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Subject: Re: [PATCH] X86/VMX: Disable VMX preempition timer if MWAIT is not
 intercepted
To: KarimAllah Ahmed <karahmed@amazon.de>, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org
Cc: =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= <rkrcmar@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
        "H . Peter Anvin" <hpa@zytor.com>, x86@kernel.org
References: <1523350211-5747-1-git-send-email-karahmed@amazon.de>
From: Paolo Bonzini <pbonzini@redhat.com>
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Message-ID: <2cd149f0-6ebe-59fc-addb-8b4b05e07d80@redhat.com>
Date: Tue, 10 Apr 2018 11:04:13 +0200
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On 10/04/2018 10:50, KarimAllah Ahmed wrote:
>  	WARN_ON(preemptible());
> -	if (!kvm_x86_ops->set_hv_timer)
> +	if (!kvm_x86_ops->has_hv_timer ||
> +	    !kvm_x86_ops->has_hv_timer(apic->vcpu))
>  		return false;
>  
>  	if (!apic_lvtt_period(apic) && atomic_read(&ktimer->pending))

Why not just return -ENOTSUP from vmx_set_hv_timer?

Thanks,

Paolo