[PATCH 1/2] memory: Allow a MemoryRegion to be marked no_vhost

[Wang Xin <wangxinxin.wang@huawei.com>]

Allow a memory region to be marked as 'no_vhost' and
exclude that region from vhost's list build.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Wang Xin <wangxinxin.wang@huawei.com>
---
 hw/virtio/vhost.c     |  5 ++++-
 include/exec/memory.h | 21 +++++++++++++++++++++
 softmmu/memory.c      | 15 +++++++++++++++
 3 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 1a1384e7a6..bd50532a30 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -415,7 +415,10 @@ static bool vhost_section(struct vhost_dev *dev, MemoryRegionSection *section)
 {
     MemoryRegion *mr = section->mr;
 
-    if (memory_region_is_ram(mr) && !memory_region_is_rom(mr)) {
+    if (memory_region_is_ram(mr) &&
+        !memory_region_is_rom(mr) &&
+        !memory_region_is_no_vhost(mr)) {
+
         uint8_t dirty_mask = memory_region_get_dirty_log_mask(mr);
         uint8_t handled_dirty;
 
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 0cfe987ab4..7258fd6996 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -380,6 +380,7 @@ struct MemoryRegion {
     bool global_locking;
     uint8_t dirty_log_mask;
     bool is_iommu;
+    bool no_vhost;
     RAMBlock *ram_block;
     Object *owner;
 
@@ -1205,6 +1206,26 @@ static inline bool memory_region_is_romd(MemoryRegion *mr)
     return mr->rom_device && mr->romd_mode;
 }
 
+/**
+ * memory_region_set_no_vhost: Make vhost ignore a memory region
+ *
+ * Makes vhost ignore a memory region, useful if it isn't real
+ * DMAble memory and is at inconvenient addresses
+ *
+ * @mr: the region being updated.
+ * @no_vhost: true to ignore
+ */
+void memory_region_set_no_vhost(MemoryRegion *mr, bool no_vhost);
+
+/**
+ * memory_region_is_no_vhost: Test if memory region is marked no vhost
+ *
+ * Test if the no_vhost flag is set on the memory region
+ *
+ * @mr: the region being tested.
+ */
+bool memory_region_is_no_vhost(const MemoryRegion *mr);
+
 /**
  * memory_region_get_iommu: check whether a memory region is an iommu
  *
diff --git a/softmmu/memory.c b/softmmu/memory.c
index 70b93104e8..5debe22978 100644
--- a/softmmu/memory.c
+++ b/softmmu/memory.c
@@ -2125,6 +2125,21 @@ void memory_region_rom_device_set_romd(MemoryRegion *mr, bool romd_mode)
     }
 }
 
+void memory_region_set_no_vhost(MemoryRegion *mr, bool no_vhost)
+{
+    if (mr->no_vhost != no_vhost) {
+        memory_region_transaction_begin();
+        mr->no_vhost = no_vhost;
+        memory_region_update_pending |= mr->enabled;
+        memory_region_transaction_commit();
+    }
+}
+
+bool memory_region_is_no_vhost(const MemoryRegion *mr)
+{
+    return mr->no_vhost;
+}
+
 void memory_region_reset_dirty(MemoryRegion *mr, hwaddr addr,
                                hwaddr size, unsigned client)
 {
-- 
2.26.0.windows.1