diff options
Diffstat (limited to 'drivers/xen')
| -rw-r--r-- | drivers/xen/Makefile | 2 | ||||
| -rw-r--r-- | drivers/xen/events/events_base.c | 2 | ||||
| -rw-r--r-- | drivers/xen/grant-table.c | 4 | ||||
| -rw-r--r-- | drivers/xen/manage.c | 18 | ||||
| -rw-r--r-- | drivers/xen/privcmd-buf.c | 210 | ||||
| -rw-r--r-- | drivers/xen/privcmd.c | 9 | ||||
| -rw-r--r-- | drivers/xen/privcmd.h | 3 | ||||
| -rw-r--r-- | drivers/xen/xen-scsiback.c | 16 |
8 files changed, 253 insertions, 11 deletions
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile index 451e833f5931..48b154276179 100644 --- a/drivers/xen/Makefile +++ b/drivers/xen/Makefile @@ -41,4 +41,4 @@ obj-$(CONFIG_XEN_PVCALLS_FRONTEND) += pvcalls-front.o xen-evtchn-y := evtchn.o xen-gntdev-y := gntdev.o xen-gntalloc-y := gntalloc.o -xen-privcmd-y := privcmd.o +xen-privcmd-y := privcmd.o privcmd-buf.o diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index 762378f1811c..08e4af04d6f2 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -628,8 +628,6 @@ static void __unbind_from_irq(unsigned int irq) xen_irq_info_cleanup(info); } - BUG_ON(info_for_irq(irq)->type == IRQT_UNBOUND); - xen_free_irq(irq); } diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 2473b0a9e6e4..ba9f3eec2bd0 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -799,7 +799,7 @@ int gnttab_alloc_pages(int nr_pages, struct page **pages) return 0; } -EXPORT_SYMBOL(gnttab_alloc_pages); +EXPORT_SYMBOL_GPL(gnttab_alloc_pages); /** * gnttab_free_pages - free pages allocated by gnttab_alloc_pages() @@ -820,7 +820,7 @@ void gnttab_free_pages(int nr_pages, struct page **pages) } free_xenballooned_pages(nr_pages, pages); } -EXPORT_SYMBOL(gnttab_free_pages); +EXPORT_SYMBOL_GPL(gnttab_free_pages); /* Handling of paged out grant targets (GNTST_eagain) */ #define MAX_DELAY 256 diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c index 8835065029d3..c93d8ef8df34 100644 --- a/drivers/xen/manage.c +++ b/drivers/xen/manage.c @@ -289,8 +289,15 @@ static void sysrq_handler(struct xenbus_watch *watch, const char *path, return; } - if (sysrq_key != '\0') - xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); + if (sysrq_key != '\0') { + err = xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); + if (err) { + pr_err("%s: Error %d writing sysrq in control/sysrq\n", + __func__, err); + xenbus_transaction_end(xbt, 1); + return; + } + } err = xenbus_transaction_end(xbt, 0); if (err == -EAGAIN) @@ -342,7 +349,12 @@ static int setup_shutdown_watcher(void) continue; snprintf(node, FEATURE_PATH_SIZE, "feature-%s", shutdown_handlers[idx].command); - xenbus_printf(XBT_NIL, "control", node, "%u", 1); + err = xenbus_printf(XBT_NIL, "control", node, "%u", 1); + if (err) { + pr_err("%s: Error %d writing %s\n", __func__, + err, node); + return err; + } } return 0; diff --git a/drivers/xen/privcmd-buf.c b/drivers/xen/privcmd-buf.c new file mode 100644 index 000000000000..df1ed37c3269 --- /dev/null +++ b/drivers/xen/privcmd-buf.c @@ -0,0 +1,210 @@ +// SPDX-License-Identifier: GPL-2.0 OR MIT + +/****************************************************************************** + * privcmd-buf.c + * + * Mmap of hypercall buffers. + * + * Copyright (c) 2018 Juergen Gross + */ + +#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/list.h> +#include <linux/miscdevice.h> +#include <linux/mm.h> +#include <linux/slab.h> + +#include "privcmd.h" + +MODULE_LICENSE("GPL"); + +static unsigned int limit = 64; +module_param(limit, uint, 0644); +MODULE_PARM_DESC(limit, "Maximum number of pages that may be allocated by " + "the privcmd-buf device per open file"); + +struct privcmd_buf_private { + struct mutex lock; + struct list_head list; + unsigned int allocated; +}; + +struct privcmd_buf_vma_private { + struct privcmd_buf_private *file_priv; + struct list_head list; + unsigned int users; + unsigned int n_pages; + struct page *pages[]; +}; + +static int privcmd_buf_open(struct inode *ino, struct file *file) +{ + struct privcmd_buf_private *file_priv; + + file_priv = kzalloc(sizeof(*file_priv), GFP_KERNEL); + if (!file_priv) + return -ENOMEM; + + mutex_init(&file_priv->lock); + INIT_LIST_HEAD(&file_priv->list); + + file->private_data = file_priv; + + return 0; +} + +static void privcmd_buf_vmapriv_free(struct privcmd_buf_vma_private *vma_priv) +{ + unsigned int i; + + vma_priv->file_priv->allocated -= vma_priv->n_pages; + + list_del(&vma_priv->list); + + for (i = 0; i < vma_priv->n_pages; i++) + if (vma_priv->pages[i]) + __free_page(vma_priv->pages[i]); + + kfree(vma_priv); +} + +static int privcmd_buf_release(struct inode *ino, struct file *file) +{ + struct privcmd_buf_private *file_priv = file->private_data; + struct privcmd_buf_vma_private *vma_priv; + + mutex_lock(&file_priv->lock); + + while (!list_empty(&file_priv->list)) { + vma_priv = list_first_entry(&file_priv->list, + struct privcmd_buf_vma_private, + list); + privcmd_buf_vmapriv_free(vma_priv); + } + + mutex_unlock(&file_priv->lock); + + kfree(file_priv); + + return 0; +} + +static void privcmd_buf_vma_open(struct vm_area_struct *vma) +{ + struct privcmd_buf_vma_private *vma_priv = vma->vm_private_data; + + if (!vma_priv) + return; + + mutex_lock(&vma_priv->file_priv->lock); + vma_priv->users++; + mutex_unlock(&vma_priv->file_priv->lock); +} + +static void privcmd_buf_vma_close(struct vm_area_struct *vma) +{ + struct privcmd_buf_vma_private *vma_priv = vma->vm_private_data; + struct privcmd_buf_private *file_priv; + + if (!vma_priv) + return; + + file_priv = vma_priv->file_priv; + + mutex_lock(&file_priv->lock); + + vma_priv->users--; + if (!vma_priv->users) + privcmd_buf_vmapriv_free(vma_priv); + + mutex_unlock(&file_priv->lock); +} + +static vm_fault_t privcmd_buf_vma_fault(struct vm_fault *vmf) +{ + pr_debug("fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n", + vmf->vma, vmf->vma->vm_start, vmf->vma->vm_end, + vmf->pgoff, (void *)vmf->address); + + return VM_FAULT_SIGBUS; +} + +static const struct vm_operations_struct privcmd_buf_vm_ops = { + .open = privcmd_buf_vma_open, + .close = privcmd_buf_vma_close, + .fault = privcmd_buf_vma_fault, +}; + +static int privcmd_buf_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct privcmd_buf_private *file_priv = file->private_data; + struct privcmd_buf_vma_private *vma_priv; + unsigned long count = vma_pages(vma); + unsigned int i; + int ret = 0; + + if (!(vma->vm_flags & VM_SHARED) || count > limit || + file_priv->allocated + count > limit) + return -EINVAL; + + vma_priv = kzalloc(sizeof(*vma_priv) + count * sizeof(void *), + GFP_KERNEL); + if (!vma_priv) + return -ENOMEM; + + vma_priv->n_pages = count; + count = 0; + for (i = 0; i < vma_priv->n_pages; i++) { + vma_priv->pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO); + if (!vma_priv->pages[i]) + break; + count++; + } + + mutex_lock(&file_priv->lock); + + file_priv->allocated += count; + + vma_priv->file_priv = file_priv; + vma_priv->users = 1; + + vma->vm_flags |= VM_IO | VM_DONTEXPAND; + vma->vm_ops = &privcmd_buf_vm_ops; + vma->vm_private_data = vma_priv; + + list_add(&vma_priv->list, &file_priv->list); + + if (vma_priv->n_pages != count) + ret = -ENOMEM; + else + for (i = 0; i < vma_priv->n_pages; i++) { + ret = vm_insert_page(vma, vma->vm_start + i * PAGE_SIZE, + vma_priv->pages[i]); + if (ret) + break; + } + + if (ret) + privcmd_buf_vmapriv_free(vma_priv); + + mutex_unlock(&file_priv->lock); + + return ret; +} + +const struct file_operations xen_privcmdbuf_fops = { + .owner = THIS_MODULE, + .open = privcmd_buf_open, + .release = privcmd_buf_release, + .mmap = privcmd_buf_mmap, +}; +EXPORT_SYMBOL_GPL(xen_privcmdbuf_fops); + +struct miscdevice xen_privcmdbuf_dev = { + .minor = MISC_DYNAMIC_MINOR, + .name = "xen/hypercall", + .fops = &xen_privcmdbuf_fops, +}; diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c index 8ae0349d9f0a..7e6e682104dc 100644 --- a/drivers/xen/privcmd.c +++ b/drivers/xen/privcmd.c @@ -1007,12 +1007,21 @@ static int __init privcmd_init(void) pr_err("Could not register Xen privcmd device\n"); return err; } + + err = misc_register(&xen_privcmdbuf_dev); + if (err != 0) { + pr_err("Could not register Xen hypercall-buf device\n"); + misc_deregister(&privcmd_dev); + return err; + } + return 0; } static void __exit privcmd_exit(void) { misc_deregister(&privcmd_dev); + misc_deregister(&xen_privcmdbuf_dev); } module_init(privcmd_init); diff --git a/drivers/xen/privcmd.h b/drivers/xen/privcmd.h index 14facaeed36f..0dd9f8f67ee3 100644 --- a/drivers/xen/privcmd.h +++ b/drivers/xen/privcmd.h @@ -1,3 +1,6 @@ #include <linux/fs.h> extern const struct file_operations xen_privcmd_fops; +extern const struct file_operations xen_privcmdbuf_fops; + +extern struct miscdevice xen_privcmdbuf_dev; diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c index 7bc88fd43cfc..e2f3e8b0fba9 100644 --- a/drivers/xen/xen-scsiback.c +++ b/drivers/xen/xen-scsiback.c @@ -1012,6 +1012,7 @@ static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state, { struct v2p_entry *entry; unsigned long flags; + int err; if (try) { spin_lock_irqsave(&info->v2p_lock, flags); @@ -1027,8 +1028,11 @@ static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state, scsiback_del_translation_entry(info, vir); } } else if (!try) { - xenbus_printf(XBT_NIL, info->dev->nodename, state, + err = xenbus_printf(XBT_NIL, info->dev->nodename, state, "%d", XenbusStateClosed); + if (err) + xenbus_dev_error(info->dev, err, + "%s: writing %s", __func__, state); } } @@ -1067,8 +1071,11 @@ static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op, snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent); val = xenbus_read(XBT_NIL, dev->nodename, str, NULL); if (IS_ERR(val)) { - xenbus_printf(XBT_NIL, dev->nodename, state, + err = xenbus_printf(XBT_NIL, dev->nodename, state, "%d", XenbusStateClosed); + if (err) + xenbus_dev_error(info->dev, err, + "%s: writing %s", __func__, state); return; } strlcpy(phy, val, VSCSI_NAMELEN); @@ -1079,8 +1086,11 @@ static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op, err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u", &vir.hst, &vir.chn, &vir.tgt, &vir.lun); if (XENBUS_EXIST_ERR(err)) { - xenbus_printf(XBT_NIL, dev->nodename, state, + err = xenbus_printf(XBT_NIL, dev->nodename, state, "%d", XenbusStateClosed); + if (err) + xenbus_dev_error(info->dev, err, + "%s: writing %s", __func__, state); return; } |