xen, gfx passthrough: basic graphics passthrough support

basic gfx passthrough support:
- add a vga type for gfx passthrough
- register/unregister legacy VGA I/O ports and MMIOs for passthrough GFX

Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/vl.c b/vl.c
index 584ca88dda..76e0bb2a89 100644
--- a/vl.c
+++ b/vl.c
@@ -1338,6 +1338,13 @@ static inline void semihosting_arg_fallback(const char *file, const char *cmd)
     }
 }
 
+/* Now we still need this for compatibility with XEN. */
+bool has_igd_gfx_passthru;
+static void igd_gfx_passthru(void)
+{
+    has_igd_gfx_passthru = current_machine->igd_gfx_passthru;
+}
+
 /***********************************************************/
 /* USB devices */
 
@@ -4528,6 +4535,9 @@ int main(int argc, char **argv, char **envp)
             exit(1);
     }
 
+    /* Check if IGD GFX passthrough. */
+    igd_gfx_passthru();
+
     /* init generic devices */
     if (qemu_opts_foreach(qemu_find_opts("device"),
                           device_init_func, NULL, NULL)) {