[Qemu-devel] [RFC 4/4] exec: Flush data cache when needed

["Jérémy Fanguède" <j.fanguede@virtualopensystems.com>]

Flush the data cache when accesses occur in the guest ram memory.

Signed-off-by: Jérémy Fanguède <j.fanguede@virtualopensystems.com>
---
 exec.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/exec.c b/exec.c
index ae37b98..0f859a3 100644
--- a/exec.c
+++ b/exec.c
@@ -2372,6 +2372,9 @@ MemTxResult address_space_rw(AddressSpace *as, hwaddr addr, MemTxAttrs attrs,
                 ptr = qemu_get_ram_ptr(addr1);
                 memcpy(ptr, buf, l);
                 invalidate_and_set_dirty(addr1, l);
+                if (kvm_enabled()) {
+                    kvm_arch_cache_flush_needed(addr, l, is_write);
+                }
             }
         } else {
             if (!memory_access_is_direct(mr, is_write)) {
@@ -2408,6 +2411,9 @@ MemTxResult address_space_rw(AddressSpace *as, hwaddr addr, MemTxAttrs attrs,
             } else {
                 /* RAM case */
                 ptr = qemu_get_ram_ptr(mr->ram_addr + addr1);
+                if (kvm_enabled()) {
+                    kvm_arch_cache_flush_needed(addr, l, is_write);
+                }
                 memcpy(buf, ptr, l);
             }
         }
@@ -2646,6 +2652,14 @@ void *address_space_map(AddressSpace *as,
         return bounce.buffer;
     }
 
+    /* Need to be flushed only if we are reading */
+    if (!is_write) {
+        /* Don't flush if it's a cpu_physical_memory_map call */
+        if (kvm_enabled() && as != &address_space_memory) {
+            kvm_arch_cache_flush_needed(addr, l, is_write);
+        }
+    }
+
     base = xlat;
     raddr = memory_region_get_ram_addr(mr);
 
@@ -2679,6 +2693,7 @@ void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len,
     if (buffer != bounce.buffer) {
         MemoryRegion *mr;
         ram_addr_t addr1;
+        hwaddr base;
 
         mr = qemu_ram_addr_from_host(buffer, &addr1);
         assert(mr != NULL);
@@ -2688,6 +2703,10 @@ void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len,
         if (xen_enabled()) {
             xen_invalidate_map_cache_entry(buffer);
         }
+        if (kvm_enabled() && as != &address_space_memory) {
+            base = object_property_get_int(OBJECT(mr), "addr", NULL);
+            kvm_arch_cache_flush_needed(addr1 + base, access_len, is_write);
+        }
         memory_region_unref(mr);
         return;
     }
-- 
1.9.1