Received-SPF: softfail (google.com: domain of transitioning linux-kernel-owner@vger.kernel.org does not designate 23.128.96.19 as permitted sender) client-ip=23.128.96.19;
Date:   Wed, 8 Jun 2022 17:45:03 +0200
From:   Vasant Karasulli <vkarasulli@suse.de>
To:     Sean Christopherson <seanjc@google.com>
Cc:     linux-kernel@vger.kernel.org, jroedel@suse.de, kvm@vger.kernel.org,
        bp@alien8.de, x86@kernel.org, thomas.lendacky@amd.com
Subject: Re: [PATCH v6 2/4] x86/tests: Add tests for AMD SEV-ES #VC handling
 Add KUnit based tests to validate Linux's VC handling for instructions cpuid
 and wbinvd. These tests: 1. install a kretprobe on the #VC handler
 (sev_es_ghcb_hv_call, to access GHCB before/after the resulting VMGEXIT). 2.
 trigger an NAE by executing either cpuid or wbinvd. 3. check that the
 kretprobe was hit with the right exit_code available in GHCB.
Message-ID: <YqDD/0IWnoMXEAWg@vasant-suse>
References: <20220318094532.7023-1-vkarasulli@suse.de>
 <20220318094532.7023-3-vkarasulli@suse.de>
 <Ykzrb1uyPZ2AKWos@google.com>
 <YqBivtMl74FGmz7r@vasant-suse>
 <YqCzy5Kngj+OgD2h@google.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <YqCzy5Kngj+OgD2h@google.com>
Precedence: bulk

On Mi 08-06-22 14:35:55, Sean Christopherson wrote:
> On Wed, Jun 08, 2022, Vasant Karasulli wrote:
> > On Mi 06-04-22 01:22:55, Sean Christopherson wrote:
> > > > +	if (ret) {
> > > > +		kunit_info(test, "Could not register kretprobe. Skipping.");
> > > > +		goto out;
> > > > +	}
> > > > +
> > > > +	test->priv = kunit_kzalloc(test, sizeof(u64), GFP_KERNEL);
> > >
> > > Allocating 8 bytes and storing the pointer an 8-byte field is rather pointless :-)
> > >
> >
> > Actually it's necessary to allocate memory to test->priv before using according to
> > https://www.kernel.org/doc/html/latest/dev-tools/kunit/tips.html
>
> If priv points at structure of some form, sure, but you're storing a simple value.

Yes, I agree. The reason it was done this way I guess is that type of priv is a
void pointer and storing a u64 value results in a compiler warning:
cast from pointer to integer of different size [-Wpointer-to-int-cast].

Thanks,
Vasant Karasulli
Kernel generalist
www.suse.com<http://www.suse.com>
[https://www.suse.com/assets/img/social-platforms-suse-logo.png]<http://www.suse.com/>
SUSE - Open Source Solutions for Enterprise Servers & Cloud<http://www.suse.com/>
Modernize your infrastructure with SUSE Linux Enterprise servers, cloud technology for IaaS, and SUSE's software-defined storage.
www.suse.com