From: Alexander Graf <agraf@suse.de>
To: Segher Boessenkool <segher@kernel.crashing.org>
Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
KVM list <kvm@vger.kernel.org>,
"kvm-ppc@vger.kernel.org" <kvm-ppc@vger.kernel.org>
Subject: Re: [PATCH 11/26] KVM: PPC: Make RMO a define
Date: Tue, 29 Jun 2010 10:04:44 +0200 [thread overview]
Message-ID: <7504F7A1-C394-4037-A951-A9AC724C0809@suse.de> (raw)
In-Reply-To: <1550A5F0-3A22-48ED-8251-96328E2FEAE3@kernel.crashing.org>
On 29.06.2010, at 09:52, Segher Boessenkool wrote:
>>>>> Also, it seems you construct the physical address by masking out =
bits from
>>>>> the effective address. Most implementations will trap or machine =
check if
>>>>> you address outside of physical address space, instead.
>>>>=20
>>>> Well the only case where I remember to have hit a real RMO case is =
on the PS3 - that issues a data/instruction storage interrupt when =
accessing anything > 8MB in real mode.
>>>>=20
>>>> So I'd argue this is heavily implementation specific.
>>>=20
>>> It is. So what is the behaviour you want to implement?
>>=20
>> The one below.
>=20
> I'm sorry, I lost it. "Below"?
Well, the ones a few lines below :).
>=20
>>>> Apart from that what I'm trying to cover is that on ppc64 accessing =
0xc0000000000000 in real mode gets you 0x0. Is there a better name for =
this?
>>>=20
>>> (You missed two zeroes).
>>> In hypervisor real mode, the top few bits are magic. They are used =
for e.g.
>>> enabling hypervisor offset real mode.
>>> In supervisor real mode, those bits are ignored (and all other bits =
that do
>>> not correspond to physical address lines may also be ignored).
>>=20
>> So which bits exactly are reserved? I couldn't find a reference to =
that part.
>=20
> If by "reserved" you mean "cannot be used for addressing", it's the =
top four
> bits. Book III-S chapter 5.7.3 in the Power Architecture 2.06 =
document.
> Implementations are allowed to ignore more bits than that.
>=20
> I believe in earlier versions of the architecture it was the top two =
bits,
> not four, but maybe I misremember.
Ah, nice. So that part is implementation specific too. Awesome ;).
>=20
>>> Maybe you want to call it physical_address_mask or similar?
>>=20
>> PAM - doesn't sound bad :).
>=20
> And miraculously nothing in the Power arch uses that acronym yet! But =
I
> would spell it out if I were you, acronyms are confusing.
Well, the bad thing about not using acronyms here is that I'll run out =
of the 80 character limit pretty soon. And that means line wraps and =
more confusingness when reading the code.
Alex
next prev parent reply other threads:[~2010-06-29 8:04 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-25 23:24 [PATCH 00/26] KVM PPC PV framework Alexander Graf
2010-06-25 23:24 ` [PATCH 01/26] KVM: PPC: Introduce shared page Alexander Graf
2010-06-27 12:12 ` Avi Kivity
2010-06-29 9:54 ` Alexander Graf
2010-06-29 10:55 ` Avi Kivity
2010-06-25 23:24 ` [PATCH 02/26] KVM: PPC: Convert MSR to " Alexander Graf
2010-06-27 8:16 ` Avi Kivity
2010-06-27 9:38 ` Alexander Graf
2010-06-27 9:50 ` Avi Kivity
2010-06-27 10:40 ` Alexander Graf
2010-06-25 23:24 ` [PATCH 03/26] KVM: PPC: Convert DSISR " Alexander Graf
2010-06-25 23:24 ` [PATCH 04/26] KVM: PPC: Convert DAR " Alexander Graf
2010-06-25 23:24 ` [PATCH 05/26] KVM: PPC: Convert SRR0 and SRR1 " Alexander Graf
2010-06-25 23:24 ` [PATCH 06/26] KVM: PPC: Convert SPRG[0-4] " Alexander Graf
2010-06-25 23:24 ` [PATCH 07/26] KVM: PPC: Implement hypervisor interface Alexander Graf
2010-06-25 23:24 ` [PATCH 08/26] KVM: PPC: Add PV guest critical sections Alexander Graf
2010-06-27 8:21 ` Avi Kivity
2010-06-27 9:40 ` Alexander Graf
2010-06-27 9:52 ` Avi Kivity
2010-06-27 10:33 ` Alexander Graf
2010-06-27 10:59 ` Avi Kivity
2010-06-27 11:49 ` Alexander Graf
2010-06-27 11:53 ` Avi Kivity
2010-06-27 12:06 ` Alexander Graf
2010-06-27 22:03 ` Benjamin Herrenschmidt
2010-06-27 10:03 ` Avi Kivity
2010-06-27 10:35 ` Alexander Graf
2010-06-25 23:24 ` [PATCH 09/26] KVM: PPC: Add PV guest scratch registers Alexander Graf
2010-06-27 8:22 ` Avi Kivity
2010-06-27 9:41 ` Alexander Graf
2010-06-27 9:53 ` Avi Kivity
2010-06-25 23:24 ` [PATCH 10/26] KVM: PPC: Tell guest about pending interrupts Alexander Graf
2010-06-25 23:24 ` [PATCH 11/26] KVM: PPC: Make RMO a define Alexander Graf
2010-06-26 16:52 ` Segher Boessenkool
2010-06-27 9:08 ` Alexander Graf
2010-06-29 7:32 ` Segher Boessenkool
2010-06-29 7:39 ` Alexander Graf
2010-06-29 7:52 ` Segher Boessenkool
2010-06-29 8:04 ` Alexander Graf [this message]
2010-06-25 23:25 ` [PATCH 12/26] KVM: PPC: First magic page steps Alexander Graf
2010-06-27 8:24 ` Avi Kivity
2010-06-27 9:44 ` Alexander Graf
2010-06-25 23:25 ` [PATCH 13/26] KVM: PPC: Magic Page Book3s support Alexander Graf
2010-06-25 23:25 ` [PATCH 14/26] KVM: PPC: Magic Page BookE support Alexander Graf
2010-06-25 23:25 ` [PATCH 15/26] KVM: PPC: Expose magic page support to guest Alexander Graf
2010-06-25 23:25 ` [PATCH 16/26] KVM: Move kvm_guest_init out of generic code Alexander Graf
2010-06-25 23:25 ` [PATCH 17/26] KVM: PPC: Generic KVM PV guest support Alexander Graf
2010-06-25 23:25 ` [PATCH 18/26] KVM: PPC: KVM PV guest stubs Alexander Graf
2010-06-27 8:28 ` Avi Kivity
2010-06-27 9:47 ` Alexander Graf
2010-06-27 10:16 ` Avi Kivity
2010-06-27 10:38 ` Alexander Graf
2010-06-27 22:04 ` Benjamin Herrenschmidt
2010-06-28 4:39 ` Matt Evans
2010-06-28 6:33 ` Alexander Graf
2010-06-28 8:15 ` Avi Kivity
2010-06-28 8:23 ` Alexander Graf
2010-06-28 8:33 ` Avi Kivity
2010-06-25 23:25 ` [PATCH 19/26] KVM: PPC: PV instructions to loads and stores Alexander Graf
2010-06-25 23:25 ` [PATCH 20/26] KVM: PPC: PV tlbsync to nop Alexander Graf
2010-06-25 23:25 ` [PATCH 21/26] KVM: PPC: Introduce kvm_tmp framework Alexander Graf
2010-06-25 23:25 ` [PATCH 22/26] KVM: PPC: PV assembler helpers Alexander Graf
2010-06-25 23:25 ` [PATCH 23/26] KVM: PPC: PV mtmsrd L=1 Alexander Graf
2010-06-25 23:25 ` [PATCH 24/26] KVM: PPC: PV mtmsrd L=0 and mtmsr Alexander Graf
2010-06-26 17:03 ` Segher Boessenkool
2010-06-27 9:10 ` Alexander Graf
2010-06-29 7:37 ` Segher Boessenkool
2010-06-25 23:25 ` [PATCH 25/26] KVM: PPC: PV wrteei Alexander Graf
2010-06-25 23:25 ` [PATCH 26/26] KVM: PPC: Add Documentation about PV interface Alexander Graf
2010-06-27 8:14 ` Avi Kivity
2010-06-27 9:33 ` Alexander Graf
[not found] ` <4C270876.2050806%40redhat.com>
2010-06-28 7:18 ` Milton Miller
2010-06-28 7:49 ` Alexander Graf
2010-06-28 8:13 ` Avi Kivity
2010-06-28 8:21 ` Alexander Graf
2010-06-28 8:32 ` Avi Kivity
2010-06-27 8:34 ` Avi Kivity
2010-06-27 9:49 ` Alexander Graf
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