Copy part of the description of commit f7b78602fd ("accel/tcg:
Add cluster number to TCG TB hash") in tcg_cpu_init_cflags(),
improving a bit CPUState::cluster_index documentation.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20230216142338.82982-2-philmd@linaro.org>
The watchpoint API is specific to TCG system emulation.
Move it to a new compile unit. The inlined stubs are used
for user-mode and non-TCG accelerators.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221209141254.68662-1-philmd@linaro.org>
Currently dying to one of the core_dump_signal()s deadlocks, because
dump_core_and_abort() calls start_exclusive() two times: first via
stop_all_tasks(), and then via preexit_cleanup() ->
qemu_plugin_user_exit().
There are a number of ways to solve this: resume after dumping core;
check cpu_in_exclusive_context() in qemu_plugin_user_exit(); or make
{start,end}_exclusive() recursive. Pick the last option, since it's
the most straightforward one.
Fixes: da91c19202 ("linux-user: Clean up when exiting due to a signal")
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20230214140829.45392-3-iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This API allows the accelerators to prevent vcpus from issuing
new ioctls while execting a critical section marked with the
accel_ioctl_inhibit_begin/end functions.
Note that all functions submitting ioctls must mark where the
ioctl is being called with accel_{cpu_}ioctl_begin/end().
This API requires the caller to always hold the BQL.
API documentation is in sysemu/accel-blocker.h
Internally, it uses a QemuLockCnt together with a per-CPU QemuLockCnt
(to minimize cache line bouncing) to keep avoid that new ioctls
run when the critical section starts, and a QemuEvent to wait
that all running ioctls finish.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20221111154758.1372674-2-eesposit@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Currently signal SIGIPI [=SIGUSR1] is used to kick the dummy CPU
when qtest accelerator is used. However SIGUSR1 is unsupported on
Windows. To support Windows, we add a QemuSemaphore CPUState::sem
to kick the dummy CPU instead for Windows.
Signed-off-by: Xuzhou Cheng <xuzhou.cheng@windriver.com>
Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20221028045736.679903-2-bin.meng@windriver.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Add a tcg_ops hook to replace the restore_state_to_opc
function call. Because these generic hooks cannot depend
on target-specific types, temporarily, copy the current
target_ulong data[] into uint64_t d64[].
Reviewed-by: Claudio Fontana <cfontana@suse.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
It's always better to convey the type of a pointer if at all
possible. So let's add the DumpState typedef to typedefs.h and move
the dump note functions from the opaque pointers to DumpState
pointers.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
CC: Peter Maydell <peter.maydell@linaro.org>
CC: Cédric Le Goater <clg@kaod.org>
CC: Daniel Henrique Barboza <danielhb413@gmail.com>
CC: David Gibson <david@gibson.dropbear.id.au>
CC: Greg Kurz <groug@kaod.org>
CC: Palmer Dabbelt <palmer@dabbelt.com>
CC: Alistair Francis <alistair.francis@wdc.com>
CC: Bin Meng <bin.meng@windriver.com>
CC: Cornelia Huck <cohuck@redhat.com>
CC: Thomas Huth <thuth@redhat.com>
CC: Richard Henderson <richard.henderson@linaro.org>
CC: David Hildenbrand <david@redhat.com>
Acked-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220811121111.9878-2-frankja@linux.ibm.com>
Wrap the bare TranslationBlock pointer into a structure.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This field is only written, not read; remove it.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The class cast checkers are quite expensive and always on (unlike the
dynamic case who's checks are gated by CONFIG_QOM_CAST_DEBUG). To
avoid the overhead of repeatedly checking something which should never
change we cache the CPUClass reference for use in the hot code paths.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220811151413.3350684-3-alex.bennee@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20220923084803.498337-3-clg@kaod.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Setup a negative feedback system when vCPU thread
handling KVM_EXIT_DIRTY_RING_FULL exit by introducing
throttle_us_per_full field in struct CPUState. Sleep
throttle_us_per_full microseconds to throttle vCPU
if dirtylimit is in service.
Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <977e808e03a1cef5151cae75984658b6821be618.1656177590.git.huangy81@chinatelecom.cn>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
The ARM virt machine currently uses sysbus-fdt to create device tree
entries for dynamically created MMIO devices.
The RISC-V virt machine can also benefit from this, so move the code to
the core directory.
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Message-Id: <20220427234146.1130752-3-alistair.francis@opensource.wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This is now used by RISC-V as well. Update the comments.
Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220421003324.1134983-7-bmeng.cn@gmail.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
G_NORETURN was introduced in glib 2.68, fallback to G_GNUC_NORETURN in
glib-compat.
Note that this attribute must be placed before the function declaration
(bringing a bit of consistency in qemu codebase usage).
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Warner Losh <imp@bsdimp.com>
Message-Id: <20220420132624.2439741-20-marcandre.lureau@redhat.com>
Convert the TARGET_WORDS_BIGENDIAN macro, similarly to what was done
with HOST_BIG_ENDIAN. The new TARGET_BIG_ENDIAN macro is either 0 or 1,
and thus should always be defined to prevent misuse.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Suggested-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323155743.1585078-8-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Replace a config-time define with a compile time condition
define (compatible with clang and gcc) that must be declared prior to
its usage. This avoids having a global configure time define, but also
prevents from bad usage, if the config header wasn't included before.
This can help to make some code independent from qemu too.
gcc supports __BYTE_ORDER__ from about 4.6 and clang from 3.2.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
[ For the s390x parts I'm involved in ]
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323155743.1585078-7-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
One less qemu-specific macro. It also helps to make some headers/units
only depend on glib, and thus moved in standalone projects eventually.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
ArchCPU is our interface with target-specific code. Use it as
a forward-declared opaque pointer (abstract type), having its
structure defined by each target.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220214183144.27402-15-f4bug@amsat.org>
Replace the boilerplate code to declare CPU QOM types
and macros, and forward-declare the CPU instance type.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220214183144.27402-14-f4bug@amsat.org>
While CPUState is our interface with generic code, CPUArchState is
our interface with target-specific code. Use CPUArchState as an
abstract type, defined by each target.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220214183144.27402-13-f4bug@amsat.org>
Move vaddr type declaration to the generic "exec/cpu-common.h" header.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220207075426.81934-4-f4bug@amsat.org>
This requires extra work for each target, but adds the
common syscall code, and the necessary flag in CPUState.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211227150127.2659293-4-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
to linux-user/host/arch/host-signal.h
- Replace TCGCPUOps.tlb_fill with TCGCPUOps.record_sigsegv for user-only
- Add TCGCPUOps.record_sigbus for user-only
- Remove a lot of target-specific cpu_loop handling for signals,
now accomplished with generic code.
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Merge remote-tracking branch 'remotes/rth/tags/pull-tcg-20211102' into staging
- Split out host signal handing from accel/tcg/user-exec.c
to linux-user/host/arch/host-signal.h
- Replace TCGCPUOps.tlb_fill with TCGCPUOps.record_sigsegv for user-only
- Add TCGCPUOps.record_sigbus for user-only
- Remove a lot of target-specific cpu_loop handling for signals,
now accomplished with generic code.
# gpg: Signature made Tue 02 Nov 2021 07:06:14 AM EDT
# gpg: using RSA key 7A481E78868B4DB6A85A05C064DF38E8AF7E215F
# gpg: issuer "richard.henderson@linaro.org"
# gpg: Good signature from "Richard Henderson <richard.henderson@linaro.org>" [ultimate]
* remotes/rth/tags/pull-tcg-20211102: (60 commits)
linux-user: Handle BUS_ADRALN in host_signal_handler
tcg: Add helper_unaligned_{ld,st} for user-only sigbus
accel/tcg: Report unaligned load/store for user-only
accel/tcg: Report unaligned atomics for user-only
target/sparc: Set fault address in sparc_cpu_do_unaligned_access
target/sparc: Split out build_sfsr
target/sparc: Remove DEBUG_UNALIGNED
target/sh4: Set fault address in superh_cpu_do_unaligned_access
target/s390x: Implement s390x_cpu_record_sigbus
linux-user/ppc: Remove POWERPC_EXCP_ALIGN handling
target/ppc: Restrict ppc_cpu_do_unaligned_access to sysemu
target/ppc: Set fault address in ppc_cpu_do_unaligned_access
target/ppc: Move SPR_DSISR setting to powerpc_excp
target/microblaze: Do not set MO_ALIGN for user-only
linux-user/hppa: Remove EXCP_UNALIGN handling
target/arm: Implement arm_cpu_record_sigbus
target/alpha: Implement alpha_cpu_record_sigbus
linux-user: Add cpu_loop_exit_sigbus
hw/core: Add TCGCPUOps.record_sigbus
accel/tcg: Restrict TCGCPUOps::tlb_fill() to sysemu
...
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Add a new user-only interface for updating cpu state before
raising a signal. This will take the place of do_unaligned_access
for user-only and should result in less boilerplate for each guest.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We have replaced tlb_fill with record_sigsegv for user mode.
Move the declaration to restrict it to system emulation.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Add a new user-only interface for updating cpu state before
raising a signal. This will replace tlb_fill for user-only
and should result in less boilerplate for each guest.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
dirty_pages is used to calculate dirtyrate via dirty ring, when
enabled, kvm-reaper will increase the dirty pages after gfns
being dirtied.
kvm_dirty_ring_enabled shows if kvm-reaper is working. dirtyrate
thread could use it to check if measurement can base on dirty
ring feature.
Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Message-Id: <fee5fb2ab17ec2159405fc54a3cff8e02322f816.1624040308.git.huangy81@chinatelecom.cn>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This reverts commit 1b36e4f5a5.
Despite a comment saying why cpu_common_props cannot be placed in
a file that is compiled once, it was moved anyway. Revert that.
Since then, Property is not defined in hw/core/cpu.h, so it is now
easier to declare a function to install the properties rather than
the Property array itself.
Cc: Eduardo Habkost <ehabkost@redhat.com>
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Despite the comment, the members were not kept at the end.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
While we may have had some thought of allowing system-mode
to return from this hook, we have no guests that require this.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
All targets call TCGCPUOps::cpu_exec_interrupt() from sysemu code.
Move its declaration to restrict it to system emulation.
Extend the code guarded.
Restrict the static inlined need_replay_interrupt() method to
avoid a "defined but not used" warning.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210911165434.531552-24-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
do_interrupt() is sysemu specific. However due to some X86
specific hack, it is also used in user-mode emulation, which
is why it couldn't be restricted to CONFIG_SOFTMMU (see the
comment around added in commit 7827168471: "cpu: tcg_ops:
move to tcg-cpu-ops.h, keep a pointer in CPUClass").
Keep the hack but rename the handler as fake_user_interrupt()
and restrict do_interrupt() to sysemu.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210911165434.531552-6-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This will allow a breakpoint hack to move out of AVR's translator.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
New hook to return true when an architectural breakpoint is
to be recognized and false when it should be suppressed.
First use must wait until other pieces are in place.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We will need more than a single field for hvf going forward. To keep
the global vcpu struct uncluttered, let's allocate a special hvf vcpu
struct, similar to how hax does it.
Signed-off-by: Alexander Graf <agraf@csgraf.de>
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Tested-by: Roman Bolshakov <r.bolshakov@yadro.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Message-id: 20210519202253.76782-12-agraf@csgraf.de
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
No more architectures set the pointer to dump_statistics, so there's no
point in keeping it, or the related cpu_dump_statistics function.
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Bruno Larsen (billionai) <bruno.larsen@eldorado.org.br>
Message-Id: <20210526202104.127910-6-bruno.larsen@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20210531145629.21300-2-bruno.larsen@eldorado.org.br>
Acked-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
We no longer have any runtime modifications to this struct,
so declare them all const.
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>
Message-ID: <20210227232519.222663-3-richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210517105140.1062037-23-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210517105140.1062037-22-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210517105140.1062037-21-f4bug@amsat.org>
[rth: Drop declaration movement from target/*/cpu.h]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210517105140.1062037-20-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The write_elf*() handlers are used to dump vmcore images.
This feature is only meaningful for system emulation.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210517105140.1062037-19-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
cpu_get_crash_info() is called on GUEST_PANICKED events,
which only occur in system emulation.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210517105140.1062037-18-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
VirtIO devices are only meaningful with system emulation.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210517105140.1062037-17-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Migration is specific to system emulation.
- Move the CPUClass::vmsd field to SysemuCPUOps,
- restrict VMSTATE_CPU() macro to sysemu,
- vmstate_dummy is now unused, remove it.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210517105140.1062037-16-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Introduce a structure to hold handler specific to sysemu.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210517105140.1062037-15-f4bug@amsat.org>
[rth: Squash "restrict hw/core/sysemu-cpu-ops.h" patch]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
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>
