Currently when CONFIG_POWERNV is not enabled, the build fails, such as
with --without-default-devices:
$ ./configure --without-default-devices
$ make
[281/283] Linking target qemu-system-ppc64
FAILED: qemu-system-ppc64
cc -m64 @qemu-system-ppc64.rsp
/usr/bin/ld: libqemu-ppc64-softmmu.a.p/target_ppc_misc_helper.c.o: in function `helper_load_sprd':
.../target/ppc/misc_helper.c:335:(.text+0xcdc): undefined reference to `pnv_chip_find_core'
/usr/bin/ld: libqemu-ppc64-softmmu.a.p/target_ppc_misc_helper.c.o: in function `helper_store_sprd':
.../target/ppc/misc_helper.c:375:(.text+0xdf4): undefined reference to `pnv_chip_find_core'
collect2: error: ld returned 1 exit status
...
This is since target/ppc/misc_helper.c references PowerNV specific
'pnv_chip_find_core' call.
Split the PowerNV specific SPRD code out of the generic PowerPC code, by
moving the SPRD code to pnv.c
Fixes: 9808ce6d5c ("target/ppc: Big-core scratch register fix")
Cc: Philippe Mathieu-Daudé <philmd@linaro.org>
Reported-by: Thomas Huth <thuth@redhat.com>
Suggested-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Aditya Gupta <adityag@linux.ibm.com>
Acked-by: Cédric Le Goater <clg@redhat.com>
Message-ID: <20250820122516.949766-2-adityag@linux.ibm.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
The per-core SCRATCH0-7 registers are shared between big cores, which
was missed in the big-core implementation. It is difficult to model
well with the big-core == 2xPnvCore scheme we moved to, this fix
uses the even PnvCore to store the scrach data.
Also remove a stray log message that came in with the same patch that
introduced patch.
Fixes: c26504afd5 ("ppc/pnv: Add a big-core mode that joins two regular cores")
Cc: qemu-stable@nongnu.org
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Linux power management code accesses these registers for pstate
management. Wire up a very simple implementation.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
After OCC fixes in QEMU pnv model and skiboot (since they have suffered
some bitrot), Linux will start performing PM SPR accesses. This is a
very simple implementation that makes it a bit happier.
Thanks,
Nick
A typo in the loop over SMT threads to set irq level for doorbells
when storing to DPDES meant everything was aimed at the CPU executing
the instruction.
Cc: qemu-stable@nongnu.org
Fixes: d24e80b2ae ("target/ppc: Add msgsnd/p and DPDES SMT support")
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
Some 32-bit SPRs are incorrectly implemented as 64-bits on 64-bit
targets.
This changes VRSAVE, DSISR, HDSISR, DAWRX0, PIDR, LPIDR, DEXCR,
HDEXCR, CTRL, TSCR, MMCRH, and PMC[1-6] from to be 32-bit registers.
This only goes by the 32/64 classification in the architecture, it
does not try to implement finer details of SPR implementation (e.g.,
not all bits implemented as simple read/write storage).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Message-Id: <20230515092655.171206-2-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
This enum defines the bit positions in env->pending_interrupts for each
interrupt. However, except for the comparison in kvmppc_set_interrupt,
the values are always used as (1 << PPC_INTERRUPT_*). Define them
directly like that to save some clutter. No functional change intended.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Message-Id: <20221011204829.1641124-2-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
