Drop more @errp parameters after previous commit

Several functions can't fail anymore: ich9_pm_add_properties(),
device_add_bootindex_property(), ppc_compat_add_property(),
spapr_caps_add_properties

Drop more @errp parameters after previous commit

Several functions can't fail anymore: ich9_pm_add_properties(),
device_add_bootindex_property(), ppc_compat_add_property(),
spapr_caps_add_properties(), PropertyInfo.create(). Drop their @errp
parameter.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-16-armbru@redhat.com>

show more ...

qom: Drop parameter @errp of object_property_add() & friends

The only way object_property_add() can fail is when a property with
the same name already exists. Since our property names are all
hardc

qom: Drop parameter @errp of object_property_add() & friends

The only way object_property_add() can fail is when a property with
the same name already exists. Since our property names are all
hardcoded, failure is a programming error, and the appropriate way to
handle it is passing &error_abort.

Same for its variants, except for object_property_add_child(), which
additionally fails when the child already has a parent. Parentage is
also under program control, so this is a programming error, too.

We have a bit over 500 callers. Almost half of them pass
&error_abort, slightly fewer ignore errors, one test case handles
errors, and the remaining few callers pass them to their own callers.

The previous few commits demonstrated once again that ignoring
programming errors is a bad idea.

Of the few ones that pass on errors, several violate the Error API.
The Error ** argument must be NULL, &error_abort, &error_fatal, or a
pointer to a variable containing NULL. Passing an argument of the
latter kind twice without clearing it in between is wrong: if the
first call sets an error, it no longer points to NULL for the second
call. ich9_pm_add_properties(), sparc32_ledma_realize(),
sparc32_dma_realize(), xilinx_axidma_realize(), xilinx_enet_realize()
are wrong that way.

When the one appropriate choice of argument is &error_abort, letting
users pick the argument is a bad idea.

Drop parameter @errp and assert the preconditions instead.

There's one exception to "duplicate property name is a programming
error": the way object_property_add() implements the magic (and
undocumented) "automatic arrayification". Don't drop @errp there.
Instead, rename object_property_add() to object_property_try_add(),
and add the obvious wrapper object_property_add().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-15-armbru@redhat.com>
[Two semantic rebase conflicts resolved]

show more ...

qom: Drop object_property_set_description() parameter @errp

object_property_set_description() and
object_class_property_set_description() fail only when property @name
is not found.

There are 85 ca

qom: Drop object_property_set_description() parameter @errp

object_property_set_description() and
object_class_property_set_description() fail only when property @name
is not found.

There are 85 calls of object_property_set_description() and
object_class_property_set_description(). None of them can fail:

* 84 immediately follow the creation of the property.

* The one in spapr_rng_instance_init() refers to a property created in
spapr_rng_class_init(), from spapr_rng_properties[].

Every one of them still gets to decide what to pass for @errp.

51 calls pass &error_abort, 32 calls pass NULL, one receives the error
and propagates it to &error_abort, and one propagates it to
&error_fatal. I'm actually surprised none of them violates the Error
API.

What are we gaining by letting callers handle the "property not found"
error? Use when the property is not known to exist is simpler: you
don't have to guard the call with a check. We haven't found such a
use in 5+ years. Until we do, let's make life a bit simpler and drop
the @errp parameter.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-8-armbru@redhat.com>
[One semantic rebase conflict resolved]

show more ...

Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-5.1-20200507' into staging

ppc patch queue for 2020-04-07

First pull request for qemu-5.1. This includes:
* Removal of all remaining cas

Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-5.1-20200507' into staging

ppc patch queue for 2020-04-07

First pull request for qemu-5.1. This includes:
* Removal of all remaining cases where we had CAS triggered reboots
* A number of improvements to NMI injection
* Support for partition scoped radix translation in softmmu
* Some fixes for NVDIMM handling
* A handful of other minor fixes

# gpg: Signature made Thu 07 May 2020 06:00:55 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-5.1-20200507:
target-ppc: fix rlwimi, rlwinm, rlwnm for Clang-9
spapr_nvdimm: Tweak error messages
spapr_nvdimm.c: make 'label-size' mandatory
target/ppc: Add support for Radix partition-scoped translation
target/ppc: Rework ppc_radix64_walk_tree() for partition-scoped translation
target/ppc: Extend ppc_radix64_check_prot() with a 'partition_scoped' bool
target/ppc: Introduce ppc_radix64_xlate() for Radix tree translation
spapr: Don't allow unplug of NVLink2 devices
target/ppc: Assert if HV mode is set when running under a pseries machine
target/ppc: Introduce a relocation bool in ppc_radix64_handle_mmu_fault()
target/ppc: Enforce that the root page directory size must be at least 5
spapr: Drop CAS reboot flag
spapr/cas: Separate CAS handling from rebuilding the FDT
spapr: Simplify selection of radix/hash during CAS
ppc/pnv: Add support for NMI interface
ppc/spapr: tweak change system reset helper
spapr: Don't check capabilities removed between CAS calls
target/ppc: Improve syscall exception logging

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

show more ...

spapr: Drop CAS reboot flag

The CAS reboot flag is false by default and all the locations that
could set it to true have been dropped. This means that all code
blocks depending on the flag being set

spapr: Drop CAS reboot flag

The CAS reboot flag is false by default and all the locations that
could set it to true have been dropped. This means that all code
blocks depending on the flag being set is dead code and the other
code blocks should be executed always.

Just do that and drop the now uneeded CAS reboot flag. Fix a
comment on the way to make checkpatch happy.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <158514994893.478799.11772512888322840990.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...

spapr/cas: Separate CAS handling from rebuilding the FDT

At the moment "ibm,client-architecture-support" ("CAS") is implemented
in SLOF and QEMU assists via the custom H_CAS hypercall which copies
a

spapr/cas: Separate CAS handling from rebuilding the FDT

At the moment "ibm,client-architecture-support" ("CAS") is implemented
in SLOF and QEMU assists via the custom H_CAS hypercall which copies
an updated flatten device tree (FDT) blob to the SLOF memory which
it then uses to update its internal tree.

When we enable the OpenFirmware client interface in QEMU, we won't need
to copy the FDT to the guest as the client is expected to fetch
the device tree using the client interface.

This moves FDT rebuild out to a separate helper which is going to be
called from the "ibm,client-architecture-support" handler and leaves
writing FDT to the guest in the H_CAS handler.

This should not cause any behavioral change.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20200310050733.29805-3-aik@ozlabs.ru>
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <158514994229.478799.2178881312094922324.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...

spapr: Simplify selection of radix/hash during CAS

The guest can select the MMU mode by setting bits 0-1 of byte 24
in OV5 to to 0b00 for hash or 0b01 for radix. As required by the
architecture, we

spapr: Simplify selection of radix/hash during CAS

The guest can select the MMU mode by setting bits 0-1 of byte 24
in OV5 to to 0b00 for hash or 0b01 for radix. As required by the
architecture, we terminate the boot process if any other value
is found there.

The usual way to negotiate features in OV5 is basically ANDing
the bitfield provided by the guest and the bitfield of features
supported by QEMU, previously populated at machine init.

For some not documented reason, MMU is treated differently : bit 1
of byte 24 (the radix/hash bit) is cleared from the guest OV5 and
explicitely set in the final negotiated OV5 if radix was requested.

Since the only expected input from the guest is the radix/hash bit
being set or not, it seems more appropriate to handle this like we
do for XIVE.

Set the radix bit in spapr->ov5 at machine init if it has a chance
to work (ie. power9, either TCG or a radix capable KVM) and rely
exclusively on spapr_ovec_intersect() to set the radix bit in
spapr->ov5_cas.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <158514993621.478799.4204740354545734293.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...

ppc/spapr: tweak change system reset helper

Rather than have the helper take an optional vector address
override, instead have its caller modify env->nip itself.
This is more consistent when adding

ppc/spapr: tweak change system reset helper

Rather than have the helper take an optional vector address
override, instead have its caller modify env->nip itself.
This is more consistent when adding pnv nmi support, and also
with mce injection added later.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20200325144147.221875-2-npiggin@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...

Merge remote-tracking branch 'remotes/stefanberger/tags/pull-tpm-2020-05-06-1' into staging

Merge tpm 2020/05/06 v1

# gpg: Signature made Wed 06 May 2020 15:16:17 BST
# gpg: using RS

Merge remote-tracking branch 'remotes/stefanberger/tags/pull-tpm-2020-05-06-1' into staging

Merge tpm 2020/05/06 v1

# gpg: Signature made Wed 06 May 2020 15:16:17 BST
# gpg: using RSA key B818B9CADF9089C2D5CEC66B75AD65802A0B4211
# gpg: Good signature from "Stefan Berger <stefanb@linux.vnet.ibm.com>" [unknown]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg: There is no indication that the signature belongs to the owner.
# Primary key fingerprint: B818 B9CA DF90 89C2 D5CE C66B 75AD 6580 2A0B 4211

* remotes/stefanberger/tags/pull-tpm-2020-05-06-1:
hw: add compat machines for 5.1
hw/arm/virt: Remove the compat forcing tpm-tis-device PPI to off
tpm: tpm-tis-device: set PPI to false by default

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

show more ...

hw: add compat machines for 5.1

Add 5.1 machine types for arm/i440fx/q35/s390x/spapr.

Acked-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-of

hw: add compat machines for 5.1

Add 5.1 machine types for arm/i440fx/q35/s390x/spapr.

Acked-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Message-id: 20200429144605.7262-1-cohuck@redhat.com

show more ...

Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-5.0-20200317' into staging

ppc patch queue 2020-03-17

Here's my final pull request for the qemu-5.0 soft freeze. Sorry this
is just under

Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-5.0-20200317' into staging

ppc patch queue 2020-03-17

Here's my final pull request for the qemu-5.0 soft freeze. Sorry this
is just under the wire - I hit some last minute problems that took a
while to fix up and retest.

Highlights are:
* Numerous fixes for the FWNMI feature
* A handful of cleanups to the device tree construction code
* Numerous fixes for the spapr-vscsi device
* A number of fixes and cleanups for real mode (MMU off) softmmu
handling
* Fixes for handling of the PAPR RMA
* Better handling of hotplug/unplug events during boot
* Assorted other fixes

# gpg: Signature made Tue 17 Mar 2020 09:55:07 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-5.0-20200317: (45 commits)
pseries: Update SLOF firmware image
ppc/spapr: Ignore common "ibm,nmi-interlock" Linux bug
ppc/spapr: Implement FWNMI System Reset delivery
target/ppc: allow ppc_cpu_do_system_reset to take an alternate vector
ppc/spapr: Allow FWNMI on TCG
ppc/spapr: Fix FWNMI machine check interrupt delivery
ppc/spapr: Add FWNMI System Reset state
ppc/spapr: Change FWNMI names
ppc/spapr: Fix FWNMI machine check failure handling
spapr: Rename DT functions to newer naming convention
spapr: Move creation of ibm,architecture-vec-5 property
spapr: Move creation of ibm,dynamic-reconfiguration-memory dt node
spapr/rtas: Reserve space for RTAS blob and log
pseries: Update SLOF firmware image
ppc/spapr: Move GPRs setup to one place
target/ppc: Fix rlwinm on ppc64
spapr/xive: use SPAPR_IRQ_IPI to define IPI ranges exposed to the guest
hw/scsi/spapr_vscsi: Convert debug fprintf() to trace event
hw/scsi/spapr_vscsi: Prevent buffer overflow
hw/scsi/spapr_vscsi: Do not mix SRP IU size with DMA buffer size
...

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

show more ...

Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

* Bugfixes all over the place
* get/set_uint cleanups (Felipe)
* Lock guard support (Stefan)
* MemoryRegion ownership cl

Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

* Bugfixes all over the place
* get/set_uint cleanups (Felipe)
* Lock guard support (Stefan)
* MemoryRegion ownership cleanup (Philippe)
* AVX512 optimization for buffer_is_zero (Robert)

# gpg: Signature made Tue 17 Mar 2020 15:01:54 GMT
# gpg: using RSA key BFFBD25F78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full]
# gpg: aka "Paolo Bonzini <pbonzini@redhat.com>" [full]
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4 E2F7 7E15 100C CD36 69B1
# Subkey fingerprint: F133 3857 4B66 2389 866C 7682 BFFB D25F 78C7 AE83

* remotes/bonzini/tags/for-upstream: (62 commits)
hw/arm: Let devices own the MemoryRegion they create
hw/arm: Remove unnecessary memory_region_set_readonly() on ROM alias
hw/ppc/ppc405: Use memory_region_init_rom() with read-only regions
hw/arm/stm32: Use memory_region_init_rom() with read-only regions
hw/char: Let devices own the MemoryRegion they create
hw/riscv: Let devices own the MemoryRegion they create
hw/dma: Let devices own the MemoryRegion they create
hw/display: Let devices own the MemoryRegion they create
hw/core: Let devices own the MemoryRegion they create
scripts/cocci: Patch to let devices own their MemoryRegions
scripts/cocci: Patch to remove unnecessary memory_region_set_readonly()
scripts/cocci: Patch to detect potential use of memory_region_init_rom
hw/sparc: Use memory_region_init_rom() with read-only regions
hw/sh4: Use memory_region_init_rom() with read-only regions
hw/riscv: Use memory_region_init_rom() with read-only regions
hw/ppc: Use memory_region_init_rom() with read-only regions
hw/pci-host: Use memory_region_init_rom() with read-only regions
hw/net: Use memory_region_init_rom() with read-only regions
hw/m68k: Use memory_region_init_rom() with read-only regions
hw/display: Use memory_region_init_rom() with read-only regions
...

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

show more ...

ppc/spapr: Implement FWNMI System Reset delivery

PAPR requires that if "ibm,nmi-register" succeeds, then the hypervisor
delivers all system reset and machine check exceptions to the registered
addre

ppc/spapr: Implement FWNMI System Reset delivery

PAPR requires that if "ibm,nmi-register" succeeds, then the hypervisor
delivers all system reset and machine check exceptions to the registered
addresses.

System Resets are delivered with registers set to the architected state,
and with no interlock.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20200316142613.121089-8-npiggin@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...

target/ppc: allow ppc_cpu_do_system_reset to take an alternate vector

Provide for an alternate delivery location, -1 defaults to the
architected address.

Signed-off-by: Nicholas Piggin <npiggin@gma

target/ppc: allow ppc_cpu_do_system_reset to take an alternate vector

Provide for an alternate delivery location, -1 defaults to the
architected address.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20200316142613.121089-7-npiggin@gmail.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...

ppc/spapr: Add FWNMI System Reset state

The FWNMI option must deliver system reset interrupts to their
registered address, and there are a few constraints on the handler
addresses specified in PAPR.

ppc/spapr: Add FWNMI System Reset state

The FWNMI option must deliver system reset interrupts to their
registered address, and there are a few constraints on the handler
addresses specified in PAPR. Add the system reset address state and
checks.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20200316142613.121089-4-npiggin@gmail.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviwed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...

ppc/spapr: Change FWNMI names

The option is called "FWNMI", and it involves more than just machine
checks, also machine checks can be delivered without the FWNMI option,
so re-name various things to

ppc/spapr: Change FWNMI names

The option is called "FWNMI", and it involves more than just machine
checks, also machine checks can be delivered without the FWNMI option,
so re-name various things to reflect that.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20200316142613.121089-3-npiggin@gmail.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...

spapr: Rename DT functions to newer naming convention

In the spapr code we've been gradually moving towards a convention that
functions which create pieces of the device tree are called spapr_dt_*()

spapr: Rename DT functions to newer naming convention

In the spapr code we've been gradually moving towards a convention that
functions which create pieces of the device tree are called spapr_dt_*().
This patch speeds that along by renaming most of the things that don't yet
match that so that they do.

For now we leave the *_dt_populate() functions which are actual methods
used in the DRCClass::dt_populate method.

While we're there we remove a few comments that don't really say anything
useful.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>

show more ...

spapr: Move creation of ibm,architecture-vec-5 property

This is currently called from spapr_dt_cas_updates() which is a hang
over from when we created this only as a diff to the DT at CAS time.
Now

spapr: Move creation of ibm,architecture-vec-5 property

This is currently called from spapr_dt_cas_updates() which is a hang
over from when we created this only as a diff to the DT at CAS time.
Now that we fully rebuild the DT at CAS time, just create it along
with the rest of the properties in /chosen.

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

show more ...

spapr: Move creation of ibm,dynamic-reconfiguration-memory dt node

Currently this node with information about hotpluggable memory is created
from spapr_dt_cas_updates(). But that's just a hangover

spapr: Move creation of ibm,dynamic-reconfiguration-memory dt node

Currently this node with information about hotpluggable memory is created
from spapr_dt_cas_updates(). But that's just a hangover from when we
created it only as a diff to the device tree at CAS time. Now that we
fully rebuild the DT as CAS time, it makes more sense to create this along
with the rest of the memory information in the device tree.

So, move it to spapr_populate_memory(). The patch is huge, but it's nearly
all just code motion.

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

show more ...

spapr/rtas: Reserve space for RTAS blob and log

At the moment SLOF reserves space for RTAS and instantiates the RTAS blob
which is 20 bytes binary blob calling an hypercall. The rest of the RTAS
are

spapr/rtas: Reserve space for RTAS blob and log

At the moment SLOF reserves space for RTAS and instantiates the RTAS blob
which is 20 bytes binary blob calling an hypercall. The rest of the RTAS
area is a log which SLOF has no idea about but QEMU does.

This moves RTAS sizing to QEMU and this overrides the size from SLOF.
The only remaining problem is that SLOF copies the number of bytes it
reserved (2KB for now) so QEMU needs to reserve at least this much;
SLOF will be fixed separately to check that rtas-size from QEMU is
enough for those 20 bytes for the H_RTAS hcall.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20200316011841.99970-1-aik@ozlabs.ru>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...

ppc/spapr: Move GPRs setup to one place

At the moment "pseries" starts in SLOF which only expects the FDT blob
pointer in r3. As we are going to introduce a OpenFirmware support in
QEMU, we will be

ppc/spapr: Move GPRs setup to one place

At the moment "pseries" starts in SLOF which only expects the FDT blob
pointer in r3. As we are going to introduce a OpenFirmware support in
QEMU, we will be booting OF clients directly and these expect a stack
pointer in r1, Linux looks at r3/r4 for the initramdisk location
(although vmlinux can find this from the device tree but zImage from
distro kernels cannot).

This extends spapr_cpu_set_entry_state() to take more registers. This
should cause no behavioral change.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20200310050733.29805-2-aik@ozlabs.ru>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...

spapr: Clean up RMA size calculation

Move the calculation of the Real Mode Area (RMA) size into a helper
function. While we're there clean it up and correct it in a few ways:
* Add comments makin

spapr: Clean up RMA size calculation

Move the calculation of the Real Mode Area (RMA) size into a helper
function. While we're there clean it up and correct it in a few ways:
* Add comments making it clearer where the various constraints come from
* Remove a pointless check that the RMA fits within Node 0 (we've just
clamped it so that it does)

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

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spapr: Don't clamp RMA to 16GiB on new machine types

In spapr_machine_init() we clamp the size of the RMA to 16GiB and the
comment saying why doesn't make a whole lot of sense. In fact, this was
do

spapr: Don't clamp RMA to 16GiB on new machine types

In spapr_machine_init() we clamp the size of the RMA to 16GiB and the
comment saying why doesn't make a whole lot of sense. In fact, this was
done because the real mode handling code elsewhere limited the RMA in TCG
mode to the maximum value configurable in LPCR[RMLS], 16GiB.

But,
* Actually LPCR[RMLS] has been able to encode a 256GiB size for a very
long time, we just didn't implement it properly in the softmmu
* LPCR[RMLS] shouldn't really be relevant anyway, it only was because we
used to abuse the RMOR based translation mode in order to handle the
fact that we're not modelling the hypervisor parts of the cpu

We've now removed those limitations in the modelling so the 16GiB clamp no
longer serves a function. However, we can't just remove the limit
universally: that would break migration to earlier qemu versions, where
the 16GiB RMLS limit still applies, no matter how bad the reasons for it
are.

So, we replace the 16GiB clamp, with a clamp to a limit defined in the
machine type class. We set it to 16 GiB for machine types 4.2 and earlier,
but set it to 0 meaning unlimited for the new 5.0 machine type.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

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spapr: Don't attempt to clamp RMA to VRMA constraint

The Real Mode Area (RMA) is the part of memory which a guest can access
when in real (MMU off) mode. Of course, for a guest under KVM, the MMU
i

spapr: Don't attempt to clamp RMA to VRMA constraint

The Real Mode Area (RMA) is the part of memory which a guest can access
when in real (MMU off) mode. Of course, for a guest under KVM, the MMU
isn't really turned off, it's just in a special translation mode - Virtual
Real Mode Area (VRMA) - which looks like real mode in guest mode.

The mechanics of how this works when using the hash MMU (HPT) put a
constraint on the size of the RMA, which depends on the size of the
HPT. So, the latter part of spapr_setup_hpt_and_vrma() clamps the RMA
we advertise to the guest based on this VRMA limit.

There are several things wrong with this:
1) spapr_setup_hpt_and_vrma() doesn't actually clamp, it takes the minimum
of Node 0 memory size and the VRMA limit. That will *often* work the
same as clamping, but there can be other constraints on RMA size which
supersede Node 0 memory size. We have real bugs caused by this
(currently worked around in the guest kernel)
2) Some callers of spapr_setup_hpt_and_vrma() are in a situation where
we're past the point that we can actually advertise an RMA limit to the
guest
3) But most fundamentally, the VRMA limit depends on host configuration
(page size) which shouldn't be visible to the guest, but this partially
exposes it. This can cause problems with migration in certain edge
cases, although we will mostly get away with it.

In practice, this clamping is almost never applied anyway. With 64kiB
pages and the normal rules for sizing of the HPT, the theoretical VRMA
limit will be 4x(guest memory size) and so never hit. It will hit with
4kiB pages, where it will be (guest memory size)/4. However all mainstream
distro kernels for POWER have used a 64kiB page size for at least 10 years.

So, simply replace this logic with a check that the RMA we've calculated
based only on guest visible configuration will fit within the host implied
VRMA limit. This can break if running HPT guests on a host kernel with
4kiB page size. As noted that's very rare. There also exist several
possible workarounds:
* Change the host kernel to use 64kiB pages
* Use radix MMU (RPT) guests instead of HPT
* Use 64kiB hugepages on the host to back guest memory
* Increase the guest memory size so that the RMA hits one of the fixed
limits before the RMA limit. This is relatively easy on POWER8 which
has a 16GiB limit, harder on POWER9 which has a 1TiB limit.
* Use a guest NUMA configuration which artificially constrains the RMA
within the VRMA limit (the RMA must always fit within Node 0).

Previously, on KVM, we also temporarily reduced the rma_size to 256M so
that the we'd load the kernel and initrd safely, regardless of the VRMA
limit. This was a) confusing, b) could significantly limit the size of
images we could load and c) introduced a behavioural difference between
KVM and TCG. So we remove that as well.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Greg Kurz <groug@kaod.org>

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spapr,ppc: Simplify signature of kvmppc_rma_size()

This function calculates the maximum size of the RMA as implied by the
host's page size of structure of the VRMA (there are a number of other
const

spapr,ppc: Simplify signature of kvmppc_rma_size()

This function calculates the maximum size of the RMA as implied by the
host's page size of structure of the VRMA (there are a number of other
constraints on the RMA size which will supersede this one in many
circumstances).

The current interface takes the current RMA size estimate, and clamps it
to the VRMA derived size. The only current caller passes in an arguably
wrong value (it will match the current RMA estimate in some but not all
cases).

We want to fix that, but for now just keep concerns separated by having the
KVM helper function just return the VRMA derived limit, and let the caller
combine it with other constraints. We call the new function
kvmppc_vrma_limit() to more clearly indicate its limited responsibility.

The helper should only ever be called in the KVM enabled case, so replace
its !CONFIG_KVM stub with an assert() rather than a dummy value.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cedric Le Goater <clg@fr.ibm.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

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