| 7abc0c6d | 13-Jun-2019 |
Greg Kurz <groug@kaod.org> |
xics/spapr: Detect old KVM XICS on POWER9 hosts
Older KVMs on POWER9 don't support destroying/recreating a KVM XICS
device, which is required by 'dual' interrupt controller mode. This
causes QEMU to
xics/spapr: Detect old KVM XICS on POWER9 hosts
Older KVMs on POWER9 don't support destroying/recreating a KVM XICS
device, which is required by 'dual' interrupt controller mode. This
causes QEMU to emit a warning when the guest is rebooted and to fall
back on XICS emulation:
qemu-system-ppc64: warning: kernel_irqchip allowed but unavailable:
Error on KVM_CREATE_DEVICE for XICS: File exists
If kernel irqchip is required, QEMU will thus exit when the guest is
first rebooted. Failing QEMU this late may be a painful experience
for the user.
Detect that and exit at machine init instead.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <156044430517.125694.6207865998817342638.stgit@bahia.lab.toulouse-stg.fr.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
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| d9293c48 | 13-Jun-2019 |
Greg Kurz <groug@kaod.org> |
xics/spapr: Register RTAS/hypercalls once at machine init
QEMU may crash when running a spapr machine in 'dual' interrupt controller
mode on some older (but not that old, eg. ubuntu 18.04.2) KVMs wi
xics/spapr: Register RTAS/hypercalls once at machine init
QEMU may crash when running a spapr machine in 'dual' interrupt controller
mode on some older (but not that old, eg. ubuntu 18.04.2) KVMs with partial
XIVE support:
qemu-system-ppc64: hw/ppc/spapr_rtas.c:411: spapr_rtas_register:
Assertion `!name || !rtas_table[token].name' failed.
XICS is controlled by the guest thanks to a set of RTAS calls. Depending
on whether KVM XICS is used or not, the RTAS calls are handled by KVM or
QEMU. In both cases, QEMU needs to expose the RTAS calls to the guest
through the "rtas" node of the device tree.
The spapr_rtas_register() helper takes care of all of that: it adds the
RTAS call token to the "rtas" node and registers a QEMU callback to be
invoked when the guest issues the RTAS call. In the KVM XICS case, QEMU
registers a dummy callback that just prints an error since it isn't
supposed to be invoked, ever.
Historically, the XICS controller was setup during machine init and
released during final teardown. This changed when the 'dual' interrupt
controller mode was added to the spapr machine: in this case we need
to tear the XICS down and set it up again during machine reset. The
crash happens because we indeed have an incompatibility with older
KVMs that forces QEMU to fallback on emulated XICS, which tries to
re-registers the same RTAS calls.
This could be fixed by adding proper rollback that would unregister
RTAS calls on error. But since the emulated RTAS calls in QEMU can
now detect when they are mistakenly called while KVM XICS is in
use, it seems simpler to register them once and for all at machine
init. This fixes the crash and allows to remove some now useless
lines of code.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <156044429963.125694.13710679451927268758.stgit@bahia.lab.toulouse-stg.fr.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
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| c29a0b0f | 12-Jun-2019 |
Cédric Le Goater <clg@kaod.org> |
ppc/pnv: remove xscom_base field from PnvChip
It has now became useless with the previous patch.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190612174345.9799-3-clg@kaod.org>
Sign
ppc/pnv: remove xscom_base field from PnvChip
It has now became useless with the previous patch.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190612174345.9799-3-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
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| 3725ef1a | 22-May-2019 |
Greg Kurz <groug@kaod.org> |
spapr: Don't migrate the hpt_maxpagesize cap to older machine types
Commit 0b8c89be7f7b added the hpt_maxpagesize capability to the migration
stream. This is okay for new machine types but it breaks
spapr: Don't migrate the hpt_maxpagesize cap to older machine types
Commit 0b8c89be7f7b added the hpt_maxpagesize capability to the migration
stream. This is okay for new machine types but it breaks backward migration
to older QEMUs, which don't expect the extra subsection.
Add a compatibility boolean flag to the sPAPR machine class and use it to
skip migration of the capability for machine types 4.0 and older. This
fixes migration to an older QEMU. Note that the destination will emit a
warning:
qemu-system-ppc64: warning: cap-hpt-max-page-size lower level (16) in incoming stream than on destination (24)
This is expected and harmless though. It is okay to migrate from a lower
HPT maximum page size (64k) to a greater one (16M).
Fixes: 0b8c89be7f7b "spapr: Add forgotten capability to migration stream"
Based-on: <20190522074016.10521-3-clg@kaod.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <155853262675.1158324.17301777846476373459.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
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| 3f777abc | 13-May-2019 |
Cédric Le Goater <clg@kaod.org> |
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. Thi
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>
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| cf435df6 | 13-May-2019 |
Cédric Le Goater <clg@kaod.org> |
spapr/irq: initialize the IRQ device only once
Add a check to make sure that the routine initializing the emulated
IRQ device is called once. We don't have much to test on the XICS
side, so we intro
spapr/irq: initialize the IRQ device only once
Add a check to make sure that the routine initializing the emulated
IRQ device is called once. We don't have much to test on the XICS
side, so we introduce a 'init' boolean under ICSState.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190513084245.25755-13-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
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| ae805ea9 | 13-May-2019 |
Cédric Le Goater <clg@kaod.org> |
spapr/irq: introduce a spapr_irq_init_device() helper
The way the XICS and the XIVE devices are initialized follows the same
pattern. First, try to connect to the KVM device and if not possible
fall
spapr/irq: introduce a spapr_irq_init_device() helper
The way the XICS and the XIVE devices are initialized follows the same
pattern. First, try to connect to the KVM device and if not possible
fallback on the emulated device, unless a kernel_irqchip is required.
The spapr_irq_init_device() routine implements this sequence in
generic way using new sPAPR IRQ handlers ->init_emu() and ->init_kvm().
The XIVE init sequence is moved under the associated sPAPR IRQ
->init() handler. This will change again when KVM support is added for
the dual interrupt mode.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190513084245.25755-12-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
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| 56b11587 | 13-May-2019 |
Cédric Le Goater <clg@kaod.org> |
spapr: introduce routines to delete the KVM IRQ device
If a new interrupt mode is chosen by CAS, the machine generates a
reset to reconfigure. At this point, the connection with the previous
KVM dev
spapr: introduce routines to delete the KVM IRQ device
If a new interrupt mode is chosen by CAS, the machine generates a
reset to reconfigure. At this point, the connection with the previous
KVM device needs to be closed and a new connection needs to opened
with the KVM device operating the chosen interrupt mode.
New routines are introduced to destroy the XICS and the XIVE KVM
devices. They make use of a new KVM device ioctl which destroys the
device and also disconnects the IRQ presenters from the vCPUs.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190513084245.25755-10-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
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| 277dd3d7 | 13-May-2019 |
Cédric Le Goater <clg@kaod.org> |
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 trans
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>
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| 9b88cd76 | 13-May-2019 |
Cédric Le Goater <clg@kaod.org> |
spapr/xive: introduce a VM state change handler
This handler is in charge of stabilizing the flow of event notifications
in the XIVE controller before migrating a guest. This is a requirement
before
spapr/xive: introduce a VM state change handler
This handler is in charge of stabilizing the flow of event notifications
in the XIVE controller before migrating a guest. This is a requirement
before transferring the guest EQ pages to a destination.
When the VM is stopped, the handler sets the source PQs to PENDING to
stop the flow of events and to possibly catch a triggered interrupt
occuring while the VM is stopped. Their previous state is saved. The
XIVE controller is then synced through KVM to flush any in-flight
event notification and to stabilize the EQs. At this stage, the EQ
pages are marked dirty to make sure the EQ pages are transferred if a
migration sequence is in progress.
The previous configuration of the sources is restored when the VM
resumes, after a migration or a stop. If an interrupt was queued while
the VM was stopped, the handler simply generates the missing trigger.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190513084245.25755-6-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
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| 7bfc759c | 13-May-2019 |
Cédric Le Goater <clg@kaod.org> |
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 dev
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>
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| 0c575703 | 13-May-2019 |
Cédric Le Goater <clg@kaod.org> |
spapr/xive: add hcall support when under KVM
XIVE hcalls are all redirected to QEMU as none are on a fast path.
When necessary, QEMU invokes KVM through specific ioctls to perform
host operations. Q
spapr/xive: add hcall support when under KVM
XIVE hcalls are all redirected to QEMU as none are on a fast path.
When necessary, QEMU invokes KVM through specific ioctls to perform
host operations. QEMU should have done the necessary checks before
calling KVM and, in case of failure, H_HARDWARE is simply returned.
H_INT_ESB is a special case that could have been handled under KVM
but the impact on performance was low when under QEMU. Here are some
figures :
kernel irqchip OFF ON
H_INT_ESB KVM QEMU
rtl8139 (LSI ) 1.19 1.24 1.23 Gbits/sec
virtio 31.80 42.30 -- Gbits/sec
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190513084245.25755-4-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
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| 38afd772 | 13-May-2019 |
Cédric Le Goater <clg@kaod.org> |
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 presenter
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>
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| 64d4a534 | 16-May-2019 |
David Gibson <david@gibson.dropbear.id.au> |
spapr: Add forgotten capability to migration stream
spapr machine capabilities are supposed to be sent in the migration stream
so that we can sanity check the source and destination have compatible
spapr: Add forgotten capability to migration stream
spapr machine capabilities are supposed to be sent in the migration stream
so that we can sanity check the source and destination have compatible
configuration. Unfortunately, when we added the hpt-max-page-size
capability, we forgot to add it to the migration state. This means that we
can generate spurious warnings when both ends are configured for large
pages, or potentially fail to warn if the source is configured for huge
pages, but the destination is not.
Fixes: 2309832afda "spapr: Maximum (HPT) pagesize property"
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
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| 64db6c70 | 21-Mar-2019 |
Cédric Le Goater <clg@kaod.org> |
spapr/rtas: modify spapr_rtas_register() to remove RTAS handlers
Removing RTAS handlers will become necessary when the new pseries
machine supporting multiple interrupt mode is introduced.
Signed-o
spapr/rtas: modify spapr_rtas_register() to remove RTAS handlers
Removing RTAS handlers will become necessary when the new pseries
machine supporting multiple interrupt mode is introduced.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190321144914.19934-9-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
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