From mboxrd@z Thu Jan 1 00:00:00 1970 From: Scott Wood Subject: Re: [PATCH] KVM: PPC: Add generic single register ioctls Date: Mon, 9 Jan 2012 14:12:19 -0600 Message-ID: <4F0B4A23.9070808@freescale.com> References: <02FFD6E9-1301-4A05-8F1F-913BE1677A90@suse.de> <1325823314-12758-1-git-send-email-agraf@suse.de> <4F074C45.5000507@freescale.com> <4F0B3AD7.9050609@freescale.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Cc: "" , kvm list , Avi Kivity , Marcelo Tosatti To: Alexander Graf Return-path: In-Reply-To: Sender: kvm-ppc-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 01/09/2012 02:11 PM, Alexander Graf wrote: > > > Am 09.01.2012 um 20:07 schrieb Scott Wood : > >> On 01/06/2012 06:52 PM, Alexander Graf wrote: >>> >>> >>> On 06.01.2012, at 20:32, Scott Wood wrote: >>> >>>> On 01/05/2012 10:15 PM, Alexander Graf wrote: >>>> >>>>> +/* >>>>> + * Architecture specific registers are to be defined in arch headers and >>>>> + * ORed with the arch identifier. >>>>> + */ >>>>> +#define KVM_REG_PPC 0x1000000000000000ULL >>>>> +#define KVM_REG_X86 0x2000000000000000ULL >>>>> +#define KVM_REG_IA64 0x3000000000000000ULL >>>>> +#define KVM_REG_ARM 0x4000000000000000ULL >>>>> +#define KVM_REG_S390 0x5000000000000000ULL >>>>> + >>>>> +#define KVM_REG_SIZE_SHIFT 52 >>>>> +#define KVM_REG_SIZE_MASK 0x00f0000000000000ULL >>>>> +#define KVM_REG_SIZE_U8 0x0000000000000000ULL >>>>> +#define KVM_REG_SIZE_U16 0x0010000000000000ULL >>>>> +#define KVM_REG_SIZE_U32 0x0020000000000000ULL >>>>> +#define KVM_REG_SIZE_U64 0x0030000000000000ULL >>>>> +#define KVM_REG_SIZE_U128 0x0040000000000000ULL >>>>> +#define KVM_REG_SIZE_U256 0x0050000000000000ULL >>>>> +#define KVM_REG_SIZE_U512 0x0060000000000000ULL >>>>> +#define KVM_REG_SIZE_U1024 0x0070000000000000ULL >>>> >>>> Why not just encode directly as number of bytes? >>> >>> Because this is 1 << n bytes :) >> >> Some registers may not be a power-of-2 number of bytes (e.g. x86 segment >> descriptors), and we've got plenty of space to spare in the id. > > If they're not a power of 2, we can still bmp it to the next power of 2 size, no? Yes, that's what I meant by it not being a huge deal and documenting whether the padding is on the right or the left. Just seems a little more awkward than necessary, given that we have room to encode it as a plain linear size. -Scott