vga optimization (Glauber Costa)

Hypervisors like KVM perform badly while doing mmio on
a loop, because it'll generate an exit on each access.
This is the case with VGA, which results in very bad
performance.

In this patch, we map the linear frame buffer as RAM,
make sure it has dirty region tracking enabled, and then
just let the region to be written.

Cleanups suggestions by:
  Stefano Stabellini <stefano.stabellini@eu.citrix.com>

Signed-off-by: Glauber Costa <glommer@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5793 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 2 insertions, 0 deletions

diff --git a/cpu-all.h b/cpu-all.h
index aa4b770fe2..5fa1e69372 100644
--- a/cpu-all.h
+++ b/cpu-all.h
@@ -948,6 +948,8 @@ int cpu_physical_memory_set_dirty_tracking(int enable);
 
 int cpu_physical_memory_get_dirty_tracking(void);
 
+void cpu_physical_sync_dirty_bitmap(target_phys_addr_t start_addr, target_phys_addr_t end_addr);
+
 void dump_exec_info(FILE *f,
                     int (*cpu_fprintf)(FILE *f, const char *fmt, ...));