Re: [PATCH 08/11] KVM: arm64: Inject AArch32 exceptions from HYP

Hi Marc,

On 27/10/2020 19:21, Marc Zyngier wrote:

quoted

quoted

+static inline u32 __vcpu_read_cp15(const struct kvm_vcpu *vcpu, int reg)
+{
+    return __vcpu_read_sys_reg(vcpu, reg / 2);
+}

quoted

Doesn't this re-implement the issue 3204be4109ad biased?

I don't think it does. The issue existed when accessing the 32bit shadow,
and we had to pick which side of the 64bit register had our 32bit value.
Here, we directly access the 64bit file, which is safe.

Because its not accessing the copro union, and the two users are both straight forward
aliases.

...

What do I get if I call:
| __vcpu_read_cp15(vcpu, c6_IFAR);

Won't this return the value of c6_DFAR instead as they live in the same 64 bit register.

But thinking of it, we may as well change the call sites to directly
use the 64bit enum, rather than playing games

Great!

(we used to use the 32bit definition for the sake of the defunct 32bit port).

Thanks,

James

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