linux-kernel - Re: [PATCH] KVM: x86: fix bogus warning about reserved bits

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Message-ID: <20150924101227.GA3774@pd.tnic>
Date:	Thu, 24 Sep 2015 12:12:28 +0200
From:	Borislav Petkov <bp@...en8.de>
To:	Xiao Guangrong <guangrong.xiao@...ux.intel.com>
Cc:	Paolo Bonzini <pbonzini@...hat.com>, linux-kernel@...r.kernel.org,
	kvm@...r.kernel.org
Subject: Re: [PATCH] KVM: x86: fix bogus warning about reserved bits

On Thu, Sep 24, 2015 at 11:23:08AM +0800, Xiao Guangrong wrote:
> >+static inline bool
> >+boot_cpu_is_amd(void)
> >+{
> >+	WARN_ON_ONCE(!tdp_enabled);
> >+	return shadow_x_mask != 0;
> 
> shadow_x_mask != 0 is Intel's CPU.
> 
> Borislav, could you please check shadow_x_mask == 0 instead and test it again?

That did the trick:

[   62.640392] kvm: zapping shadow pages for mmio generation wraparound
[   63.100301] cpuid(0).ebx = 68747541
[   63.193426] kvm [3748]: vcpu0 unhandled rdmsr: 0xc0010112
[   64.538294] kvm [3748]: vcpu0 unhandled rdmsr: 0xc0011021
[   64.866263] kvm [3748]: vcpu1 unhandled rdmsr: 0xc0011021
[   64.971972] kvm [3748]: vcpu2 unhandled rdmsr: 0xc0011021
[   65.070376] kvm [3748]: vcpu3 unhandled rdmsr: 0xc0011021
[   65.170625] kvm [3748]: vcpu4 unhandled rdmsr: 0xc0011021
[   65.272838] kvm [3748]: vcpu5 unhandled rdmsr: 0xc0011021
[   65.374288] kvm [3748]: vcpu6 unhandled rdmsr: 0xc0011021
[   65.474825] kvm [3748]: vcpu7 unhandled rdmsr: 0xc0011021

That's all I got in dmesg from booting the guest - no more mmio PF
warnings.

Thanks.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
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