[Xen-devel] [PATCH v1 7/8]: PVH privcmd changes

[Mukesh Rathor <mukesh.rathor@xxxxxxxxxx>]

---
 drivers/xen/privcmd.c |   77 ++++++++++++++++++++++++++++++++++++++++++++----
 1 files changed, 70 insertions(+), 7 deletions(-)

diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index ccee0f1..195d89f 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -33,6 +33,7 @@
 #include <xen/features.h>
 #include <xen/page.h>
 #include <xen/xen-ops.h>
+#include <xen/balloon.h>
 
 #include "privcmd.h"
 
@@ -178,7 +179,7 @@ static int mmap_mfn_range(void *data, void *state)
                                        msg->va & PAGE_MASK,
                                        msg->mfn, msg->npages,
                                        vma->vm_page_prot,
-                                       st->domain);
+                                       st->domain, NULL);
        if (rc < 0)
                return rc;
 
@@ -199,6 +200,10 @@ static long privcmd_ioctl_mmap(void __user *udata)
        if (!xen_initial_domain())
                return -EPERM;
 
+       /* PVH: TBD/FIXME. For now we only support privcmd_ioctl_mmap_batch */
+       if (xen_pv_domain() && xen_feature(XENFEAT_auto_translated_physmap))
+               return -ENOSYS;
+
        if (copy_from_user(&mmapcmd, udata, sizeof(mmapcmd)))
                return -EFAULT;
 
@@ -251,13 +256,18 @@ struct mmap_batch_state {
        xen_pfn_t __user *user;
 };
 
+/* PVH dom0 fyi: if domU being created is PV, then mfn is mfn(addr on bus). If 
+ * it's PVH then mfn is pfn (input to HAP). */
 static int mmap_batch_fn(void *data, void *state)
 {
        xen_pfn_t *mfnp = data;
        struct mmap_batch_state *st = state;
+       struct vm_area_struct *vma = st->vma;
+       struct xen_pvh_pfn_info *pvhp = vma ? vma->vm_private_data : NULL;
 
-       if (xen_remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, *mfnp, 1,
-                                      st->vma->vm_page_prot, st->domain) < 0) {
+       if (xen_remap_domain_mfn_range(vma, st->va & PAGE_MASK, *mfnp, 1,
+                                      vma->vm_page_prot, st->domain, 
+                                      pvhp) < 0) {
                *mfnp |= 0xf0000000U;
                st->err++;
        }
@@ -274,6 +284,40 @@ static int mmap_return_errors(void *data, void *state)
        return put_user(*mfnp, st->user++);
 }
 
+/* Allocate pfns that are then mapped with gmfns from foreign domid. Update
+ * the vma with the page info to use later.
+ * Returns: 0 if success, otherwise -errno
+ */ 
+static int pvh_privcmd_resv_pfns(struct vm_area_struct *vma, int numpgs)
+{
+       int rc;
+       struct xen_pvh_pfn_info *pvhp;
+
+       pvhp = kzalloc(sizeof(struct xen_pvh_pfn_info), GFP_KERNEL);
+       if (pvhp == NULL)
+               return -ENOMEM;
+
+       pvhp->pi_paga = kcalloc(numpgs, sizeof(pvhp->pi_paga[0]), GFP_KERNEL);
+       if (pvhp->pi_paga == NULL) {
+               kfree(pvhp);
+               return -ENOMEM;
+       }
+
+       rc = alloc_xenballooned_pages(numpgs, pvhp->pi_paga, 0);
+       if (rc != 0) {
+               pr_warn("%s Could not alloc %d pfns rc:%d\n", __FUNCTION__, 
+                       numpgs, rc);
+               kfree(pvhp->pi_paga);
+               kfree(pvhp);
+               return -ENOMEM;
+       }
+       pvhp->pi_num_pgs = numpgs;
+       BUG_ON(vma->vm_private_data != (void *)1);
+       vma->vm_private_data = pvhp;
+
+       return 0;
+}
+
 static struct vm_operations_struct privcmd_vm_ops;
 
 static long privcmd_ioctl_mmap_batch(void __user *udata)
@@ -315,6 +359,12 @@ static long privcmd_ioctl_mmap_batch(void __user *udata)
                goto out;
        }
 
+       if (xen_pv_domain() && xen_feature(XENFEAT_auto_translated_physmap)) {
+               if ((ret=pvh_privcmd_resv_pfns(vma, m.num))) {
+                       up_write(&mm->mmap_sem);
+                       goto out;
+               }
+       }
        state.domain = m.dom;
        state.vma = vma;
        state.va = m.addr;
@@ -365,6 +415,22 @@ static long privcmd_ioctl(struct file *file,
        return ret;
 }
 
+static void privcmd_close(struct vm_area_struct *vma)
+{
+       int count;
+       struct xen_pvh_pfn_info *pvhp = vma ? vma->vm_private_data : NULL;
+
+       if (!xen_pv_domain()  || !pvhp ||
+           !xen_feature(XENFEAT_auto_translated_physmap))
+               return;
+
+       count = xen_unmap_domain_mfn_range(vma, pvhp);
+       while (count--)
+               free_xenballooned_pages(1, &pvhp->pi_paga[count]);
+       kfree(pvhp->pi_paga);
+       kfree(pvhp);
+}
+
 static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
        printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n",
@@ -375,15 +441,12 @@ static int privcmd_fault(struct vm_area_struct *vma, 
struct vm_fault *vmf)
 }
 
 static struct vm_operations_struct privcmd_vm_ops = {
+       .close = privcmd_close,
        .fault = privcmd_fault
 };
 
 static int privcmd_mmap(struct file *file, struct vm_area_struct *vma)
 {
-       /* Unsupported for auto-translate guests. */
-       if (xen_feature(XENFEAT_auto_translated_physmap))
-               return -ENOSYS;
-
        /* DONTCOPY is essential for Xen because copy_page_range doesn't know
         * how to recreate these mappings */
        vma->vm_flags |= VM_RESERVED | VM_IO | VM_DONTCOPY | VM_PFNMAP;
-- 
1.7.2.3


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