[PATCH] x86/xen: support priv-mapping in an HVM tools domain

[Paul Durrant]

If the domain has XENFEAT_auto_translated_physmap then use of the PV-
specific HYPERVISOR_mmu_update hypercall is clearly incorrect.

This patch adds checks in xen_remap_domain_gfn_array() and
xen_unmap_domain_gfn_array() which call through to the approprate
xlate_mmu function if the feature is present. A check is also added
to xen_remap_domain_gfn_range() to fail with -EOPNOTSUPP since this
should not be used in an HVM tools domain.

Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
---
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
---
 arch/x86/xen/mmu.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 3e15345abfe7..d33e7dbe3129 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -172,6 +172,9 @@ int xen_remap_domain_gfn_range(struct vm_area_struct *vma,
 			       pgprot_t prot, unsigned domid,
 			       struct page **pages)
 {
+	if (xen_feature(XENFEAT_auto_translated_physmap))
+		return -EOPNOTSUPP;
+
 	return do_remap_gfn(vma, addr, &gfn, nr, NULL, prot, domid, pages);
 }
 EXPORT_SYMBOL_GPL(xen_remap_domain_gfn_range);
@@ -182,6 +185,10 @@ int xen_remap_domain_gfn_array(struct vm_area_struct *vma,
 			       int *err_ptr, pgprot_t prot,
 			       unsigned domid, struct page **pages)
 {
+	if (xen_feature(XENFEAT_auto_translated_physmap))
+		return xen_xlate_remap_gfn_array(vma, addr, gfn, nr, err_ptr,
+						 prot, domid, pages);
+
 	/* We BUG_ON because it's a programmer error to pass a NULL err_ptr,
 	 * and the consequences later is quite hard to detect what the actual
 	 * cause of "wrong memory was mapped in".
@@ -193,9 +200,12 @@ EXPORT_SYMBOL_GPL(xen_remap_domain_gfn_array);
 
 /* Returns: 0 success */
 int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
-			       int numpgs, struct page **pages)
+			       int nr, struct page **pages)
 {
-	if (!pages || !xen_feature(XENFEAT_auto_translated_physmap))
+	if (xen_feature(XENFEAT_auto_translated_physmap))
+		return xen_xlate_unmap_gfn_range(vma, nr, pages);
+
+	if (!pages)
 		return 0;
 
 	return -EINVAL;
-- 
2.11.0