ppc/pnv: Implement Power9 CPU core thread state indirect register

Power9 CPUs have a core thread state register accessible via SPRC/SPRD
indirect registers. This register includes a bit for big-core

ppc/pnv: Implement Power9 CPU core thread state indirect register

Power9 CPUs have a core thread state register accessible via SPRC/SPRD
indirect registers. This register includes a bit for big-core mode,
which skiboot requires.

Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

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target/ppc: Add helpers to check for SMT sibling threads

Add helpers for TCG code to determine if there are SMT siblings
sharing per-core and per-lpar registers. This simplifies the
callers and make

target/ppc: Add helpers to check for SMT sibling threads

Add helpers for TCG code to determine if there are SMT siblings
sharing per-core and per-lpar registers. This simplifies the
callers and makes SMT register topology simpler to modify with
later changes.

Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

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target/ppc: Move SPR indirect registers into PnvCore

SPRC/SPRD were recently added to all BookS CPUs supported, but
they are only tested on POWER9 and POWER10, so restrict them to
those CPUs.

SPR i

target/ppc: Move SPR indirect registers into PnvCore

SPRC/SPRD were recently added to all BookS CPUs supported, but
they are only tested on POWER9 and POWER10, so restrict them to
those CPUs.

SPR indirect scratch registers presently replicated per-CPU like
SMT SPRs, but the PnvCore is a better place for them since they
are restricted to P9/P10.

Also add SPR indirect read access to core thread state for POWER9
since skiboot accesses that when booting to check for big-core
mode.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

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target/ppc: Implement SPRC/SPRD SPRs

This implements the POWER SPRC/SPRD SPRs, and SCRATCH0-7 registers that
can be accessed via these indirect SPRs.

SCRATCH registers only provide storage, but the

target/ppc: Implement SPRC/SPRD SPRs

This implements the POWER SPRC/SPRD SPRs, and SCRATCH0-7 registers that
can be accessed via these indirect SPRs.

SCRATCH registers only provide storage, but they are used by firmware
for low level crash and progress data, so this implementation logs
writes to the registers to help with analysis.

Reviewed-by: Glenn Miles <milesg@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

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target/ppc: Add SMT support to PTCR SPR

PTCR is a per-core register.

Reviewed-by: Glenn Miles <milesg@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

target/ppc: Add clrbhrb and mfbhrbe instructions

Add support for the clrbhrb and mfbhrbe instructions.

Since neither instruction is believed to be critical to
performance, both instructions were im

target/ppc: Add clrbhrb and mfbhrbe instructions

Add support for the clrbhrb and mfbhrbe instructions.

Since neither instruction is believed to be critical to
performance, both instructions were implemented using helper
functions.

Access to both instructions is controlled by bits in the
HFSCR (for privileged state) and MMCR0 (for problem state).
A new function, helper_mmcr0_facility_check, was added for
checking MMCR0[BHRBA] and raising a facility_unavailable exception
if required.

NOTE: For P8 and P9, due to a performance issue, branch history will
not be kept, but the instructions will be allowed to execute
as normal with the exception that the mfbhrbe instruction will
always return a zero value.

Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Glenn Miles <milesg@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

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ppc/pnv: Improve pervasive topology calculation for big-core

Big (SMT8) cores have a complicated function to map the core, thread ID
to pervasive topology (PIR). Fix this for power8, power9, and pow

ppc/pnv: Improve pervasive topology calculation for big-core

Big (SMT8) cores have a complicated function to map the core, thread ID
to pervasive topology (PIR). Fix this for power8, power9, and power10.

Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Caleb Schlossin <calebs@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

show more ...

ppc/pnv: Improve pervasive topology calculation for big-core

Big (SMT8) cores have a complicated function to map the core, thread ID
to pervasive topology (PIR). Fix this for power8, power9, and pow

ppc/pnv: Improve pervasive topology calculation for big-core

Big (SMT8) cores have a complicated function to map the core, thread ID
to pervasive topology (PIR). Fix this for power8, power9, and power10.

Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Caleb Schlossin <calebs@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

show more ...

ppc/pnv: Improve pervasive topology calculation for big-core

Big (SMT8) cores have a complicated function to map the core, thread ID
to pervasive topology (PIR). Fix this for power8, power9, and pow

ppc/pnv: Improve pervasive topology calculation for big-core

Big (SMT8) cores have a complicated function to map the core, thread ID
to pervasive topology (PIR). Fix this for power8, power9, and power10.

Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Caleb Schlossin <calebs@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

show more ...

ppc/pnv: Improve pervasive topology calculation for big-core

Big (SMT8) cores have a complicated function to map the core, thread ID
to pervasive topology (PIR). Fix this for power8, power9, and pow

ppc/pnv: Improve pervasive topology calculation for big-core

Big (SMT8) cores have a complicated function to map the core, thread ID
to pervasive topology (PIR). Fix this for power8, power9, and power10.

Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Caleb Schlossin <calebs@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

show more ...

ppc/pnv: Improve pervasive topology calculation for big-core

Big (SMT8) cores have a complicated function to map the core, thread ID
to pervasive topology (PIR). Fix this for power8, power9, and pow

ppc/pnv: Improve pervasive topology calculation for big-core

Big (SMT8) cores have a complicated function to map the core, thread ID
to pervasive topology (PIR). Fix this for power8, power9, and power10.

Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Caleb Schlossin <calebs@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

show more ...

system/cpus: rename qemu_mutex_lock_iothread() to bql_lock()

The Big QEMU Lock (BQL) has many names and they are confusing. The
actual QemuMutex variable is called qemu_global_mutex but it's commonl

system/cpus: rename qemu_mutex_lock_iothread() to bql_lock()

The Big QEMU Lock (BQL) has many names and they are confusing. The
actual QemuMutex variable is called qemu_global_mutex but it's commonly
referred to as the BQL in discussions and some code comments. The
locking APIs, however, are called qemu_mutex_lock_iothread() and
qemu_mutex_unlock_iothread().

The "iothread" name is historic and comes from when the main thread was
split into into KVM vcpu threads and the "iothread" (now called the main
loop thread). I have contributed to the confusion myself by introducing
a separate --object iothread, a separate concept unrelated to the BQL.

The "iothread" name is no longer appropriate for the BQL. Rename the
locking APIs to:
- void bql_lock(void)
- void bql_unlock(void)
- bool bql_locked(void)

There are more APIs with "iothread" in their names. Subsequent patches
will rename them. There are also comments and documentation that will be
updated in later patches.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Acked-by: Fabiano Rosas <farosas@suse.de>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Acked-by: Hyman Huang <yong.huang@smartx.com>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-id: 20240102153529.486531-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

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target/ppc: Implement watchpoint debug facility for v2.07S

ISA v2.07S introduced the watchpoint facility based on the DAWR0
and DAWRX0 SPRs. Implement this in TCG.

Signed-off-by: Nicholas Piggin <n

target/ppc: Implement watchpoint debug facility for v2.07S

ISA v2.07S introduced the watchpoint facility based on the DAWR0
and DAWRX0 SPRs. Implement this in TCG.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

show more ...

target/ppc: Implement breakpoint debug facility for v2.07S

ISA v2.07S introduced the breakpoint facility based on the CIABR SPR.
Implement this in TCG.

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

target/ppc: Implement breakpoint debug facility for v2.07S

ISA v2.07S introduced the breakpoint facility based on the CIABR SPR.
Implement this in TCG.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

show more ...

target/ppc: Implement watchpoint debug facility for v2.07S

ISA v2.07S introduced the watchpoint facility based on the DAWR0
and DAWRX0 SPRs. Implement this in TCG.

Signed-off-by: Nicholas Piggin <n

target/ppc: Implement watchpoint debug facility for v2.07S

ISA v2.07S introduced the watchpoint facility based on the DAWR0
and DAWRX0 SPRs. Implement this in TCG.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

show more ...

target/ppc: Implement breakpoint debug facility for v2.07S

ISA v2.07S introduced the breakpoint facility based on the CIABR SPR.
Implement this in TCG.

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

target/ppc: Implement breakpoint debug facility for v2.07S

ISA v2.07S introduced the breakpoint facility based on the CIABR SPR.
Implement this in TCG.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

show more ...

target/ppc: SMT support for the HID SPR

HID is a per-core shared register, skiboot sets this (e.g., setting
HILE) on one thread and that must affect all threads of the core.

Reviewed-by: Cédric Le

target/ppc: SMT support for the HID SPR

HID is a per-core shared register, skiboot sets this (e.g., setting
HILE) on one thread and that must affect all threads of the core.

Reviewed-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-ID: <20230705120631.27670-3-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

show more ...

target/ppc: Add LPAR-per-core vs per-thread mode flag

The Power ISA has the concept of sub-processors:

Hardware is allowed to sub-divide a multi-threaded processor into
"sub-processors" that ap

target/ppc: Add LPAR-per-core vs per-thread mode flag

The Power ISA has the concept of sub-processors:

Hardware is allowed to sub-divide a multi-threaded processor into
"sub-processors" that appear to privileged programs as multi-threaded
processors with fewer threads.

POWER9 and POWER10 have two modes, either every thread is a
sub-processor or all threads appear as one multi-threaded processor. In
the user manuals these are known as "LPAR per thread" / "Thread LPAR",
and "LPAR per core" / "1 LPAR", respectively.

The practical difference is: in thread LPAR mode, non-hypervisor SPRs
are not shared between threads and msgsndp can not be used to message
siblings. In 1 LPAR mode, some SPRs are shared and msgsndp is usable.
Thrad LPAR allows multiple partitions to run concurrently on the same
core, and is a requirement for KVM to run on POWER9/10 (which does not
gang-schedule an LPAR on all threads of a core like POWER8 KVM).

Traditionally, SMT in PAPR environments including PowerVM and the
pseries QEMU machine with KVM acceleration behaves as in 1 LPAR mode.
In OPAL systems, Thread LPAR is used. When adding SMT to the powernv
machine, it is therefore preferable to emulate Thread LPAR.

To account for this difference between pseries and powernv, an LPAR mode
flag is added such that SPRs can be implemented as per-LPAR shared, and
that becomes either per-thread or per-core depending on the flag.

Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-ID: <20230705120631.27670-2-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

show more ...

target/ppc: SMT support for the HID SPR

HID is a per-core shared register, skiboot sets this (e.g., setting
HILE) on one thread and that must affect all threads of the core.

Reviewed-by: Cédric Le

target/ppc: SMT support for the HID SPR

HID is a per-core shared register, skiboot sets this (e.g., setting
HILE) on one thread and that must affect all threads of the core.

Reviewed-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-ID: <20230705120631.27670-3-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

show more ...

target/ppc: Add LPAR-per-core vs per-thread mode flag

The Power ISA has the concept of sub-processors:

Hardware is allowed to sub-divide a multi-threaded processor into
"sub-processors" that ap

target/ppc: Add LPAR-per-core vs per-thread mode flag

The Power ISA has the concept of sub-processors:

Hardware is allowed to sub-divide a multi-threaded processor into
"sub-processors" that appear to privileged programs as multi-threaded
processors with fewer threads.

POWER9 and POWER10 have two modes, either every thread is a
sub-processor or all threads appear as one multi-threaded processor. In
the user manuals these are known as "LPAR per thread" / "Thread LPAR",
and "LPAR per core" / "1 LPAR", respectively.

The practical difference is: in thread LPAR mode, non-hypervisor SPRs
are not shared between threads and msgsndp can not be used to message
siblings. In 1 LPAR mode, some SPRs are shared and msgsndp is usable.
Thrad LPAR allows multiple partitions to run concurrently on the same
core, and is a requirement for KVM to run on POWER9/10 (which does not
gang-schedule an LPAR on all threads of a core like POWER8 KVM).

Traditionally, SMT in PAPR environments including PowerVM and the
pseries QEMU machine with KVM acceleration behaves as in 1 LPAR mode.
In OPAL systems, Thread LPAR is used. When adding SMT to the powernv
machine, it is therefore preferable to emulate Thread LPAR.

To account for this difference between pseries and powernv, an LPAR mode
flag is added such that SPRs can be implemented as per-LPAR shared, and
that becomes either per-thread or per-core depending on the flag.

Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-ID: <20230705120631.27670-2-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

show more ...

target/ppc: SMT support for the HID SPR

HID is a per-core shared register, skiboot sets this (e.g., setting
HILE) on one thread and that must affect all threads of the core.

Reviewed-by: Cédric Le

target/ppc: SMT support for the HID SPR

HID is a per-core shared register, skiboot sets this (e.g., setting
HILE) on one thread and that must affect all threads of the core.

Reviewed-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-ID: <20230705120631.27670-3-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

show more ...

target/ppc: Add LPAR-per-core vs per-thread mode flag

The Power ISA has the concept of sub-processors:

Hardware is allowed to sub-divide a multi-threaded processor into
"sub-processors" that ap

target/ppc: Add LPAR-per-core vs per-thread mode flag

The Power ISA has the concept of sub-processors:

Hardware is allowed to sub-divide a multi-threaded processor into
"sub-processors" that appear to privileged programs as multi-threaded
processors with fewer threads.

POWER9 and POWER10 have two modes, either every thread is a
sub-processor or all threads appear as one multi-threaded processor. In
the user manuals these are known as "LPAR per thread" / "Thread LPAR",
and "LPAR per core" / "1 LPAR", respectively.

The practical difference is: in thread LPAR mode, non-hypervisor SPRs
are not shared between threads and msgsndp can not be used to message
siblings. In 1 LPAR mode, some SPRs are shared and msgsndp is usable.
Thrad LPAR allows multiple partitions to run concurrently on the same
core, and is a requirement for KVM to run on POWER9/10 (which does not
gang-schedule an LPAR on all threads of a core like POWER8 KVM).

Traditionally, SMT in PAPR environments including PowerVM and the
pseries QEMU machine with KVM acceleration behaves as in 1 LPAR mode.
In OPAL systems, Thread LPAR is used. When adding SMT to the powernv
machine, it is therefore preferable to emulate Thread LPAR.

To account for this difference between pseries and powernv, an LPAR mode
flag is added such that SPRs can be implemented as per-LPAR shared, and
that becomes either per-thread or per-core depending on the flag.

Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-ID: <20230705120631.27670-2-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

show more ...

target/ppc: Add msgsnd/p and DPDES SMT support

Doorbells in SMT need to coordinate msgsnd/msgclr and DPDES access from
multiple threads that affect the same state.

Signed-off-by: Nicholas Piggin <n

target/ppc: Add msgsnd/p and DPDES SMT support

Doorbells in SMT need to coordinate msgsnd/msgclr and DPDES access from
multiple threads that affect the same state.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

show more ...

target/ppc: Add support for SMT CTRL register

A relatively simple case to begin with, CTRL is a SMT shared register
where reads and writes need to synchronise against state changes by
other threads

target/ppc: Add support for SMT CTRL register

A relatively simple case to begin with, CTRL is a SMT shared register
where reads and writes need to synchronise against state changes by
other threads in the core.

Atomic serialisation operations are used to achieve this.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

show more ...

target/ppc: Add msgsnd/p and DPDES SMT support

Doorbells in SMT need to coordinate msgsnd/msgclr and DPDES access from
multiple threads that affect the same state.

Signed-off-by: Nicholas Piggin <n

target/ppc: Add msgsnd/p and DPDES SMT support

Doorbells in SMT need to coordinate msgsnd/msgclr and DPDES access from
multiple threads that affect the same state.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

show more ...