xen: unify foreign GFN map/unmap for auto-xlated physmap guests

Auto-translated physmap guests (arm, arm64 and x86 PVHVM/PVH) map and
unmap foreign GFNs using the same method (updating the physmap).
Unify the two arm and x86 implementations into one commont one.

Note that on arm and arm64, the correct error code will be returned
(instead of always -EFAULT) and map/unmap failure warnings are no
longer printed.  These changes are required if the foreign domain is
paging (-ENOENT failures are expected and must be propagated up to the
caller).

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

1 files changed, 3 insertions, 87 deletions

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 263a2044c65b..5c04389fc9ef 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -53,105 +53,21 @@ EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);
 
 static __read_mostly int xen_events_irq = -1;
 
-/* map fgmfn of domid to lpfn in the current domain */
-static int map_foreign_page(unsigned long lpfn, unsigned long fgmfn,
-			    unsigned int domid)
-{
-	int rc;
-	struct xen_add_to_physmap_range xatp = {
-		.domid = DOMID_SELF,
-		.foreign_domid = domid,
-		.size = 1,
-		.space = XENMAPSPACE_gmfn_foreign,
-	};
-	xen_ulong_t idx = fgmfn;
-	xen_pfn_t gpfn = lpfn;
-	int err = 0;
-
-	set_xen_guest_handle(xatp.idxs, &idx);
-	set_xen_guest_handle(xatp.gpfns, &gpfn);
-	set_xen_guest_handle(xatp.errs, &err);
-
-	rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp);
-	if (rc || err) {
-		pr_warn("Failed to map pfn to mfn rc:%d:%d pfn:%lx mfn:%lx\n",
-			rc, err, lpfn, fgmfn);
-		return 1;
-	}
-	return 0;
-}
-
-struct remap_data {
-	xen_pfn_t fgmfn; /* foreign domain's gmfn */
-	pgprot_t prot;
-	domid_t  domid;
-	struct vm_area_struct *vma;
-	int index;
-	struct page **pages;
-	struct xen_remap_mfn_info *info;
-};
-
-static int remap_pte_fn(pte_t *ptep, pgtable_t token, unsigned long addr,
-			void *data)
-{
-	struct remap_data *info = data;
-	struct page *page = info->pages[info->index++];
-	unsigned long pfn = page_to_pfn(page);
-	pte_t pte = pte_mkspecial(pfn_pte(pfn, info->prot));
-
-	if (map_foreign_page(pfn, info->fgmfn, info->domid))
-		return -EFAULT;
-	set_pte_at(info->vma->vm_mm, addr, ptep, pte);
-
-	return 0;
-}
-
 int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
 			       unsigned long addr,
 			       xen_pfn_t mfn, int nr,
 			       pgprot_t prot, unsigned domid,
 			       struct page **pages)
 {
-	int err;
-	struct remap_data data;
-
-	/* TBD: Batching, current sole caller only does page at a time */
-	if (nr > 1)
-		return -EINVAL;
-
-	data.fgmfn = mfn;
-	data.prot = prot;
-	data.domid = domid;
-	data.vma = vma;
-	data.index = 0;
-	data.pages = pages;
-	err = apply_to_page_range(vma->vm_mm, addr, nr << PAGE_SHIFT,
-				  remap_pte_fn, &data);
-	return err;
+	return xen_xlate_remap_gfn_range(vma, addr, mfn, nr,
+					 prot, domid, pages);
 }
 EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
 
 int xen_unmap_domain_mfn_range(struct vm_area_struct *vma,
 			       int nr, struct page **pages)
 {
-	int i;
-
-	for (i = 0; i < nr; i++) {
-		struct xen_remove_from_physmap xrp;
-		unsigned long rc, pfn;
-
-		pfn = page_to_pfn(pages[i]);
-
-		xrp.domid = DOMID_SELF;
-		xrp.gpfn = pfn;
-		rc = HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &xrp);
-		if (rc) {
-			pr_warn("Failed to unmap pfn:%lx rc:%ld\n",
-				pfn, rc);
-			return rc;
-		}
-	}
-	return 0;
+	return xen_xlate_unmap_gfn_range(vma, nr, pages);
 }
 EXPORT_SYMBOL_GPL(xen_unmap_domain_mfn_range);