Commit Graph

11 Commits

Author SHA1 Message Date
Daniel Henrique Barboza
8043effd9b target/riscv: deprecate capital 'Z' CPU properties
At this moment there are eleven CPU extension properties that starts
with capital 'Z': Zifencei, Zicsr, Zihintntl, Zihintpause, Zawrs, Zfa,
Zfh, Zfhmin, Zve32f, Zve64f and Zve64d. All other extensions are named
with lower-case letters.

We want all properties to be named with lower-case letters since it's
consistent with the riscv-isa string that we create in the FDT. Having
these 11 properties to be exceptions can be confusing.

Deprecate all of them. Create their lower-case counterpart to be used as
maintained CPU properties. When trying to use any deprecated property a
warning message will be displayed, recommending users to switch to the
lower-case variant:

./build/qemu-system-riscv64 -M virt -cpu rv64,Zifencei=true --nographic
qemu-system-riscv64: warning: CPU property 'Zifencei' is deprecated. Please use 'zifencei' instead

This will give users some time to change their scripts before we remove
the capital 'Z' properties entirely.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Message-ID: <20231009112817.8896-2-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2023-10-12 12:42:41 +10:00
Daniel Henrique Barboza
9b9741c38f target/riscv/tcg: remove RVG warning
Vendor CPUs that set RVG are displaying user warnings about other
extensions that RVG must enable, one warning per CPU. E.g.:

$ ./build/qemu-system-riscv64 -smp 8 -M virt -cpu veyron-v1 -nographic
qemu-system-riscv64: warning: Setting G will also set IMAFD_Zicsr_Zifencei
qemu-system-riscv64: warning: Setting G will also set IMAFD_Zicsr_Zifencei
qemu-system-riscv64: warning: Setting G will also set IMAFD_Zicsr_Zifencei
qemu-system-riscv64: warning: Setting G will also set IMAFD_Zicsr_Zifencei
qemu-system-riscv64: warning: Setting G will also set IMAFD_Zicsr_Zifencei
qemu-system-riscv64: warning: Setting G will also set IMAFD_Zicsr_Zifencei
qemu-system-riscv64: warning: Setting G will also set IMAFD_Zicsr_Zifencei
qemu-system-riscv64: warning: Setting G will also set IMAFD_Zicsr_Zifencei

This happens because we decided a while ago that, for simplicity, vendor
CPUs could set RVG instead of setting each G extension individually in
their cpu_init(). Our warning isn't taking that into account, and we're
bugging users with a warning that we're causing ourselves.

In a closer look we conclude that this warning is not warranted in any
other circumstance since we're just following the ISA [1], which states
in chapter 24:

"One goal of the RISC-V project is that it be used as a stable software
development target. For this purpose, we define a combination of a base
ISA (RV32I or RV64I) plus selected standard extensions (IMAFD, Zicsr,
Zifencei) as a 'general-purpose' ISA, and we use the abbreviation G for
the IMAFDZicsr Zifencei combination of instruction-set extensions."

With this in mind, enabling IMAFD_Zicsr_Zifencei if the user explicitly
enables 'G' is an expected behavior and the warning is unneeded. Any
user caught by surprise should refer to the ISA.

Remove the warning when handling RVG.

[1] https://github.com/riscv/riscv-isa-manual/releases/download/Ratified-IMAFDQC/riscv-spec-20191213.pdf

Reported-by: Paul A. Clarke <pclarke@ventanamicro.com>
Suggested-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Message-ID: <20231003122539.775932-1-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2023-10-12 12:39:45 +10:00
Daniel Henrique Barboza
eb992b6091 target/riscv/tcg-cpu.c: add extension properties for all cpus
At this moment we do not expose extension properties for vendor CPUs
because that would allow users to change them via command line. The
drawback is that if we were to add an API that shows all CPU properties,
e.g. qmp-query-cpu-model-expansion, we won't be able to show extensions
state of vendor CPUs.

We have the required machinery to create extension properties for vendor
CPUs while not allowing users to enable extensions. Disabling existing
extensions is allowed since it can be useful for debugging.

Change the set() callback cpu_set_multi_ext_cfg() to allow enabling
extensions only for generic CPUs. In cpu_add_multi_ext_prop() let's not
set the default values for the properties if we're not dealing with
generic CPUs, otherwise the values set in cpu_init() of vendor CPUs will
be overwritten. And finally, in tcg_cpu_instance_init(), add cpu user
properties for all CPUs.

For the veyron-v1 CPU, we're now able to disable existing extensions
like smstateen:

$ ./build/qemu-system-riscv64 --nographic -M virt \
    -cpu veyron-v1,smstateen=false

But setting extensions that the CPU didn't set during cpu_init(), like
V, is not allowed:

$ ./build/qemu-system-riscv64 --nographic -M virt \
    -cpu veyron-v1,v=true
qemu-system-riscv64: can't apply global veyron-v1-riscv-cpu.v=true:
  'veyron-v1' CPU does not allow enabling extensions

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20230926183109.165878-3-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2023-10-12 12:31:17 +10:00
Daniel Henrique Barboza
b933720be2 target/riscv: add riscv_cpu_get_name()
We'll introduce generic errors that will output a CPU type name via its
RISCVCPU pointer. Create a helper for that.

Use the helper in tcg_cpu_realizefn() instead of hardcoding the 'host'
CPU name.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20230926183109.165878-2-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2023-10-12 12:30:16 +10:00
Daniel Henrique Barboza
31778448f2 target/riscv/cpu: move priv spec functions to tcg-cpu.c
Priv spec validation is TCG specific. Move it to the TCG accel class.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20230925175709.35696-20-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2023-10-12 12:29:03 +10:00
Daniel Henrique Barboza
4de9151b20 target/riscv/tcg: move riscv_cpu_add_misa_properties() to tcg-cpu.c
All code related to MISA TCG properties is also moved.

At this point, all TCG properties handling is done in tcg-cpu.c, all KVM
properties handling is done in kvm-cpu.c.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20230925175709.35696-18-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2023-10-12 12:26:30 +10:00
Daniel Henrique Barboza
fce8bb5d08 target/riscv/tcg: introduce tcg_cpu_instance_init()
tcg_cpu_instance_init() will be the 'cpu_instance_init' impl for the TCG
accelerator. It'll be called from within riscv_cpu_post_init(), via
accel_cpu_instance_init(), similar to what happens with KVM. In fact, to
preserve behavior, the implementation will be similar to what
riscv_cpu_post_init() already does.

In this patch we'll move riscv_cpu_add_user_properties() and
riscv_init_max_cpu_extensions() and all their dependencies to tcg-cpu.c.
All multi-extension properties code was moved. The 'multi_ext_user_opts'
hash table was also moved to tcg-cpu.c since it's a TCG only structure,
meaning that we won't have to worry about initializing a TCG hash table
when running a KVM CPU anymore.

riscv_cpu_add_user_properties() will remain in cpu.c for now due to how
much code it requires to be moved at the same time. We'll do that in the
next patch.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20230925175709.35696-16-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2023-10-12 12:24:07 +10:00
Daniel Henrique Barboza
e7443334a8 target/riscv: move riscv_tcg_ops to tcg-cpu.c
Move the remaining of riscv_tcg_ops now that we have a working realize()
implementation.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20230925175709.35696-5-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2023-10-12 11:59:03 +10:00
Daniel Henrique Barboza
36c1118d50 target/riscv: move riscv_cpu_validate_set_extensions() to tcg-cpu.c
This function is the core of the RISC-V validations for TCG CPUs, and it
has a lot going on.

Functions in cpu.c were made public to allow them to be used by the KVM
accelerator class later on. 'cpu_cfg_ext_get_min_version()' is notably
hard to move it to another file due to its dependency with isa_edata_arr[]
array, thus make it public and use it as is for now.

riscv_cpu_validate_set_extensions() is kept public because it's used by
csr.c in write_misa().

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20230925175709.35696-4-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2023-10-12 11:57:46 +10:00
Daniel Henrique Barboza
9dcecbd724 target/riscv: move riscv_cpu_realize_tcg() to TCG::cpu_realizefn()
riscv_cpu_realize_tcg() was added to allow TCG cpus to have a different
realize() path during the common riscv_cpu_realize(), making it a good
choice to start moving TCG exclusive code to tcg-cpu.c.

Rename it to tcg_cpu_realizefn() and assign it as a implementation of
accel::cpu_realizefn(). tcg_cpu_realizefn() will then be called during
riscv_cpu_realize() via cpu_exec_realizefn(). We'll use a similar
approach with KVM in the near future.

riscv_cpu_validate_set_extensions() is too big and with too many
dependencies to be moved in this same patch. We'll do that next.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Message-ID: <20230925175709.35696-3-dbarboza@ventanamicro.com>
[ Changes by AF:
 - Renames to fix build failures after rebase
]
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2023-10-12 11:56:28 +10:00
Daniel Henrique Barboza
9c5180d799 target/riscv: introduce TCG AccelCPUClass
target/riscv/cpu.c needs to handle all possible accelerators (TCG and
KVM at this moment) during both init() and realize() time. This forces
us to resort to a lot of "if tcg" and "if kvm" throughout the code,
which isn't wrong, but can get cluttered over time. Splitting
acceleration specific code from cpu.c to its own file will help to
declutter the existing code and it will also make it easier to support
KVM/TCG only builds in the future.

We'll start by adding a new subdir called 'tcg' and a new file called
'tcg-cpu.c'. This file will be used to introduce a new accelerator class
for TCG acceleration in RISC-V, allowing us to center all TCG exclusive
code in its file instead of using 'cpu.c' for everything. This design is
inpired by the work Claudio Fontana did in x86 a few years ago in commit
f5cc5a5c1 ("i386: split cpu accelerators from cpu.c, using
AccelCPUClass").

To avoid moving too much code at once we'll start by adding the new file
and TCG AccelCPUClass declaration. The 'class_init' from the accel class
will init 'tcg_ops', relieving the common riscv_cpu_class_init() from
doing it.

'riscv_tcg_ops' is being exported from 'cpu.c' for now to avoid having
to deal with moving code and files around right now. We'll focus on
decoupling the realize() logic first.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20230925175709.35696-2-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2023-10-12 11:55:21 +10:00