video: fix handling framebuffer located above 4GB

On some machines (for example Thinkpad P52), UEFI GOP reports
framebuffer located above 4GB (0x4000000000 on that machine). This
address does not fit in {xen,dom0}_vga_console_info.u.vesa_lfb.lfb_base
field, which is 32bit. The overflow here cause all kind of memory
corruption when anything tries to write something on the screen,
starting with zeroing the whole framebuffer in vesa_init().

Fix this similar to how it's done in Linux: add ext_lfb_base field at
the end of the structure, to hold upper 32bits of the address. Since the
field is added at the end of the structure, it will work with older
Linux versions too (other than using possibly truncated address - no
worse than without this change). Thanks to ABI containing size of the
structure (start_info.console.dom0.info_size), Linux can detect when
this field is present and use it appropriately then.

Since this change public interface and use __XEN_INTERFACE_VERSION__,
bump __XEN_LATEST_INTERFACE_VERSION__.

Note: if/when backporting this change to Xen <= 4.12, #if in xen.h needs
to be extended with " || defined(__XEN__)".

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

diff --git a/xen/arch/x86/efi/efi-boot.h b/xen/arch/x86/efi/efi-boot.h
index 5789d2cb70726a556785e823ee4eafcdb514aa6c..7a13a30bc077f1233cc00fcbe94b2fbc54238e8b 100644 (file)
--- a/xen/arch/x86/efi/efi-boot.h
+++ b/xen/arch/x86/efi/efi-boot.h
@@ -550,6 +550,7 @@ static void __init efi_arch_video_init(EFI_GRAPHICS_OUTPUT_PROTOCOL *gop,
         vga_console_info.u.vesa_lfb.bytes_per_line =
             (mode_info->PixelsPerScanLine * bpp + 7) >> 3;
         vga_console_info.u.vesa_lfb.lfb_base = gop->Mode->FrameBufferBase;
+        vga_console_info.u.vesa_lfb.ext_lfb_base = gop->Mode->FrameBufferBase >> 32;
         vga_console_info.u.vesa_lfb.lfb_size =
             (gop->Mode->FrameBufferSize + 0xffff) >> 16;
     }

diff --git a/xen/drivers/video/vesa.c b/xen/drivers/video/vesa.c
index 26d4962b0e9f04dbbc98935e387f8ca92ceb384c..fd2cb1312d56a6eff7140b731d8965341bff82de 100644 (file)
--- a/xen/drivers/video/vesa.c
+++ b/xen/drivers/video/vesa.c
@@ -40,6 +40,11 @@ static int __init parse_font_height(const char *s)
 }
 custom_param("font", parse_font_height);
 
+static inline paddr_t lfb_base(void)
+{
+    return ((paddr_t)vlfb_info.ext_lfb_base << 32) | vlfb_info.lfb_base;
+}
+
 void __init vesa_early_init(void)
 {
     unsigned int vram_vmode;
@@ -97,15 +102,14 @@ void __init vesa_init(void)
     lfbp.text_columns = vlfb_info.width / font->width;
     lfbp.text_rows = vlfb_info.height / font->height;
 
-    lfbp.lfb = lfb = ioremap(vlfb_info.lfb_base, vram_remap);
+    lfbp.lfb = lfb = ioremap(lfb_base(), vram_remap);
     if ( !lfb )
         return;
 
     memset(lfb, 0, vram_remap);
 
-    printk(XENLOG_INFO "vesafb: framebuffer at %#x, mapped to 0x%p, "
-           "using %uk, total %uk\n",
-           vlfb_info.lfb_base, lfb,
+    printk(XENLOG_INFO "vesafb: framebuffer at 0x%" PRIpaddr ", mapped to 0x%p, using %uk, total %uk\n",
+           lfb_base(), lfb,
            vram_remap >> 10, vram_total >> 10);
     printk(XENLOG_INFO "vesafb: mode is %dx%dx%u, linelength=%d, font %ux%u\n",
            vlfb_info.width, vlfb_info.height,
@@ -167,7 +171,7 @@ void __init vesa_mtrr_init(void)
 
     /* Try and find a power of two to add */
     do {
-        rc = mtrr_add(vlfb_info.lfb_base, size_total, type, 1);
+        rc = mtrr_add(lfb_base(), size_total, type, 1);
         size_total >>= 1;
     } while ( (size_total >= PAGE_SIZE) && (rc == -EINVAL) );
 }

diff --git a/xen/include/public/xen-compat.h b/xen/include/public/xen-compat.h
index 6fabca1889484de00a11a9c831fd21d12a125a53..6708132394df7938b2b0cc827ac4f6eb4b934ce6 100644 (file)
--- a/xen/include/public/xen-compat.h
+++ b/xen/include/public/xen-compat.h
@@ -27,7 +27,7 @@
 #ifndef __XEN_PUBLIC_XEN_COMPAT_H__
 #define __XEN_PUBLIC_XEN_COMPAT_H__
 
-#define __XEN_LATEST_INTERFACE_VERSION__ 0x00040a00
+#define __XEN_LATEST_INTERFACE_VERSION__ 0x00040d00
 
 #if defined(__XEN__) || defined(__XEN_TOOLS__)
 /* Xen is built with matching headers and implements the latest interface. */

diff --git a/xen/include/public/xen.h b/xen/include/public/xen.h
index ccdffc0ad116abdc7f5f75daebdb3544948627e1..cb2917e74b810b17e2ad752be0cce12a2d3c2ca8 100644 (file)
--- a/xen/include/public/xen.h
+++ b/xen/include/public/xen.h
@@ -922,6 +922,11 @@ typedef struct dom0_vga_console_info {
             uint32_t gbl_caps;
             /* Mode attributes (offset 0x0, VESA command 0x4f01). */
             uint16_t mode_attrs;
+            uint16_t pad;
+#endif
+#if __XEN_INTERFACE_VERSION__ >= 0x00040d00
+            /* high 32 bits of lfb_base */
+            uint32_t ext_lfb_base;
 #endif
         } vesa_lfb;
     } u;