Userspace need access to PMU SPRs to be able to operate the PMU. One of
such SPRs is MMCR0.
MMCR0, as defined by PowerISA v3.1, is classified as a 'group A' PMU
register. This class of registers has common read/write rules that are
governed by MMCR0 PMCC bits. MMCR0 is also not fully exposed to problem
state: only MMCR0_FC, MMCR0_PMAO and MMCR0_PMAE bits are
readable/writable in this case.
This patch exposes MMCR0 to userspace by doing the following:
- two new callbacks, spr_read_MMCR0_ureg() and spr_write_MMCR0_ureg(),
are added to be used as problem state read/write callbacks of UMMCR0.
Both callbacks filters the amount of bits userspace is able to
read/write by using a MMCR0_UREG_MASK;
- problem state access control is done by the spr_groupA_read_allowed()
and spr_groupA_write_allowed() helpers. These helpers will read the
current PMCC bits from DisasContext and check whether the read/write
MMCR0 operation is valid or noti;
- to avoid putting exclusive PMU logic into the already loaded
translate.c file, let's create a new 'power8-pmu-regs.c.inc' file that
will hold all the spr_read/spr_write functions of PMU registers.
The 'power8' name of this new file intends to hint about the proven
support of the PMU logic to be added. The code has been tested with the
IBM POWER chip family, POWER8 being the oldest version tested. This
doesn't mean that the PMU logic will break with any other PPC64 chip
that implements Book3s, but rather that we can't assert that it works
properly with any Book3s compliant chip.
CC: Gustavo Romero <gustavo.romero@linaro.org>
Signed-off-by: Gustavo Romero <gromero@linux.ibm.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20211018010133.315842-3-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The POWER10 DD2 CPU adds an extra LPCR[HAIL] bit. DD1 doesn't have
HAIL but since it does not break the modeling and that we don't plan
to support DD1, modify the LPCR mask of all the POWER10 family.
Setting the HAIL bit is a requirement to support the scv instruction
on PowerNV POWER10 platforms since glibc-2.33.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20210809134547.689560-2-clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
excp_helper.c, mmu-hash64.c and mmu_helper.c have some function
declarations that are TCG-only, and couldn't be easily moved to a
TCG only file, so ifdefs were added around them.
We also needed ifdefs around some header files because helper-proto.h
includes trace/generated-helpers.h, which is never created when building
without TCG, and cpu_ldst.h includes tcg/tcg.h, whose containing folder
is not included as a -iquote. As future cleanup, we could change the
part of the configuration script to add those.
cpu_init.c also had a callback definition that is TCG only and could be
removed as part of a future cleanup (all the dump_statistics part is
almost never used and will become obsolete as we transition to using
decodetree).
Signed-off-by: Bruno Larsen (billionai) <bruno.larsen@eldorado.org.br>
Message-Id: <20210525115355.8254-3-bruno.larsen@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The write calback decision when registering the MAS SPR has been turned
into a ternary operation, rather than an if-then-else block.
This was done because when building without TCG, even though the
compiler will optimize away the pointers to spr_write_generic*, it
doesn't optimize away the decision and assignment to the local pointer,
creating compiler errors. This cleanup looked better than using ifdefs,
so we decided to with it.
Signed-off-by: Bruno Larsen (billionai) <bruno.larsen@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210525115355.8254-2-bruno.larsen@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Quoting Peter Maydell [*]:
There are two ways to handle migration for
a CPU object:
(1) like any other device, so it has a dc->vmsd that covers
migration for the whole object. As usual for objects that are a
subclass of a parent that has state, the first entry in the
VMStateDescription field list is VMSTATE_CPU(), which migrates
the cpu_common fields, followed by whatever the CPU's own migration
fields are.
(2) a backwards-compatible mechanism for CPUs that were
originally migrated using manual "write fields to the migration
stream structures". The on-the-wire migration format
for those is based on the 'env' pointer (which isn't a QOM object),
and the cpu_common part of the migration data is elsewhere.
cpu_exec_realizefn() handles both possibilities:
* for type 1, dc->vmsd is set and cc->vmsd is not,
so cpu_exec_realizefn() does nothing, and the standard
"register dc->vmsd for a device" code does everything needed
* for type 2, dc->vmsd is NULL and so we register the
vmstate_cpu_common directly to handle the cpu-common fields,
and the cc->vmsd to handle the per-CPU stuff
You can't change a CPU from one type to the other without breaking
migration compatibility, which is why some guest architectures
are stuck on the cc->vmsd form. New targets should use dc->vmsd.
To avoid new targets to start using type (2), rename cc->vmsd as
cc->legacy_vmsd. The correct field to implement is dc->vmsd (the
DeviceClass one).
See also commit b170fce3dd ("cpu: Register VMStateDescription
through CPUState") for historic background.
[*] https://www.mail-archive.com/qemu-devel@nongnu.org/msg800849.html
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Cc: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20210517105140.1062037-13-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
