linux-kernel - Re: [PATCH] x86: kvm: Demote level of already loaded message from error to info

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Message-ID: <f9ba6fec-f764-dae7-e4f9-c532f4672359@maciej.szmigiero.name>
Date:   Wed, 18 Aug 2021 15:36:41 +0200
From:   "Maciej S. Szmigiero" <mail@...iej.szmigiero.name>
To:     Paul Menzel <pmenzel@...gen.mpg.de>
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        Paolo Bonzini <pbonzini@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, Ingo Molnar <mingo@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Borislav Petkov <bp@...en8.de>, x86@...nel.org,
        "H. Peter Anvin" <hpa@...or.com>
Subject: Re: [PATCH] x86: kvm: Demote level of already loaded message from
 error to info

On 18.08.2021 13:49, Paul Menzel wrote:
> In scripts, running
> 
>      modprobe kvm_amd     2>/dev/null
>      modprobe kvm_intel   2>/dev/null
> 
> to ensure the modules are loaded causes Linux to log errors.
> 
>      $ dmesg --level=err
>      [    0.641747] [Firmware Bug]: TSC_DEADLINE disabled due to Errata; please update microcode to version: 0x3a (or later)
>      [   40.196868] kvm: already loaded the other module
>      [   40.219857] kvm: already loaded the other module
>      [   55.501362] kvm [1177]: vcpu0, guest rIP: 0xffffffff96e5b644 disabled perfctr wrmsr: 0xc2 data 0xffff
>      [   56.397974] kvm [1418]: vcpu0, guest rIP: 0xffffffff81046158 disabled perfctr wrmsr: 0xc1 data 0xabcd
>      [1007981.827781] kvm: already loaded the other module
>      [1008000.394089] kvm: already loaded the other module
>      [1008030.706999] kvm: already loaded the other module
>      [1020396.054470] kvm: already loaded the other module
>      [1020405.614774] kvm: already loaded the other module
>      [1020410.140069] kvm: already loaded the other module
>      [1020704.049231] kvm: already loaded the other module
> 
> As one of the two KVM modules is already loaded, KVM is functioning, and
> their is no error condition. Therefore, demote the log message level to
> informational.
> 

Shouldn't this return ENODEV when loading one of these modules instead
as there is no hardware that supports both VMX and SVM?

Thanks,
Maciej