Re: [PATCH v2 1/2] KVM: VMX: Notify if VMX is already in use

["Andreas Färber" <afaerber@suse.de>]

Am 07.12.2011 15:34, schrieb Sasha Levin:
> Currently we silently fail if VMX is already in use by a different
> virtualization technology.
> 
> This is bad since it's non-obvious for the user, and its not too uncommon
> for users to have several of these installed on same host.
> 
> This patch adds a message to notify the user of the problem.

Being more verbose is a good move.

> Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
> ---
>  arch/x86/kvm/vmx.c |    5 ++++-
>  1 files changed, 4 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 4ceced2..0ef59ed 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -2300,8 +2300,11 @@ static int hardware_enable(void *garbage)
>  	u64 phys_addr = __pa(per_cpu(vmxarea, cpu));
>  	u64 old, test_bits;
>  
> -	if (read_cr4() & X86_CR4_VMXE)
> +	if (read_cr4() & X86_CR4_VMXE) {
> +		printk_once(KERN_ERR "hardware_enable: VMX already in use on CPU%d. "
> +				"Are you already another hypervisor?\n", cpu);

Since this question addresses the user, it should read:
"Are you already using another hypervisor?\n" (or the like)

Applies to 2/2 as well.

Andreas

>  		return -EBUSY;
> +	}
>  
>  	INIT_LIST_HEAD(&per_cpu(loaded_vmcss_on_cpu, cpu));
>  	rdmsrl(MSR_IA32_FEATURE_CONTROL, old);


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