On Fri, Jun 01, 2018 at 10:42:24AM +0100, Mark Rutland wrote:
> Hi,
>
> On Tue, May 29, 2018 at 03:20:47PM +0100, Dave Martin wrote:
> > Currently, the {read,write}_sysreg_el*() accessors for accessing
> > particular ELs' sysregs in the presence of VHE rely on some local
> > hacks and define their system register encodings in a way that is
> > inconsistent with the core definitions in <asm/sysreg.h>.
> >
> > As a result, it is necessary to add duplicate definitions for any
> > system register that already needs a definition in sysreg.h for
> > other reasons.
> >
> > This is a bit of a maintenance headache, and the reasons for the
> > _el*() accessors working the way they do is a bit historical.
> >
> > This patch gets rid of the shadow sysreg definitions in
> > <asm/kvm_hyp.h>, converts the _el*() accessors to use the core
> > msr_s/mrs_s interface, and converts all call sites to use the
> > standard sysreg #define names (i.e., upper case, with SYS_ prefix).
>
> Nice!
>
> [...]
>
> > static inline unsigned long vcpu_read_elr_el1(const struct kvm_vcpu *vcpu)
> > {
> > if (vcpu->arch.sysregs_loaded_on_cpu)
> > - return read_sysreg_el1(elr);
> > + return read_sysreg_el1(SYS_ELR);
>
> Could we have the macro implicitly handle the SYS_ prefix?
>
> A further bit of cleanup that I'd like to do is make {read,write}_sysreg() use
> {mrs,msr}_s, implicitly handling the SYS_ prefix, so that we can kill off
> {read,write}_sysreg_s(), and always use a {read,write}_sysreg().
>
> A minor pain point is that we'd have to convert callers to pass the sysreg name
> in upper-case, but that conversion can be scripted fairly easily.
>
> e.g. for the above, read_sysreg() would take ELR_EL1, and read_sysreg_el1()
> would take ELR.
Ideally yes.
I will bear that in mind for the next iteration, but I hadn't figured
out how to solve the whole problem yet. I'll see if I can push a bit
further in that direction.
Cheers
---Dave
_______________________________________________
kvmarm mailing list
kvmarm@xxxxxxxxxxxxxxxxxxxxx
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
