xen pvfb: Dynamic mode support (screen resizing)
The pvfb backend indicates dynamic mode support by creating node
feature_resize with a non-zero value in its xenstore directory.
xen-fbfront sends a resize notification event on mode change. Fully
backwards compatible both ways.
Framebuffer size and initial resolution can be controlled through
kernel parameter xen_fbfront.video. The backend enforces a separate
size limit, which it advertises in node videoram in its xenstore
directory.
xen-kbdfront gets the maximum screen resolution from nodes width and
height in the backend's xenstore directory instead of hardcoding it.
Additional goodie: support for larger framebuffers (512M on a 64-bit
system with 4K pages).
Changing the number of bits per pixels dynamically is not supported,
yet.
Ported from
http://xenbits.xensource.com/linux-2.6.18-xen.hg?rev/92f7b3144f41
http://xenbits.xensource.com/linux-2.6.18-xen.hg?rev/bfc040135633
Signed-off-by: Pat Campbell <plc@novell.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/xen/interface/io/fbif.h b/include/xen/interface/io/fbif.h
index 5a934dd..974a51e 100644
--- a/include/xen/interface/io/fbif.h
+++ b/include/xen/interface/io/fbif.h
@@ -49,11 +49,27 @@
int32_t height; /* rect height */
};
+/*
+ * Framebuffer resize notification event
+ * Capable backend sets feature-resize in xenstore.
+ */
+#define XENFB_TYPE_RESIZE 3
+
+struct xenfb_resize {
+ uint8_t type; /* XENFB_TYPE_RESIZE */
+ int32_t width; /* width in pixels */
+ int32_t height; /* height in pixels */
+ int32_t stride; /* stride in bytes */
+ int32_t depth; /* depth in bits */
+ int32_t offset; /* start offset within framebuffer */
+};
+
#define XENFB_OUT_EVENT_SIZE 40
union xenfb_out_event {
uint8_t type;
struct xenfb_update update;
+ struct xenfb_resize resize;
char pad[XENFB_OUT_EVENT_SIZE];
};
@@ -105,15 +121,18 @@
* Each directory page holds PAGE_SIZE / sizeof(*pd)
* framebuffer pages, and can thus map up to PAGE_SIZE *
* PAGE_SIZE / sizeof(*pd) bytes. With PAGE_SIZE == 4096 and
- * sizeof(unsigned long) == 4, that's 4 Megs. Two directory
- * pages should be enough for a while.
+ * sizeof(unsigned long) == 4/8, that's 4 Megs 32 bit and 2
+ * Megs 64 bit. 256 directories give enough room for a 512
+ * Meg framebuffer with a max resolution of 12,800x10,240.
+ * Should be enough for a while with room leftover for
+ * expansion.
*/
- unsigned long pd[2];
+ unsigned long pd[256];
};
/*
- * Wart: xenkbd needs to know resolution. Put it here until a better
- * solution is found, but don't leak it to the backend.
+ * Wart: xenkbd needs to know default resolution. Put it here until a
+ * better solution is found, but don't leak it to the backend.
*/
#ifdef __KERNEL__
#define XENFB_WIDTH 800