PowerPC CPUs use big endian by default but starting with POWER7,
server grade CPUs use the ILE bit of the LPCR special purpose
register to decide on the endianness to use when handling
interrupts. This gives a clue to QEMU on the endianness the
guest kernel is running, which is needed when generating an
ELF dump of the guest or when delivering an FWNMI machine
check interrupt.
Commit 382d2db62b ("target-ppc: Introduce callback for interrupt
endianness") added a class method to PowerPCCPUClass to modelize
this : default implementation returns a fixed "big endian" value,
while POWER7 and newer do the LPCR_ILE check. This is suboptimal
as it forces to implement the method for every new CPU family, and
it is very unlikely that this will ever be different than what we
have today.
We basically only have three cases to consider:
a) CPU doesn't have an LPCR => big endian
b) CPU has an LPCR but doesn't support the ILE bit => big endian
c) CPU has an LPCR and supports the ILE bit => little or big endian
Instead of class methods, introduce an inline helper that checks the
ILE bit in the LPCR_MASK to decide on the outcome. The new helper
words little endian instead of big endian. This allows to drop a !
operator in ppc_cpu_do_fwnmi_machine_check().
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20210622140926.677618-2-groug@kaod.org>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
We will shortly be interested in distinguishing pointers
from integers in the helper's declaration, as well as a
true void return. We currently have two parallel 1 bit
fields; merge them and expand to a 3 bit field.
Our current maximum is 7 helper arguments, plus the return
makes 8 * 3 = 24 bits used within the uint32_t typemask.
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Additionally, REQUIRE_64BIT when L=1 to match what is specified in The
Programming Environments Manual:
"For 32-bit implementations, the L field must be cleared, otherwise the
instruction form is invalid."
Some CPUs are known to deviate from this specification by ignoring the
L bit [1]. The stricter behavior, however, can help users that test
software with qemu, making it more likely to detect bugs that would
otherwise be silent.
If deemed necessary, a future patch can adapt this behavior based on
the specific CPU model.
[1] The 601 manual is the only one I've found that explicitly states
that the L bit is ignored, but we also observe this behavior in a 7447A
v1.2.
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Message-Id: <20210601193528.2533031-15-matheus.ferst@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[dwg: Corrected whitespace error]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The only difference in the code for Instruction fetch, Data load and
Data store TLB miss errors is that when called from an unsupported
processor (i.e. not one of 602, 603, 603e, G2, 7x5 or 74xx), they
abort with a message specific to the operation type (insn fetch, data
load/store).
If a processor does not support those interrupts we should not be
registering them in init_excp_<proc> to begin with, so that error
message would never be used.
I'm leaving the message in for completeness, but making it generic and
consolidating the three interrupts into the same case statement body.
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20210601214649.785647-4-farosas@linux.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Followed the suggested overhaul to store_fpscr logic, and moved it to
cpu.c where it can be accessed in !TCG builds.
The overhaul was suggested because storing a value to fpscr should
never raise an exception, so we could remove all the mess that happened
with POWERPC_EXCP_FP.
We also moved fpscr_set_rounding_mode into cpu.c as it could now be moved
there, and it is needed when a value for the fpscr is being stored
directly.
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Bruno Larsen (billionai) <bruno.larsen@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210527163522.23019-1-bruno.larsen@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Created a file with stubs needed to compile disabling TCG. *_ppc_opcodes
were created to make cpu_init.c have a few less ifdefs, since they are
not needed. softmmu_resize_hpt_* have to be created because the compiler
can't automatically know they aren't used, but they should never be
reached.
Signed-off-by: Bruno Larsen (billionai) <bruno.larsen@eldorado.org.br>
Message-Id: <20210525115355.8254-4-bruno.larsen@eldorado.org.br>
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>
Commit e50caf4a5c ("tracing: convert documentation to rST")
converted docs/devel/tracing.txt to docs/devel/tracing.rst.
We still have several references to the old file, so let's fix them
with the following command:
sed -i s/tracing.txt/tracing.rst/ $(git grep -l docs/devel/tracing.txt)
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210517151702.109066-2-sgarzare@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
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>
Richard Henderson
Greg Kurz
Luis Pires
Matheus Ferst
Fabiano Rosas
Bruno Larsen (billionai)
Stefano Garzarella
Philippe Mathieu-Daudé