History log of /qemu/hw/ppc/spapr_drc.c (Results 26 – 50 of 216)
Revision Date Author Comments
# d90f1548 05-May-2021 Peter Maydell <peter.maydell@linaro.org>

Merge remote-tracking branch 'remotes/dg-gitlab/tags/ppc-for-6.1-20210504' into staging

ppc patch queue 2021-05-04

Here's the first ppc pull request for qemu-6.1. It has a wide variety
of stuff ac

Merge remote-tracking branch 'remotes/dg-gitlab/tags/ppc-for-6.1-20210504' into staging

ppc patch queue 2021-05-04

Here's the first ppc pull request for qemu-6.1. It has a wide variety
of stuff accumulated during the 6.0 freeze. Highlights are:

* Multi-phase reset cleanups for PAPR
* Preliminary cleanups towards allowing !CONFIG_TCG for the ppc target
* Cleanup of AIL logic and extension to POWER10
* Further improvements to handling of hot unplug failures on PAPR
* Allow much larger numbers of CPU on pseries
* Support for the H_SCM_HEALTH hypercall
* Add support for the Pegasos II board
* Substantial cleanup to hflag handling
* Assorted minor fixes and cleanups

# gpg: Signature made Tue 04 May 2021 06:52:39 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/dg-gitlab/tags/ppc-for-6.1-20210504: (46 commits)
hw/ppc/pnv_psi: Use device_cold_reset() instead of device_legacy_reset()
hw/ppc/spapr_vio: Reset TCE table object with device_cold_reset()
hw/intc/spapr_xive: Use device_cold_reset() instead of device_legacy_reset()
target/ppc: removed VSCR from SPR registration
target/ppc: Reduce the size of ppc_spr_t
target/ppc: Clean up _spr_register et al
target/ppc: Add POWER10 exception model
target/ppc: rework AIL logic in interrupt delivery
target/ppc: move opcode table logic to translate.c
target/ppc: code motion from translate_init.c.inc to gdbstub.c
spapr_drc.c: handle hotunplug errors in drc_unisolate_logical()
spapr.h: increase FDT_MAX_SIZE
spapr.c: do not use MachineClass::max_cpus to limit CPUs
ppc: Rename current DAWR macros and variables
target/ppc: POWER10 supports scv
target/ppc: Fix POWER9 radix guest HV interrupt AIL behaviour
docs/system: ppc: Add documentation for ppce500 machine
roms/u-boot: Bump ppce500 u-boot to v2021.04 to fix broken pci support
roms/Makefile: Update ppce500 u-boot build directory name
ppc/spapr: Add support for implement support for H_SCM_HEALTH
...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...


# d45a5270 05-May-2021 Peter Maydell <peter.maydell@linaro.org>

Merge remote-tracking branch 'remotes/vivier2/tags/trivial-branch-for-6.1-pull-request' into staging

Trivial patches pull request 20210503

# gpg: Signature made Mon 03 May 2021 09:34:56 BST
# gpg:

Merge remote-tracking branch 'remotes/vivier2/tags/trivial-branch-for-6.1-pull-request' into staging

Trivial patches pull request 20210503

# gpg: Signature made Mon 03 May 2021 09:34:56 BST
# gpg: using RSA key CD2F75DDC8E3A4DC2E4F5173F30C38BD3F2FBE3C
# gpg: issuer "laurent@vivier.eu"
# gpg: Good signature from "Laurent Vivier <lvivier@redhat.com>" [full]
# gpg: aka "Laurent Vivier <laurent@vivier.eu>" [full]
# gpg: aka "Laurent Vivier (Red Hat) <lvivier@redhat.com>" [full]
# Primary key fingerprint: CD2F 75DD C8E3 A4DC 2E4F 5173 F30C 38BD 3F2F BE3C

* remotes/vivier2/tags/trivial-branch-for-6.1-pull-request: (23 commits)
hw/rx/rx-gdbsim: Do not accept invalid memory size
docs: More precisely describe memory-backend-*::id's user
scripts: fix generation update-binfmts templates
docs/system: Document the removal of "compat" property for POWER CPUs
mc146818rtc: put it into the 'misc' category
Do not include exec/address-spaces.h if it's not really necessary
Do not include cpu.h if it's not really necessary
Do not include hw/boards.h if it's not really necessary
Do not include sysemu/sysemu.h if it's not really necessary
hw: Do not include qemu/log.h if it is not necessary
hw: Do not include hw/irq.h if it is not necessary
hw: Do not include hw/sysbus.h if it is not necessary
hw: Remove superfluous includes of hw/hw.h
ui: Fix memory leak in qemu_xkeymap_mapping_table()
hw/usb: Constify VMStateDescription
hw/display/qxl: Constify VMStateDescription
hw/arm: Constify VMStateDescription
vmstate: Constify some VMStateDescriptions
Fix typo in CFI build documentation
hw/pcmcia: Do not register PCMCIA type if not required
...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

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# 87758fed 20-Apr-2021 Daniel Henrique Barboza <danielhb413@gmail.com>

spapr_drc.c: handle hotunplug errors in drc_unisolate_logical()

At this moment, PAPR does not provide a way to report errors during a
device removal operation. This led the pSeries machine to implem

spapr_drc.c: handle hotunplug errors in drc_unisolate_logical()

At this moment, PAPR does not provide a way to report errors during a
device removal operation. This led the pSeries machine to implement
extra mechanisms to try to fallback and recover from an error that might
have happened during the hotunplug in the guest side. This started to
change a bit with commit fe1831eff8a4 ("spapr_drc.c: use DRC
reconfiguration to cleanup DIMM unplug state"), where one way to
fallback from a memory removal error was introduced.

Around the same time, in [1], the idea of using RTAS set-indicator for
this role was first introduced. The RTAS set-indicator call, when
attempting to UNISOLATE a DRC that is already UNISOLATED or CONFIGURED,
returns RTAS_OK and does nothing else for both QEMU and phyp. This gives
us an opportunity to use this behavior to signal the hypervisor layer
when a device removal errir happens, allowing QEMU/phyp to do a proper
error handling. Using set-indicator to report HP errors isn't strange to
PAPR, as per R1-13.5.3.4-4. of table 13.7 of current PAPR [2]:

"For all DR options: If this is a DR operation that involves the user
insert- ing a DR entity, then if the firmware can determine that the
inserted entity would cause a system disturbance, then the set-indicator
RTAS call must not unisolate the entity and must return an error status
which is unique to the particular error."

A change was proposed to the pSeries Linux kernel to call set-indicator
to move a DRC to 'unisolate' in the case of a hotunplug error in the
guest side [3]. Setting a DRC that is already unisolated or configured to
'unisolate' is a no-op (returns RTAS_OK) for QEMU and also for phyp.
Being a benign change for hypervisors that doesn't care about handling
such errors, we expect the kernel to accept this change at some point.

This patch prepares the pSeries machine for this new kernel feature by
changing drc_unisolate_logical() to handle guest side hotunplug errors.
For CPUs it's a simple matter of setting drc->unplug_requested to 'false',
while for LMBs the process is similar to the rollback that is done in
rtas_ibm_configure_connector().

[1] https://lists.gnu.org/archive/html/qemu-devel/2021-02/msg06395.html
[2] https://openpowerfoundation.org/wp-content/uploads/2020/07/LoPAR-20200611.pdf
[3] https://patchwork.ozlabs.org/project/linuxppc-dev/patch/20210416210216.380291-3-danielhb413@gmail.com/

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210420165100.108368-2-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...


# 2068cabd 16-Apr-2021 Thomas Huth <thuth@redhat.com>

Do not include cpu.h if it's not really necessary

Stop including cpu.h in files that don't need it.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210416171314.2074665-4-thuth@redhat.

Do not include cpu.h if it's not really necessary

Stop including cpu.h in files that don't need it.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210416171314.2074665-4-thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

show more ...


# dce628a9 13-Apr-2021 Peter Maydell <peter.maydell@linaro.org>

Merge remote-tracking branch 'remotes/dg-gitlab/tags/ppc-for-6.0-20210412' into staging

ppc patch queue for 2021-04-21

Here's what I hope is the last ppc related pull request for qemu-6.0.

The 2 p

Merge remote-tracking branch 'remotes/dg-gitlab/tags/ppc-for-6.0-20210412' into staging

ppc patch queue for 2021-04-21

Here's what I hope is the last ppc related pull request for qemu-6.0.

The 2 patches here revert a behavioural change that after further
discussion we concluded was a bad idea (adding a timeout for
possibly-failed hot unplug requests). Instead it implements a
different approach to the original problem: we again let unplug
requests the guest doesn't respond to remain pending indefinitely, but
no longer allow those to block attempts to retry the same unplug
again.

The change is a bit more complex than I'd like for this late in the
freeze. Nonetheless, I think it's important to merge this for 6.0, so
we don't allow a release which has the probably-a-bad-idea timeout
behaviour.

# gpg: Signature made Mon 12 Apr 2021 06:25:58 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/dg-gitlab/tags/ppc-for-6.0-20210412:
spapr.c: always pulse guest IRQ in spapr_core_unplug_request()
spapr: rollback 'unplug timeout' for CPU hotunplugs

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

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# d522cb52 01-Apr-2021 Daniel Henrique Barboza <danielhb413@gmail.com>

spapr: rollback 'unplug timeout' for CPU hotunplugs

The pseries machines introduced the concept of 'unplug timeout' for CPU
hotunplugs. The idea was to circunvent a deficiency in the pSeries
specifi

spapr: rollback 'unplug timeout' for CPU hotunplugs

The pseries machines introduced the concept of 'unplug timeout' for CPU
hotunplugs. The idea was to circunvent a deficiency in the pSeries
specification (PAPR), that currently does not define a proper way for
the hotunplug to fail. If the guest refuses to release the CPU (see [1]
for an example) there is no way for QEMU to detect the failure.

Further discussions about how to send a QAPI event to inform about the
hotunplug timeout [2] exposed problems that weren't predicted back when
the idea was developed. Other QEMU machines don't have any type of
hotunplug timeout mechanism for any device, e.g. ACPI based machines
have a way to make hotunplug errors visible to the hypervisor. This
would make this timeout mechanism exclusive to pSeries, which is not
ideal.

The real problem is that a QAPI event that reports hotunplug timeouts
puts the management layer (namely Libvirt) in a weird spot. We're not
telling that the hotunplug failed, because we can't be 100% sure of
that, and yet we're resetting the unplug state back, preventing any
DEVICE_DEL events to reach out in case the guest decides to release the
device. Libvirt would need to inspect the guest itself to see if the
device was released or not, otherwise the internal domain states will be
inconsistent. Moreover, Libvirt already has an 'unplug timeout'
concept, and a QEMU side timeout would need to be juggled together with
the existing Libvirt timeout.

All this considered, this solution ended up creating more trouble than
it solved. This patch reverts the 3 commits that introduced the timeout
mechanism for CPU hotplugs in pSeries machines.

This reverts commit 4515a5f786024fabf0bef4cf3d28adf5647e6e82
"qemu_timer.c: add timer_deadline_ms() helper"

This reverts commit d1c2e3ce3d5a5424651967bce1cf1f4caa0c6d91
"spapr_drc.c: add hotunplug timeout for CPUs"

This reverts commit 51254ffb320183a4636635840c23ee0e3a1efffa
"spapr_drc.c: introduce unplug_timeout_timer"

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1911414
[2] https://lists.gnu.org/archive/html/qemu-devel/2021-03/msg04682.html

CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210401000437.131140-2-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...


# 19418584 12-Mar-2021 Peter Maydell <peter.maydell@linaro.org>

Merge remote-tracking branch 'remotes/dg-gitlab/tags/ppc-for-6.0-20210310' into staging

ppc patch queue for 2021-03-10

Next batch of patches for the ppc target and machine types. Includes:
* Seve

Merge remote-tracking branch 'remotes/dg-gitlab/tags/ppc-for-6.0-20210310' into staging

ppc patch queue for 2021-03-10

Next batch of patches for the ppc target and machine types. Includes:
* Several cleanups for sm501 from Peter Maydell
* An update to the SLOF guest firmware
* Improved handling of hotplug failures in spapr, associated cleanups
to the hotplug handling code
* Several etsec fixes and cleanups from Bin Meng
* Assorted other fixes and cleanups

# gpg: Signature made Wed 10 Mar 2021 04:08:53 GMT
# 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/dg-gitlab/tags/ppc-for-6.0-20210310:
spapr.c: send QAPI event when memory hotunplug fails
spapr.c: remove duplicated assert in spapr_memory_unplug_request()
target/ppc: fix icount support on Book-e vms accessing SPRs
qemu_timer.c: add timer_deadline_ms() helper
spapr_pci.c: add 'unplug already in progress' message for PCI unplug
spapr.c: add 'unplug already in progress' message for PHB unplug
hw/ppc: e500: Add missing <ranges> in the eTSEC node
hw/net: fsl_etsec: Fix build error when HEX_DUMP is on
spapr_drc.c: use DRC reconfiguration to cleanup DIMM unplug state
spapr_drc.c: add hotunplug timeout for CPUs
spapr_drc.c: introduce unplug_timeout_timer
target/ppc: Fix bcdsub. emulation when result overflows
docs/system: Extend PPC section
spapr: rename spapr_drc_detach() to spapr_drc_unplug_request()
spapr_drc.c: use spapr_drc_release() in isolate_physical/set_unusable
pseries: Update SLOF firmware image
spapr_drc.c: do not call spapr_drc_detach() in drc_isolate_logical()
hw/display/sm501: Inline template header into C file
hw/display/sm501: Expand out macros in template header
hw/display/sm501: Remove dead code for non-32-bit RGB surfaces

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...


# eb7f80fd 02-Mar-2021 Daniel Henrique Barboza <danielhb413@gmail.com>

spapr.c: send QAPI event when memory hotunplug fails

Recent changes allowed the pSeries machine to rollback the hotunplug
process for the DIMM when the guest kernel signals, via a
reconfiguration of

spapr.c: send QAPI event when memory hotunplug fails

Recent changes allowed the pSeries machine to rollback the hotunplug
process for the DIMM when the guest kernel signals, via a
reconfiguration of the DR connector, that it's not going to release the
LMBs.

Let's also warn QAPI listerners about it. One place to do it would be
right after the unplug state is cleaned up,
spapr_clear_pending_dimm_unplug_state(). This would mean that the
function is now doing more than cleaning up the pending dimm state
though.

This patch does the following changes in spapr.c:

- send a QAPI event to inform that we experienced a failure in the
hotunplug of the DIMM;

- rename spapr_clear_pending_dimm_unplug_state() to
spapr_memory_unplug_rollback(). This is a better fit for what the
function is now doing, and it makes callers care more about what the
function goal is and less about spapr.c internals such as clearing
the pending dimm unplug state.

Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210302141019.153729-3-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...


# 4515a5f7 01-Mar-2021 Daniel Henrique Barboza <danielhb413@gmail.com>

qemu_timer.c: add timer_deadline_ms() helper

The pSeries machine is using QEMUTimer internals to return the timeout
in seconds for a timer object, in hw/ppc/spapr.c, function
spapr_drc_unplug_timeou

qemu_timer.c: add timer_deadline_ms() helper

The pSeries machine is using QEMUTimer internals to return the timeout
in seconds for a timer object, in hw/ppc/spapr.c, function
spapr_drc_unplug_timeout_remaining_sec().

Create a helper in qemu-timer.c to retrieve the deadline for a QEMUTimer
object, in ms, to avoid exposing timer internals to the PPC code.

CC: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210301124133.23800-2-danielhb413@gmail.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...


# fe1831ef 22-Feb-2021 Daniel Henrique Barboza <danielhb413@gmail.com>

spapr_drc.c: use DRC reconfiguration to cleanup DIMM unplug state

Handling errors in memory hotunplug in the pSeries machine is more
complex than any other device type, because there are all the
com

spapr_drc.c: use DRC reconfiguration to cleanup DIMM unplug state

Handling errors in memory hotunplug in the pSeries machine is more
complex than any other device type, because there are all the
complications that other devices has, and more.

For instance, determining a timeout for a DIMM hotunplug must consider
if it's a Hash-MMU or a Radix-MMU guest, because Hash guests takes
longer to hotunplug DIMMs. The size of the DIMM is also a factor, given
that longer DIMMs naturally takes longer to be hotunplugged from the
kernel. And there's also the guest memory usage to be considered: if
there's a process that is consuming memory that would be lost by the
DIMM unplug, the kernel will postpone the unplug process until the
process finishes, and then initiate the regular hotunplug process. The
first two considerations are manageable, but the last one is a deal
breaker.

There is no sane way for the pSeries machine to determine the memory
load in the guest when attempting a DIMM hotunplug - and even if there
was a way, the guest can start using all the RAM in the middle of the
unplug process and invalidate our previous assumptions - and in result
we can't even begin to calculate a timeout for the operation. This means
that we can't implement a viable timeout mechanism for memory unplug in
pSeries.

Going back to why we would consider an unplug timeout, the reason is
that we can't know if the kernel is giving up the unplug. Turns out
that, sometimes, we can. Consider a failed memory hotunplug attempt
where the kernel will error out with the following message:

'pseries-hotplug-mem: Memory indexed-count-remove failed, adding any
removed LMBs'

This happens when there is a LMB that the kernel gave up in removing,
and the LMBs previously marked for removal are now being added back.
This happens in the pseries kernel in [1], dlpar_memory_remove_by_ic()
into dlpar_add_lmb(), and after that update_lmb_associativity_index().
In this function, the kernel is configuring the LMB DRC connector again.
Note that this is a valid usage in LOPAR, as stated in section
"ibm,configure-connector RTAS Call":

'A subsequent sequence of calls to ibm,configure-connector with the same
entry from the “ibm,drc-indexes” or “ibm,drc-info” property will restart
the configuration of devices which were not completely configured.'

We can use this kernel behavior in our favor. If a DRC connector
reconfiguration for a LMB that we marked as unplug pending happens, this
indicates that the kernel changed its mind about the unplug and is
reasserting that it will keep using all the LMBs of the DIMM. In this
case, it's safe to assume that the whole DIMM device unplug was
cancelled.

This patch hops into rtas_ibm_configure_connector() and, in the scenario
described above, clear the unplug state for the DIMM device. This will
not solve all the problems we still have with memory unplug, but it will
cover this case where the kernel reconfigures LMBs after a failed
unplug. We are a bit more resilient, without using an unreliable
timeout, and we didn't make the remaining error cases any worse.

[1] arch/powerpc/platforms/pseries/hotplug-memory.c

Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210222194531.62717-6-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

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# d1c2e3ce 22-Feb-2021 Daniel Henrique Barboza <danielhb413@gmail.com>

spapr_drc.c: add hotunplug timeout for CPUs

There is a reliable way to make a CPU hotunplug fail in the pseries
machine. Hotplug a CPU A, then offline all other CPUs inside the guest
but A. When try

spapr_drc.c: add hotunplug timeout for CPUs

There is a reliable way to make a CPU hotunplug fail in the pseries
machine. Hotplug a CPU A, then offline all other CPUs inside the guest
but A. When trying to hotunplug A the guest kernel will refuse to do it,
because A is now the last online CPU of the guest. PAPR has no 'error
callback' in this situation to report back to the platform, so the guest
kernel will deny the unplug in silent and QEMU will never know what
happened. The unplug pending state of A will remain until the guest is
shutdown or rebooted.

Previous attempts of fixing it (see [1] and [2]) were aimed at trying to
mitigate the effects of the problem. In [1] we were trying to guess
which guest CPUs were online to forbid hotunplug of the last online CPU
in the QEMU layer, avoiding the scenario described above because QEMU is
now failing in behalf of the guest. This is not robust because the last
online CPU of the guest can change while we're in the middle of the
unplug process, and our initial assumptions are now invalid. In [2] we
were accepting that our unplug process is uncertain and the user should
be allowed to spam the IRQ hotunplug queue of the guest in case the CPU
hotunplug fails.

This patch presents another alternative, using the timeout
infrastructure introduced in the previous patch. CPU hotunplugs in the
pSeries machine will now timeout after 15 seconds. This is a long time
for a single CPU unplug to occur, regardless of guest load - although
the user is *strongly* encouraged to *not* hotunplug devices from a
guest under high load - and we can be sure that something went wrong if
it takes longer than that for the guest to release the CPU (the same
can't be said about memory hotunplug - more on that in the next patch).

Timing out the unplug operation will reset the unplug state of the CPU
and allow the user to try it again, regardless of the error situation
that prevented the hotunplug to occur. Of all the not so pretty
fixes/mitigations for CPU hotunplug errors in pSeries, timing out the
operation is an admission that we have no control in the process, and
must assume the worst case if the operation doesn't succeed in a
sensible time frame.

[1] https://lists.gnu.org/archive/html/qemu-devel/2021-01/msg03353.html
[2] https://lists.gnu.org/archive/html/qemu-devel/2021-01/msg04400.html

Reported-by: Xujun Ma <xuma@redhat.com>
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1911414
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210222194531.62717-5-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...


# 51254ffb 22-Feb-2021 Daniel Henrique Barboza <danielhb413@gmail.com>

spapr_drc.c: introduce unplug_timeout_timer

The LoPAR spec provides no way for the guest kernel to report failure of
hotplug/hotunplug events. This wouldn't be bad if those operations were
granted t

spapr_drc.c: introduce unplug_timeout_timer

The LoPAR spec provides no way for the guest kernel to report failure of
hotplug/hotunplug events. This wouldn't be bad if those operations were
granted to always succeed, but that's far for the reality.

What ends up happening is that, in the case of a failed hotunplug,
regardless of whether it was a QEMU error or a guest misbehavior, the
pSeries machine is retaining the unplug state of the device in the
running guest. This state is cleanup in machine reset, where it is
assumed that this state represents a device that is pending unplug, and
the device is hotunpluged from the board. Until the reset occurs, any
hotunplug operation of the same device is forbid because there is a
pending unplug state.

This behavior has at least one undesirable side effect. A long standing
pending unplug state is, more often than not, the result of a hotunplug
error. The user had to dealt with it, since retrying to unplug the
device is noy allowed, and then in the machine reset we're removing the
device from the guest. This means that we're failing the user twice -
failed to hotunplug when asked, then hotunplugged without notice.

Solutions to this problem range between trying to predict when the
hotunplug will fail and forbid the operation from the QEMU layer, from
opening up the IRQ queue to allow for multiple hotunplug attempts, from
telling the users to 'reboot the machine if something goes wrong'. The
first solution is flawed because we can't fully predict guest behavior
from QEMU, the second solution is a trial and error remediation that
counts on a hope that the unplug will eventually succeed, and the third
is ... well.

This patch introduces a crude, but effective solution to hotunplug
errors in the pSeries machine. For each unplug done, we'll timeout after
some time. If a certain amount of time passes, we'll cleanup the
hotunplug state from the machine. During the timeout period, any unplug
operations in the same device will still be blocked. After that, we'll
assume that the guest failed the operation, and allow the user to try
again. If the timeout is too short we'll prevent legitimate hotunplug
situations to occur, so we'll need to overestimate the regular time an
unplug operation takes to succeed to account that.

The true solution for the hotunplug errors in the pSeries machines is a
PAPR change to allow for the guest to warn the platform about it. For
now, the work done in this timeout design can be used for the new PAPR
'abort hcall' in the future, given that for both cases we'll need code
to cleanup the existing unplug states of the DRCs.

At this moment we're adding the basic wiring of the timer into the DRC.
Next patch will use the timer to timeout failed CPU hotunplugs.

Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210222194531.62717-4-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...


# a03509cd 22-Feb-2021 Daniel Henrique Barboza <danielhb413@gmail.com>

spapr: rename spapr_drc_detach() to spapr_drc_unplug_request()

spapr_drc_detach() is not the best name for what the function does. The
function does not detach the DRC, it makes an uncommited attemp

spapr: rename spapr_drc_detach() to spapr_drc_unplug_request()

spapr_drc_detach() is not the best name for what the function does. The
function does not detach the DRC, it makes an uncommited attempt to do
it. It'll mark the DRC as pending unplug, via the 'unplug_request'
flag, and only if the DRC state is drck->empty_state it will detach the
DRC, via spapr_drc_release().

This is a contrast with its pair spapr_drc_attach(), where the function
is indeed creating the DRC QOM object. If you know what
spapr_drc_attach() does, you can be misled into thinking that
spapr_drc_detach() is removing the DRC from QEMU internal state, which
isn't true.

The current role of this function is better described as a request for
detach, since there's no guarantee that we're going to detach the DRC in
the end. Rename the function to spapr_drc_unplug_request to reflect
what is is doing.

The initial idea was to change the name to spapr_drc_detach_request(),
and later on change the unplug_request flag to detach_request. However,
unplug_request is a migratable boolean for a long time now and renaming
it is not worth the trouble. spapr_drc_unplug_request() setting
drc->unplug_request is more natural than spapr_drc_detach_request
setting drc->unplug_request.

Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210222194531.62717-3-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...


# 66d10d32 22-Feb-2021 Daniel Henrique Barboza <danielhb413@gmail.com>

spapr_drc.c: use spapr_drc_release() in isolate_physical/set_unusable

When moving a physical DRC to "Available", drc_isolate_physical() will
move the DRC state to STATE_PHYSICAL_POWERON and, if the

spapr_drc.c: use spapr_drc_release() in isolate_physical/set_unusable

When moving a physical DRC to "Available", drc_isolate_physical() will
move the DRC state to STATE_PHYSICAL_POWERON and, if the DRC is marked
for unplug, call spapr_drc_detach(). For physical DRCs,
drck->empty_state is STATE_PHYSICAL_POWERON, meaning that we're sure
that spapr_drc_detach() will end up calling spapr_drc_release() in the
end.

Likewise, for logical DRCs, drc_set_unusable will move the DRC to
"Unusable" state, setting drc->state to STATE_LOGICAL_UNUSABLE, which is
the drck->empty_state for logical DRCs. spapr_drc_detach() will call
spapr_drc_release() in this case as well.

In both scenarios, spapr_drc_detach() is being used as a
spapr_drc_release(), wrapper, where we also set unplug_requested (which
is already true, otherwise spapr_drc_detach() wouldn't be called in the
first place) and check if drc->state == drck->empty_state, which we also
know it's guaranteed to be true because we just set it.

Just use spapr_drc_release() in these functions to be clear of our
intentions in both these functions.

Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210222194531.62717-2-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...


# 382907b1 11-Feb-2021 Daniel Henrique Barboza <danielhb413@gmail.com>

spapr_drc.c: do not call spapr_drc_detach() in drc_isolate_logical()

drc_isolate_logical() is used to move the DRC from the "Configured" to
the "Available" state, erroring out if the DRC is in the u

spapr_drc.c: do not call spapr_drc_detach() in drc_isolate_logical()

drc_isolate_logical() is used to move the DRC from the "Configured" to
the "Available" state, erroring out if the DRC is in the unexpected
"Unisolate" state and doing nothing (with RTAS_OUT_SUCCESS) if the DRC
is already in "Available" or in "Unusable" state.

When moving from "Configured" to "Available", the DRC is moved to the
LOGICAL_AVAILABLE state, a drc->unplug_requested check is done and, if
true, spapr_drc_detach() is called.

What spapr_drc_detach() does then is:

- set drc->unplug_requested to true. In fact, this is the only place
where unplug_request is set to true;
- does nothing else if drc->state != drck->empty_state. If the DRC
state is equal to drck->empty_state, spapr_drc_release() is
called. For logical DRCs, drck->empty_state = LOGICAL_UNUSABLE.

In short, calling spapr_drc_detach() in drc_isolate_logical() does
nothing. It'll set unplug_request to true again ('again' since it was
already true - otherwise the function wouldn't be called), and will
return without calling spapr_drc_release() because the DRC is not in
LOGICAL_UNUSABLE, since drc_isolate_logical() just moved it to
LOGICAL_AVAILABLE. The only place where the logical DRC is released is
when called from drc_set_unusable(), when it is moved to the
"Unusable" state. As it should, according to PAPR.

Even though calling spapr_drc_detach() in drc_isolate_logical() is
benign, removing it will avoid further thought about the matter. So
let's go ahead and do that.

As a note, this logic was introduced in commit bbf5c878ab76. Since
then, the DRC handling code was refactored and enhanced, and PAPR
itself went through some changes in the DRC area as well. It is
expected that some assumptions we had back then are now deprecated.

Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210211225246.17315-2-danielhb413@gmail.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...


# 7a5fd934 06-Jan-2021 Peter Maydell <peter.maydell@linaro.org>

Merge remote-tracking branch 'remotes/dg-gitlab/tags/ppc-for-6.0-20210106' into staging

ppc patch queue 2021-01-06

First pull request for 2021, which has a bunch of things accumulated
over the holi

Merge remote-tracking branch 'remotes/dg-gitlab/tags/ppc-for-6.0-20210106' into staging

ppc patch queue 2021-01-06

First pull request for 2021, which has a bunch of things accumulated
over the holidays. Includes:
* A number of cleanups to sam460ex and ppc440 code from BALATON Zoltan
* Several fixes for builds with --without-default-devices from Greg Kurz
* Fixes for some DRC reset problems from Greg Kurz
* QOM conversion of the PPC 4xx UIC devices from Peter Maydell
* Some other assorted fixes and cleanups

# gpg: Signature made Wed 06 Jan 2021 03:33:19 GMT
# 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/dg-gitlab/tags/ppc-for-6.0-20210106: (22 commits)
ppc440_pcix: Fix up pci config access
ppc440_pcix: Fix register write trace event
ppc440_pcix: Improve comment for IRQ mapping
sam460ex: Remove FDT_PPC dependency from KConfig
ppc4xx: Move common dependency on serial to common option
pnv: Fix reverse dependency on PCI express root ports
ppc: Simplify reverse dependencies of POWERNV and PSERIES on XICS and XIVE
ppc: Fix build with --without-default-devices
spapr: Add drc_ prefix to the DRC realize and unrealize functions
spapr: Use spapr_drc_reset_all() at machine reset
spapr: Introduce spapr_drc_reset_all()
spapr: Fix reset of transient DR connectors
spapr: Call spapr_drc_reset() for all DRCs at CAS
spapr: Fix buffer overflow in spapr_numa_associativity_init()
spapr: Allow memory unplug to always succeed
spapr: Fix DR properties of the root node
spapr/xive: Make spapr_xive_pic_print_info() static
spapr: DRC lookup cannot fail
hw/ppc/ppc440_bamboo: Drop use of ppcuic_init()
hw/ppc/virtex_ml507: Drop use of ppcuic_init()
...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...


# 00f46c92 18-Dec-2020 Greg Kurz <groug@kaod.org>

spapr: Add drc_ prefix to the DRC realize and unrealize functions

Use a less generic name for an easier experience with tools such as
cscope or grep.

Signed-off-by: Greg Kurz <groug@kaod.org>
Messa

spapr: Add drc_ prefix to the DRC realize and unrealize functions

Use a less generic name for an easier experience with tools such as
cscope or grep.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20201218103400.689660-6-groug@kaod.org>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Tested-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...


# babb819f 18-Dec-2020 Greg Kurz <groug@kaod.org>

spapr: Introduce spapr_drc_reset_all()

No need to expose the way DRCs are traversed outside of spapr_drc.c.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20201218103400.689660-4-groug@kaod

spapr: Introduce spapr_drc_reset_all()

No need to expose the way DRCs are traversed outside of spapr_drc.c.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20201218103400.689660-4-groug@kaod.org>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Tested-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...


# 930ef3b5 18-Dec-2020 Greg Kurz <groug@kaod.org>

spapr: Fix reset of transient DR connectors

Documentation of object_property_iter_init() clearly stipulates that
"it is forbidden to modify the property list while iterating". But this
is exactly wh

spapr: Fix reset of transient DR connectors

Documentation of object_property_iter_init() clearly stipulates that
"it is forbidden to modify the property list while iterating". But this
is exactly what we do when resetting transient DR connectors during CAS.
The call to spapr_drc_reset() can finalize the hot-unplug sequence of a
PHB or a PCI bridge, both of which will then in turn destroy their PCI
DRCs. This could potentially invalidate the iterator. It is pure luck
that this haven't caused any issues so far.

Change spapr_drc_reset() to return true if it caused a device to be
removed. Restart from scratch in this case. This can potentially
increase the overall DRC reset time, especially with a high maxmem
which generates a lot of LMB DRCs. But this kind of setup is rare,
and so is the use case of rebooting a guest while doing hot-unplug.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20201218103400.689660-3-groug@kaod.org>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Tested-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...


# cd725bd7 18-Dec-2020 Greg Kurz <groug@kaod.org>

spapr: Call spapr_drc_reset() for all DRCs at CAS

Non-transient DRCs are either in the empty or the ready state,
which means spapr_drc_reset() doesn't change their state. It
is thus not needed to do

spapr: Call spapr_drc_reset() for all DRCs at CAS

Non-transient DRCs are either in the empty or the ready state,
which means spapr_drc_reset() doesn't change their state. It
is thus not needed to do any checking. Call spapr_drc_reset()
unconditionally and squash spapr_drc_transient() into its
only user, spapr_drc_needed().

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20201218103400.689660-2-groug@kaod.org>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Tested-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...


# 776e887f 14-Dec-2020 Greg Kurz <groug@kaod.org>

spapr: Fix DR properties of the root node

Section 13.5.2 of LoPAPR mandates various DR related indentifiers
for all hot-pluggable entities to be exposed in the "ibm,drc-indexes",
"ibm,drc-power-doma

spapr: Fix DR properties of the root node

Section 13.5.2 of LoPAPR mandates various DR related indentifiers
for all hot-pluggable entities to be exposed in the "ibm,drc-indexes",
"ibm,drc-power-domains", "ibm,drc-names" and "ibm,drc-types" properties
of their parent node. These properties are created with spapr_dt_drc().

PHBs and LMBs are both children of the machine. Their DR identifiers
are thus supposed to be exposed in the afore mentioned properties of
the root node.

When PHB hot-plug support was added, an extra call to spapr_dt_drc()
was introduced: this overwrites the existing properties, previously
populated with the LMB identifiers, and they end up containing only
PHB identifiers. This went unseen so far because linux doesn't care,
but this is still not conformant with LoPAPR.

Fortunately spapr_dt_drc() is able to handle multiple DR entity types
at the same time. Use that to handle DR indentifiers for PHBs and LMBs
with a single call to spapr_dt_drc(). While here also account for PMEM
DR identifiers, which were forgotten when NVDIMM hot-plug support was
added. Also add an assert to prevent further misuse of spapr_dt_drc().

With -m 1G,maxmem=2G,slots=8 passed on the QEMU command line we get:

Without this patch:

/proc/device-tree/ibm,drc-indexes
0000001f 20000001 20000002 20000003
20000000 20000005 20000006 20000007
20000004 20000009 20000008 20000010
20000011 20000012 20000013 20000014
20000015 20000016 20000017 20000018
20000019 2000000a 2000000b 2000000c
2000000d 2000000e 2000000f 2000001a
2000001b 2000001c 2000001d 2000001e

These are the DRC indexes for the 31 possible PHBs.

With this patch:

/proc/device-tree/ibm,drc-indexes
0000002b 90000000 90000001 90000002
90000003 90000004 90000005 90000006
90000007 20000001 20000002 20000003
20000000 20000005 20000006 20000007
20000004 20000009 20000008 20000010
20000011 20000012 20000013 20000014
20000015 20000016 20000017 20000018
20000019 2000000a 2000000b 2000000c
2000000d 2000000e 2000000f 2000001a
2000001b 2000001c 2000001d 2000001e
80000004 80000005 80000006 80000007

And now we also have the 4 ((2G - 1G) / 256M) LMBs and the
8 (slots) PMEMs.

Fixes: 3998ccd09298 ("spapr: populate PHB DRC entries for root DT node")
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <160794479566.35245.17809158217760761558.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...


# 37f04b71 14-Dec-2020 Peter Maydell <peter.maydell@linaro.org>

Merge remote-tracking branch 'remotes/dg-gitlab/tags/ppc-for-6.0-20201214' into staging

ppc patch queue 2020-12-14

Here's my first pull request for qemu-6.0, with a bunch of things
queued over the

Merge remote-tracking branch 'remotes/dg-gitlab/tags/ppc-for-6.0-20201214' into staging

ppc patch queue 2020-12-14

Here's my first pull request for qemu-6.0, with a bunch of things
queued over the freeze. Highlights are:
* A bunch of cleanups to hotplug error paths from Greg Kurz
* A number of TCG fixes from new contributor Giuseppe Musacchio
* Added Greg Kurz as co-maintainer
* Assorted other bugfixes and cleanups

This supersedes ppc-for-6.0-20201211, the only change are some patch
authors to better match qemu conventions.

# gpg: Signature made Mon 14 Dec 2020 04:57:09 GMT
# 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/dg-gitlab/tags/ppc-for-6.0-20201214: (30 commits)
spapr.c: set a 'kvm-type' default value instead of relying on NULL
spapr: Pass sPAPR machine state to some RTAS events handling functions
spapr: Don't use qdev_get_machine() in spapr_msi_write()
spapr: Pass sPAPR machine state down to spapr_pci_switch_vga()
target/ppc: Introduce an mmu_is_64bit() helper
ppc/translate: Use POWERPC_MMU_64 to detect 64-bit MMU models
ppc/e500: Free irqs array to avoid memleak
MAINTAINERS: Add Greg Kurz as co-maintainer for ppc
hw/ppc: Do not re-read the clock on pre_save if doing savevm
target/ppc: Remove "compat" property of server class POWER CPUs
spapr: spapr_drc_attach() cannot fail
spapr: Simplify error path of spapr_core_plug()
spapr: Abort if ppc_set_compat() fails for hot-plugged CPUs
spapr: Fix pre-2.10 dummy ICP hack
xive: Add trace events
hw/ppc/spapr_tpm_proxy: Fix hexadecimal format string specifier
ppc/translate: Rewrite gen_lxvdsx to use gvec primitives
ppc/translate: Raise exceptions after setting the cc
ppc/translate: Delay NaN checking after comparison
ppc/translate: Turn the helper macros into functions
...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...


# bc370a65 01-Dec-2020 Greg Kurz <groug@kaod.org>

spapr: spapr_drc_attach() cannot fail

All users are passing &error_abort already. Document the fact
that spapr_drc_attach() should only be passed a free DRC, which
is supposedly the case if appropri

spapr: spapr_drc_attach() cannot fail

All users are passing &error_abort already. Document the fact
that spapr_drc_attach() should only be passed a free DRC, which
is supposedly the case if appropriate checking is done earlier.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20201201113728.885700-5-groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...


# a19d4bc4 29-Oct-2020 Peter Maydell <peter.maydell@linaro.org>

Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-5.2-20201028' into staging

ppc patch queue 2020-10-28

Here's the next pull request for ppc and spapr related patches, which
should be the

Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-5.2-20201028' into staging

ppc patch queue 2020-10-28

Here's the next pull request for ppc and spapr related patches, which
should be the last things for soft freeze. Includes:

* Numerous error handling cleanups from Greg Kurz
* Cleanups to cpu realization and hotplug handling from Greg Kurz
* A handful of other small fixes and cleanups

This does include a change to pc_dimm_plug() that isn't in my normal
areas of concern. That's there as a a prerequisite for ppc specific
changes, and has an ack from Igor.

# gpg: Signature made Tue 27 Oct 2020 14:13:21 GMT
# 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-5.2-20201028:
ppc/: fix some comment spelling errors
spapr: Improve spapr_reallocate_hpt() error reporting
target/ppc: Fix kvmppc_load_htab_chunk() error reporting
spapr: Use error_append_hint() in spapr_reallocate_hpt()
spapr: Simplify error handling in spapr_memory_plug()
spapr: Pass &error_abort when getting some PC DIMM properties
spapr: Use appropriate getter for PC_DIMM_SLOT_PROP
spapr: Use appropriate getter for PC_DIMM_ADDR_PROP
pc-dimm: Drop @errp argument of pc_dimm_plug()
spapr: Simplify spapr_cpu_core_realize() and spapr_cpu_core_unrealize()
spapr: Make spapr_cpu_core_unrealize() idempotent
spapr: Drop spapr_delete_vcpu() unused argument
spapr: Unrealize vCPUs with qdev_unrealize()
spapr: Fix leak of CPU machine specific data
spapr: Move spapr_create_nvdimm_dr_connectors() to core machine code
hw/net: move allocation to the heap due to very large stack frame
ppc/spapr: re-assert IRQs during event-scan if there are pending
spapr: Clarify why DR connectors aren't user creatable

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...


# eaf1ffbe 12-Oct-2020 Greg Kurz <groug@kaod.org>

spapr: Clarify why DR connectors aren't user creatable

DR connector is a device that emulates a firmware abstraction used by PAPR
compliant guests to manage hotplug/dynamic-reconfiguration of PHBs,

spapr: Clarify why DR connectors aren't user creatable

DR connector is a device that emulates a firmware abstraction used by PAPR
compliant guests to manage hotplug/dynamic-reconfiguration of PHBs, PCI
devices, memory, and CPUs.

It is internally created by the spapr platform and requires to be owned by
either the machine (PHBs, CPUs, memory) or by a PHB (PCI devices).

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <160250199940.765467.6896806997161856576.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...


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