1 files changed, 133 insertions, 0 deletions

diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index 0a778d30d333..8ae0349d9f0a 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -33,6 +33,7 @@
 #include <xen/xen.h>
 #include <xen/privcmd.h>
 #include <xen/interface/xen.h>
+#include <xen/interface/memory.h>
 #include <xen/interface/hvm/dm_op.h>
 #include <xen/features.h>
 #include <xen/page.h>
@@ -722,6 +723,134 @@ static long privcmd_ioctl_restrict(struct file *file, void __user *udata)
         return 0;
 }
 
+struct remap_pfn {
+        struct mm_struct *mm;
+        struct page **pages;
+        pgprot_t prot;
+        unsigned long i;
+};
+
+static int remap_pfn_fn(pte_t *ptep, pgtable_t token, unsigned long addr,
+                        void *data)
+{
+        struct remap_pfn *r = data;
+        struct page *page = r->pages[r->i];
+        pte_t pte = pte_mkspecial(pfn_pte(page_to_pfn(page), r->prot));
+
+        set_pte_at(r->mm, addr, ptep, pte);
+        r->i++;
+
+        return 0;
+}
+
+static long privcmd_ioctl_mmap_resource(struct file *file, void __user *udata)
+{
+        struct privcmd_data *data = file->private_data;
+        struct mm_struct *mm = current->mm;
+        struct vm_area_struct *vma;
+        struct privcmd_mmap_resource kdata;
+        xen_pfn_t *pfns = NULL;
+        struct xen_mem_acquire_resource xdata;
+        int rc;
+
+        if (copy_from_user(&kdata, udata, sizeof(kdata)))
+                return -EFAULT;
+
+        /* If restriction is in place, check the domid matches */
+        if (data->domid != DOMID_INVALID && data->domid != kdata.dom)
+                return -EPERM;
+
+        down_write(&mm->mmap_sem);
+
+        vma = find_vma(mm, kdata.addr);
+        if (!vma || vma->vm_ops != &privcmd_vm_ops) {
+                rc = -EINVAL;
+                goto out;
+        }
+
+        pfns = kcalloc(kdata.num, sizeof(*pfns), GFP_KERNEL);
+        if (!pfns) {
+                rc = -ENOMEM;
+                goto out;
+        }
+
+        if (xen_feature(XENFEAT_auto_translated_physmap)) {
+                unsigned int nr = DIV_ROUND_UP(kdata.num, XEN_PFN_PER_PAGE);
+                struct page **pages;
+                unsigned int i;
+
+                rc = alloc_empty_pages(vma, nr);
+                if (rc < 0)
+                        goto out;
+
+                pages = vma->vm_private_data;
+                for (i = 0; i < kdata.num; i++) {
+                        xen_pfn_t pfn =
+                                page_to_xen_pfn(pages[i / XEN_PFN_PER_PAGE]);
+
+                        pfns[i] = pfn + (i % XEN_PFN_PER_PAGE);
+                }
+        } else
+                vma->vm_private_data = PRIV_VMA_LOCKED;
+
+        memset(&xdata, 0, sizeof(xdata));
+        xdata.domid = kdata.dom;
+        xdata.type = kdata.type;
+        xdata.id = kdata.id;
+        xdata.frame = kdata.idx;
+        xdata.nr_frames = kdata.num;
+        set_xen_guest_handle(xdata.frame_list, pfns);
+
+        xen_preemptible_hcall_begin();
+        rc = HYPERVISOR_memory_op(XENMEM_acquire_resource, &xdata);
+        xen_preemptible_hcall_end();
+
+        if (rc)
+                goto out;
+
+        if (xen_feature(XENFEAT_auto_translated_physmap)) {
+                struct remap_pfn r = {
+                        .mm = vma->vm_mm,
+                        .pages = vma->vm_private_data,
+                        .prot = vma->vm_page_prot,
+                };
+
+                rc = apply_to_page_range(r.mm, kdata.addr,
+                                         kdata.num << PAGE_SHIFT,
+                                         remap_pfn_fn, &r);
+        } else {
+                unsigned int domid =
+                        (xdata.flags & XENMEM_rsrc_acq_caller_owned) ?
+                        DOMID_SELF : kdata.dom;
+                int num;
+
+                num = xen_remap_domain_mfn_array(vma,
+                                                 kdata.addr & PAGE_MASK,
+                                                 pfns, kdata.num, (int *)pfns,
+                                                 vma->vm_page_prot,
+                                                 domid,
+                                                 vma->vm_private_data);
+                if (num < 0)
+                        rc = num;
+                else if (num != kdata.num) {
+                        unsigned int i;
+
+                        for (i = 0; i < num; i++) {
+                                rc = pfns[i];
+                                if (rc < 0)
+                                        break;
+                        }
+                } else
+                        rc = 0;
+        }
+
+out:
+        up_write(&mm->mmap_sem);
+        kfree(pfns);
+
+        return rc;
+}
+
 static long privcmd_ioctl(struct file *file,
                           unsigned int cmd, unsigned long data)
 {
@@ -753,6 +882,10 @@ static long privcmd_ioctl(struct file *file,
                 ret = privcmd_ioctl_restrict(file, udata);
                 break;
 
+        case IOCTL_PRIVCMD_MMAP_RESOURCE:
+                ret = privcmd_ioctl_mmap_resource(file, udata);
+                break;
+
         default:
                 break;
         }