Re: [Xen-devel] [PATCH] x86/amd: fix crash as Xen Dom0 on AMDTrinity systems
From: Konrad Rzeszutek Wilk
Date: Wed May 30 2012 - 10:46:50 EST
On Wed, May 30, 2012 at 03:10:02PM +0200, Andre Przywara wrote:
> Because we are behind a family check before tweaking the topology
> bit, we can use the standard rd/wrmsr variants for the CPUID feature
> register.
> This fixes a crash when using the kernel as a Xen Dom0 on affected
> Trinity systems. The wrmsrl_amd_safe is not properly paravirtualized
> yet (this will be fixed in another patch).
So with a rdmsrl_amd_safe and wrmsrl_amd_safe being implemented in
the pv_cpu_ops - would this patch even be neccessary?
>
> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx # 3.4+
> ---
> arch/x86/kernel/cpu/amd.c | 4 ++--
> 1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
> index 146bb62..80ccd99 100644
> --- a/arch/x86/kernel/cpu/amd.c
> +++ b/arch/x86/kernel/cpu/amd.c
> @@ -586,9 +586,9 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
> !cpu_has(c, X86_FEATURE_TOPOEXT)) {
> u64 val;
>
> - if (!rdmsrl_amd_safe(0xc0011005, &val)) {
> + if (!rdmsrl_safe(0xc0011005, &val)) {
> val |= 1ULL << 54;
> - wrmsrl_amd_safe(0xc0011005, val);
> + checking_wrmsrl(0xc0011005, val);
> rdmsrl(0xc0011005, val);
> if (val & (1ULL << 54)) {
> set_cpu_cap(c, X86_FEATURE_TOPOEXT);
> --
> 1.7.4.4
>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel
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