kvm tools, ui: Add support for SDL framebuffer output target

This patch adds support for SDL based framebuffer. Use the '--sdl' command line
option to enable the feature.

Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: John Floren <john@jfloren.net>
Cc: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

Makefile

@@ -71,6 +71,14 @@ ifeq ($(has_vncserver),y)
 	LIBS	+= -lvncserver
 endif
 
+FLAGS_SDL=$(CFLAGS) -lSDL
+has_SDL := $(call try-cc,$(SOURCE_SDL),$(FLAGS_SDL))
+ifeq ($(has_SDL),y)
+	OBJS	+= ui/sdl.o
+	CFLAGS	+= -DCONFIG_HAS_SDL
+	LIBS	+= -lSDL
+endif
+
 DEPS	:= $(patsubst %.o,%.d,$(OBJS))
 
 # Exclude BIOS object files from header dependencies.

config/feature-tests.mak

@@ -136,3 +136,13 @@ int main(void)
 	return 0;
 }
 endef
+
+define SOURCE_SDL
+#include <SDL/SDL.h>
+
+int main(void)
+{
+	SDL_Init(SDL_INIT_VIDEO);
+	return 0;
+}
+endef

include/kvm/sdl.h

@@ -0,0 +1,17 @@
+#ifndef KVM__SDL_H
+#define KVM__SDL_H
+
+#include "kvm/util.h"
+
+struct framebuffer;
+
+#ifdef CONFIG_HAS_SDL
+void sdl__init(struct framebuffer *fb);
+#else
+static inline void sdl__init(struct framebuffer *fb)
+{
+	die("SDL support not compiled in. (install the SDL-dev[el] package)");
+}
+#endif
+
+#endif /* KVM__SDL_H */

kvm-run.c

@@ -32,6 +32,7 @@
 #include <kvm/ioeventfd.h>
 #include <kvm/i8042.h>
 #include <kvm/vnc.h>
+#include <kvm/sdl.h>
 #include <kvm/framebuffer.h>
 
 /* header files for gitish interface  */
@@ -72,6 +73,7 @@ static const char *virtio_9p_dir;
 static bool single_step;
 static bool readonly_image[MAX_DISK_IMAGES];
 static bool vnc;
+static bool sdl;
 extern bool ioport_debug;
 extern int  active_console;
 
@@ -117,6 +119,7 @@ static const struct option options[] = {
 	OPT_STRING('\0', "virtio-9p", &virtio_9p_dir, "root dir",
 			"Enable 9p over virtio"),
 	OPT_BOOLEAN('\0', "vnc", &vnc, "Enable VNC framebuffer"),
+	OPT_BOOLEAN('\0', "sdl", &sdl, "Enable SDL framebuffer"),
 
 	OPT_GROUP("Kernel options:"),
 	OPT_STRING('k', "kernel", &kernel_filename, "kernel",
@@ -538,7 +541,7 @@ int kvm_cmd_run(int argc, const char **argv, const char *prefix)
 
 	memset(real_cmdline, 0, sizeof(real_cmdline));
 	strcpy(real_cmdline, "notsc noapic noacpi pci=conf1");
-	if (vnc) {
+	if (vnc || sdl) {
 		strcat(real_cmdline, " video=vesafb console=tty0");
 		vidmode = 0x312;
 	} else {
@@ -630,13 +633,19 @@ int kvm_cmd_run(int argc, const char **argv, const char *prefix)
 
 	kvm__init_ram(kvm);
 
+	if (vnc || sdl)
+		fb = vesa__init(kvm);
+
 	if (vnc) {
 		kbd__init(kvm);
-		fb = vesa__init(kvm);
+		if (fb)
+			vnc__init(fb);
 	}
 
-	if (fb)
-		vnc__init(fb);
+	if (sdl) {
+		if (fb)
+			sdl__init(fb);
+	}
 
 	fb__start();
 

ui/sdl.c

@@ -0,0 +1,76 @@
+#include "kvm/sdl.h"
+
+#include "kvm/framebuffer.h"
+#include "kvm/util.h"
+
+#include <SDL/SDL.h>
+#include <pthread.h>
+
+#define FRAME_RATE		25
+
+static void sdl__write(struct framebuffer *fb, u64 addr, u8 *data, u32 len)
+{
+	memcpy(&fb->mem[addr - fb->mem_addr], data, len);
+}
+
+static void *sdl__thread(void *p)
+{
+	Uint32 rmask, gmask, bmask, amask;
+	struct framebuffer *fb = p;
+	SDL_Surface *guest_screen;
+	SDL_Surface *screen;
+	SDL_Event ev;
+	Uint32 flags;
+
+	if (SDL_Init(SDL_INIT_VIDEO) != 0)
+		die("Unable to initialize SDL");
+
+	rmask = 0x000000ff;
+	gmask = 0x0000ff00;
+	bmask = 0x00ff0000;
+	amask = 0x00000000;
+
+	guest_screen = SDL_CreateRGBSurfaceFrom(fb->mem, fb->width, fb->height, fb->depth, fb->width * fb->depth / 8, rmask, gmask, bmask, amask);
+	if (!guest_screen)
+		die("Unable to create SDL RBG surface");
+
+	flags = SDL_HWSURFACE | SDL_ASYNCBLIT | SDL_HWACCEL;
+
+	screen = SDL_SetVideoMode(fb->width, fb->height, fb->depth, flags);
+	if (!screen)
+		die("Unable to set SDL video mode");
+
+	for (;;) {
+		SDL_BlitSurface(guest_screen, NULL, screen, NULL);
+		SDL_UpdateRect(screen, 0, 0, 0, 0);
+		while (SDL_PollEvent(&ev)) {
+			switch (ev.type) {
+			case SDL_QUIT:
+				goto exit;
+			}
+		}
+		SDL_Delay(1000 / FRAME_RATE);
+	}
+exit:
+	return NULL;
+}
+
+static int sdl__start(struct framebuffer *fb)
+{
+	pthread_t thread;
+
+	if (pthread_create(&thread, NULL, sdl__thread, fb) != 0)
+		return -1;
+
+	return 0;
+}
+
+static struct fb_target_operations sdl_ops = {
+	.start			= sdl__start,
+	.write			= sdl__write,
+};
+
+void sdl__init(struct framebuffer *fb)
+{
+	fb__attach(fb, &sdl_ops);
+}