Re: [PATCH] target/riscv/kvm: do not use non-portable strerrorname_np()

[Peter Maydell]

On Mon, 18 Dec 2023 at 17:22, Daniel Henrique Barboza
<dbarboza@ventanamicro.com> wrote:
>
>
>
> On 12/18/23 13:22, Natanael Copa wrote:
> > strerrorname_np is non-portable and breaks building with musl libc.
> >
> > Use strerror(errno) instead, like we do other places.
> >
> > Cc: qemu-stable@nongnu.org
> > Fixes: commit 082e9e4a58ba (target/riscv/kvm: improve 'init_multiext_cfg' 
> > error msg)
> > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2041
> > Buglink: https://gitlab.alpinelinux.org/alpine/aports/-/issues/15541
> > Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>
> > ---
> >   target/riscv/kvm/kvm-cpu.c | 18 ++++++++----------
> >   1 file changed, 8 insertions(+), 10 deletions(-)
> >
> > diff --git a/target/riscv/kvm/kvm-cpu.c b/target/riscv/kvm/kvm-cpu.c
> > index 45b6cf1cfa..117e33cf90 100644
> > --- a/target/riscv/kvm/kvm-cpu.c
> > +++ b/target/riscv/kvm/kvm-cpu.c
> > @@ -832,9 +832,8 @@ static void kvm_riscv_read_multiext_legacy(RISCVCPU 
> > *cpu,
> >                   multi_ext_cfg->supported = false;
> >                   val = false;
> >               } else {
> > -                error_report("Unable to read ISA_EXT KVM register %s, "
> > -                             "error code: %s", multi_ext_cfg->name,
> > -                             strerrorname_np(errno));
> > +                error_report("Unable to read ISA_EXT KVM register %s: %s",
> > +                             multi_ext_cfg->name, strerror(errno));
>
>
> The reason I did this change, as described in 082e9e4a58ba mentioned in the 
> commit
> message, was precisely to avoid things like this:
>
> qemu-system-riscv64: Unable to read ISA_EXT KVM register ssaia, error: no 
> such file or directory
>
> The generic description of the error works well with file descriptors and so 
> on but it's
> weird in the KVM context. This patch is re-introducing it.

We don't seem to worry about that in any of the other
KVM code -- accel/kvm/ has lots of places that
use strerror() or error_setg_errno().

thanks
-- PMM