From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Subject: Re: [PATCH v13 08/12] KVM: x86: Add Intel PT context switch for each vcpu
Date: Wed, 24 Oct 2018 13:13:44 +0300
Message-ID: <87a7n37iuf.fsf@ashishki-desk.ger.corp.intel.com>
References: <1540368316-12998-1-git-send-email-luwei.kang@intel.com> <1540368316-12998-9-git-send-email-luwei.kang@intel.com>
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Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com,
        pbonzini@redhat.com, rkrcmar@redhat.com, joro@8bytes.org,
        songliubraving@fb.com, peterz@infradead.org,
        kstewart@linuxfoundation.org, gregkh@linuxfoundation.org,
        thomas.lendacky@amd.com, konrad.wilk@oracle.com,
        mattst88@gmail.com, Janakarajan.Natarajan@amd.com,
        dwmw@amazon.co.uk, jpoimboe@redhat.com, marcorr@google.com,
        ubizjak@gmail.com, sean.j.christopherson@intel.com,
        jmattson@google.com, linux-kernel@vger.kernel.org,
        Chao Peng <chao.p.peng@linux.intel.com>,
        Luwei Kang <luwei.kang@intel.com>
To: Luwei Kang <luwei.kang@intel.com>, kvm@vger.kernel.org,
        x86@kernel.org
Return-path: <linux-kernel-owner@vger.kernel.org>
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List-Id: kvm.vger.kernel.org

Luwei Kang <luwei.kang@intel.com> writes:

> +static void pt_guest_enter(struct vcpu_vmx *vmx)
> +{
> +	if (pt_mode == PT_MODE_SYSTEM)
> +		return;
> +
> +	/* Save host state before VM entry */
> +	rdmsrl(MSR_IA32_RTIT_CTL, vmx->pt_desc.host.ctl);
> +
> +	/*
> +	 * Set guest state of MSR_IA32_RTIT_CTL MSR (PT will be disabled
> +	 * on VM entry when it has been disabled in guest before).
> +	 */
> +	vmcs_write64(GUEST_IA32_RTIT_CTL, vmx->pt_desc.guest.ctl);
> +
> +	if (vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) {
> +		wrmsrl(MSR_IA32_RTIT_CTL, 0);
> +		pt_save_msr(&vmx->pt_desc.host, vmx->pt_desc.addr_range);
> +		pt_load_msr(&vmx->pt_desc.guest, vmx->pt_desc.addr_range);
> +	}
> +}

>>From my side this is still a NAK, because [1].

[1] https://marc.info/?l=kvm&m=153847567226248&w=2

Thanks,
--
Alex