[PATCH v3 18/20] vfio: Add a new element bypass_ro in VFIOContainerBase

[Zhenzhong Duan <zhenzhong.duan@intel.com>]

When bypass_ro is true, read only memory section is bypassed from
mapping in the container.

This is a preparing patch to workaround Intel ERRATA_772415.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
---
 hw/vfio/listener.c                    | 13 +++++++++----
 include/hw/vfio/vfio-container-base.h |  1 +
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/hw/vfio/listener.c b/hw/vfio/listener.c
index f498e23a93..c64aa4539e 100644
--- a/hw/vfio/listener.c
+++ b/hw/vfio/listener.c
@@ -364,7 +364,8 @@ static bool vfio_known_safe_misalignment(MemoryRegionSection *section)
     return true;
 }
 
-static bool vfio_listener_valid_section(MemoryRegionSection *section,
+static bool vfio_listener_valid_section(VFIOContainerBase *bcontainer,
+                                        MemoryRegionSection *section,
                                         const char *name)
 {
     if (vfio_listener_skipped_section(section)) {
@@ -375,6 +376,10 @@ static bool vfio_listener_valid_section(MemoryRegionSection *section,
         return false;
     }
 
+    if (bcontainer && bcontainer->bypass_ro && section->readonly) {
+        return false;
+    }
+
     if (unlikely((section->offset_within_address_space &
                   ~qemu_real_host_page_mask()) !=
                  (section->offset_within_region & ~qemu_real_host_page_mask()))) {
@@ -494,7 +499,7 @@ void vfio_container_region_add(VFIOContainerBase *bcontainer,
     int ret;
     Error *err = NULL;
 
-    if (!vfio_listener_valid_section(section, "region_add")) {
+    if (!vfio_listener_valid_section(bcontainer, section, "region_add")) {
         return;
     }
 
@@ -655,7 +660,7 @@ static void vfio_listener_region_del(MemoryListener *listener,
     int ret;
     bool try_unmap = true;
 
-    if (!vfio_listener_valid_section(section, "region_del")) {
+    if (!vfio_listener_valid_section(bcontainer, section, "region_del")) {
         return;
     }
 
@@ -812,7 +817,7 @@ static void vfio_dirty_tracking_update(MemoryListener *listener,
         container_of(listener, VFIODirtyRangesListener, listener);
     hwaddr iova, end;
 
-    if (!vfio_listener_valid_section(section, "tracking_update") ||
+    if (!vfio_listener_valid_section(NULL, section, "tracking_update") ||
         !vfio_get_section_iova_range(dirty->bcontainer, section,
                                      &iova, &end, NULL)) {
         return;
diff --git a/include/hw/vfio/vfio-container-base.h b/include/hw/vfio/vfio-container-base.h
index bded6e993f..31fd784d76 100644
--- a/include/hw/vfio/vfio-container-base.h
+++ b/include/hw/vfio/vfio-container-base.h
@@ -51,6 +51,7 @@ typedef struct VFIOContainerBase {
     QLIST_HEAD(, VFIODevice) device_list;
     GList *iova_ranges;
     NotifierWithReturn cpr_reboot_notifier;
+    bool bypass_ro;
 } VFIOContainerBase;
 
 typedef struct VFIOGuestIOMMU {
-- 
2.47.1