Based-on: 20230926183109.165878-1-dbarb...@ventanamicro.com
("[PATCH 0/2] riscv: add extension properties for all cpus")
Hi,
These patches implements the base profile support for qemu-riscv and the
first profile, RVA22U64.
As discussed in this thread [1] we're aiming for a flag that enables all
mandatory extensions of a profile. Optional extensions were left behind
and must be enabled by hand if desired. Since this is the first profile
we're adding, we'll need to add the base framework as well.
The RVA22U64 profile was chosen because qemu-riscv implements all its
extensions, both mandatory and optional. That includes 'zicntr' and
'zihpm', which we support for awhile but aren't adverting to userspace.
Other design decisions made:
- disabling a profile flag does nothing, i.e. we won't mass disable
mandatory extensions of the rva22U64 profile if the user sets
rva22u64=false;
- profile support for vendor CPUs consists into checking if the CPU
happens to have the mandatory extensions required for it. In case it
doesn't we'll error out. This is done to follow the same prerogative
we always had of not allowing extensions being enabled for vendor
CPUs;
- the KVM driver doesn't support profiles. In theory we could apply the
same logic as for the vendor CPUs, but KVM has a long way to go before
that becomes a factor. We'll revisit this decision when KVM is able to
support at least one profile.
Patch 5 ("enable profile support for vendor CPUs") needs the following
series to be applied beforehand:
"[PATCH 0/2] riscv: add extension properties for all cpus"
Otherwise we won't be able to add the profile flag to vendor CPUs.
[1]
https://lore.kernel.org/qemu-riscv/35a847a1-2720-14ab-61b0-c72d77d5f...@ventanamicro.com/
Daniel Henrique Barboza (6):
target/riscv/cpu.c: add zicntr extension flag
target/riscv/cpu.c: add zihpm extension flag
target/riscv: add rva22u64 profile definition
target/riscv/tcg: implement rva22u64 profile
target/riscv/tcg-cpu.c: enable profile support for vendor CPUs
target/riscv/kvm: add 'rva22u64' flag as unavailable
target/riscv/cpu.c | 25 ++++++++++
target/riscv/cpu.h | 10 ++++
target/riscv/cpu_cfg.h | 2 +
target/riscv/kvm/kvm-cpu.c | 5 +-
target/riscv/tcg/tcg-cpu.c | 98 ++++++++++++++++++++++++++++++++++++++
5 files changed, 139 insertions(+), 1 deletion(-)
--
2.41.0
