adulau/aha
1
0
Fork 0
mirror of https://github.com/adulau/aha.git synced 2024-12-28 11:46:19 +00:00
Code Issues Projects Releases Packages Wiki Activity

lguest: restrict CPUID to avoid perf counter wrmsr

Browse source 
Avoid the following:
[    0.012093] WARNING: at arch/x86/kernel/apic/apic.c:249 native_apic_write_dummy+0x2f/0x40()

Rather than chase each new cpuid-detected feature, just lie about the highest
valid CPUID so this code is never run.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Rusty Russell 2009-07-17 21:47:44 -06:00
parent 27de22d03d
commit 7a5049205f
1 changed files with 5 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
arch/x86/lguest/boot.c
View file

@ -379,6 +379,11 @@ static void lguest_cpuid(unsigned int *ax, unsigned int *bx,
native_cpuid(ax, bx, cx, dx);
switch (function) {
case 0: /* ID and highest CPUID. Futureproof a little by sticking to
* older ones. */
if (*ax > 5)
*ax = 5;
break;
case 1: /* Basic feature request. */
/* We only allow kernel to see SSE3, CMPXCHG16B and SSSE3 */
*cx &= 0x00002201;