Commit Graph

34 Commits

Author SHA1 Message Date
Cédric Le Goater
f56275a2fc spapr/irq: remove spapr_ics_create()
spapr_ics_create() is only called once. Merge it in spapr_irq_init_xics()
and simplify a bit the error handling by using 'error_fatal' .

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190321144914.19934-13-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-04-26 10:41:23 +10:00
Cédric Le Goater
273fef83f6 spapr/irq: Add XIVE sanity checks on non-P9 machines
On non-P9 machines, the XIVE interrupt mode is not advertised, see
spapr_dt_ov5_platform_support(). Add a couple of checks on the machine
configuration to filter bogus setups and prevent OS failures :

                     Interrupt modes

  CPU/Compat      XICS    XIVE                dual

   P8/P8          OK      QEMU failure (1)    OK (3)
   P9/P8          OK      QEMU failure (2)    OK (3)
   P9/P9          OK      OK                  OK

  (1) CPU exception model is incompatible with XIVE and the presenters
      will fail to realize.

  (2) CPU exception model is compatible with XIVE, but the XIVE CAS
      advertisement is dropped when in POWER8 mode. So we could ended up
      booting with the XIVE DT properties but without the HCALLs. Avoid
      confusing Linux with such settings and fail under QEMU.

  (3) force XICS in machine init

Remove the check on XIVE-only machines in spapr_machine_init(), which
has now become redundant.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190328100044.11408-1-clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-03-29 10:38:20 +11:00
David Gibson
ce2918cbc3 spapr: Use CamelCase properly
The qemu coding standard is to use CamelCase for type and structure names,
and the pseries code follows that... sort of.  There are quite a lot of
places where we bend the rules in order to preserve the capitalization of
internal acronyms like "PHB", "TCE", "DIMM" and most commonly "sPAPR".

That was a bad idea - it frequently leads to names ending up with hard to
read clusters of capital letters, and means they don't catch the eye as
type identifiers, which is kind of the point of the CamelCase convention in
the first place.

In short, keeping type identifiers look like CamelCase is more important
than preserving standard capitalization of internal "words".  So, this
patch renames a heap of spapr internal type names to a more standard
CamelCase.

In addition to case changes, we also make some other identifier renames:
  VIOsPAPR* -> SpaprVio*
    The reverse word ordering was only ever used to mitigate the capital
    cluster, so revert to the natural ordering.
  VIOsPAPRVTYDevice -> SpaprVioVty
  VIOsPAPRVLANDevice -> SpaprVioVlan
    Brevity, since the "Device" didn't add useful information
  sPAPRDRConnector -> SpaprDrc
  sPAPRDRConnectorClass -> SpaprDrcClass
    Brevity, and makes it clearer this is the same thing as a "DRC"
    mentioned in many other places in the code

This is 100% a mechanical search-and-replace patch.  It will, however,
conflict with essentially any and all outstanding patches touching the
spapr code.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-03-12 14:33:05 +11:00
Greg Kurz
ad62bff638 spapr_irq: Expose the phandle of the interrupt controller
This will be used by PHB hotplug in order to create the "interrupt-map"
property of the PHB node.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <155059669374.1466090.12943228478046223856.stgit@bahia.lab.toulouse-stg.fr.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-02-26 09:21:25 +11:00
Greg Kurz
743ed566c1 spapr: Expose the name of the interrupt controller node
This will be needed by PHB hotplug in order to access the "phandle"
property of the interrupt controller node.

Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <155059668867.1466090.6339199751719123386.stgit@bahia.lab.toulouse-stg.fr.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-02-26 09:21:25 +11:00
Greg Kurz
3272752a8b xics: Drop the KVM ICS class
The KVM ICS class isn't used anymore. Drop it.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <155023084177.1011724.14693955932559990358.stgit@bahia.lan>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-02-18 10:52:08 +11:00
Greg Kurz
444d6ca301 spapr/irq: Use the "simple" ICS class for KVM
The "simple" ICS class knows how to interract with KVM. Adapt sPAPR to use
it instead of the ICS KVM class.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <155023083585.1011724.2868047424353921455.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-02-18 10:50:19 +11:00
Greg Kurz
557b456729 xics: Handle KVM interrupt presentation from "simple" ICS code
We want to use the "simple" ICS type in both KVM and non-KVM setups.
Teach the "simple" ICS how to present interrupts to KVM and adapt
sPAPR accordingly.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <155023082996.1011724.16237920586343905010.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-02-18 10:43:19 +11:00
Greg Kurz
56af66566d spapr/irq: Use the base ICP class for KVM
The base ICP class knows how to interact with KVM. Adapt sPAPR to use it
instead of the ICP KVM class.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <155023080638.1011724.792095453419098948.stgit@bahia.lan>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-02-18 10:34:56 +11:00
Cédric Le Goater
3a0d802c17 spapr/irq: remove the XICS offset adjustment
Now that we have changed the XICS and the XIVE interrupt backend to
have different size for their IRQ number space, we do not need to
align their source numbers anymore. Remove the offset adjustment and
wire the dual 'qirq' handler to the 'qirq' handler of the current
interrupt mode in use.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190213210756.27032-3-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-02-17 21:54:02 +11:00
Cédric Le Goater
2e66cdb715 spapr/irq: add an 'nr_irq' parameter to initialize the backend.
When using the 'dual' interrupt mode, the source numbers of both sPAPR
IRQ backends are aligned to share a common IRQ number space and to use
a similar mapping of the machine qemu_irq array which is indexed by
the source number.

The XICS IRQ number range initially being [ 0x1000 - 0x2000 ], this
requires to change the XICS ICSState offset to 0 and to provision for
an extra 4K of source numbers and qemu_irqs which will never be used
by the machine when running under the XICS interrupt mode. This is not
an optimal solution.

Change the init() method to allocate an IRQ number space of the
expected size for the XICS sPAPR IRQ backend. It breaks the interrupt
signaling when under the 'dual' mode because source numbers have
unexpected values but next patch will fix that.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190213210756.27032-2-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-02-17 21:54:02 +11:00
Greg Kurz
1a51134087 spapr: Disallow unsupported kernel-irqchip settings
Split mode doesn't make sense on pseries, neither with XICS nor XIVE. But
passing kernel-irqchip=split silently behaves like kernel-irqchip=on.
Other architectures that support kernel-irqchip do terminate QEMU when
split mode is requested but not available though. Do the same with pseries
for consistency.

Similarly, passing kernel-irqchip=on,accel=tcg starts the machine with the
emulated interrupt controller, ie, behaves like kernel-irqchip=off. However,
when passing  kernel-irqchip=on,accel=kvm, if we can't initialize the KVM
XICS for some reason, ie, xics_kvm_init() fails, then QEMU is terminated.
This is inconsistent. Terminate QEMU all the same when requesting the
in-kernel interrupt controller without KVM.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <154964986747.291716.2679312373018476920.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-02-17 21:54:02 +11:00
Cédric Le Goater
a28b9a5a8d spapr: move the interrupt presenters under machine_data
Next step is to remove them from under the PowerPCCPU

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-02-04 18:44:18 +11:00
Thomas Huth
a51d5afc69 ppc: Move spapr-related prototypes from xics.h into a seperate header file
When compiling with Clang in -std=gnu99 mode, there is a warning/error:

  CC      ppc64-softmmu/hw/intc/xics_spapr.o
In file included from /home/thuth/devel/qemu/hw/intc/xics_spapr.c:34:
/home/thuth/devel/qemu/include/hw/ppc/xics.h:203:34: error: redefinition of typedef 'sPAPRMachineState' is a C11 feature
      [-Werror,-Wtypedef-redefinition]
typedef struct sPAPRMachineState sPAPRMachineState;
                                 ^
/home/thuth/devel/qemu/include/hw/ppc/spapr_irq.h:25:34: note: previous definition is here
typedef struct sPAPRMachineState sPAPRMachineState;
                                 ^

We have to remove the duplicated typedef here and include "spapr.h" instead.
But "spapr.h" should not be included for the pnv machine files. So move
the spapr-related prototypes into a new file called "xics_spapr.h" instead.

Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2019-01-22 05:14:33 +01:00
Cédric Le Goater
3a8eb78e6c spapr: enable XIVE MMIOs at reset
Depending on the interrupt mode of the machine, enable or disable the
XIVE MMIOs.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-01-09 09:28:14 +11:00
Cédric Le Goater
13db0cd9b8 spapr: introduce a new sPAPR IRQ backend supporting XIVE and XICS
The 'dual' sPAPR IRQ backend supports both interrupt mode, XIVE
exploitation mode and the legacy compatibility mode (XICS). both modes
are not supported at the same time.

The machine starts with the legacy mode and a new interrupt mode can
then be negotiated by the CAS process. In this case, the new mode is
activated after a reset to take into account the required changes in
the machine. These impact the device tree layout, the interrupt
presenter object and the exposed MMIO regions in the case of XIVE.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-01-09 09:28:14 +11:00
Cédric Le Goater
872ff3dea3 spapr: move the qemu_irq array under the machine
The qemu_irq array is now allocated at the machine level using a sPAPR
IRQ set_irq handler depending on the chosen interrupt mode. The use of
this handler is slightly inefficient today but it will become necessary
when the 'dual' interrupt mode is introduced.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-01-09 09:28:14 +11:00
Cédric Le Goater
3ff73aa241 ppc: replace the 'Object *intc' by a 'ICPState *icp' pointer under the CPU
Now that the 'intc' pointer is only used by the XICS interrupt mode,
let's make things clear and use a XICS type and name.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-01-09 09:28:14 +11:00
Cédric Le Goater
129dbe6926 ppc/xive: introduce a XiveTCTX pointer under PowerPCCPU
which will be used by the machine only when the XIVE interrupt mode is
in use.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-01-09 09:28:14 +11:00
Cédric Le Goater
8fa1f4ef38 spapr: modify the prototype of the cpu_intc_create() method
Today, the interrupt presenter is linked to a CPU using the
cpu_intc_create() method of the sPAPR IRQ backend. The resulting
object is assigned to the PowerPCCPU 'intc' pointer whatever the
interrupt mode, XICS or XIVE.

To support the 'dual' interrupt mode, we will need to distinguish
between the two presenter objects and for that, we plan to introduce a
second interrupt presenter object pointer under the PowerPCCPU. The
modifications below move the assignment of the presenter object under
the cpu_intc_create() method to prepare ground for the future changes.

Both sPAPR and PowerNV machines are impacted.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-01-09 09:28:14 +11:00
Cédric Le Goater
a0c493ae67 spapr/xive: simplify the sPAPR IRQ qirq method for XIVE
The qirq routines of the XiveSource and the sPAPRXive model are only
used under the sPAPR IRQ backend. Simplify the overall call stack and
gather all the code under spapr_qirq_xive(). It will ease future
changes.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-01-09 09:28:14 +11:00
Cédric Le Goater
3ba3d0bc33 spapr: introduce an 'ic-mode' machine option
This option is used to select the interrupt controller mode (XICS or
XIVE) with which the machine will operate. XICS being the default
mode for now.

When running a machine with the XIVE interrupt mode backend, the guest
OS is required to have support for the XIVE exploitation mode. In the
case of legacy OS, the mode selected by CAS should be XICS and the OS
should fail to boot. However, QEMU could possibly detect it, terminate
the boot process and reset to stop in the SLOF firmware. This is not
yet handled.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21 09:40:43 +11:00
Cédric Le Goater
db592b5b16 spapr: add an extra OV5 field to the sPAPR IRQ backend
The interrupt modes supported by the hypervisor are advertised to the
guest with new bits definitions of the option vector 5 of property
"ibm,arch-vec-5-platform-support. The byte 23 bits 0-1 of the OV5 are
defined as follow :

  0b00   PAPR 2.7 and earlier (Legacy systems)
  0b01   XIVE Exploitation mode only
  0b10   Either available

If the client/guest selects the XIVE interrupt mode, it informs the
hypervisor by returning the value 0b01 in byte 23 bits 0-1. A 0b00
value indicates the use of the XICS interrupt mode (Legacy systems).

The sPAPR IRQ backend is extended with these definitions and the
values are directly used to populate the "ibm,arch-vec-5-platform-support"
property. The interrupt mode is advertised under TCG and under KVM.
Although a KVM XIVE device is not yet available, the machine can still
operate with kernel_irqchip=off. However, we apply a restriction on
the CPU which is required to be a POWER9 when a XIVE interrupt
controller is in use.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21 09:40:43 +11:00
Cédric Le Goater
b2e2247716 spapr: add a 'reset' method to the sPAPR IRQ backend
For the time being, the XIVE reset handler updates the OS CAM line of
the vCPU as it is done under a real hypervisor when a vCPU is
scheduled to run on a HW thread. This will let the XIVE presenter
engine find a match among the NVTs dispatched on the HW threads.

This handler will become even more useful when we introduce the
machine supporting both interrupt modes, XIVE and XICS. In this
machine, the interrupt mode is chosen by the CAS negotiation process
and activated after a reset.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
[dwg: Fix style nits]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21 09:40:35 +11:00
Cédric Le Goater
1c53b06c03 spapr: extend the sPAPR IRQ backend for XICS migration
Introduce a new sPAPR IRQ handler to handle resend after migration
when the machine is using a KVM XICS interrupt controller model.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21 09:39:13 +11:00
Cédric Le Goater
1a937ad7e7 spapr: allocate the interrupt thread context under the CPU core
Each interrupt mode has its own specific interrupt presenter object,
that we store under the CPU object, one for XICS and one for XIVE.

Extend the sPAPR IRQ backend with a new handler to support them both.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21 09:39:13 +11:00
Cédric Le Goater
6e21de4a50 spapr: add device tree support for the XIVE exploitation mode
The XIVE interface for the guest is described in the device tree under
the "interrupt-controller" node. A couple of new properties are
specific to XIVE :

 - "reg"

   contains the base address and size of the thread interrupt
   managnement areas (TIMA), for the User level and for the Guest OS
   level. Only the Guest OS level is taken into account today.

 - "ibm,xive-eq-sizes"

   the size of the event queues. One cell per size supported, contains
   log2 of size, in ascending order.

 - "ibm,xive-lisn-ranges"

   the IRQ interrupt number ranges assigned to the guest for the IPIs.

and also under the root node :

 - "ibm,plat-res-int-priorities"

   contains a list of priorities that the hypervisor has reserved for
   its own use. OPAL uses the priority 7 queue to automatically
   escalate interrupts for all other queues (DD2.X POWER9). So only
   priorities [0..6] are allowed for the guest.

Extend the sPAPR IRQ backend with a new handler to populate the DT
with the appropriate "interrupt-controller" node.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
[dwg: Fix style nits]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21 09:39:07 +11:00
Cédric Le Goater
23bcd5eb9a spapr: add hcalls support for the XIVE exploitation interrupt mode
The different XIVE virtualization structures (sources and event queues)
are configured with a set of Hypervisor calls :

 - H_INT_GET_SOURCE_INFO

   used to obtain the address of the MMIO page of the Event State
   Buffer (ESB) entry associated with the source.

 - H_INT_SET_SOURCE_CONFIG

   assigns a source to a "target".

 - H_INT_GET_SOURCE_CONFIG

   determines which "target" and "priority" is assigned to a source

 - H_INT_GET_QUEUE_INFO

   returns the address of the notification management page associated
   with the specified "target" and "priority".

 - H_INT_SET_QUEUE_CONFIG

   sets or resets the event queue for a given "target" and "priority".
   It is also used to set the notification configuration associated
   with the queue, only unconditional notification is supported for
   the moment. Reset is performed with a queue size of 0 and queueing
   is disabled in that case.

 - H_INT_GET_QUEUE_CONFIG

   returns the queue settings for a given "target" and "priority".

 - H_INT_RESET

   resets all of the guest's internal interrupt structures to their
   initial state, losing all configuration set via the hcalls
   H_INT_SET_SOURCE_CONFIG and H_INT_SET_QUEUE_CONFIG.

 - H_INT_SYNC

   issue a synchronisation on a source to make sure all notifications
   have reached their queue.

Calls that still need to be addressed :

   H_INT_SET_OS_REPORTING_LINE
   H_INT_GET_OS_REPORTING_LINE

See the code for more documentation on each hcall.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
[dwg: Folded in fix for field accessors]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21 09:37:38 +11:00
Cédric Le Goater
dcc345b61e spapr: introduce a new machine IRQ backend for XIVE
The XIVE IRQ backend uses the same layout as the new XICS backend but
covers the full range of the IRQ number space. The IRQ numbers for the
CPU IPIs are allocated at the bottom of this space, below 4K, to
preserve compatibility with XICS which does not use that range.

This should be enough given that the maximum number of CPUs is 1024
for the sPAPR machine under QEMU. For the record, the biggest POWER8
or POWER9 system has a maximum of 1536 HW threads (16 sockets, 192
cores, SMT8).

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21 09:37:38 +11:00
Cédric Le Goater
fab397d84a spapr: introduce a spapr_irq_init() routine
Initialize the MSI bitmap from it as this will be necessary for the
sPAPR IRQ backend for XIVE.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21 09:28:47 +11:00
Cédric Le Goater
ae83740237 spapr: increase the size of the IRQ number space
The new layout using static IRQ number does not leave much space to
the dynamic MSI range, only 0x100 IRQ numbers. Increase the total
number of IRQS for newer machines and introduce a legacy XICS backend
for pre-3.1 machines to maintain compatibility.

For the old backend, provide a 'nr_msis' value covering the full IRQ
number space as it does not use the bitmap allocator to allocate MSI
interrupt numbers.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-09-25 11:12:25 +10:00
Cédric Le Goater
e39de895f6 spapr: introduce a spapr_irq class 'nr_msis' attribute
The number of MSI interrupts a sPAPR machine can allocate is in direct
relation with the number of interrupts of the sPAPRIrq backend. Define
statically this value at the sPAPRIrq class level and use it for the
"ibm,pe-total-#msi" property of the sPAPR PHB.

According to the PAPR specs, "ibm,pe-total-#msi" defines the maximum
number of MSIs that are available to the PE. We choose to advertise
the maximum number of MSIs that are available to the machine for
simplicity of the model and to avoid segmenting the MSI interrupt pool
which can be easily shared. If the pool limit is reached, it can be
extended dynamically.

Finally, remove XICS_IRQS_SPAPR which is now unused.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-09-25 11:12:25 +10:00
Cédric Le Goater
ef01ed9d19 spapr: introduce a IRQ controller backend to the machine
This proposal moves all the related IRQ routines of the sPAPR machine
behind a sPAPR IRQ backend interface 'spapr_irq' to prepare for future
changes. First of which will be to increase the size of the IRQ number
space, then, will follow a new backend for the POWER9 XIVE IRQ controller.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-08-21 14:28:45 +10:00
Cédric Le Goater
82cffa2eb2 spapr: introduce a fixed IRQ number space
This proposal introduces a new IRQ number space layout using static
numbers for all devices, depending on a device index, and a bitmap
allocator for the MSI IRQ numbers which are negotiated by the guest at
runtime.

As the VIO device model does not have a device index but a "reg"
property, we introduce a formula to compute an IRQ number from a "reg"
value. It should minimize most of the collisions.

The previous layout is kept in pre-3.1 machines raising the
'legacy_irq_allocation' machine class flag.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-08-21 14:28:45 +10:00