From ae8b787543d872cf89a7f9ef8aa302f3ef9bcbd7 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Mon, 23 Nov 2015 11:12:23 +0100 Subject: x86/cpu/amd, kvm: Satisfy guest kernel reads of IC_CFG MSR The kernel accesses IC_CFG MSR (0xc0011021) on AMD because it checks whether the way access filter is enabled on some F15h models, and, if so, disables it. kvm doesn't handle that MSR access and complains about it, which can get really noisy in dmesg when one starts kvm guests all the time for testing. And it is useless anyway - guest kernel shouldn't be doing such changes anyway so tell it that that filter is disabled. Signed-off-by: Borislav Petkov Reviewed-by: Paolo Bonzini Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1448273546-2567-4-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/amd.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index a8816b325162..e229640c19ab 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -678,9 +678,9 @@ static void init_amd_bd(struct cpuinfo_x86 *c) * Disable it on the affected CPUs. */ if ((c->x86_model >= 0x02) && (c->x86_model < 0x20)) { - if (!rdmsrl_safe(0xc0011021, &value) && !(value & 0x1E)) { + if (!rdmsrl_safe(MSR_F15H_IC_CFG, &value) && !(value & 0x1E)) { value |= 0x1E; - wrmsrl_safe(0xc0011021, value); + wrmsrl_safe(MSR_F15H_IC_CFG, value); } } } -- cgit