[PATCH] lguest: fix TSC "divide error: 0000 [#1]" boot crash

From: Rusty Russell
Date: Thu Jun 28 2007 - 21:30:54 EST


Configuring a guest with < CONFIG_M586TSC reveals an lguest bug: the
TSC code expects to see the TSC capability bit, but we weren't setting
up the capabilities until much later in check_bugs ->
identify_boot_cpu -> identify_boot_cpu.

Do the same thing as Xen and the head.S native code: populate the
first capability word before start_kernel().

Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>

diff -r 7743cd1639b7 drivers/lguest/lguest.c
--- a/drivers/lguest/lguest.c Thu Jun 28 23:21:41 2007 +1000
+++ b/drivers/lguest/lguest.c Fri Jun 29 06:23:59 2007 +1000
@@ -598,6 +598,9 @@ __init void lguest_init(void *boot)
paravirt_disable_iospace();

cpu_detect(&new_cpu_data);
+ /* head.S usually sets up the first capability word, so do it here. */
+ new_cpu_data.x86_capability[0] = cpuid_edx(1);
+
/* Math is always hard! */
new_cpu_data.hard_math = 1;



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