grant-table: call set_phys_to_machine after mapping grant refs

When mapping/unmapping grant refs, call
set_phys_to_machine to update the P2M with the new mappings for
autotranslate guests.
This is (almost) a nop on x86.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

Changes in v9:
- add in-code comments.

1 files changed, 17 insertions, 2 deletions

diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index c4d2298893b1..62ccf5424ba8 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -49,6 +49,7 @@
 #include <xen/grant_table.h>
 #include <xen/interface/memory.h>
 #include <xen/hvc-console.h>
+#include <xen/swiotlb-xen.h>
 #include <asm/xen/hypercall.h>
 #include <asm/xen/interface.h>
 
@@ -898,8 +899,16 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
                         gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, map_ops + i,
                                                 &map_ops[i].status, __func__);
 
-        if (xen_feature(XENFEAT_auto_translated_physmap))
+        /* this is basically a nop on x86 */
+        if (xen_feature(XENFEAT_auto_translated_physmap)) {
+                for (i = 0; i < count; i++) {
+                        if (map_ops[i].status)
+                                continue;
+                        set_phys_to_machine(map_ops[i].host_addr >> PAGE_SHIFT,
+                                        map_ops[i].dev_bus_addr >> PAGE_SHIFT);
+                }
                 return ret;
+        }
 
         if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) {
                 arch_enter_lazy_mmu_mode();
@@ -942,8 +951,14 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
         if (ret)
                 return ret;
 
-        if (xen_feature(XENFEAT_auto_translated_physmap))
+        /* this is basically a nop on x86 */
+        if (xen_feature(XENFEAT_auto_translated_physmap)) {
+                for (i = 0; i < count; i++) {
+                        set_phys_to_machine(unmap_ops[i].host_addr >> PAGE_SHIFT,
+                                        INVALID_P2M_ENTRY);
+                }
                 return ret;
+        }
 
         if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) {
                 arch_enter_lazy_mmu_mode();