diff options
Diffstat (limited to 'drivers/s390/kvm/kvm_virtio.c')
| -rw-r--r-- | drivers/s390/kvm/kvm_virtio.c | 223 |
1 files changed, 186 insertions, 37 deletions
diff --git a/drivers/s390/kvm/kvm_virtio.c b/drivers/s390/kvm/kvm_virtio.c index 292b60da6dc..a1349653c6d 100644 --- a/drivers/s390/kvm/kvm_virtio.c +++ b/drivers/s390/kvm/kvm_virtio.c @@ -1,5 +1,5 @@ /* - * kvm_virtio.c - virtio for kvm on s390 + * virtio for kvm on s390 * * Copyright IBM Corp. 2008 * @@ -10,20 +10,24 @@ * Author(s): Christian Borntraeger <borntraeger@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/export.h> #include <linux/pfn.h> #include <asm/io.h> #include <asm/kvm_para.h> #include <asm/kvm_virtio.h> +#include <asm/sclp.h> #include <asm/setup.h> -#include <asm/s390_ext.h> +#include <asm/irq.h> #define VIRTIO_SUBCODE_64 0x0D00 @@ -31,6 +35,7 @@ * The pointer to our (page) of device descriptions. */ static void *kvm_devices; +static struct work_struct hotplug_work; struct kvm_device { struct virtio_device vdev; @@ -161,11 +166,15 @@ static void kvm_reset(struct virtio_device *vdev) * make a hypercall. We hand the address of the virtqueue so the Host * knows which virtqueue we're talking about. */ -static void kvm_notify(struct virtqueue *vq) +static bool kvm_notify(struct virtqueue *vq) { + long rc; struct kvm_vqconfig *config = vq->priv; - kvm_hypercall1(KVM_S390_VIRTIO_NOTIFY, config->address); + rc = kvm_hypercall1(KVM_S390_VIRTIO_NOTIFY, config->address); + if (rc < 0) + return false; + return true; } /* @@ -173,8 +182,9 @@ static void kvm_notify(struct virtqueue *vq) * this device and sets it up. */ static struct virtqueue *kvm_find_vq(struct virtio_device *vdev, - unsigned index, - void (*callback)(struct virtqueue *vq)) + unsigned index, + void (*callback)(struct virtqueue *vq), + const char *name) { struct kvm_device *kdev = to_kvmdev(vdev); struct kvm_vqconfig *config; @@ -184,15 +194,20 @@ static struct virtqueue *kvm_find_vq(struct virtio_device *vdev, if (index >= kdev->desc->num_vq) return ERR_PTR(-ENOENT); + if (!name) + return NULL; + config = kvm_vq_config(kdev->desc)+index; err = vmem_add_mapping(config->address, - vring_size(config->num, PAGE_SIZE)); + vring_size(config->num, + KVM_S390_VIRTIO_RING_ALIGN)); if (err) goto out; - vq = vring_new_virtqueue(config->num, vdev, (void *) config->address, - kvm_notify, callback); + vq = vring_new_virtqueue(index, config->num, KVM_S390_VIRTIO_RING_ALIGN, + vdev, true, (void *) config->address, + kvm_notify, callback, name); if (!vq) { err = -ENOMEM; goto unmap; @@ -208,7 +223,8 @@ static struct virtqueue *kvm_find_vq(struct virtio_device *vdev, return vq; unmap: vmem_remove_mapping(config->address, - vring_size(config->num, PAGE_SIZE)); + vring_size(config->num, + KVM_S390_VIRTIO_RING_ALIGN)); out: return ERR_PTR(err); } @@ -219,13 +235,51 @@ static void kvm_del_vq(struct virtqueue *vq) vring_del_virtqueue(vq); vmem_remove_mapping(config->address, - vring_size(config->num, PAGE_SIZE)); + vring_size(config->num, + KVM_S390_VIRTIO_RING_ALIGN)); +} + +static void kvm_del_vqs(struct virtio_device *vdev) +{ + struct virtqueue *vq, *n; + + list_for_each_entry_safe(vq, n, &vdev->vqs, list) + kvm_del_vq(vq); +} + +static int kvm_find_vqs(struct virtio_device *vdev, unsigned nvqs, + struct virtqueue *vqs[], + vq_callback_t *callbacks[], + const char *names[]) +{ + struct kvm_device *kdev = to_kvmdev(vdev); + int i; + + /* We must have this many virtqueues. */ + if (nvqs > kdev->desc->num_vq) + return -ENOENT; + + for (i = 0; i < nvqs; ++i) { + vqs[i] = kvm_find_vq(vdev, i, callbacks[i], names[i]); + if (IS_ERR(vqs[i])) + goto error; + } + return 0; + +error: + kvm_del_vqs(vdev); + return PTR_ERR(vqs[i]); +} + +static const char *kvm_bus_name(struct virtio_device *vdev) +{ + return ""; } /* * The config ops structure as defined by virtio config */ -static struct virtio_config_ops kvm_vq_configspace_ops = { +static const struct virtio_config_ops kvm_vq_configspace_ops = { .get_features = kvm_get_features, .finalize_features = kvm_finalize_features, .get = kvm_get, @@ -233,18 +287,16 @@ static struct virtio_config_ops kvm_vq_configspace_ops = { .get_status = kvm_get_status, .set_status = kvm_set_status, .reset = kvm_reset, - .find_vq = kvm_find_vq, - .del_vq = kvm_del_vq, + .find_vqs = kvm_find_vqs, + .del_vqs = kvm_del_vqs, + .bus_name = kvm_bus_name, }; /* * The root device for the kvm virtio devices. * This makes them appear as /sys/devices/kvm_s390/0,1,2 not /sys/devices/0,1,2. */ -static struct device kvm_root = { - .parent = NULL, - .bus_id = "kvm_s390", -}; +static struct device *kvm_root; /* * adds a new device and register it with virtio @@ -261,7 +313,7 @@ static void add_kvm_device(struct kvm_device_desc *d, unsigned int offset) return; } - kdev->vdev.dev.parent = &kvm_root; + kdev->vdev.dev.parent = kvm_root; kdev->vdev.id.device = d->type; kdev->vdev.config = &kvm_vq_configspace_ops; kdev->desc = d; @@ -293,46 +345,139 @@ static void scan_devices(void) } /* + * match for a kvm device with a specific desc pointer + */ +static int match_desc(struct device *dev, void *data) +{ + struct virtio_device *vdev = dev_to_virtio(dev); + struct kvm_device *kdev = to_kvmdev(vdev); + + return kdev->desc == data; +} + +/* + * hotplug_device tries to find changes in the device page. + */ +static void hotplug_devices(struct work_struct *dummy) +{ + unsigned int i; + struct kvm_device_desc *d; + struct device *dev; + + for (i = 0; i < PAGE_SIZE; i += desc_size(d)) { + d = kvm_devices + i; + + /* end of list */ + if (d->type == 0) + break; + + /* device already exists */ + dev = device_find_child(kvm_root, d, match_desc); + if (dev) { + /* XXX check for hotplug remove */ + put_device(dev); + continue; + } + + /* new device */ + printk(KERN_INFO "Adding new virtio device %p\n", d); + add_kvm_device(d, i); + } +} + +/* * we emulate the request_irq behaviour on top of s390 extints */ -static void kvm_extint_handler(u16 code) +static void kvm_extint_handler(struct ext_code ext_code, + unsigned int param32, unsigned long param64) { - void *data = (void *) *(long *) __LC_PFAULT_INTPARM; - u16 subcode = S390_lowcore.cpu_addr; + struct virtqueue *vq; + u32 param; - if ((subcode & 0xff00) != VIRTIO_SUBCODE_64) + if ((ext_code.subcode & 0xff00) != VIRTIO_SUBCODE_64) return; + inc_irq_stat(IRQEXT_VRT); + + /* The LSB might be overloaded, we have to mask it */ + vq = (struct virtqueue *)(param64 & ~1UL); + + /* We use ext_params to decide what this interrupt means */ + param = param32 & VIRTIO_PARAM_MASK; - vring_interrupt(0, data); + switch (param) { + case VIRTIO_PARAM_CONFIG_CHANGED: + { + struct virtio_driver *drv; + drv = container_of(vq->vdev->dev.driver, + struct virtio_driver, driver); + if (drv->config_changed) + drv->config_changed(vq->vdev); + + break; + } + case VIRTIO_PARAM_DEV_ADD: + schedule_work(&hotplug_work); + break; + case VIRTIO_PARAM_VRING_INTERRUPT: + default: + vring_interrupt(0, vq); + break; + } } /* + * For s390-virtio, we expect a page above main storage containing + * the virtio configuration. Try to actually load from this area + * in order to figure out if the host provides this page. + */ +static int __init test_devices_support(unsigned long addr) +{ + int ret = -EIO; + + asm volatile( + "0: lura 0,%1\n" + "1: xgr %0,%0\n" + "2:\n" + EX_TABLE(0b,2b) + EX_TABLE(1b,2b) + : "+d" (ret) + : "a" (addr) + : "0", "cc"); + return ret; +} +/* * Init function for virtio - * devices are in a single page above top of "normal" mem + * devices are in a single page above top of "normal" + standby mem */ static int __init kvm_devices_init(void) { int rc; + unsigned long total_memory_size = sclp_get_rzm() * sclp_get_rnmax(); if (!MACHINE_IS_KVM) return -ENODEV; - rc = device_register(&kvm_root); - if (rc) { - printk(KERN_ERR "Could not register kvm_s390 root device"); + if (test_devices_support(total_memory_size) < 0) + return -ENODEV; + + rc = vmem_add_mapping(total_memory_size, PAGE_SIZE); + if (rc) return rc; - } - rc = vmem_add_mapping(PFN_PHYS(max_pfn), PAGE_SIZE); - if (rc) { - device_unregister(&kvm_root); + kvm_devices = (void *) total_memory_size; + + kvm_root = root_device_register("kvm_s390"); + if (IS_ERR(kvm_root)) { + rc = PTR_ERR(kvm_root); + printk(KERN_ERR "Could not register kvm_s390 root device"); + vmem_remove_mapping(total_memory_size, PAGE_SIZE); return rc; } - kvm_devices = (void *) PFN_PHYS(max_pfn); + INIT_WORK(&hotplug_work, hotplug_devices); - ctl_set_bit(0, 9); - register_external_interrupt(0x2603, kvm_extint_handler); + irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL); + register_external_irq(EXT_IRQ_CP_SERVICE, kvm_extint_handler); scan_devices(); return 0; @@ -352,10 +497,14 @@ static __init int early_put_chars(u32 vtermno, const char *buf, int count) return len; } -void __init s390_virtio_console_init(void) +static int __init s390_virtio_console_init(void) { - virtio_cons_early_init(early_put_chars); + if (sclp_has_vt220() || sclp_has_linemode()) + return -ENODEV; + return virtio_cons_early_init(early_put_chars); } +console_initcall(s390_virtio_console_init); + /* * We do this after core stuff, but before the drivers. |