On Tue, 20 Feb 2024 11:31:27 +0000,
Joey Gouly <joey.gouly@xxxxxxx> wrote:
>
> On Mon, Feb 19, 2024 at 09:20:03AM +0000, Marc Zyngier wrote:
> > The ESR_ELx_ERET_ISS_ERET* macros are a bit confusing:
> >
> > - ESR_ELx_ERET_ISS_ERET really indicates that we have trapped an
> > ERETA* instruction, as opposed to an ERET
> >
> > - ESR_ELx_ERET_ISS_ERETA reallu indicates that we have trapped
> > an ERETAB instruction, as opposed to an ERETAA.
> >
> > Repaint the two helpers such as:
> >
> > - ESR_ELx_ERET_ISS_ERET becomes ESR_ELx_ERET_ISS_ERETA
> >
> > - ESR_ELx_ERET_ISS_ERETA becomes ESR_ELx_ERET_ISS_ERETAB
> >
> > At the same time, use BIT() instead of raw values.
> >
> > Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
>
> I'm somewhat against this, as the original names are what the Arm
> ARM specifies.
I don't disagree, but that doesn't make the ARM ARM right! ;-)
>
> > ---
> > arch/arm64/include/asm/esr.h | 4 ++--
> > arch/arm64/kvm/handle_exit.c | 2 +-
> > 2 files changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h
> > index 353fe08546cf..72c7810ccf2c 100644
> > --- a/arch/arm64/include/asm/esr.h
> > +++ b/arch/arm64/include/asm/esr.h
> > @@ -290,8 +290,8 @@
> > ESR_ELx_SYS64_ISS_OP2_SHIFT))
> >
> > /* ISS field definitions for ERET/ERETAA/ERETAB trapping */
> > -#define ESR_ELx_ERET_ISS_ERET 0x2
> > -#define ESR_ELx_ERET_ISS_ERETA 0x1
> > +#define ESR_ELx_ERET_ISS_ERETA BIT(1)
> > +#define ESR_ELx_ERET_ISS_ERETAB BIT(0)
> >
> > /*
> > * ISS field definitions for floating-point exception traps
> > diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
> > index 617ae6dea5d5..0646c623d1da 100644
> > --- a/arch/arm64/kvm/handle_exit.c
> > +++ b/arch/arm64/kvm/handle_exit.c
> > @@ -219,7 +219,7 @@ static int kvm_handle_ptrauth(struct kvm_vcpu *vcpu)
> >
> > static int kvm_handle_eret(struct kvm_vcpu *vcpu)
> > {
> > - if (kvm_vcpu_get_esr(vcpu) & ESR_ELx_ERET_ISS_ERET)
> > + if (kvm_vcpu_get_esr(vcpu) & ESR_ELx_ERET_ISS_ERETA)
>
> If this part is confusing due to the name, maybe introduce a function in esr.h
> esr_is_pac_eret() (name pending bikeshedding)?
That's indeed a better option. Now for the bikeshed aspect:
- esr_iss_is_eretax(): check for ESR_ELx_ERET_ISS_ERET being set
- esr_iss_is_eretab(): check for ESR_ELx_ERET_ISS_ERETA being set
Thoughts?
M.
--
Without deviation from the norm, progress is not possible.
