[RFC PATCH 8/8]: PVH: privcmd changes

[Mukesh Rathor <mukesh.rathor@oracle.com>]

---
 drivers/xen/privcmd.c |   68 +++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index ccee0f1..0a240ab 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"
 
@@ -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_pvh_domain())
+		return -ENOSYS;
+
 	if (copy_from_user(&mmapcmd, udata, sizeof(mmapcmd)))
 		return -EFAULT;
 
@@ -251,6 +256,8 @@ struct mmap_batch_state {
 	xen_pfn_t __user *user;
 };
 
+/* PVH dom0: 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;
@@ -274,6 +281,40 @@ 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_sav_pfn_info *savp;
+
+	savp = kzalloc(sizeof(struct xen_pvh_sav_pfn_info), GFP_KERNEL);
+	if (savp == NULL)
+		return -ENOMEM;
+
+	savp->sp_paga = kcalloc(numpgs, sizeof(savp->sp_paga[0]), GFP_KERNEL);
+	if (savp->sp_paga == NULL) {
+		kfree(savp);
+		return -ENOMEM;
+	}
+
+	rc = alloc_xenballooned_pages(numpgs, savp->sp_paga, 0);
+	if (rc != 0) {
+		pr_warn("%s Could not alloc %d pfns rc:%d\n", __FUNCTION__,
+			numpgs, rc);
+		kfree(savp->sp_paga);
+		kfree(savp);
+		return -ENOMEM;
+	}
+	savp->sp_num_pgs = numpgs;
+	BUG_ON(vma->vm_private_data);
+	vma->vm_private_data = savp;
+
+	return 0;
+}
+
 static struct vm_operations_struct privcmd_vm_ops;
 
 static long privcmd_ioctl_mmap_batch(void __user *udata)
@@ -315,6 +356,12 @@ static long privcmd_ioctl_mmap_batch(void __user *udata)
 		goto out;
 	}
 
+	if (xen_pvh_domain()) {
+		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 +412,19 @@ static long privcmd_ioctl(struct file *file,
 	return ret;
 }
 
+static void privcmd_close(struct vm_area_struct *vma)
+{
+	struct xen_pvh_sav_pfn_info *savp;
+
+	if (!xen_pvh_domain() || ((savp=vma->vm_private_data) == NULL))
+		return;
+
+	while (savp->sp_next_todo--) {
+		xen_pfn_t pfn = page_to_pfn(savp->sp_paga[savp->sp_next_todo]);
+		pvh_rem_xen_p2m(pfn, 1);
+	}
+}
+
 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",
@@ -375,13 +435,14 @@ 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))
+	/* Unsupported for auto-translate guests unless PVH */
+	if (xen_feature(XENFEAT_auto_translated_physmap) && !xen_pvh_domain())
 		return -ENOSYS;
 
 	/* DONTCOPY is essential for Xen because copy_page_range doesn't know
@@ -395,6 +456,9 @@ static int privcmd_mmap(struct file *file, struct vm_area_struct *vma)
 
 static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma)
 {
+	if (xen_pvh_domain())
+		return (vma->vm_private_data == NULL);
+
 	return (xchg(&vma->vm_private_data, (void *)1) == NULL);
 }
 
-- 
1.7.2.3