* [PATCH] KVM: arm64: nv: Advertise the lack of AArch32 EL0 support
@ 2024-12-21 10:11 Marc Zyngier
2024-12-21 21:59 ` Oliver Upton
0 siblings, 1 reply; 2+ messages in thread
From: Marc Zyngier @ 2024-12-21 10:11 UTC (permalink / raw)
To: kvmarm, linux-arm-kernel
Cc: Joey Gouly, Suzuki K Poulose, Oliver Upton, Zenghui Yu
Although we never supported 32bit anywhere in NV, we fail to
advertise so for EL0, probably owing to the relative lack of
hardware supporting both NV2 and 32bit EL0.
Add some sanitising to ID_AA64PFR0_EL1.EL0, and reaffirm that
"in 64bit-only we trust".
Reported-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/nested.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index 9b36218b48def..9e74f7b38e056 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -830,8 +830,10 @@ static void limit_nv_id_regs(struct kvm *kvm)
NV_FTR(PFR0, RAS) |
NV_FTR(PFR0, EL3) |
NV_FTR(PFR0, EL2) |
- NV_FTR(PFR0, EL1));
- /* 64bit EL1/EL2/EL3 only */
+ NV_FTR(PFR0, EL1) |
+ NV_FTR(PFR0, EL0));
+ /* 64bit only at any EL */
+ val |= FIELD_PREP(NV_FTR(PFR0, EL0), 0b0001);
val |= FIELD_PREP(NV_FTR(PFR0, EL1), 0b0001);
val |= FIELD_PREP(NV_FTR(PFR0, EL2), 0b0001);
val |= FIELD_PREP(NV_FTR(PFR0, EL3), 0b0001);
--
2.39.2
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] KVM: arm64: nv: Advertise the lack of AArch32 EL0 support
2024-12-21 10:11 [PATCH] KVM: arm64: nv: Advertise the lack of AArch32 EL0 support Marc Zyngier
@ 2024-12-21 21:59 ` Oliver Upton
0 siblings, 0 replies; 2+ messages in thread
From: Oliver Upton @ 2024-12-21 21:59 UTC (permalink / raw)
To: Marc Zyngier
Cc: kvmarm, linux-arm-kernel, Joey Gouly, Suzuki K Poulose,
Zenghui Yu
On Sat, Dec 21, 2024 at 10:11:37AM +0000, Marc Zyngier wrote:
> Although we never supported 32bit anywhere in NV, we fail to
> advertise so for EL0, probably owing to the relative lack of
> hardware supporting both NV2 and 32bit EL0.
>
> Add some sanitising to ID_AA64PFR0_EL1.EL0, and reaffirm that
> "in 64bit-only we trust".
>
> Reported-by: Oliver Upton <oliver.upton@linux.dev>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
Thanks!
Acked-by: Oliver Upton <oliver.upton@linux.dev>
--
Thanks,
Oliver
^ permalink raw reply [flat|nested] 2+ messages in thread
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