x86/xen: map foreign pfns for autotranslated guests
When running as a dom0 in PVH mode, foreign pfns that are accessed
must be added to our p2m which is managed by xen. This is done via
XENMEM_add_to_physmap_range hypercall. This is needed for toolstack
building guests and mapping guest memory, xentrace mapping xen pages,
etc.
Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index d916024..6f6e15d 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -2510,6 +2510,95 @@
}
#endif
+#ifdef CONFIG_XEN_PVH
+/*
+ * Map foreign gfn (fgfn), to local pfn (lpfn). This for the user
+ * space creating new guest on pvh dom0 and needing to map domU pages.
+ */
+static int xlate_add_to_p2m(unsigned long lpfn, unsigned long fgfn,
+ unsigned int domid)
+{
+ int rc, err = 0;
+ xen_pfn_t gpfn = lpfn;
+ xen_ulong_t idx = fgfn;
+
+ struct xen_add_to_physmap_range xatp = {
+ .domid = DOMID_SELF,
+ .foreign_domid = domid,
+ .size = 1,
+ .space = XENMAPSPACE_gmfn_foreign,
+ };
+ 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 < 0)
+ return rc;
+ return err;
+}
+
+static int xlate_remove_from_p2m(unsigned long spfn, int count)
+{
+ struct xen_remove_from_physmap xrp;
+ int i, rc;
+
+ for (i = 0; i < count; i++) {
+ xrp.domid = DOMID_SELF;
+ xrp.gpfn = spfn+i;
+ rc = HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &xrp);
+ if (rc)
+ break;
+ }
+ return rc;
+}
+
+struct xlate_remap_data {
+ unsigned long fgfn; /* foreign domain's gfn */
+ pgprot_t prot;
+ domid_t domid;
+ int index;
+ struct page **pages;
+};
+
+static int xlate_map_pte_fn(pte_t *ptep, pgtable_t token, unsigned long addr,
+ void *data)
+{
+ int rc;
+ struct xlate_remap_data *remap = data;
+ unsigned long pfn = page_to_pfn(remap->pages[remap->index++]);
+ pte_t pteval = pte_mkspecial(pfn_pte(pfn, remap->prot));
+
+ rc = xlate_add_to_p2m(pfn, remap->fgfn, remap->domid);
+ if (rc)
+ return rc;
+ native_set_pte(ptep, pteval);
+
+ return 0;
+}
+
+static int xlate_remap_gfn_range(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long mfn,
+ int nr, pgprot_t prot, unsigned domid,
+ struct page **pages)
+{
+ int err;
+ struct xlate_remap_data pvhdata;
+
+ BUG_ON(!pages);
+
+ pvhdata.fgfn = mfn;
+ pvhdata.prot = prot;
+ pvhdata.domid = domid;
+ pvhdata.index = 0;
+ pvhdata.pages = pages;
+ err = apply_to_page_range(vma->vm_mm, addr, nr << PAGE_SHIFT,
+ xlate_map_pte_fn, &pvhdata);
+ flush_tlb_all();
+ return err;
+}
+#endif
+
#define REMAP_BATCH_SIZE 16
struct remap_data {
@@ -2544,11 +2633,18 @@
unsigned long range;
int err = 0;
- if (xen_feature(XENFEAT_auto_translated_physmap))
- return -EINVAL;
-
BUG_ON(!((vma->vm_flags & (VM_PFNMAP | VM_IO)) == (VM_PFNMAP | VM_IO)));
+ if (xen_feature(XENFEAT_auto_translated_physmap)) {
+#ifdef CONFIG_XEN_PVH
+ /* We need to update the local page tables and the xen HAP */
+ return xlate_remap_gfn_range(vma, addr, mfn, nr, prot,
+ domid, pages);
+#else
+ return -EINVAL;
+#endif
+ }
+
rmd.mfn = mfn;
rmd.prot = prot;
@@ -2586,6 +2682,25 @@
if (!pages || !xen_feature(XENFEAT_auto_translated_physmap))
return 0;
+#ifdef CONFIG_XEN_PVH
+ while (numpgs--) {
+ /*
+ * The mmu has already cleaned up the process mmu
+ * resources at this point (lookup_address will return
+ * NULL).
+ */
+ unsigned long pfn = page_to_pfn(pages[numpgs]);
+
+ xlate_remove_from_p2m(pfn, 1);
+ }
+ /*
+ * We don't need to flush tlbs because as part of
+ * xlate_remove_from_p2m, the hypervisor will do tlb flushes
+ * after removing the p2m entries from the EPT/NPT
+ */
+ return 0;
+#else
return -EINVAL;
+#endif
}
EXPORT_SYMBOL_GPL(xen_unmap_domain_mfn_range);