Commit Graph

90 Commits

Author SHA1 Message Date
Cédric Le Goater
53e934921d ppc/xive: Provide unconditional escalation support
When the 'u' bit is set the escalation is said to be 'unconditional'
which means that the ESe PQ bits are not used. Introduce a
xive_router_end_es_notify() routine to share code with the ESn
notification.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190718115420.19919-7-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-08-21 17:17:39 +10:00
Cédric Le Goater
b4e3066684 ppc/xive: Provide escalation support
If the XIVE presenter can not find the NVT dispatched on any of the HW
threads, it can not deliver the interrupt. XIVE offers an escalation
mechanism to handle such scenarios and inform the hypervisor that an
action should be taken.

Escalation is configured by setting the 'e' bit and the EAS in word 4
& 5 to let the HW look for the escalation END on which to trigger a
new event.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190718115420.19919-6-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-08-21 17:17:39 +10:00
Cédric Le Goater
52c5acf04e ppc/xive: Provide backlog support
If backlog is activated ('b' bit) on the END, the pending priority of
a missed event is recorded in the IPB field of the NVT for a later
resend.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190718115420.19919-5-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-08-21 17:17:39 +10:00
Cédric Le Goater
d98ec603c6 ppc/xive: Implement TM_PULL_OS_CTX special command
When a vCPU is not dispatched anymore on a HW thread, the Hypervisor
(KVM on Linux) invalidates the OS interrupt context of a vCPU with
this special command. It returns the OS CAM line value and resets the
VO bit.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190718115420.19919-4-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-08-21 17:17:39 +10:00
Markus Armbruster
d645427057 Include migration/vmstate.h less
In my "build everything" tree, changing migration/vmstate.h triggers a
recompile of some 2700 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).

hw/hw.h supposedly includes it for convenience.  Several other headers
include it just to get VMStateDescription.  The previous commit made
that unnecessary.

Include migration/vmstate.h only where it's still needed.  Touching it
now recompiles only some 1600 objects.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-16-armbru@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-08-16 13:31:52 +02:00
Markus Armbruster
64552b6be4 Include hw/irq.h a lot less
In my "build everything" tree, changing hw/irq.h triggers a recompile
of some 5400 out of 6600 objects (not counting tests and objects that
don't depend on qemu/osdep.h).

hw/hw.h supposedly includes it for convenience.  Several other headers
include it just to get qemu_irq and.or qemu_irq_handler.

Move the qemu_irq and qemu_irq_handler typedefs from hw/irq.h to
qemu/typedefs.h, and then include hw/irq.h only where it's still
needed.  Touching it now recompiles only some 500 objects.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190812052359.30071-13-armbru@redhat.com>
2019-08-16 13:31:52 +02:00
Markus Armbruster
71e8a91585 Include sysemu/reset.h a lot less
In my "build everything" tree, changing sysemu/reset.h triggers a
recompile of some 2600 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).

The main culprit is hw/hw.h, which supposedly includes it for
convenience.

Include sysemu/reset.h only where it's needed.  Touching it now
recompiles less than 200 objects.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190812052359.30071-9-armbru@redhat.com>
2019-08-16 13:31:52 +02:00
Cédric Le Goater
310cda5b5e spapr/xive: Fix migration of hot-plugged CPUs
The migration sequence of a guest using the XIVE exploitation mode
relies on the fact that the states of all devices are restored before
the machine is. This is not true for hot-plug devices such as CPUs
which state come after the machine. This breaks migration because the
thread interrupt context registers are not correctly set.

Fix migration of hotplugged CPUs by restoring their context in the
'post_load' handler of the XiveTCTX model.

Fixes: 277dd3d771 ("spapr/xive: add migration support for KVM")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190813064853.29310-1-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-08-13 16:50:30 +10:00
Cédric Le Goater
aaa450300e ppc/xive: Fix TM_PULL_POOL_CTX special operation
When a CPU is reseted, the hypervisor (Linux or OPAL) invalidates the
POOL interrupt context of a CPU with this special command. It returns
the POOL CAM line value and resets the VP bit.

Fixes: 4836b45510 ("ppc/xive: activate HV support")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190630204601.30574-5-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-07-02 09:43:58 +10:00
Cédric Le Goater
8256870ada ppc/xive: Make the PIPR register readonly
When the hypervisor (KVM) dispatches a vCPU on a HW thread, it restores
its thread interrupt context. The Pending Interrupt Priority Register
(PIPR) is computed from the Interrupt Pending Buffer (IPB) and stores
should not be allowed to change its value.

Fixes: 207d9fe985 ("ppc/xive: introduce the XIVE interrupt thread context")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190630204601.30574-3-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-07-02 09:43:58 +10:00
Cédric Le Goater
fe9a9d527d ppc/xive: Force the Physical CAM line value to group mode
When an interrupt needs to be delivered, the XIVE interrupt controller
presenter scans the CAM lines of the thread interrupt contexts of the
HW threads of the chip to find a matching vCPU. The interrupt context
is composed of 4 different sets of registers: Physical, HV, OS and
User.

The encoding of the Physical CAM line depends on the mode in which the
interrupt controller is operating: CAM mode or block group mode.
Block group mode being the default configuration today on POWER9 and
the only one available on the next POWER10 generation, enforce this
encoding in the Physical CAM line :

    chip << 19 | 0000000 0 0001 thread (7Bit)

It fits the overall encoding of the NVT ids and simplifies the matching
algorithm in the presenter.

Fixes: d514c48d41 ("ppc/xive: hardwire the Physical CAM line of the thread context")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190630204601.30574-2-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-07-02 09:43:58 +10:00
Peter Maydell
a050901d4b ppc patch queue 2019-06-12
Next pull request against qemu-4.1.  The big thing here is adding
 support for hot plug of P2P bridges, and PCI devices under P2P bridges
 on the "pseries" machine (which doesn't use SHPC).  Other than that
 there's just a handful of fixes and small enhancements.
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Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-4.1-20190612' into staging

ppc patch queue 2019-06-12

Next pull request against qemu-4.1.  The big thing here is adding
support for hot plug of P2P bridges, and PCI devices under P2P bridges
on the "pseries" machine (which doesn't use SHPC).  Other than that
there's just a handful of fixes and small enhancements.

# gpg: Signature made Wed 12 Jun 2019 06:47:56 BST
# gpg:                using RSA key 75F46586AE61A66CC44E87DC6C38CACA20D9B392
# gpg: Good signature from "David Gibson <david@gibson.dropbear.id.au>" [full]
# gpg:                 aka "David Gibson (Red Hat) <dgibson@redhat.com>" [full]
# gpg:                 aka "David Gibson (ozlabs.org) <dgibson@ozlabs.org>" [full]
# gpg:                 aka "David Gibson (kernel.org) <dwg@kernel.org>" [unknown]
# Primary key fingerprint: 75F4 6586 AE61 A66C C44E  87DC 6C38 CACA 20D9 B392

* remotes/dgibson/tags/ppc-for-4.1-20190612:
  ppc/xive: Make XIVE generate the proper interrupt types
  ppc/pnv: activate the "dumpdtb" option on the powernv machine
  target/ppc: Use tcg_gen_gvec_bitsel
  spapr: Allow hot plug/unplug of PCI bridges and devices under PCI bridges
  spapr: Direct all PCI hotplug to host bridge, rather than P2P bridge
  spapr: Don't use bus number for building DRC ids
  spapr: Clean up DRC index construction
  spapr: Clean up spapr_drc_populate_dt()
  spapr: Clean up dt creation for PCI buses
  spapr: Clean up device tree construction for PCI devices
  spapr: Clean up device node name generation for PCI devices
  target/ppc: Fix lxvw4x, lxvh8x and lxvb16x
  spapr_pci: Improve error message

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-06-12 14:43:47 +01:00
Markus Armbruster
0b8fa32f55 Include qemu/module.h where needed, drop it from qemu-common.h
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-4-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
hw/usb/dev-hub.c hw/misc/exynos4210_rng.c hw/misc/bcm2835_rng.c
hw/misc/aspeed_scu.c hw/display/virtio-vga.c hw/arm/stm32f205_soc.c;
ui/cocoa.m fixed up]
2019-06-12 13:18:33 +02:00
Benjamin Herrenschmidt
4aca978654 ppc/xive: Make XIVE generate the proper interrupt types
It should be generic Hypervisor Virtualization interrupts for HV
directed rings and traditional External Interrupts for the OS directed
ring.

Don't generate anything for the user ring as it isn't actually
supported.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190606174409.12502-1-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-06-12 10:41:50 +10:00
Cédric Le Goater
3f777abc71 spapr/irq: add KVM support to the 'dual' machine
The interrupt mode is chosen by the CAS negotiation process and
activated after a reset to take into account the required changes in
the machine. This brings new constraints on how the associated KVM IRQ
device is initialized.

Currently, each model takes care of the initialization of the KVM
device in their realize method but this is not possible anymore as the
initialization needs to be done globaly when the interrupt mode is
known, i.e. when machine is reseted. It also means that we need a way
to delete a KVM device when another mode is chosen.

Also, to support migration, the QEMU objects holding the state to
transfer should always be available but not necessarily activated.

The overall approach of this proposal is to initialize both interrupt
mode at the QEMU level to keep the IRQ number space in sync and to
allow switching from one mode to another. For the KVM side of things,
the whole initialization of the KVM device, sources and presenters, is
grouped in a single routine. The XICS and XIVE sPAPR IRQ reset
handlers are modified accordingly to handle the init and the delete
sequences of the KVM device.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190513084245.25755-15-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-05-29 11:39:46 +10:00
Cédric Le Goater
277dd3d771 spapr/xive: add migration support for KVM
When the VM is stopped, the VM state handler stabilizes the XIVE IC
and marks the EQ pages dirty. These are then transferred to destination
before the transfer of the device vmstates starts.

The SpaprXive interrupt controller model captures the XIVE internal
tables, EAT and ENDT and the XiveTCTX model does the same for the
thread interrupt context registers.

At restart, the SpaprXive 'post_load' method restores all the XIVE
states. It is called by the sPAPR machine 'post_load' method, when all
XIVE states have been transferred and loaded.

Finally, the source states are restored in the VM change state handler
when the machine reaches the running state.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190513084245.25755-7-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-05-29 11:39:46 +10:00
Cédric Le Goater
7bfc759c02 spapr/xive: add state synchronization with KVM
This extends the KVM XIVE device backend with 'synchronize_state'
methods used to retrieve the state from KVM. The HW state of the
sources, the KVM device and the thread interrupt contexts are
collected for the monitor usage and also migration.

These get operations rely on their KVM counterpart in the host kernel
which acts as a proxy for OPAL, the host firmware. The set operations
will be added for migration support later.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190513084245.25755-5-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-05-29 11:39:46 +10:00
Cédric Le Goater
38afd772f8 spapr/xive: add KVM support
This introduces a set of helpers when KVM is in use, which create the
KVM XIVE device, initialize the interrupt sources at a KVM level and
connect the interrupt presenters to the vCPU.

They also handle the initialization of the TIMA and the source ESB
memory regions of the controller. These have a different type under
KVM. They are 'ram device' memory mappings, similarly to VFIO, exposed
to the guest and the associated VMAs on the host are populated
dynamically with the appropriate pages using a fault handler.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190513084245.25755-3-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-05-29 11:39:45 +10:00
Cédric Le Goater
13df93244e spapr/xive: fix EQ page addresses above 64GB
The high order bits of the address of the OS event queue is stored in
bits [4-31] of word2 of the XIVE END internal structures and the low
order bits in word3. This structure is using Big Endian ordering and
computing the value requires some simple arithmetic which happens to
be wrong. The mask removing bits [0-3] of word2 is applied to the
wrong value and the resulting address is bogus when above 64GB.

Guests with more than 64GB of RAM will allocate pages for the OS event
queues which will reside above the 64GB limit. In this case, the XIVE
device model will wake up the CPUs in case of a notification, such as
IPIs, but the update of the event queue will be written at the wrong
place in memory. The result is uncertain as the guest memory is
trashed and IPI are not delivered.

Introduce a helper xive_end_qaddr() to compute this value correctly in
all places where it is used.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190508171946.657-3-clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-05-29 11:39:44 +10:00
Cédric Le Goater
4836b45510 ppc/xive: activate HV support
The NSR register of the HV ring has a different, although similar, bit
layout. TM_QW3_NSR_HE_PHYS bit should now be raised when the
Hypervisor interrupt line is signaled. Other bits TM_QW3_NSR_HE_POOL
and TM_QW3_NSR_HE_LSI are not modeled. LSI are for special interrupts
reserved for HW bringup and the POOL bit is used when signaling a
group of VPs. This is not currently implemented in Linux but it is in
pHyp.

The most important special commands on the HV TIMA page are added to
let the core manage interrupts : acking and changing the CPU priority.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190306085032.15744-10-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-03-12 14:33:04 +11:00
Cédric Le Goater
a58a18adee ppc/pnv: export the xive_router_notify() routine
The PowerNV machine with need to encode the block id in the source
interrupt number before forwarding the source event notification to
the Router.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190306085032.15744-5-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-03-12 14:33:04 +11:00
Cédric Le Goater
f9b9db3860 ppc/xive: export the TIMA memory accessors
The PowerNV machine can perform indirect loads and stores on the TIMA
on behalf of another CPU. Give the controller the possibility to call
the TIMA memory accessors with a XiveTCTX of its choice.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190306085032.15744-4-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-03-12 14:33:04 +11:00
Cédric Le Goater
d514c48d41 ppc/xive: hardwire the Physical CAM line of the thread context
By default on P9, the HW CAM line (23bits) is hardwired to :

      0x000||0b1||4Bit chip number||7Bit Thread number.

When the block group mode is enabled at the controller level (PowerNV),
the CAM line is changed for CAM compares to :

      4Bit chip number||0x001||7Bit Thread number

This will require changes in xive_presenter_tctx_match() possibly.
This is a lowlevel functionality of the HW controller and it is not
strictly needed. Leave it for later.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190306085032.15744-2-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-03-12 14:33:04 +11:00
Cédric Le Goater
3dbe65c178 ppc/xive: xive does not have a POWER7 interrupt model
Patch "target/ppc: Add POWER9 external interrupt model" should have
removed the section covering PPC_FLAGS_INPUT_POWER7.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190219142530.17807-1-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-02-26 09:21:25 +11:00
Benjamin Herrenschmidt
67afe7759d target/ppc: Add POWER9 external interrupt model
Adds support for the Hypervisor directed interrupts in addition to the
OS ones.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[clg: - modified the icp_realize() and xive_tctx_realize() to take
        into account explicitely the POWER9 interrupt model
      - introduced a specific power9_set_irq for POWER9 ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190215161648.9600-10-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-02-26 09:21:24 +11:00
Cédric Le Goater
40a5056c41 xive: add a get_tctx() method to the XiveRouter
It provides a mean to retrieve the XiveTCTX of a CPU. This will become
necessary with future changes which move the interrupt presenter
object pointers under the PowerPCCPU machine_data.

The PowerNV machine has an extra requirement on TIMA accesses that
this new method addresses. The machine can perform indirect loads and
stores on the TIMA on behalf of another CPU. The PIR being defined in
the controller registers, we need a way to peek in the controller
model to find the PIR value.

The XiveTCTX is moved above the XiveRouter definition to avoid forward
typedef declarations.

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
Cédric Le Goater
6bf6f3a1d1 ppc/xive: fix remaining XiveFabric names
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 18:44:17 +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
734d9c8905 ppc: export the XICS and XIVE set_irq handlers
To support the 'dual' interrupt mode, XICS and XIVE, we plan to move
the qemu_irq array of each interrupt controller under the machine and
do the allocation under the sPAPR IRQ init method.

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
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
cdd4de68ed ppc/xive: notify the CPU when the interrupt priority is more privileged
After the event data was enqueued in the O/S Event Queue, the IVPE
raises the bit corresponding to the priority of the pending interrupt
in the register IBP (Interrupt Pending Buffer) to indicate there is an
event pending in one of the 8 priority queues. The Pending Interrupt
Priority Register (PIPR) is also updated using the IPB. This register
represent the priority of the most favored pending notification.

The PIPR is then compared to the the Current Processor Priority
Register (CPPR). If it is more favored (numerically less than), the
CPU interrupt line is raised and the EO bit of the Notification Source
Register (NSR) is updated to notify the presence of an exception for
the O/S. The check needs to be done whenever the PIPR or the CPPR are
changed.

The O/S acknowledges the interrupt with a special load in the Thread
Interrupt Management Area. If the EO bit of the NSR is set, the CPPR
takes the value of PIPR. The bit number in the IBP corresponding to
the priority of the pending interrupt is reseted and so is the EO bit
of the NSR.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
[dwg: Fix style nits]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21 09:37:33 +11:00
Cédric Le Goater
af53dbf622 ppc/xive: introduce a simplified XIVE presenter
The last sub-engine of the XIVE architecture is the Interrupt
Virtualization Presentation Engine (IVPE). On HW, the IVRE and the
IVPE share elements, the Power Bus interface (CQ), the routing table
descriptors, and they can be combined in the same HW logic. We do the
same in QEMU and combine both engines in the XiveRouter for
simplicity.

When the IVRE has completed its job of matching an event source with a
Notification Virtual Target (NVT) to notify, it forwards the event
notification to the IVPE sub-engine. The IVPE scans the thread
interrupt contexts of the Notification Virtual Targets (NVT)
dispatched on the HW processor threads and if a match is found, it
signals the thread. If not, the IVPE escalates the notification to
some other targets and records the notification in a backlog queue.

The IVPE maintains the thread interrupt context state for each of its
NVTs not dispatched on HW processor threads in the Notification
Virtual Target table (NVTT).

The model currently only supports single NVT notifications.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
[dwg: Folded in fix for field accessors]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21 09:37:04 +11:00
Cédric Le Goater
207d9fe985 ppc/xive: introduce the XIVE interrupt thread context
Each POWER9 processor chip has a XIVE presenter that can generate four
different exceptions to its threads:

  - hypervisor exception,
  - O/S exception
  - Event-Based Branch (EBB)
  - msgsnd (doorbell).

Each exception has a state independent from the others called a Thread
Interrupt Management context. This context is a set of registers which
lets the thread handle priority management and interrupt acknowledgment
among other things. The most important ones being :

  - Interrupt Priority Register  (PIPR)
  - Interrupt Pending Buffer     (IPB)
  - Current Processor Priority   (CPPR)
  - Notification Source Register (NSR)

These registers are accessible through a specific MMIO region, called
the Thread Interrupt Management Area (TIMA), four aligned pages, each
exposing a different view of the registers. First page (page address
ending in 0b00) gives access to the entire context and is reserved for
the ring 0 view for the physical thread context. The second (page
address ending in 0b01) is for the hypervisor, ring 1 view. The third
(page address ending in 0b10) is for the operating system, ring 2
view. The fourth (page address ending in 0b11) is for user level, ring
3 view.

The thread interrupt context is modeled with a XiveTCTX object
containing the values of the different exception registers. The TIMA
region is mapped at the same address for each CPU.

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 09:29:12 +11:00
Cédric Le Goater
002686be42 ppc/xive: add support for the END Event State Buffers
The Event Notification Descriptor (END) XIVE structure also contains
two Event State Buffers providing further coalescing of interrupts,
one for the notification event (ESn) and one for the escalation events
(ESe). A MMIO page is assigned for each to control the EOI through
loads only. Stores are not allowed.

The END ESBs are modeled through an object resembling the 'XiveSource'
It is stateless as the END state bits are backed into the XiveEND
structure under the XiveRouter and the MMIO accesses follow the same
rules as for the XiveSource ESBs.

END ESBs are not supported by the Linux drivers neither on OPAL nor on
sPAPR. Nevetherless, it provides a mean to study the question in the
future and validates a bit more the XIVE model.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
[dwg: Fold in a later fix for field access]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21 09:29:12 +11:00
Cédric Le Goater
e4ddaac67f ppc/xive: introduce the XIVE Event Notification Descriptors
To complete the event routing, the IVRE sub-engine uses a second table
containing Event Notification Descriptor (END) structures.

An END specifies on which Event Queue (EQ) the event notification
data, defined in the associated EAS, should be posted when an
exception occurs. It also defines which Notification Virtual Target
(NVT) should be notified.

The Event Queue is a memory page provided by the O/S defining a
circular buffer, one per server and priority couple, containing Event
Queue entries. These are 4 bytes long, the first bit being a
'generation' bit and the 31 following bits the END Data field. They
are pulled by the O/S when the exception occurs.

The END Data field is a way to set an invariant logical event source
number for an IRQ. On sPAPR machines, it is set with the
H_INT_SET_SOURCE_CONFIG hcall when the EISN flag is used.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
[dwg: Fold in a later fix from Cédric fixing field accessors]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21 09:26:42 +11:00
Cédric Le Goater
7ff7ea9280 ppc/xive: introduce the XiveRouter model
The XiveRouter models the second sub-engine of the XIVE architecture :
the Interrupt Virtualization Routing Engine (IVRE).

The IVRE handles event notifications of the IVSE and performs the
interrupt routing process. For this purpose, it uses a set of tables
stored in system memory, the first of which being the Event Assignment
Structure (EAS) table.

The EAT associates an interrupt source number with an Event Notification
Descriptor (END) which will be used in a second phase of the routing
process to identify a Notification Virtual Target.

The XiveRouter is an abstract class which needs to be inherited from
to define a storage for the EAT, and other upcoming tables.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
[dwg: Folded in parts of a later fix by Cédric fixing field access]
[dwg: Fix style nits]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21 09:26:31 +11:00
Cédric Le Goater
5e79b155a8 ppc/xive: introduce the XiveNotifier interface
The XiveNotifier offers a simple interface, between the XiveSource
object and the main interrupt controller of the machine. It will
forward event notifications to the XIVE Interrupt Virtualization
Routing Engine (IVRE).

Signed-off-by: Cédric Le Goater <clg@kaod.org>
[dwg: Adjust type name string for XiveNotifier]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21 09:24:23 +11:00
Cédric Le Goater
5fd9ef18a9 ppc/xive: add support for the LSI interrupt sources
The 'sent' status of the LSI interrupt source is modeled with the 'P'
bit of the ESB and the assertion status of the source is maintained
with an extra bit under the main XiveSource object. The type of the
source is stored in the same array for practical reasons.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
[dwg: Fix style nit]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21 09:24:23 +11:00
Cédric Le Goater
02e3ff548d ppc/xive: introduce a XIVE interrupt source model
The first sub-engine of the overall XIVE architecture is the Interrupt
Virtualization Source Engine (IVSE). An IVSE can be integrated into
another logic, like in a PCI PHB or in the main interrupt controller
to manage IPIs.

Each IVSE instance is associated with an Event State Buffer (ESB) that
contains a two bit state entry for each possible event source. When an
event is signaled to the IVSE, by MMIO or some other means, the
associated interrupt state bits are fetched from the ESB and
modified. Depending on the resulting ESB state, the event is forwarded
to the IVRE sub-engine of the controller doing the routing.

Each supported ESB entry is associated with either a single or a
even/odd pair of pages which provides commands to manage the source:
to EOI, to turn off the source for instance.

On a sPAPR machine, the O/S will obtain the page address of the ESB
entry associated with a source and its characteristic using the
H_INT_GET_SOURCE_INFO hcall. On PowerNV, a similar OPAL call is used.

The xive_source_notify() routine is in charge forwarding the source
event notification to the routing engine. It will be filled later on.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21 09:24:23 +11:00