From: Greg Kurz <groug@kaod.org>
To: David Gibson <david@gibson.dropbear.id.au>
Cc: qemu-devel@nongnu.org, qemu-ppc@nongnu.org,
qemu-s390x@nongnu.org, "Alexey Kardashevskiy" <aik@ozlabs.ru>,
"Cédric Le Goater" <clg@kaod.org>,
"Michael Roth" <mdroth@linux.vnet.ibm.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
"Marcel Apfelbaum" <marcel@redhat.com>,
"Eduardo Habkost" <ehabkost@redhat.com>,
"David Hildenbrand" <david@redhat.com>,
"Cornelia Huck" <cohuck@redhat.com>,
"Gerd Hoffmann" <kraxel@redhat.com>,
"Dmitry Fleytman" <dmitry.fleytman@gmail.com>,
"Thomas Huth" <thuth@redhat.com>
Subject: Re: [Qemu-devel] [PATCH v3 03/19] xics: Disintricate allocation and type setting of interrupts
Date: Tue, 5 Feb 2019 15:59:15 +0100 [thread overview]
Message-ID: <20190205155915.32033d52@bahia.lan> (raw)
In-Reply-To: <20190205061346.GM22661@umbus.fritz.box>
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On Tue, 5 Feb 2019 17:13:46 +1100
David Gibson <david@gibson.dropbear.id.au> wrote:
> On Thu, Jan 17, 2019 at 06:14:46PM +0100, Greg Kurz wrote:
> > The current code assumes that an interrupt is allocated as soon as its
> > type is set to MSI or LSI. PHB hotplug will require to be able to set
> > the type of an interrupt before actually allocating it.
>
> Hm.. why?
>
The justification for that is given in patch 6 actually:
Every PHB needs to claim 4 LSIs to support legacy PCI devices. This is
currently done at PHB realize. When using in-kernel XICS (or upcoming
in-kernel XIVE), QEMU synchronizes the state of all irqs, including
these LSIs, later on at machine reset.
In order to support PHB hotplug, we need a way to tell KVM about the
LSIs that doesn't require a machine reset. Since these irq numbers are
fixed values derived from the PHB index, let's identify them all at
machine init. Older machines that don't have fixed irq numbers cannot
support PHB hotplug and keep the existing behavior.
FYI, I'm currently reworking that part entirely. Maybe not worth wasting to
much time on reviewing this v3.
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next prev parent reply other threads:[~2019-02-05 14:59 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-17 17:14 [Qemu-devel] [PATCH v3 00/19] spapr: Add support for PHB hotplug Greg Kurz
2019-01-17 17:14 ` [Qemu-devel] [PATCH v3 01/19] ppc: Move spapr-related prototypes from xics.h into a seperate header file Greg Kurz
2019-01-17 17:14 ` [Qemu-devel] [PATCH v3 02/19] spapr: Rename xics to intc in interrupt controller agnostic code Greg Kurz
2019-01-18 13:56 ` Cédric Le Goater
2019-01-20 14:22 ` Greg Kurz
2019-02-05 6:03 ` David Gibson
2019-01-17 17:14 ` [Qemu-devel] [PATCH v3 03/19] xics: Disintricate allocation and type setting of interrupts Greg Kurz
2019-01-18 11:47 ` Greg Kurz
2019-01-18 12:26 ` Cédric Le Goater
2019-01-20 14:24 ` Greg Kurz
2019-02-05 6:13 ` David Gibson
2019-02-05 14:59 ` Greg Kurz [this message]
2019-02-06 1:47 ` David Gibson
2019-01-17 17:14 ` [Qemu-devel] [PATCH v3 04/19] spapr/xive: Don't set irq type in spapr_xive_irq_claim() Greg Kurz
2019-01-18 12:27 ` Cédric Le Goater
2019-01-17 17:14 ` [Qemu-devel] [PATCH v3 05/19] spapr: Set irq type in a dedicated function Greg Kurz
2019-01-18 12:34 ` Cédric Le Goater
2019-01-20 14:31 ` Greg Kurz
2019-01-17 17:15 ` [Qemu-devel] [PATCH v3 06/19] spapr: Identify LSIs of all possible PHBs at machine init Greg Kurz
2019-01-18 12:38 ` Cédric Le Goater
2019-01-20 14:37 ` Greg Kurz
2019-01-17 17:15 ` [Qemu-devel] [PATCH v3 07/19] spapr_pci: add PHB unrealize Greg Kurz
2019-01-18 11:54 ` Greg Kurz
2019-01-17 17:15 ` [Qemu-devel] [PATCH v3 08/19] spapr: create DR connectors for PHBs Greg Kurz
2019-01-17 17:15 ` [Qemu-devel] [PATCH v3 09/19] spapr: populate PHB DRC entries for root DT node Greg Kurz
2019-01-17 17:15 ` [Qemu-devel] [PATCH v3 10/19] spapr_events: add support for phb hotplug events Greg Kurz
2019-01-17 17:15 ` [Qemu-devel] [PATCH v3 11/19] qdev: pass an Object * to qbus_set_hotplug_handler() Greg Kurz
2019-01-17 17:15 ` [Qemu-devel] [PATCH v3 12/19] spapr_pci: provide node start offset via spapr_populate_pci_dt() Greg Kurz
2019-01-17 17:15 ` [Qemu-devel] [PATCH v3 13/19] spapr_pci: add ibm, my-drc-index property for PHB hotplug Greg Kurz
2019-01-17 17:15 ` [Qemu-devel] [PATCH v3 14/19] spapr: Factor out setting of "phandle" DT property to sPAPR irq frontend Greg Kurz
2019-01-18 12:45 ` Cédric Le Goater
2019-01-20 15:41 ` Greg Kurz
2019-01-17 17:16 ` [Qemu-devel] [PATCH v3 15/19] spapr_xive: Cache device tree nodename in sPAPRXive Greg Kurz
2019-01-18 13:38 ` Cédric Le Goater
2019-01-22 13:27 ` Greg Kurz
2019-01-22 14:26 ` Cédric Le Goater
2019-01-22 14:35 ` Greg Kurz
2019-01-17 17:16 ` [Qemu-devel] [PATCH v3 16/19] spapr: Expose the name of the interrupt controller node Greg Kurz
2019-01-18 13:44 ` Cédric Le Goater
2019-01-17 17:16 ` [Qemu-devel] [PATCH v3 17/19] spapr_irq: Expose the phandle of the interrupt controller Greg Kurz
2019-01-18 13:46 ` Cédric Le Goater
2019-01-22 13:32 ` Greg Kurz
2019-01-17 17:16 ` [Qemu-devel] [PATCH v3 18/19] spapr: add hotplug hooks for PHB hotplug Greg Kurz
2019-01-18 13:55 ` Cédric Le Goater
2019-01-17 17:16 ` [Qemu-devel] [PATCH v3 19/19] spapr: enable PHB hotplug for default pseries machine type Greg Kurz
2019-01-22 5:44 ` [Qemu-devel] [PATCH v3 00/19] spapr: Add support for PHB hotplug Alexey Kardashevskiy
2019-01-22 7:22 ` Greg Kurz
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