KVM for RISC-V started supporting KVM_GET_REG_LIST in Linux 6.6. It
consists of a KVM ioctl() that retrieves a list of all available regs
for get_one_reg/set_one_reg. Regs that aren't present in the list aren't
supported in the host.
This simplifies our lives when initing the KVM regs since we don't have
to always attempt a KVM_GET_ONE_REG for all regs QEMU knows. We'll only
attempt a get_one_reg() if we're sure the reg is supported, i.e. it was
retrieved by KVM_GET_REG_LIST. Any error in get_one_reg() will then
always considered fatal, instead of having to handle special error codes
that might indicate a non-fatal failure.
Start by moving the current kvm_riscv_init_multiext_cfg() logic into a
new kvm_riscv_read_multiext_legacy() helper. We'll prioritize using
KVM_GET_REG_LIST, so check if we have it available and, in case we
don't, use the legacy() logic.
Otherwise, retrieve the available reg list and use it to check if the
host supports our known KVM regs, doing the usual get_one_reg() for
the supported regs and setting cpu->cfg accordingly.
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Message-ID: <20231003132148.797921-3-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Our error message is returning the value of 'ret', which will be always
-1 in case of error, and will not be that useful:
qemu-system-riscv64: Unable to read ISA_EXT KVM register ssaia, error -1
Improve the error message by outputting 'errno' instead of 'ret'. Use
strerrorname_np() to output the error name instead of the error code.
This will give us what we need to know right away:
qemu-system-riscv64: Unable to read ISA_EXT KVM register ssaia, error code: ENOENT
Given that we're going to exit(1) in this condition instead of
attempting to recover, remove the 'kvm_riscv_destroy_scratch_vcpu()'
call.
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20231003132148.797921-2-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
riscv_cpu_add_misa_properties() is being used to fill the missing KVM
MISA properties but it is a TCG helper that was adapted to do so. We'll
move it to tcg-cpu.c in the next patches, meaning that KVM needs to fill
the remaining MISA properties on its own.
Do not use riscv_cpu_add_misa_properties(). Let's create a new array
with all available MISA bits we support that can be read by KVM. The
array is zero terminate to allow us to iterate through it without
knowing its size.
Then, inside kvm_riscv_add_cpu_user_properties(), we'll create all KVM
MISA properties as usual and then use this array to add any missing MISA
properties with the riscv_cpu_add_kvm_unavail_prop() helper.
Note that we're creating misa_bits[], and not using the existing
'riscv_single_letter_exts[]', because the latter is tuned for riscv,isa
related functions and it doesn't have all MISA bits we support. Commit
0e2c377023 ("target/riscv: misa to ISA string conversion fix") has the
full context.
While we're at it, move both satp and the multi-letter extension
properties to kvm_riscv_add_cpu_user_properties() as well.
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: <20230925175709.35696-14-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Move the files to a 'kvm' dir to promote more code separation between
accelerators and making our lives easier supporting build options such
as --disable-tcg.
Rename kvm.c to kvm-cpu.c to keep it in line with its TCG counterpart.
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: <20230925175709.35696-13-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
