Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   "Sironi, Filippo" <sironi@amazon.de>
To:     "Graf, Alexander" <graf@amazon.com>
CC:     LKML <linux-kernel@vger.kernel.org>,
        KVM list <kvm@vger.kernel.org>,
        Christian Borntraeger <borntraeger@de.ibm.com>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        "cohuck@redhat.com" <cohuck@redhat.com>,
        "konrad.wilk@oracle.com" <konrad.wilk@oracle.com>,
        "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>,
        "vasu.srinivasan@oracle.com" <vasu.srinivasan@oracle.com>
Subject: Re: [PATCH v2 2/2] KVM: x86: Implement the arch-specific hook to
 report the VM UUID
Thread-Topic: [PATCH v2 2/2] KVM: x86: Implement the arch-specific hook to
 report the VM UUID
Thread-Index: AQHVCmgxSNZRVPU/lkacpReSlg9JAaZtyWCAgAAY24A=
Date:   Thu, 16 May 2019 15:25:00 +0000
Message-ID: <7395EFE9-0B38-4B61-81D4-E8450561AABE@amazon.de>
References: <1539078879-4372-1-git-send-email-sironi@amazon.de>
 <1557847002-23519-1-git-send-email-sironi@amazon.de>
 <1557847002-23519-3-git-send-email-sironi@amazon.de>
 <f51a6a84-b21c-ab75-7e30-bfbe2ac6b98b@amazon.com>
In-Reply-To: <f51a6a84-b21c-ab75-7e30-bfbe2ac6b98b@amazon.com>
Accept-Language: en-US
Content-Language: en-US
x-ms-exchange-messagesentrepresentingtype: 1
x-ms-exchange-transport-fromentityheader: Hosted
x-originating-ip: [10.43.166.108]
Content-Type: text/plain; charset="us-ascii"
Content-ID: <322B72780715F949BC86D7AC0C1B0C37@amazon.com>
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org


> On 16. May 2019, at 15:56, Graf, Alexander <graf@amazon.com> wrote:
> =

> On 14.05.19 08:16, Filippo Sironi wrote:
>> On x86, we report the UUID in DMI System Information (i.e., DMI Type 1)
>> as VM UUID.
>> =

>> Signed-off-by: Filippo Sironi <sironi@amazon.de>
>> ---
>> arch/x86/kernel/kvm.c | 7 +++++++
>> 1 file changed, 7 insertions(+)
>> =

>> diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
>> index 5c93a65ee1e5..441cab08a09d 100644
>> --- a/arch/x86/kernel/kvm.c
>> +++ b/arch/x86/kernel/kvm.c
>> @@ -25,6 +25,7 @@
>> #include <linux/kernel.h>
>> #include <linux/kvm_para.h>
>> #include <linux/cpu.h>
>> +#include <linux/dmi.h>
>> #include <linux/mm.h>
>> #include <linux/highmem.h>
>> #include <linux/hardirq.h>
>> @@ -694,6 +695,12 @@ bool kvm_para_available(void)
>> }
>> EXPORT_SYMBOL_GPL(kvm_para_available);
>> =

>> +const char *kvm_para_get_uuid(void)
>> +{
>> +	return dmi_get_system_info(DMI_PRODUCT_UUID);
> =

> This adds a new dependency on CONFIG_DMI. Probably best to guard it with
> an #if IS_ENABLED(CONFIG_DMI).
> =

> The concept seems sound though.
> =

> Alex

include/linux/dmi.h contains a dummy implementation of
dmi_get_system_info that returns NULL if CONFIG_DMI isn't defined.
This is enough unless we decide to return "<denied>" like in Xen.
If then, we can have the check in the generic code to turn NULL
into "<denied>".

Filippo


>> +}
>> +EXPORT_SYMBOL_GPL(kvm_para_get_uuid);
>> +
>> unsigned int kvm_arch_para_features(void)
>> {
>> 	return cpuid_eax(kvm_cpuid_base() | KVM_CPUID_FEATURES);


Amazon Development Center Germany GmbH
Krausenstr. 38
10117 Berlin
Geschaeftsfuehrer: Christian Schlaeger, Ralf Herbrich
Ust-ID: DE 289 237 879
Eingetragen am Amtsgericht Charlottenburg HRB 149173 B