[PATCH v5 16/69] KVM: arm64: nv: Handle trapped ERET from virtual EL2
Marc Zyngier
maz at kernel.org
Thu Jan 27 03:50:40 PST 2022
On Tue, 18 Jan 2022 16:36:59 +0000,
Alexandru Elisei <alexandru.elisei at arm.com> wrote:
>
> Hi Marc,
>
> On Mon, Nov 29, 2021 at 08:00:57PM +0000, Marc Zyngier wrote:
> > From: Christoffer Dall <christoffer.dall at arm.com>
> >
> > When a guest hypervisor running virtual EL2 in EL1 executes an ERET
> > instruction, we will have set HCR_EL2.NV which traps ERET to EL2, so
> > that we can emulate the exception return in software.
> >
> > Signed-off-by: Christoffer Dall <christoffer.dall at arm.com>
> > Signed-off-by: Marc Zyngier <maz at kernel.org>
> > ---
> > arch/arm64/include/asm/esr.h | 5 +++++
> > arch/arm64/include/asm/kvm_arm.h | 2 +-
> > arch/arm64/kvm/handle_exit.c | 10 ++++++++++
> > 3 files changed, 16 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h
> > index d52a0b269ee8..6835e4231119 100644
> > --- a/arch/arm64/include/asm/esr.h
> > +++ b/arch/arm64/include/asm/esr.h
> > @@ -257,6 +257,11 @@
> > (((e) & ESR_ELx_SYS64_ISS_OP2_MASK) >> \
> > ESR_ELx_SYS64_ISS_OP2_SHIFT))
> >
> > +/* ISS field definitions for ERET/ERETAA/ERETAB trapping */
> > +
> > +#define ESR_ELx_ERET_ISS_ERET_ERETAx 0x2
> > +#define ESR_ELx_ERET_ISS_ERETA_ERATAB 0x1
> ^^^^^
> Shouldn't that be ERETAA?
Hmm, this is rather ambiguous indeed. I'm going to repaint it as:
#define ESR_ELx_ERET_ISS_ERET 0x2
#define ESR_ELx_ERET_ISS_ERETA 0x1
which matches the ARM ARM wording as of DDI0487G.b.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
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