIG_S390_GUEST) += kvm_virtio.o virtio_ccw.o diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c new file mode 100644 index 0000000..4be878f --- /dev/null +++ b/drivers/s390/kvm/virtio_ccw.c @@ -0,0 +1,842 @@ +/* + * ccw based virtio transport + * + * Copyright IBM Corp. 2012 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License (version 2 only) + * as published by the Free Software Foundation. + * + * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com> + */ + +#include <linux/kernel_stat.h> +#include <linux/init.h> +#include <linux/bootmem.h> +#include <linux/err.h> +#include <linux/virtio.h> +#include <linux/virtio_config.h> +#include <linux/slab.h> +#include <linux/virtio_console.h> +#include <linux/interrupt.h> +#include <linux/virtio_ring.h> +#include <linux/pfn.h> +#include <linux/async.h> +#include <linux/wait.h> +#include <linux/list.h> +#include <linux/bitops.h> +#include <linux/module.h> +#include <asm/io.h> +#include <asm/kvm_para.h> +#include <asm/setup.h> +#include <asm/irq.h> +#include <asm/cio.h> +#include <asm/ccwdev.h> +#include <asm/schid.h> + +/* + * virtio related functions + */ + +struct vq_config_block { + __u16 index; + __u16 num; +} __attribute__ ((packed)); + +#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 status; + __u8 config[VIRTIO_CCW_CONFIG_SIZE]; + struct ccw_device *cdev; + struct ccw1 *ccw; + __u32 area; + __u32 curr_io; + int err; + wait_queue_head_t wait_q; + spinlock_t lock; + struct list_head virtqueues; + unsigned long indicators; + unsigned long indicators2; + struct vq_config_block *config_block; +}; + +struct vq_info_block { + __u64 queue; + __u32 align; + __u16 index; + __u16 num; +} __attribute__ ((packed)); + +struct virtio_feature_desc { + __u32 features; + __u8 index; +} __attribute__ ((packed)); + +struct virtio_ccw_vq_info { + struct virtqueue *vq; + int num; + int queue_index; + void *queue; + struct vq_info_block *info_block; + struct list_head node; +}; + +#define KVM_VIRTIO_CCW_RING_ALIGN 4096 + +#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 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_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 int doing_io(struct virtio_ccw_device *vcdev, __u32 flag) +{ + unsigned long flags; + __u32 ret; + + spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags); + if (vcdev->err) + ret = 0; + else + ret = vcdev->curr_io & flag; + spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags); + return ret; +} + +static int ccw_io_helper(struct virtio_ccw_device *vcdev, __u32 intparm) +{ + int ret; + unsigned long flags; + int flag = intparm & VIRTIO_CCW_INTPARM_MASK; + + spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags); + ret = ccw_device_start(vcdev->cdev, vcdev->ccw, intparm, 0, 0); + if (!ret) + vcdev->curr_io |= flag; + spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags); + wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0); + return ret ? ret : vcdev->err; +} + +static void virtio_ccw_kvm_notify(struct virtqueue *vq) +{ + struct virtio_ccw_vq_info *info = vq->priv; + struct virtio_ccw_device *vcdev; + struct subchannel_id schid; + __u32 reg2; + + vcdev = to_vc_device(info->vq->vdev); + ccw_device_get_schid(vcdev->cdev, &schid); + reg2 = *(__u32 *)&schid; + kvm_hypercall2(3 /* CCW_NOTIFY */, reg2, info->queue_index); +} + +static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev, int index) +{ + vcdev->config_block->index = index; + vcdev->ccw->cmd_code = CCW_CMD_READ_VQ_CONF; + vcdev->ccw->flags = 0; + vcdev->ccw->count = sizeof(struct vq_config_block); + vcdev->ccw->cda = (__u32)(unsigned long)(vcdev->config_block); + ccw_io_helper(vcdev, VIRTIO_CCW_DOING_READ_VQ_CONF); + return vcdev->config_block->num; +} + +static void virtio_ccw_del_vq(struct virtqueue *vq) +{ + struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev); + struct virtio_ccw_vq_info *info = vq->priv; + unsigned long flags; + unsigned long size; + int ret; + + /* Remove from our list. */ + spin_lock_irqsave(&vcdev->lock, flags); + list_del(&info->node); + spin_unlock_irqrestore(&vcdev->lock, flags); + + /* Release from host. */ + info->info_block->queue = 0; + info->info_block->align = 0; + info->info_block->index = info->queue_index; + info->info_block->num = 0; + vcdev->ccw->cmd_code = CCW_CMD_SET_VQ; + vcdev->ccw->flags = 0; + vcdev->ccw->count = sizeof(*info->info_block); + vcdev->ccw->cda = (__u32)(unsigned long)(info->info_block); + ret = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_SET_VQ | info->queue_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", + ret, info->queue_index); + + vring_del_virtqueue(vq); + size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN)); + free_pages_exact(info->queue, size); + kfree(info->info_block); + kfree(info); +} + +static void virtio_ccw_del_vqs(struct virtio_device *vdev) +{ + struct virtqueue *vq, *n; + + list_for_each_entry_safe(vq, n, &vdev->vqs, list) + virtio_ccw_del_vq(vq); +} + +static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev, + int i, vq_callback_t *callback, + const char *name) +{ + struct virtio_ccw_device *vcdev = to_vc_device(vdev); + int err; + struct virtqueue *vq; + struct virtio_ccw_vq_info *info; + unsigned long size; + unsigned long flags; + + /* Allocate queue. */ + info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL); + if (!info) { + dev_warn(&vcdev->cdev->dev, "no info\n"); + err = -ENOMEM; + goto out_err; + } + info->info_block = kzalloc(sizeof(*info->info_block), + GFP_DMA | GFP_KERNEL); + if (!info->info_block) { + dev_warn(&vcdev->cdev->dev, "no info block\n"); + err = -ENOMEM; + goto out_err; + } + info->queue_index = i; + info->num = virtio_ccw_read_vq_conf(vcdev, i); + size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN)); + info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO); + if (info->queue == NULL) { + dev_warn(&vcdev->cdev->dev, "no queue\n"); + err = -ENOMEM; + goto out_err; + } + + vq = vring_new_virtqueue(info->num, KVM_VIRTIO_CCW_RING_ALIGN, vdev, + true, info->queue, virtio_ccw_kvm_notify, + callback, name); + if (!vq) { + /* For now, we fail if we can't get the requested size. */ + dev_warn(&vcdev->cdev->dev, "no vq\n"); + err = -ENOMEM; + free_pages_exact(info->queue, size); + goto out_err; + } + info->vq = vq; + vq->priv = info; + + /* Register it with the host. */ + info->info_block->queue = (__u64)info->queue; + info->info_block->align = KVM_VIRTIO_CCW_RING_ALIGN; + info->info_block->index = info->queue_index; + info->info_block->num = info->num; + vcdev->ccw->cmd_code = CCW_CMD_SET_VQ; + vcdev->ccw->flags = 0; + vcdev->ccw->count = sizeof(*info->info_block); + vcdev->ccw->cda = (__u32)(unsigned long)(info->info_block); + err = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_SET_VQ | info->queue_index); + if (err) { + dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n"); + free_pages_exact(info->queue, size); + info->vq = NULL; + vq->priv = NULL; + goto out_err; + } + + /* 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 (info) + kfree(info->info_block); + kfree(info); + return ERR_PTR(err); +} + +static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs, + struct virtqueue *vqs[], + vq_callback_t *callbacks[], + const char *names[]) +{ + struct virtio_ccw_device *vcdev = to_vc_device(vdev); + unsigned long *indicatorp = NULL; + int ret, i; + + for (i = 0; i < nvqs; ++i) { + vqs[i] = virtio_ccw_setup_vq(vdev, i, callbacks[i], names[i]); + if (IS_ERR(vqs[i])) { + ret = PTR_ERR(vqs[i]); + vqs[i] = NULL; + goto out; + } + } + ret = -ENOMEM; + /* We need a data area under 2G to communicate. */ + indicatorp = kmalloc(sizeof(&vcdev->indicators), GFP_DMA | GFP_KERNEL); + if (!indicatorp) + goto out; + *indicatorp = (unsigned long) &vcdev->indicators; + /* Register queue indicators with host. */ + vcdev->indicators = 0; + vcdev->ccw->cmd_code = CCW_CMD_SET_IND; + vcdev->ccw->flags = 0; + vcdev->ccw->count = sizeof(vcdev->indicators); + vcdev->ccw->cda = (__u32)(unsigned long) indicatorp; + ret = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_SET_IND); + if (ret) + goto out; + /* Register indicators2 with host for config changes */ + *indicatorp = (unsigned long) &vcdev->indicators2; + vcdev->indicators2 = 0; + vcdev->ccw->cmd_code = CCW_CMD_SET_CONF_IND; + vcdev->ccw->flags = 0; + vcdev->ccw->count = sizeof(vcdev->indicators2); + vcdev->ccw->cda = (__u32)(unsigned long) indicatorp; + ret = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_SET_CONF_IND); + if (ret) + goto out; + + kfree(indicatorp); + return 0; +out: + kfree(indicatorp); + virtio_ccw_del_vqs(vdev); + return ret; +} + +static void virtio_ccw_reset(struct virtio_device *vdev) +{ + struct virtio_ccw_device *vcdev = to_vc_device(vdev); + + /* Zero status bits. */ + vcdev->status = 0; + + /* Send a reset ccw on device. */ + vcdev->ccw->cmd_code = CCW_CMD_VDEV_RESET; + vcdev->ccw->flags = 0; + vcdev->ccw->count = 0; + vcdev->ccw->cda = 0; + ccw_io_helper(vcdev, VIRTIO_CCW_DOING_RESET); +} + +static u32 virtio_ccw_get_features(struct virtio_device *vdev) +{ + struct virtio_ccw_device *vcdev = to_vc_device(vdev); + struct virtio_feature_desc features; + int ret; + + /* Read the feature bits from the host. */ + /* TODO: Features > 32 bits */ + features.index = 0; + vcdev->ccw->cmd_code = CCW_CMD_READ_FEAT; + vcdev->ccw->flags = 0; + vcdev->ccw->count = sizeof(features); + vcdev->ccw->cda = vcdev->area; + ret = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_READ_FEAT); + if (ret) + return 0; + + memcpy(&features, (void *)(unsigned long)vcdev->area, + sizeof(features)); + return le32_to_cpu(features.features); +} + +static void virtio_ccw_finalize_features(struct virtio_device *vdev) +{ + struct virtio_ccw_device *vcdev = to_vc_device(vdev); + struct virtio_feature_desc features; + int i; + + /* Give virtio_ring a chance to accept features. */ + vring_transport_features(vdev); + + for (i = 0; i < sizeof(*vdev->features) / sizeof(features.features); + i++) { + int highbits = i % 2 ? 32 : 0; + features.index = i; + features.features = cpu_to_le32(vdev->features[i / 2] + >> highbits); + memcpy((void *)(unsigned long)vcdev->area, &features, + sizeof(features)); + /* Write the feature bits to the host. */ + vcdev->ccw->cmd_code = CCW_CMD_WRITE_FEAT; + vcdev->ccw->flags = 0; + vcdev->ccw->count = sizeof(features); + vcdev->ccw->cda = vcdev->area; + ccw_io_helper(vcdev, VIRTIO_CCW_DOING_WRITE_FEAT); + } +} + +static void virtio_ccw_get_config(struct virtio_device *vdev, + unsigned int offset, void *buf, unsigned len) +{ + struct virtio_ccw_device *vcdev = to_vc_device(vdev); + int ret; + + /* Read the config area from the host. */ + vcdev->ccw->cmd_code = CCW_CMD_READ_CONF; + vcdev->ccw->flags = 0; + vcdev->ccw->count = offset + len; + vcdev->ccw->cda = vcdev->area; + ret = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_READ_CONFIG); + if (ret) + return; + + memcpy(vcdev->config, (void *)(unsigned long)vcdev->area, + sizeof(vcdev->config)); + memcpy(buf, &vcdev->config[offset], len); +} + +static void virtio_ccw_set_config(struct virtio_device *vdev, + unsigned int offset, const void *buf, + unsigned len) +{ + struct virtio_ccw_device *vcdev = to_vc_device(vdev); + + memcpy(&vcdev->config[offset], buf, len); + /* Write the config area to the host. */ + memcpy((void *)(unsigned long)vcdev->area, vcdev->config, + sizeof(vcdev->config)); + vcdev->ccw->cmd_code = CCW_CMD_WRITE_CONF; + vcdev->ccw->flags = 0; + vcdev->ccw->count = offset + len; + vcdev->ccw->cda = vcdev->area; + ccw_io_helper(vcdev, VIRTIO_CCW_DOING_WRITE_CONFIG); +} + +static u8 virtio_ccw_get_status(struct virtio_device *vdev) +{ + struct virtio_ccw_device *vcdev = to_vc_device(vdev); + + return vcdev->status; +} + +static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status) +{ + struct virtio_ccw_device *vcdev = to_vc_device(vdev); + + /* Write the status to the host. */ + vcdev->status = status; + memcpy((void *)(unsigned long)vcdev->area, &status, sizeof(status)); + vcdev->ccw->cmd_code = CCW_CMD_WRITE_STATUS; + vcdev->ccw->flags = 0; + vcdev->ccw->count = sizeof(status); + vcdev->ccw->cda = vcdev->area; + ccw_io_helper(vcdev, VIRTIO_CCW_DOING_WRITE_STATUS); +} + +static struct virtio_config_ops virtio_ccw_config_ops = { + .get_features = virtio_ccw_get_features, + .finalize_features = virtio_ccw_finalize_features, + .get = virtio_ccw_get_config, + .set = virtio_ccw_set_config, + .get_status = virtio_ccw_get_status, + .set_status = virtio_ccw_set_status, + .reset = virtio_ccw_reset, + .find_vqs = virtio_ccw_find_vqs, + .del_vqs = virtio_ccw_del_vqs, +}; + + +/* + * ccw bus driver related functions + */ + +static void virtio_ccw_release_dev(struct device *_d) +{ + struct virtio_device *dev = container_of(_d, struct virtio_device, + dev); + struct virtio_ccw_device *vcdev = to_vc_device(dev); + + kfree((void *)(unsigned long)vcdev->area); + kfree(vcdev->config_block); + kfree(vcdev->ccw); + kfree(vcdev); +} + +static int irb_is_error(struct irb *irb) +{ + if (scsw_cstat(&irb->scsw) != 0) + return 1; + if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END)) + return 1; + if (scsw_cc(&irb->scsw) != 0) + return 1; + return 0; +} + +static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev, + int index) +{ + struct virtio_ccw_vq_info *info; + unsigned long flags; + struct virtqueue *vq; + + vq = NULL; + spin_lock_irqsave(&vcdev->lock, flags); + list_for_each_entry(info, &vcdev->virtqueues, node) { + if (info->queue_index == index) { + vq = info->vq; + break; + } + } + spin_unlock_irqrestore(&vcdev->lock, flags); + return vq; +} + +static void virtio_ccw_int_handler(struct ccw_device *cdev, + unsigned long intparm, + struct irb *irb) +{ + __u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK; + struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev); + int i; + struct virtqueue *vq; + struct virtio_driver *drv; + + /* Check if it's a notification from the host. */ + if ((intparm == 0) && + (scsw_stctl(&irb->scsw) == + (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) { + /* OK */ + } + if (irb_is_error(irb)) + vcdev->err = -EIO; /* XXX - use real error */ + if (vcdev->curr_io & activity) { + switch (activity) { + case VIRTIO_CCW_DOING_READ_FEAT: + case VIRTIO_CCW_DOING_WRITE_FEAT: + case VIRTIO_CCW_DOING_READ_CONFIG: + case VIRTIO_CCW_DOING_WRITE_CONFIG: + case VIRTIO_CCW_DOING_WRITE_STATUS: + case VIRTIO_CCW_DOING_SET_VQ: + case VIRTIO_CCW_DOING_SET_IND: + case VIRTIO_CCW_DOING_SET_CONF_IND: + case VIRTIO_CCW_DOING_RESET: + case VIRTIO_CCW_DOING_READ_VQ_CONF: + vcdev->curr_io &= ~activity; + wake_up(&vcdev->wait_q); + break; + default: + /* don't know what to do... */ + dev_warn(&cdev->dev, "Suspicious activity '%08x'\n", + activity); + WARN_ON(1); + break; + } + } + for_each_set_bit(i, &vcdev->indicators, + sizeof(vcdev->indicators) * BITS_PER_BYTE) { + /* The bit clear must happen before the vring kick. */ + clear_bit(i, &vcdev->indicators); + barrier(); + vq = virtio_ccw_vq_by_ind(vcdev, i); + vring_interrupt(0, vq); + } + if (test_bit(0, &vcdev->indicators2)) { + drv = container_of(vcdev->vdev.dev.driver, + struct virtio_driver, driver); + + if (drv && drv->config_changed) + drv->config_changed(&vcdev->vdev); + clear_bit(0, &vcdev->indicators2); + } +} + +/* + * We usually want to autoonline all devices, but give the admin + * a way to exempt devices from this. + */ +#define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \ + (8*sizeof(long))) +static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS]; + +static char *no_auto = ""; + +module_param(no_auto, charp, 0444); +MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined"); + +static int virtio_ccw_check_autoonline(struct ccw_device *cdev) +{ + struct ccw_dev_id id; + + ccw_device_get_id(cdev, &id); + if (test_bit(id.devno, devs_no_auto[id.ssid])) + return 0; + return 1; +} + +static void virtio_ccw_auto_online(void *data, async_cookie_t cookie) +{ + struct ccw_device *cdev = data; + int ret; + + ret = ccw_device_set_online(cdev); + if (ret) + dev_warn(&cdev->dev, "Failed to set online: %d\n", ret); +} + +static int virtio_ccw_probe(struct ccw_device *cdev) +{ + cdev->handler = virtio_ccw_int_handler; + + if (virtio_ccw_check_autoonline(cdev)) + async_schedule(virtio_ccw_auto_online, cdev); + return 0; +} + +static void virtio_ccw_remove(struct ccw_device *cdev) +{ + struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev); + + if (cdev->online) { + unregister_virtio_device(&vcdev->vdev); + dev_set_drvdata(&cdev->dev, NULL); + } + cdev->handler = NULL; +} + +static int virtio_ccw_offline(struct ccw_device *cdev) +{ + struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev); + + unregister_virtio_device(&vcdev->vdev); + dev_set_drvdata(&cdev->dev, NULL); + return 0; +} + + +/* Area needs to be big enough to fit status, features or configuration. */ +#define VIRTIO_AREA_SIZE VIRTIO_CCW_CONFIG_SIZE /* biggest possible use */ + +static int virtio_ccw_online(struct ccw_device *cdev) +{ + int ret; + struct virtio_ccw_device *vcdev; + + vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL); + if (!vcdev) { + dev_warn(&cdev->dev, "Could not get memory for virtio\n"); + ret = -ENOMEM; + goto out_free; + } + vcdev->area = (__u32)(unsigned long)kzalloc(VIRTIO_AREA_SIZE, + GFP_DMA | GFP_KERNEL); + if (!vcdev->area) { + dev_warn(&cdev->dev, "Cound not get memory for virtio\n"); + ret = -ENOMEM; + goto out_free; + } + vcdev->config_block = kzalloc(sizeof(*vcdev->config_block), + GFP_DMA | GFP_KERNEL); + if (!vcdev->config_block) { + ret = -ENOMEM; + goto out_free; + } + vcdev->ccw = kzalloc(sizeof(*vcdev->ccw), GFP_DMA | GFP_KERNEL); + if (!vcdev->ccw) { + ret = -ENOMEM; + goto out_free; + } + + vcdev->vdev.dev.parent = &cdev->dev; + vcdev->vdev.dev.release = virtio_ccw_release_dev; + vcdev->vdev.config = &virtio_ccw_config_ops; + vcdev->cdev = cdev; + init_waitqueue_head(&vcdev->wait_q); + INIT_LIST_HEAD(&vcdev->virtqueues); + spin_lock_init(&vcdev->lock); + + dev_set_drvdata(&cdev->dev, vcdev); + vcdev->vdev.id.vendor = cdev->id.cu_type; + vcdev->vdev.id.device = cdev->id.cu_model; + ret = register_virtio_device(&vcdev->vdev); + if (ret) { + dev_warn(&cdev->dev, "Failed to register virtio device: %d\n", + ret); + goto out_put; + } + return 0; +out_put: + dev_set_drvdata(&cdev->dev, NULL); + put_device(&vcdev->vdev.dev); + return ret; +out_free: + if (vcdev) { + kfree((void *)(unsigned long)vcdev->area); + kfree(vcdev->config_block); + kfree(vcdev->ccw); + } + kfree(vcdev); + return ret; +} + +static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event) +{ + /* TODO: Check whether we need special handling here. */ + return 0; +} + +static struct ccw_device_id virtio_ids[] = { + { CCW_DEVICE(0x3832, 0) }, + {}, +}; +MODULE_DEVICE_TABLE(ccw, virtio_ids); + +static struct ccw_driver virtio_ccw_driver = { + .driver = { + .owner = THIS_MODULE, + .name = "virtio_ccw", + }, + .ids = virtio_ids, + .probe = virtio_ccw_probe, + .remove = virtio_ccw_remove, + .set_offline = virtio_ccw_offline, + .set_online = virtio_ccw_online, + .notify = virtio_ccw_cio_notify, + .int_class = IOINT_VIR, +}; + +static int __init pure_hex(char **cp, unsigned int *val, int min_digit, + int max_digit, int max_val) +{ + int diff; + + diff = 0; + *val = 0; + + while (diff <= max_digit) { + int value = hex_to_bin(**cp); + + if (value < 0) + break; + *val = *val * 16 + value; + (*cp)++; + diff++; + } + + if ((diff < min_digit) || (diff > max_digit) || (*val > max_val)) + return 1; + + return 0; +} + +static int __init parse_busid(char *str, unsigned int *cssid, + unsigned int *ssid, unsigned int *devno) +{ + char *str_work; + int rc, ret; + + rc = 1; + + if (*str == '\0') + goto out; + + str_work = str; + ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID); + if (ret || (str_work[0] != '.')) + goto out; + str_work++; + ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID); + if (ret || (str_work[0] != '.')) + goto out; + str_work++; + ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL); + if (ret || (str_work[0] != '\0')) + goto out; + + rc = 0; +out: + return rc; +} + +static void __init no_auto_parse(void) +{ + unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to; + char *parm, *str; + int rc; + + str = no_auto; + while ((parm = strsep(&str, ","))) { + rc = parse_busid(strsep(&parm, "-"), &from_cssid, + &from_ssid, &from); + if (rc) + continue; + if (parm != NULL) { + rc = parse_busid(parm, &to_cssid, + &to_ssid, &to); + if ((from_ssid > to_ssid) || + ((from_ssid == to_ssid) && (from > to))) + rc = -EINVAL; + } else { + to_cssid = from_cssid; + to_ssid = from_ssid; + to = from; + } + if (rc) + continue; + while ((from_ssid < to_ssid) || + ((from_ssid == to_ssid) && (from <= to))) { + set_bit(from, devs_no_auto[from_ssid]); + from++; + if (from > __MAX_SUBCHANNEL) { + from_ssid++; + from = 0; + } + } + } +} + +static int __init virtio_ccw_init(void) +{ + /* parse no_auto string before we do anything further */ + no_auto_parse(); + return ccw_driver_register(&virtio_ccw_driver); +} +module_init(virtio_ccw_init); + +static void __exit virtio_ccw_exit(void) +{ + ccw_driver_unregister(&virtio_ccw_driver); +} +module_exit(virtio_ccw_exit);

[4/5] KVM: s390: Add a channel I/O based virtio transport driver.

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