hw/xen: Add foreignmem operations to allow redirection to internal emulation

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>

1 files changed, 45 insertions, 0 deletions

diff --git a/hw/xen/xen-operations.c b/hw/xen/xen-operations.c
index c5956d28c6..440e566bb1 100644
--- a/hw/xen/xen-operations.c
+++ b/hw/xen/xen-operations.c
@@ -22,6 +22,7 @@
  */
 #undef XC_WANT_COMPAT_EVTCHN_API
 #undef XC_WANT_COMPAT_GNTTAB_API
+#undef XC_WANT_COMPAT_MAP_FOREIGN_API
 
 #include <xenctrl.h>
 
@@ -56,10 +57,13 @@ typedef xc_gnttab xengnttab_handle;
 #define xengnttab_map_domain_grant_refs(h, c, d, r, p) \
     xc_gnttab_map_domain_grant_refs(h, c, d, r, p)
 
+typedef xc_interface xenforeignmemory_handle;
+
 #else /* CONFIG_XEN_CTRL_INTERFACE_VERSION >= 40701 */
 
 #include <xenevtchn.h>
 #include <xengnttab.h>
+#include <xenforeignmemory.h>
 
 #endif
 
@@ -218,6 +222,46 @@ static struct gnttab_backend_ops libxengnttab_backend_ops = {
     .unmap = libxengnttab_backend_unmap,
 };
 
+#if CONFIG_XEN_CTRL_INTERFACE_VERSION < 40701
+
+static void *libxenforeignmem_backend_map(uint32_t dom, void *addr, int prot,
+                                          size_t pages, xfn_pfn_t *pfns,
+                                          int *errs)
+{
+    if (errs) {
+        return xc_map_foreign_bulk(xen_xc, dom, prot, pfns, errs, pages);
+    } else {
+        return xc_map_foreign_pages(xen_xc, dom, prot, pfns, pages);
+    }
+}
+
+static int libxenforeignmem_backend_unmap(void *addr, size_t pages)
+{
+    return munmap(addr, pages * XC_PAGE_SIZE);
+}
+
+#else /* CONFIG_XEN_CTRL_INTERFACE_VERSION >= 40701 */
+
+static void *libxenforeignmem_backend_map(uint32_t dom, void *addr, int prot,
+                                          size_t pages, xen_pfn_t *pfns,
+                                          int *errs)
+{
+    return xenforeignmemory_map2(xen_fmem, dom, addr, prot, 0, pages, pfns,
+                                 errs);
+}
+
+static int libxenforeignmem_backend_unmap(void *addr, size_t pages)
+{
+    return xenforeignmemory_unmap(xen_fmem, addr, pages);
+}
+
+#endif
+
+struct foreignmem_backend_ops libxenforeignmem_backend_ops = {
+    .map = libxenforeignmem_backend_map,
+    .unmap = libxenforeignmem_backend_unmap,
+};
+
 void setup_xen_backend_ops(void)
 {
 #if CONFIG_XEN_CTRL_INTERFACE_VERSION >= 40800
@@ -232,4 +276,5 @@ void setup_xen_backend_ops(void)
 #endif
     xen_evtchn_ops = &libxenevtchn_backend_ops;
     xen_gnttab_ops = &libxengnttab_backend_ops;
+    xen_foreignmem_ops = &libxenforeignmem_backend_ops;
 }