Re: [Qemu-devel] [RFC PATCH v2 04/15] cpu-model/s390: Introduce S390 CPU models

From: Christian Borntraeger <borntraeger@de.ibm.com>
To: Alexander Graf <agraf@suse.de>,
	Michael Mueller <mimu@linux.vnet.ibm.com>
Cc: "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"linux-s390@vger.kernel.org" <linux-s390@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Gleb Natapov <gleb@kernel.org>,
	"Jason J. Herne" <jjherne@linux.vnet.ibm.com>,
	Cornelia Huck <cornelia.huck@de.ibm.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Andreas Faerber <afaerber@suse.de>,
	Richard Henderson <rth@twiddle.net>
Subject: Re: [Qemu-devel] [RFC PATCH v2 04/15] cpu-model/s390: Introduce S390 CPU models
Date: Mon, 23 Feb 2015 14:27:10 +0100	[thread overview]
Message-ID: <54EB2AAE.3010009@de.ibm.com> (raw)
In-Reply-To: <54EB2399.5090500@de.ibm.com>

Am 23.02.2015 um 13:56 schrieb Christian Borntraeger:
> Am 20.02.2015 um 16:22 schrieb Alexander Graf:
>>
>>
>>
>>> Am 20.02.2015 um 16:00 schrieb Michael Mueller <mimu@linux.vnet.ibm.com>:
>>>
>>> On Fri, 20 Feb 2015 14:54:23 +0100
>>> Alexander Graf <agraf@suse.de> wrote:
>>>
>>>>>
>>>>> +/* machine related properties */
>>>>> +typedef struct S390CPUMachineProps {
>>>>> +    uint16_t class;      /* machine class */
>>>>> +    uint16_t ga;         /* availability number of machine */
>>>>> +    uint16_t order;      /* order of availability */
>>>>> +} S390CPUMachineProps;
>>>>> +
>>>>> +/* processor related properties */
>>>>> +typedef struct S390CPUProcessorProps {
>>>>> +    uint16_t gen;        /* S390 CMOS generation */
>>>>> +    uint16_t ver;        /* version of processor */
>>>>> +    uint32_t id;         /* processor identification*/
>>>>> +    uint16_t type;       /* machine type */
>>>>> +    uint16_t ibc;        /* IBC value */
>>>>> +    uint64_t *fac_list;  /* list of facilities */  
>>>>
>>>> Just make this uint64_t fac_list[2]. That way we don't have to track any
>>>> messy allocations.
>>>
>>> It will be something like "uint64_t fac_list[S390_CPU_FAC_LIST_SIZE_UINT64]" and in total 2KB not
>>> just 16 bytes but I will change it. 
>>
>> Why? Do we actually need that many? This is a qemu internal struct.
> 
> The kernel already enabled the 3rd word for z13 support, 
> https://git.kernel.org/cgit/linux/kernel/git/s390/linux.git/commit/?id=f8b2dcbd9e6d1479b9b5a9e9e78bbaf783bde819
> 
> so make it at least 3.

This should have been 

commit 8070361799ae1e3f4ef347bd10f0a508ac10acfb
Author: Martin Schwidefsky <schwidefsky@de.ibm.com>
Date:   Mon Oct 6 17:53:53 2014 +0200

    s390: add support for vector extension

which uses bit 129.