[PATCH v4 7/7] tools, libxl: handle the iomem parameter with the memory_mapping hcall

[Arianna Avanzini <avanzini.arianna@gmail.com>]

Currently, the configuration-parsing code concerning the handling of the
iomem parameter only invokes the XEN_DOMCTL_iomem_permission hypercall.
This commit lets the XEN_DOMCTL_memory_mapping hypercall be invoked
after XEN_DOMCTL_iomem_permission when the iomem parameter is parsed
from a domU configuration file, so that the address range can be mapped
to the address space of the domU. The hypercall is invoked only in case
of domains using an auto-translated physmap.

Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
Cc: Dario Faggioli <dario.faggioli@citrix.com>
Cc: Paolo Valente <paolo.valente@unimore.it>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Julien Grall <julien.grall@citrix.com>
Cc: Ian Campbell <Ian.Campbell@eu.citrix.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Keir Fraser <keir@xen.org>
Cc: Tim Deegan <tim@xen.org>
Cc: Ian Jackson <Ian.Jackson@eu.citrix.com>
Cc: Eric Trudeau <etrudeau@broadcom.com>
Cc: Viktor Kleinik <viktor.kleinik@globallogic.com>

---

    v4:
        - Let the hypercall be called only in case the guest uses an
          auto-translated physmap.

    v3:
        - Add ifdefs to let the hypercall be called only by ARM or x86
          HVM guests, with a whitelist approach.
        - Remove the NOTE comment.

    v2:
        - Add a comment explaining outstanding issues. 

---
 tools/libxl/libxl_create.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index a604cd8..fbabb40 100644
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -1099,6 +1099,19 @@ static void domcreate_launch_dm(libxl__egc *egc, libxl__multidev *multidev,
                  "failed give dom%d access to iomem range %"PRIx64"-%"PRIx64,
                  domid, io->start, io->start + io->number - 1);
             ret = ERROR_FAIL;
+            continue;
+        }
+        if (!libxl__arch_auto_translated_physmap(d_config))
+            continue;
+        ret = xc_domain_memory_mapping(CTX->xch, domid,
+                                       io->gfn, io->start,
+                                       io->number, 1);
+        if (ret < 0) {
+            LOGE(ERROR,
+                 "failed to map to dom%d iomem range %"PRIx64"-%"PRIx64
+                 " to guest address %"PRIx64,
+                 domid, io->start, io->start + io->number - 1, io->gfn);
+            ret = ERROR_FAIL;
         }
     }
 
-- 
1.9.0