diff options
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/xen/gntdev.c | 117 | ||||
-rw-r--r-- | drivers/xen/grant-table.c | 6 |
2 files changed, 89 insertions, 34 deletions
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 256162b..bcaf797 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -32,6 +32,7 @@ #include <linux/sched.h> #include <linux/spinlock.h> #include <linux/slab.h> +#include <linux/highmem.h> #include <xen/xen.h> #include <xen/grant_table.h> @@ -52,6 +53,8 @@ MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by " static atomic_t pages_mapped = ATOMIC_INIT(0); +static int use_ptemod; + struct gntdev_priv { struct list_head maps; /* lock protects maps from concurrent changes */ @@ -74,6 +77,8 @@ struct grant_map { struct page **pages; }; +static int unmap_grant_pages(struct grant_map *map, int offset, int pages); + /* ------------------------------------------------------------------ */ static void gntdev_print_maps(struct gntdev_priv *priv, @@ -179,11 +184,34 @@ static void gntdev_put_map(struct grant_map *map) atomic_sub(map->count, &pages_mapped); - if (map->pages) + if (map->pages) { + if (!use_ptemod) + unmap_grant_pages(map, 0, map->count); + for (i = 0; i < map->count; i++) { - if (map->pages[i]) + uint32_t check, *tmp; + if (!map->pages[i]) + continue; + /* XXX When unmapping in an HVM domain, Xen will + * sometimes end up mapping the GFN to an invalid MFN. + * In this case, writes will be discarded and reads will + * return all 0xFF bytes. Leak these unusable GFNs + * until Xen supports fixing their p2m mapping. + * + * Confirmed present in Xen 4.1-RC3 with HVM source + */ + tmp = kmap(map->pages[i]); + *tmp = 0xdeaddead; + mb(); + check = *tmp; + kunmap(map->pages[i]); + if (check == 0xdeaddead) __free_page(map->pages[i]); + else + pr_debug("Discard page %d=%ld\n", i, + page_to_pfn(map->pages[i])); } + } kfree(map->pages); kfree(map->grants); kfree(map->map_ops); @@ -198,17 +226,16 @@ static int find_grant_ptes(pte_t *pte, pgtable_t token, { struct grant_map *map = data; unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT; + int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte; u64 pte_maddr; BUG_ON(pgnr >= map->count); pte_maddr = arbitrary_virt_to_machine(pte).maddr; - gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, - GNTMAP_contains_pte | map->flags, + gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags, map->grants[pgnr].ref, map->grants[pgnr].domid); - gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, - GNTMAP_contains_pte | map->flags, + gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags, 0 /* handle */); return 0; } @@ -216,6 +243,19 @@ static int find_grant_ptes(pte_t *pte, pgtable_t token, static int map_grant_pages(struct grant_map *map) { int i, err = 0; + phys_addr_t addr; + + if (!use_ptemod) { + for (i = 0; i < map->count; i++) { + addr = (phys_addr_t) + pfn_to_kaddr(page_to_pfn(map->pages[i])); + gnttab_set_map_op(&map->map_ops[i], addr, map->flags, + map->grants[i].ref, + map->grants[i].domid); + gnttab_set_unmap_op(&map->unmap_ops[i], addr, + map->flags, 0 /* handle */); + } + } pr_debug("map %d+%d\n", map->index, map->count); err = gnttab_map_refs(map->map_ops, map->pages, map->count); @@ -260,17 +300,8 @@ static void gntdev_vma_close(struct vm_area_struct *vma) gntdev_put_map(map); } -static int gntdev_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) -{ - pr_debug("vaddr %p, pgoff %ld (shouldn't happen)\n", - vmf->virtual_address, vmf->pgoff); - vmf->flags = VM_FAULT_ERROR; - return 0; -} - static struct vm_operations_struct gntdev_vmops = { .close = gntdev_vma_close, - .fault = gntdev_vma_fault, }; /* ------------------------------------------------------------------ */ @@ -355,14 +386,16 @@ static int gntdev_open(struct inode *inode, struct file *flip) INIT_LIST_HEAD(&priv->maps); spin_lock_init(&priv->lock); - priv->mm = get_task_mm(current); - if (!priv->mm) { - kfree(priv); - return -ENOMEM; + if (use_ptemod) { + priv->mm = get_task_mm(current); + if (!priv->mm) { + kfree(priv); + return -ENOMEM; + } + priv->mn.ops = &gntdev_mmu_ops; + ret = mmu_notifier_register(&priv->mn, priv->mm); + mmput(priv->mm); } - priv->mn.ops = &gntdev_mmu_ops; - ret = mmu_notifier_register(&priv->mn, priv->mm); - mmput(priv->mm); if (ret) { kfree(priv); @@ -390,7 +423,8 @@ static int gntdev_release(struct inode *inode, struct file *flip) } spin_unlock(&priv->lock); - mmu_notifier_unregister(&priv->mn, priv->mm); + if (use_ptemod) + mmu_notifier_unregister(&priv->mn, priv->mm); kfree(priv); return 0; } @@ -515,7 +549,7 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) int index = vma->vm_pgoff; int count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; struct grant_map *map; - int err = -EINVAL; + int i, err = -EINVAL; if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED)) return -EINVAL; @@ -527,9 +561,9 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) map = gntdev_find_map_index(priv, index, count); if (!map) goto unlock_out; - if (map->vma) + if (use_ptemod && map->vma) goto unlock_out; - if (priv->mm != vma->vm_mm) { + if (use_ptemod && priv->mm != vma->vm_mm) { printk(KERN_WARNING "Huh? Other mm?\n"); goto unlock_out; } @@ -541,20 +575,24 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) vma->vm_flags |= VM_RESERVED|VM_DONTCOPY|VM_DONTEXPAND|VM_PFNMAP; vma->vm_private_data = map; - map->vma = vma; - map->flags = GNTMAP_host_map | GNTMAP_application_map; + if (use_ptemod) + map->vma = vma; + + map->flags = GNTMAP_host_map; if (!(vma->vm_flags & VM_WRITE)) map->flags |= GNTMAP_readonly; spin_unlock(&priv->lock); - err = apply_to_page_range(vma->vm_mm, vma->vm_start, - vma->vm_end - vma->vm_start, - find_grant_ptes, map); - if (err) { - printk(KERN_WARNING "find_grant_ptes() failure.\n"); - return err; + if (use_ptemod) { + err = apply_to_page_range(vma->vm_mm, vma->vm_start, + vma->vm_end - vma->vm_start, + find_grant_ptes, map); + if (err) { + printk(KERN_WARNING "find_grant_ptes() failure.\n"); + return err; + } } err = map_grant_pages(map); @@ -565,6 +603,15 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) map->is_mapped = 1; + if (!use_ptemod) { + for (i = 0; i < count; i++) { + err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE, + map->pages[i]); + if (err) + return err; + } + } + return 0; unlock_out: @@ -595,6 +642,8 @@ static int __init gntdev_init(void) if (!xen_domain()) return -ENODEV; + use_ptemod = xen_pv_domain(); + err = misc_register(&gntdev_miscdev); if (err != 0) { printk(KERN_ERR "Could not register gntdev device\n"); diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 9ef54eb..9428ced 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -458,6 +458,9 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, if (ret) return ret; + if (xen_feature(XENFEAT_auto_translated_physmap)) + return ret; + for (i = 0; i < count; i++) { /* m2p override only supported for GNTMAP_contains_pte mappings */ if (!(map_ops[i].flags & GNTMAP_contains_pte)) @@ -483,6 +486,9 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, if (ret) return ret; + if (xen_feature(XENFEAT_auto_translated_physmap)) + return ret; + for (i = 0; i < count; i++) { ret = m2p_remove_override(pages[i]); if (ret) |