From: David Gibson <david@gibson.dropbear.id.au>
To: "Cédric Le Goater" <clg@kaod.org>
Cc: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org,
Paul Mackerras <paulus@samba.org>,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v2 06/16] KVM: PPC: Book3S HV: XIVE: add controls for the EQ configuration
Date: Thu, 14 Mar 2019 14:29:27 +1100 [thread overview]
Message-ID: <20190314032927.GP8211@umbus.fritz.box> (raw)
In-Reply-To: <badcd1dc-2eef-590e-b362-0d3dfdf52d34@kaod.org>
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On Wed, Mar 13, 2019 at 09:46:08AM +0100, Cédric Le Goater wrote:
> On 3/13/19 5:03 AM, David Gibson wrote:
> > On Tue, Mar 12, 2019 at 06:00:38PM +0100, Cédric Le Goater wrote:
> >> On 2/25/19 3:39 AM, David Gibson wrote:
> >>> On Fri, Feb 22, 2019 at 12:28:30PM +0100, Cédric Le Goater wrote:
> >>>> These controls will be used by the H_INT_SET_QUEUE_CONFIG and
> >>>> H_INT_GET_QUEUE_CONFIG hcalls from QEMU. They will also be used to
> >>>> restore the configuration of the XIVE EQs in the KVM device and to
> >>>> capture the internal runtime state of the EQs. Both 'get' and 'set'
> >>>> rely on an OPAL call to access from the XIVE interrupt controller the
> >>>> EQ toggle bit and EQ index which are updated by the HW when event
> >>>> notifications are enqueued in the EQ.
> >>>>
> >>>> The value of the guest physical address of the event queue is saved in
> >>>> the XIVE internal xive_q structure for later use. That is when
> >>>> migration needs to mark the EQ pages dirty to capture a consistent
> >>>> memory state of the VM.
> >>>>
> >>>> To be noted that H_INT_SET_QUEUE_CONFIG does not require the extra
> >>>> OPAL call setting the EQ toggle bit and EQ index to configure the EQ,
> >>>> but restoring the EQ state will.
> >>
> >> I think we need to add some kind of flags to differentiate the hcall
> >> H_INT_SET_QUEUE_CONFIG from the restore of the EQ. The hcall does
> >> not need OPAL support call and this could help in the code
> >> transition.
> >
> > Hrm. What's the actual difference in the semantics between the two
> > cases.
>
> None.
>
> But we don't need to set the EQ state in the case of the HCALL and it's
> (very) practical to run guests with XIVE enabled without the OPAL support.
> The latter is the main reason clearly.
>
> Thinking of it, I could test the EQ toggle bit and index passed to KVM
> and skip the OPAL call which restores the EQ state if they are zero.
> This is because I know that the OPAL call configuring the EQ resets them.
>
> That will do. No need for a flag.
That's a much better idea.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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next prev parent reply other threads:[~2019-03-14 3:53 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-22 11:28 [PATCH v2 00/16] KVM: PPC: Book3S HV: add XIVE native exploitation mode Cédric Le Goater
2019-02-22 11:28 ` [PATCH v2 01/16] powerpc/xive: add OPAL extensions for the XIVE native exploitation support Cédric Le Goater
2019-02-24 23:42 ` David Gibson
2019-02-25 3:50 ` Michael Ellerman
2019-02-25 10:11 ` Cédric Le Goater
2019-02-26 4:21 ` David Gibson
2019-03-12 18:25 ` Cédric Le Goater
2019-02-22 11:28 ` [PATCH v2 02/16] KVM: PPC: Book3S HV: add a new KVM device for the XIVE native exploitation mode Cédric Le Goater
2019-02-25 0:08 ` David Gibson
2019-03-12 11:14 ` Cédric Le Goater
2019-02-22 11:28 ` [PATCH v2 03/16] KVM: PPC: Book3S HV: XIVE: introduce a new capability KVM_CAP_PPC_IRQ_XIVE Cédric Le Goater
2019-02-25 0:35 ` David Gibson
2019-02-25 4:59 ` Paul Mackerras
2019-03-12 14:10 ` Cédric Le Goater
2019-03-12 14:03 ` Cédric Le Goater
2019-03-13 4:05 ` David Gibson
2019-02-25 4:35 ` Paul Mackerras
2019-03-13 8:34 ` Cédric Le Goater
2019-03-14 2:29 ` David Gibson
2019-02-22 11:28 ` [PATCH v2 04/16] KVM: PPC: Book3S HV: XIVE: add a control to initialize a source Cédric Le Goater
2019-02-25 2:10 ` David Gibson
2019-02-26 4:25 ` Paul Mackerras
2019-02-26 23:20 ` David Gibson
2019-03-12 15:19 ` Cédric Le Goater
2019-03-14 2:15 ` David Gibson
2019-02-25 5:30 ` Paul Mackerras
2019-02-22 11:28 ` [PATCH v2 05/16] KVM: PPC: Book3S HV: XIVE: add a control to configure " Cédric Le Goater
2019-02-25 2:21 ` David Gibson
2019-02-22 11:28 ` [PATCH v2 06/16] KVM: PPC: Book3S HV: XIVE: add controls for the EQ configuration Cédric Le Goater
2019-02-25 2:39 ` David Gibson
2019-03-12 17:00 ` Cédric Le Goater
2019-03-13 4:03 ` David Gibson
2019-03-13 8:46 ` Cédric Le Goater
2019-03-14 3:29 ` David Gibson [this message]
2019-02-26 5:24 ` Paul Mackerras
2019-03-13 9:40 ` Cédric Le Goater
2019-03-14 2:32 ` David Gibson
2019-03-14 7:11 ` Cédric Le Goater
2019-03-15 0:29 ` David Gibson
2019-02-22 11:28 ` [PATCH v2 07/16] KVM: PPC: Book3S HV: XIVE: add a global reset control Cédric Le Goater
2019-02-25 2:43 ` David Gibson
2019-02-22 11:28 ` [PATCH v2 08/16] KVM: PPC: Book3S HV: XIVE: add a control to sync the sources Cédric Le Goater
2019-02-25 2:45 ` David Gibson
2019-02-22 11:28 ` [PATCH v2 09/16] KVM: PPC: Book3S HV: XIVE: add a control to dirty the XIVE EQ pages Cédric Le Goater
2019-02-25 2:53 ` David Gibson
2019-03-13 11:48 ` Cédric Le Goater
2019-03-14 2:33 ` David Gibson
2019-02-22 11:28 ` [PATCH v2 10/16] KVM: PPC: Book3S HV: XIVE: add get/set accessors for the VP XIVE state Cédric Le Goater
2019-02-25 3:31 ` David Gibson
2019-03-13 13:19 ` Cédric Le Goater
2019-03-14 3:09 ` David Gibson
2019-03-14 7:08 ` Cédric Le Goater
2019-02-22 11:28 ` [PATCH v2 11/16] KVM: introduce a 'mmap' method for KVM devices Cédric Le Goater
2019-02-25 3:33 ` David Gibson
2019-02-25 10:57 ` Cédric Le Goater
2019-02-26 12:52 ` Paolo Bonzini
2019-02-26 23:22 ` David Gibson
2019-02-22 11:28 ` [PATCH v2 12/16] KVM: PPC: Book3S HV: XIVE: add a TIMA mapping Cédric Le Goater
2019-02-25 3:42 ` David Gibson
2019-02-22 11:28 ` [PATCH v2 13/16] KVM: PPC: Book3S HV: XIVE: add a mapping for the source ESB pages Cédric Le Goater
2019-02-25 3:47 ` David Gibson
2019-02-22 11:28 ` [PATCH v2 14/16] KVM: PPC: Book3S HV: XIVE: add passthrough support Cédric Le Goater
2019-02-25 4:13 ` David Gibson
2019-02-22 11:28 ` [PATCH v2 15/16] KVM: introduce a KVM_DESTROY_DEVICE ioctl Cédric Le Goater
2019-02-25 4:15 ` David Gibson
2019-03-13 8:02 ` Cédric Le Goater
2019-03-15 17:57 ` Paolo Bonzini
2019-02-22 11:28 ` [PATCH v2 16/16] KVM: PPC: Book3S HV: XIVE: clear the vCPU interrupt presenters Cédric Le Goater
2019-02-25 4:18 ` David Gibson
2019-03-13 8:17 ` Cédric Le Goater
2019-03-14 2:26 ` David Gibson
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