From: "Liu Yu-B13201" <Yu.Liu@freescale.com>
To: "Anthony Liguori" <anthony@codemonkey.ws>,
"Hollis Blanchard" <hollisb@us.ibm.com>
Cc: "Gregory Haskins" <ghaskins@novell.com>,
"Avi Kivity" <avi@redhat.com>,
"Chris Wright" <chrisw@sous-sol.org>,
"Gregory Haskins" <gregory.haskins@gmail.com>,
<linux-kernel@vger.kernel.org>, <kvm@vger.kernel.org>
Subject: RE: PowerPC page faults
Date: Tue, 12 May 2009 13:46:25 +0800 [thread overview]
Message-ID: <0A1FE637C2C7E148B9573BB60CC630E52565C7@zch01exm26.fsl.freescale.net> (raw)
In-Reply-To: <4A08A411.9060104@codemonkey.ws>
> -----Original Message-----
> From: kvm-owner@vger.kernel.org
> [mailto:kvm-owner@vger.kernel.org] On Behalf Of Anthony Liguori
> Sent: Tuesday, May 12, 2009 6:18 AM
> To: Hollis Blanchard
> Cc: Gregory Haskins; Avi Kivity; Chris Wright; Gregory
> Haskins; linux-kernel@vger.kernel.org; kvm@vger.kernel.org
> Subject: Re: PowerPC page faults
>
> Hollis Blanchard wrote:
> > On Mon, 2009-05-11 at 12:54 -0500, Anthony Liguori wrote:
> >
> >> For future ppcemb's, do you know if there is an equivalent
> of a PF exit
> >> type? Does the hardware squirrel away the faulting
> address somewhere
> >> and set PC to the start of the instruction? If so, no
> guest memory load
> >> should be required.
> >>
> >
> > Ahhh... you're saying that the address itself (or offset
> within a page)
> > is the hypercall token, totally separate from IO emulation,
> and so we
> > could ignore the access size.
>
> No, I'm not being nearly that clever.
>
> I was suggesting that hardware virtualization support in future PPC
> systems might contain a mechanism to intercept a guest-mode
> TLB miss.
> If it did, it would be useful if that guest-mode TLB miss "exit"
> contained extra information somewhere that included the PC of the
> faulting instruction, the address response for the fault, and enough
> information to handle the fault without instruction decoding.
I don't think this can come true if it is software managed TLB.
For guest will never know the content of its TLB without the help of software.
>
> I assume all MMIO comes from the same set of instructions in PPC?
> Something like ld/st instructions? Presumably all you need
> to know from
> instruction decoding is the destination register and whether it was a
> read or write?
Yes, but more there is a search in guest TLB to see if it is a guest TLB miss currently.
A big overhead, especially for a large TLB without being organized by sth. like rbtree.
next prev parent reply other threads:[~2009-05-12 5:46 UTC|newest]
Thread overview: 104+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-05 13:24 [RFC PATCH 0/3] generic hypercall support Gregory Haskins
2009-05-05 13:24 ` [RFC PATCH 1/3] add " Gregory Haskins
2009-05-05 17:03 ` Hollis Blanchard
2009-05-06 13:52 ` Anthony Liguori
2009-05-06 15:16 ` Gregory Haskins
2009-05-06 16:52 ` Arnd Bergmann
2009-05-05 13:24 ` [RFC PATCH 2/3] x86: " Gregory Haskins
2009-05-05 13:24 ` [RFC PATCH 3/3] kvm: add pv_cpu_ops.hypercall support to the guest Gregory Haskins
2009-05-05 13:36 ` [RFC PATCH 0/3] generic hypercall support Avi Kivity
2009-05-05 13:40 ` Gregory Haskins
2009-05-05 14:00 ` Avi Kivity
2009-05-05 14:14 ` Gregory Haskins
2009-05-05 14:21 ` Gregory Haskins
2009-05-05 15:02 ` Avi Kivity
2009-05-05 23:17 ` Chris Wright
2009-05-06 3:51 ` Gregory Haskins
2009-05-06 7:22 ` Chris Wright
2009-05-06 13:17 ` Gregory Haskins
2009-05-06 16:07 ` Chris Wright
2009-05-07 17:03 ` Gregory Haskins
2009-05-07 18:05 ` Avi Kivity
2009-05-07 18:08 ` Gregory Haskins
2009-05-07 18:12 ` Avi Kivity
2009-05-07 18:16 ` Gregory Haskins
2009-05-07 18:24 ` Avi Kivity
2009-05-07 18:37 ` Gregory Haskins
2009-05-07 19:00 ` Avi Kivity
2009-05-07 19:05 ` Gregory Haskins
2009-05-07 19:43 ` Avi Kivity
2009-05-07 20:07 ` Gregory Haskins
2009-05-07 20:15 ` Avi Kivity
2009-05-07 20:26 ` Gregory Haskins
2009-05-08 8:35 ` Avi Kivity
2009-05-08 11:29 ` Gregory Haskins
2009-05-07 19:07 ` Chris Wright
2009-05-07 19:12 ` Gregory Haskins
2009-05-07 19:21 ` Chris Wright
2009-05-07 19:26 ` Avi Kivity
2009-05-07 19:44 ` Avi Kivity
2009-05-07 19:29 ` Gregory Haskins
2009-05-07 20:25 ` Chris Wright
2009-05-07 20:34 ` Gregory Haskins
2009-05-07 20:54 ` Arnd Bergmann
2009-05-07 21:13 ` Gregory Haskins
2009-05-07 21:57 ` Chris Wright
2009-05-07 22:11 ` Arnd Bergmann
2009-05-08 22:33 ` Benjamin Herrenschmidt
2009-05-11 13:01 ` Arnd Bergmann
2009-05-11 13:04 ` Gregory Haskins
2009-05-07 20:00 ` Arnd Bergmann
2009-05-07 20:31 ` Gregory Haskins
2009-05-07 20:42 ` Arnd Bergmann
2009-05-07 20:47 ` Arnd Bergmann
2009-05-07 20:50 ` Chris Wright
2009-05-07 23:35 ` Marcelo Tosatti
2009-05-07 23:43 ` Marcelo Tosatti
2009-05-08 3:17 ` Gregory Haskins
2009-05-08 7:55 ` Avi Kivity
[not found] ` <20090508103253.GC3011@amt.cnet>
2009-05-08 11:37 ` Avi Kivity
2009-05-08 3:13 ` Gregory Haskins
2009-05-08 7:59 ` Avi Kivity
2009-05-08 11:09 ` Gregory Haskins
[not found] ` <20090508104228.GD3011@amt.cnet>
2009-05-08 12:43 ` Gregory Haskins
2009-05-08 15:33 ` Marcelo Tosatti
2009-05-08 19:02 ` Avi Kivity
2009-05-08 16:48 ` Paul E. McKenney
2009-05-08 19:55 ` Gregory Haskins
2009-05-08 14:15 ` Gregory Haskins
2009-05-08 14:53 ` Anthony Liguori
2009-05-08 18:50 ` Avi Kivity
2009-05-08 19:02 ` Anthony Liguori
2009-05-08 19:06 ` Avi Kivity
2009-05-11 16:37 ` Jeremy Fitzhardinge
2009-05-07 12:29 ` Avi Kivity
2009-05-08 14:59 ` Anthony Liguori
2009-05-09 12:01 ` Gregory Haskins
2009-05-10 18:38 ` Anthony Liguori
2009-05-11 13:14 ` Gregory Haskins
2009-05-11 16:35 ` Hollis Blanchard
2009-05-11 17:06 ` Avi Kivity
2009-05-11 17:29 ` Gregory Haskins
2009-05-11 17:53 ` Avi Kivity
2009-05-11 17:51 ` Anthony Liguori
2009-05-11 18:02 ` Avi Kivity
2009-05-11 18:18 ` Anthony Liguori
2009-05-11 17:31 ` Anthony Liguori
2009-05-13 10:53 ` Gregory Haskins
2009-05-13 14:45 ` Gregory Haskins
2009-05-11 16:44 ` Hollis Blanchard
2009-05-11 17:54 ` Anthony Liguori
2009-05-11 19:24 ` PowerPC page faults Hollis Blanchard
2009-05-11 22:17 ` Anthony Liguori
2009-05-12 5:46 ` Liu Yu-B13201 [this message]
2009-05-12 14:50 ` Hollis Blanchard
2009-05-06 13:56 ` [RFC PATCH 0/3] generic hypercall support Anthony Liguori
2009-05-06 16:03 ` Gregory Haskins
2009-05-08 8:17 ` Avi Kivity
2009-05-08 15:20 ` Gregory Haskins
2009-05-08 17:00 ` Avi Kivity
2009-05-08 18:55 ` Gregory Haskins
2009-05-08 19:05 ` Anthony Liguori
2009-05-08 19:12 ` Avi Kivity
2009-05-08 19:59 ` Gregory Haskins
2009-05-10 9:59 ` Avi Kivity
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