From 4d08ebd4f8dc19dfc36495473b34c34d53650632 Mon Sep 17 00:00:00 2001

From: Ladi Prosek <lprosek@redhat.com>

Date: Mon, 31 Oct 2016 19:33:05 +0100

Subject: vgabios: Reorder video modes to work around a Windows bug

RH-Author: Ladi Prosek <lprosek@redhat.com>

Message-id: <1477924385-6169-1-git-send-email-lprosek@redhat.com>

Patchwork-id: 72677

O-Subject: [RHEL-7.4/7.3.z seabios PATCH] vgabios: Reorder video modes to work around a Windows bug

Bugzilla: 1392028

RH-Acked-by: Laszlo Ersek <lersek@redhat.com>

RH-Acked-by: Gerd Hoffmann <kraxel@redhat.com>

RH-Acked-by: vrozenfe <vrozenfe@redhat.com>

Windows Server 2016 and Windows 10 RS1 come with a bug in its blue screen

of death rendering logic which prevents it from generating crash dumps.

The bug does not manifest if Windows sees a suitable 32 bpp video mode

before a suitable 24 bpp video mode in the list of modes returned from

vgabios. This commit moves all 32 bpp modes to the front of the list to

make sure that this is always the case.

Upstream patch:

https://www.coreboot.org/pipermail/seabios/2016-October/010963.html

There are valid concerns upstream about the breaking nature of the fix

but for the limited set of operating systems supported by RHEL/RHEV we

can easily verify that they are unaffected. So as things stand now, this

is a downstream-only patch which will be reverted in the near future;

the exact time will depend on Windows 10 RS2 schedule and other factors.

The goal is to make sure that our customers running Windows 10 VMs can

generate crash dumps.

Signed-off-by: Ladi Prosek <lprosek@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

diff --git a/vgasrc/svgamodes.c b/vgasrc/svgamodes.c

index 6e494c7..008f1b9 100644

--- a/vgasrc/svgamodes.c

+++ b/vgasrc/svgamodes.c

@@ -12,6 +12,25 @@

 #include "svgamodes.h"

 struct generic_svga_mode svga_modes[] VAR16 = {

+    /* 32 bpp BOCHS modes */

+    { 0x140, { MM_DIRECT, 320,  200,  32, 8, 16, SEG_GRAPH } },

+    { 0x141, { MM_DIRECT, 640,  400,  32, 8, 16, SEG_GRAPH } },

+    { 0x142, { MM_DIRECT, 640,  480,  32, 8, 16, SEG_GRAPH } },

+    { 0x143, { MM_DIRECT, 800,  600,  32, 8, 16, SEG_GRAPH } },

+    { 0x144, { MM_DIRECT, 1024, 768,  32, 8, 16, SEG_GRAPH } },

+    { 0x145, { MM_DIRECT, 1280, 1024, 32, 8, 16, SEG_GRAPH } },

+    { 0x147, { MM_DIRECT, 1600, 1200, 32, 8, 16, SEG_GRAPH } },

+    { 0x14c, { MM_DIRECT, 1152, 864,  32, 8, 16, SEG_GRAPH } },

+    { 0x177, { MM_DIRECT, 1280, 768,  32, 8, 16, SEG_GRAPH } },

+    { 0x17a, { MM_DIRECT, 1280, 800,  32, 8, 16, SEG_GRAPH } },

+    { 0x17d, { MM_DIRECT, 1280, 960,  32, 8, 16, SEG_GRAPH } },

+    { 0x180, { MM_DIRECT, 1440, 900,  32, 8, 16, SEG_GRAPH } },

+    { 0x183, { MM_DIRECT, 1400, 1050, 32, 8, 16, SEG_GRAPH } },

+    { 0x186, { MM_DIRECT, 1680, 1050, 32, 8, 16, SEG_GRAPH } },

+    { 0x189, { MM_DIRECT, 1920, 1200, 32, 8, 16, SEG_GRAPH } },

+    { 0x18c, { MM_DIRECT, 2560, 1600, 32, 8, 16, SEG_GRAPH } },

+    { 0x18f, { MM_DIRECT, 1280, 720,  32, 8, 16, SEG_GRAPH } },

+    { 0x192, { MM_DIRECT, 1920, 1080, 32, 8, 16, SEG_GRAPH } },

     /* standard modes */

     { 0x100, { MM_PACKED, 640,  400,  8,  8, 16, SEG_GRAPH } },

     { 0x101, { MM_PACKED, 640,  480,  8,  8, 16, SEG_GRAPH } },

@@ -41,49 +60,32 @@ struct generic_svga_mode svga_modes[] VAR16 = {

     { 0x11E, { MM_DIRECT, 1600, 1200, 16, 8, 16, SEG_GRAPH } },

     { 0x11F, { MM_DIRECT, 1600, 1200, 24, 8, 16, SEG_GRAPH } },

     /* other modes */

-    { 0x140, { MM_DIRECT, 320,  200,  32, 8, 16, SEG_GRAPH } },

-    { 0x141, { MM_DIRECT, 640,  400,  32, 8, 16, SEG_GRAPH } },

-    { 0x142, { MM_DIRECT, 640,  480,  32, 8, 16, SEG_GRAPH } },

-    { 0x143, { MM_DIRECT, 800,  600,  32, 8, 16, SEG_GRAPH } },

-    { 0x144, { MM_DIRECT, 1024, 768,  32, 8, 16, SEG_GRAPH } },

-    { 0x145, { MM_DIRECT, 1280, 1024, 32, 8, 16, SEG_GRAPH } },

+    /* 8, 15, 16, and 24 bpp BOCHS modes */

     { 0x146, { MM_PACKED, 320,  200,  8,  8, 16, SEG_GRAPH } },

-    { 0x147, { MM_DIRECT, 1600, 1200, 32, 8, 16, SEG_GRAPH } },

     { 0x148, { MM_PACKED, 1152, 864,  8,  8, 16, SEG_GRAPH } },

     { 0x149, { MM_DIRECT, 1152, 864,  15, 8, 16, SEG_GRAPH } },

     { 0x14a, { MM_DIRECT, 1152, 864,  16, 8, 16, SEG_GRAPH } },

     { 0x14b, { MM_DIRECT, 1152, 864,  24, 8, 16, SEG_GRAPH } },

-    { 0x14c, { MM_DIRECT, 1152, 864,  32, 8, 16, SEG_GRAPH } },

     { 0x175, { MM_DIRECT, 1280, 768,  16, 8, 16, SEG_GRAPH } },

     { 0x176, { MM_DIRECT, 1280, 768,  24, 8, 16, SEG_GRAPH } },

-    { 0x177, { MM_DIRECT, 1280, 768,  32, 8, 16, SEG_GRAPH } },

     { 0x178, { MM_DIRECT, 1280, 800,  16, 8, 16, SEG_GRAPH } },

     { 0x179, { MM_DIRECT, 1280, 800,  24, 8, 16, SEG_GRAPH } },

-    { 0x17a, { MM_DIRECT, 1280, 800,  32, 8, 16, SEG_GRAPH } },

     { 0x17b, { MM_DIRECT, 1280, 960,  16, 8, 16, SEG_GRAPH } },

     { 0x17c, { MM_DIRECT, 1280, 960,  24, 8, 16, SEG_GRAPH } },

-    { 0x17d, { MM_DIRECT, 1280, 960,  32, 8, 16, SEG_GRAPH } },

     { 0x17e, { MM_DIRECT, 1440, 900,  16, 8, 16, SEG_GRAPH } },

     { 0x17f, { MM_DIRECT, 1440, 900,  24, 8, 16, SEG_GRAPH } },

-    { 0x180, { MM_DIRECT, 1440, 900,  32, 8, 16, SEG_GRAPH } },

     { 0x181, { MM_DIRECT, 1400, 1050, 16, 8, 16, SEG_GRAPH } },

     { 0x182, { MM_DIRECT, 1400, 1050, 24, 8, 16, SEG_GRAPH } },

-    { 0x183, { MM_DIRECT, 1400, 1050, 32, 8, 16, SEG_GRAPH } },

     { 0x184, { MM_DIRECT, 1680, 1050, 16, 8, 16, SEG_GRAPH } },

     { 0x185, { MM_DIRECT, 1680, 1050, 24, 8, 16, SEG_GRAPH } },

-    { 0x186, { MM_DIRECT, 1680, 1050, 32, 8, 16, SEG_GRAPH } },

     { 0x187, { MM_DIRECT, 1920, 1200, 16, 8, 16, SEG_GRAPH } },

     { 0x188, { MM_DIRECT, 1920, 1200, 24, 8, 16, SEG_GRAPH } },

-    { 0x189, { MM_DIRECT, 1920, 1200, 32, 8, 16, SEG_GRAPH } },

     { 0x18a, { MM_DIRECT, 2560, 1600, 16, 8, 16, SEG_GRAPH } },

     { 0x18b, { MM_DIRECT, 2560, 1600, 24, 8, 16, SEG_GRAPH } },

-    { 0x18c, { MM_DIRECT, 2560, 1600, 32, 8, 16, SEG_GRAPH } },

     { 0x18d, { MM_DIRECT, 1280, 720,  16, 8, 16, SEG_GRAPH } },

     { 0x18e, { MM_DIRECT, 1280, 720,  24, 8, 16, SEG_GRAPH } },

-    { 0x18f, { MM_DIRECT, 1280, 720,  32, 8, 16, SEG_GRAPH } },

     { 0x190, { MM_DIRECT, 1920, 1080, 16, 8, 16, SEG_GRAPH } },

     { 0x191, { MM_DIRECT, 1920, 1080, 24, 8, 16, SEG_GRAPH } },

-    { 0x192, { MM_DIRECT, 1920, 1080, 32, 8, 16, SEG_GRAPH } },

     /* custom resolutions for 16:9 displays */

     { 0x193, { MM_DIRECT, 1600,  900, 16, 8, 16, SEG_GRAPH } },