Re: [PATCH v2 3/4] Add support for AMD Core Perf Extension in guest

From: Borislav Petkov <bp@suse.de>
To: "Natarajan, Janakarajan" <Janakarajan.Natarajan@amd.com>
Cc: kvm@vger.kernel.org, x86@kernel.org,
	linux-kernel@vger.kernel.org,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, "H . Peter Anvin" <hpa@zytor.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Radim Krcmar <rkrcmar@redhat.com>,
	Len Brown <len.brown@intel.com>, Kyle Huey <me@kylehuey.com>,
	Kan Liang <Kan.liang@intel.com>,
	Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	Tony Luck <tony.luck@intel.com>
Subject: Re: [PATCH v2 3/4] Add support for AMD Core Perf Extension in guest
Date: Thu, 16 Nov 2017 18:25:20 +0100	[thread overview]
Message-ID: <20171116172520.4lgdvpcdxuxenxc7@pd.tnic> (raw)
In-Reply-To: <c94fbc32-307f-01b9-564d-cfc68c94648a@amd.com>

On Thu, Nov 16, 2017 at 11:13:47AM -0600, Natarajan, Janakarajan wrote:
> On 11/15/2017 1:07 PM, Borislav Petkov wrote:
> > On Wed, Nov 15, 2017 at 01:04:03PM -0600, Natarajan, Janakarajan wrote:
> > > So, when the amd_pmu_init is called, a query to guest_cpuid_family() gives a
> > > value of -1.
> > And that is because...? And it can be fixed to give the proper guest family I
> > presume ...?
> 
> Qemu initially creates a vcpu with KVM_CREATE_VCPU which in kvm initializes
> the pmu. Later on
> the cpuid is set using KVM_SET_CPUID2 which sets all the cpuid entries in
> kvm and the pmu refresh is called.

That doesn't answer my questions above.

-- 
Regards/Gruss,
    Boris.

SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
-- 