From: Paul Mackerras <paulus@ozlabs.org>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org,
"Cédric Le Goater" <clg@kaod.org>,
linuxppc-dev@lists.ozlabs.org,
"David Gibson" <david@gibson.dropbear.id.au>
Subject: Re: [PATCH 18/19] KVM: PPC: Book3S HV: add passthrough support
Date: Mon, 28 Jan 2019 15:43:54 +1100 [thread overview]
Message-ID: <20190128044354.GB3237@blackberry> (raw)
In-Reply-To: <bcb5d487547503ceaf0aefad4a63889a52ea0a02.camel@kernel.crashing.org>
On Thu, Jan 24, 2019 at 08:25:15AM +1100, Benjamin Herrenschmidt wrote:
> On Wed, 2019-01-23 at 21:30 +1100, Paul Mackerras wrote:
> > > Afaik bcs we change the mapping to point to the real HW irq ESB page
> > > instead of the "IPI" that was there at VM init time.
> >
> > So that makes it sound like there is a whole lot going on that hasn't
> > even been hinted at in the patch descriptions... It sounds like we
> > need a good description of how all this works and fits together
> > somewhere under Documentation/.
> >
> > In any case we need much more informative patch descriptions. I
> > realize that it's all currently in Cedric's head, but I bet that in
> > two or three years' time when we come to try to debug something, it
> > won't be in anyone's head...
>
> The main problem is understanding XIVE itself. It's not realistic to
> ask Cedric to write a proper documentation for XIVE as part of the
> patch series, but sadly IBM doesn't have a good one to provide either.
There are: (a) the XIVE hardware, (b) the definition of the XIVE
hypercalls that guests use, and (c) the design decisions around how to
implement that hypercall interface. We need to get (b) published
somehow, but it is mostly (c) that I would expect the patch
descriptions to explain.
It sounds like there will be a mapping to userspace where the pages
can sometimes point to an IPI page and sometimes point to a real HW
irq ESB page. That is, the same guest "hardware" irq number sometimes
refers to a software-generated interrupt (what you called an "IPI"
above) and sometimes to a hardware-generated interrupt. That fact,
the reason why it is so and the consequences all need to be explained
somewhere. They are really not obvious and I don't believe they are
part of either the XIVE hardware spec or the XIVE hypercall spec.
Paul.
next prev parent reply other threads:[~2019-01-28 4:45 UTC|newest]
Thread overview: 135+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-07 18:43 [PATCH 00/19] KVM: PPC: Book3S HV: add XIVE native exploitation mode Cédric Le Goater
2019-01-07 18:43 ` [PATCH 01/19] powerpc/xive: export flags for the XIVE native exploitation mode hcalls Cédric Le Goater
2019-01-09 3:33 ` David Gibson
2019-01-09 13:08 ` Michael Ellerman
2019-01-09 13:38 ` Cédric Le Goater
2019-01-07 18:43 ` [PATCH 02/19] powerpc/xive: add OPAL extensions for the XIVE native exploitation support Cédric Le Goater
2019-01-09 4:26 ` David Gibson
2019-01-07 18:43 ` [PATCH 03/19] KVM: PPC: Book3S HV: check the IRQ controller type Cédric Le Goater
2019-01-09 4:27 ` David Gibson
2019-01-22 4:56 ` Paul Mackerras
2019-01-23 16:24 ` Cédric Le Goater
2019-02-04 0:50 ` David Gibson
2019-02-04 10:16 ` Cédric Le Goater
2019-01-07 18:43 ` [PATCH 04/19] KVM: PPC: Book3S HV: export services for the XIVE native exploitation device Cédric Le Goater
2019-01-11 4:09 ` David Gibson
2019-01-07 18:43 ` [PATCH 05/19] KVM: PPC: Book3S HV: add a new KVM device for the XIVE native exploitation mode Cédric Le Goater
2019-01-22 5:05 ` Paul Mackerras
2019-01-23 16:28 ` Cédric Le Goater
2019-01-28 17:35 ` Cédric Le Goater
2019-01-30 4:29 ` Paul Mackerras
2019-01-30 7:01 ` Cédric Le Goater
2019-01-31 3:01 ` Paul Mackerras
2019-02-01 17:03 ` Cédric Le Goater
2019-02-04 4:25 ` David Gibson
2019-02-04 11:19 ` Cédric Le Goater
2019-02-05 5:26 ` David Gibson
2019-01-07 18:43 ` [PATCH 06/19] KVM: PPC: Book3S HV: add a GET_ESB_FD control to the XIVE native device Cédric Le Goater
2019-01-22 5:09 ` Paul Mackerras
2019-01-23 16:48 ` Cédric Le Goater
2019-02-04 4:45 ` David Gibson
2019-02-04 11:30 ` Cédric Le Goater
2019-02-05 5:28 ` David Gibson
2019-02-05 12:55 ` Cédric Le Goater
2019-02-06 1:23 ` David Gibson
2019-02-06 7:21 ` Cédric Le Goater
2019-02-07 2:49 ` David Gibson
2019-02-07 9:03 ` Cédric Le Goater
2019-02-08 5:15 ` David Gibson
2019-02-08 7:58 ` Cédric Le Goater
2019-02-08 21:53 ` Paul Mackerras
2019-02-09 9:41 ` Cédric Le Goater
2019-02-11 2:38 ` David Gibson
2019-02-11 6:42 ` Benjamin Herrenschmidt
2019-02-12 22:07 ` Cédric Le Goater
2019-01-07 18:43 ` [PATCH 07/19] KVM: PPC: Book3S HV: add a GET_TIMA_FD control to " Cédric Le Goater
2019-01-07 18:43 ` [PATCH 08/19] KVM: PPC: Book3S HV: add a VC_BASE control to the " Cédric Le Goater
2019-01-22 5:14 ` Paul Mackerras
2019-01-23 16:56 ` Cédric Le Goater
2019-02-04 4:49 ` David Gibson
2019-02-04 15:36 ` Cédric Le Goater
2019-01-07 18:43 ` [PATCH 09/19] KVM: PPC: Book3S HV: add a SET_SOURCE " Cédric Le Goater
2019-02-04 4:57 ` David Gibson
2019-02-04 19:07 ` Cédric Le Goater
2019-02-05 5:35 ` David Gibson
2019-02-05 13:39 ` Cédric Le Goater
2019-01-07 18:43 ` [PATCH 10/19] KVM: PPC: Book3S HV: add a EISN attribute to kvmppc_xive_irq_state Cédric Le Goater
2019-01-07 18:43 ` [PATCH 11/19] KVM: PPC: Book3S HV: add support for the XIVE native exploitation mode hcalls Cédric Le Goater
2019-01-22 5:23 ` Paul Mackerras
2019-01-23 6:44 ` Benjamin Herrenschmidt
2019-01-23 8:48 ` Cédric Le Goater
2019-01-23 10:26 ` Paul Mackerras
2019-01-23 10:48 ` Cédric Le Goater
2019-01-23 21:23 ` Benjamin Herrenschmidt
2019-01-07 18:43 ` [PATCH 12/19] KVM: PPC: Book3S HV: record guest queue page address Cédric Le Goater
2019-02-04 5:15 ` David Gibson
2019-02-04 15:37 ` Cédric Le Goater
2019-01-07 18:43 ` [PATCH 13/19] KVM: PPC: Book3S HV: add a SYNC control for the XIVE native migration Cédric Le Goater
2019-02-04 5:17 ` David Gibson
2019-02-04 15:39 ` Cédric Le Goater
2019-01-07 18:43 ` [PATCH 14/19] KVM: PPC: Book3S HV: add a control to make the XIVE EQ pages dirty Cédric Le Goater
2019-02-04 5:18 ` David Gibson
2019-02-04 15:46 ` Cédric Le Goater
2019-02-05 5:30 ` David Gibson
2019-01-07 18:43 ` [PATCH 15/19] KVM: PPC: Book3S HV: add get/set accessors for the source configuration Cédric Le Goater
2019-02-04 5:21 ` David Gibson
2019-02-04 16:07 ` Cédric Le Goater
2019-02-05 5:32 ` David Gibson
2019-02-05 13:03 ` Cédric Le Goater
2019-02-06 1:23 ` David Gibson
2019-02-06 1:24 ` David Gibson
2019-02-06 7:07 ` Cédric Le Goater
2019-02-07 2:48 ` David Gibson
2019-02-07 9:13 ` Cédric Le Goater
2019-02-08 5:15 ` David Gibson
2019-02-14 16:50 ` Cédric Le Goater
2019-01-07 18:43 ` [PATCH 16/19] KVM: PPC: Book3S HV: add get/set accessors for the EQ configuration Cédric Le Goater
2019-02-04 5:24 ` David Gibson
2019-02-05 17:45 ` Cédric Le Goater
2019-01-07 19:10 ` [PATCH 17/19] KVM: PPC: Book3S HV: add get/set accessors for the VP XIVE state Cédric Le Goater
2019-01-07 19:10 ` [PATCH 18/19] KVM: PPC: Book3S HV: add passthrough support Cédric Le Goater
2019-01-22 5:26 ` Paul Mackerras
2019-01-23 6:45 ` Benjamin Herrenschmidt
2019-01-23 10:30 ` Paul Mackerras
2019-01-23 11:07 ` Cédric Le Goater
2019-01-28 6:13 ` Paul Mackerras
2019-01-28 18:26 ` Cédric Le Goater
2019-01-29 2:45 ` Paul Mackerras
2019-01-29 13:47 ` Cédric Le Goater
2019-01-30 6:20 ` Paul Mackerras
2019-01-30 15:54 ` Cédric Le Goater
2019-01-31 2:48 ` Paul Mackerras
2019-01-29 4:12 ` Paul Mackerras
2019-01-29 17:44 ` Cédric Le Goater
2019-01-30 5:55 ` Paul Mackerras
2019-01-30 7:06 ` Cédric Le Goater
2019-01-23 21:25 ` Benjamin Herrenschmidt
2019-01-24 8:41 ` Cédric Le Goater
2019-01-28 4:43 ` Paul Mackerras [this message]
2019-01-29 13:46 ` Cédric Le Goater
2019-01-07 19:10 ` [PATCH 19/19] KVM: introduce a KVM_DELETE_DEVICE ioctl Cédric Le Goater
2019-01-22 5:42 ` Paul Mackerras
2019-01-23 18:39 ` Cédric Le Goater
2019-01-23 21:32 ` Benjamin Herrenschmidt
2019-02-04 5:26 ` [PATCH 17/19] KVM: PPC: Book3S HV: add get/set accessors for the VP XIVE state David Gibson
2019-02-04 18:57 ` Cédric Le Goater
2019-02-05 5:33 ` David Gibson
2019-02-05 11:58 ` Cédric Le Goater
2019-02-06 1:19 ` David Gibson
2019-01-22 4:46 ` [PATCH 00/19] KVM: PPC: Book3S HV: add XIVE native exploitation mode Paul Mackerras
2019-01-23 19:07 ` Cédric Le Goater
2019-01-23 21:35 ` Benjamin Herrenschmidt
2019-01-26 8:25 ` Cédric Le Goater
2019-02-04 5:36 ` David Gibson
2019-02-05 11:31 ` Cédric Le Goater
2019-02-05 22:13 ` Paul Mackerras
2019-02-06 1:18 ` David Gibson
2019-02-06 7:35 ` Cédric Le Goater
2019-02-07 2:51 ` David Gibson
2019-02-07 8:31 ` Cédric Le Goater
2019-02-08 5:07 ` David Gibson
2019-02-08 7:38 ` Cédric Le Goater
2019-01-28 5:51 ` Paul Mackerras
2019-01-29 13:51 ` Cédric Le Goater
2019-01-30 5:40 ` Paul Mackerras
2019-01-30 15:36 ` Cédric Le Goater
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