Re: [PATCH v1 2/3] kvm: svm: Add kvm_fast_pio_in support

[Paolo Bonzini]

On 14/11/2016 23:15, Brijesh Singh wrote:
> +     /* For size less than 4 we merge, else we zero extend */
> +     val = (size < 4) ? kvm_register_read(vcpu, VCPU_REGS_RAX) : 0;

Are you sure it shouldn't always zero extend the high 32-bits?  So "val"
should be declared as u32.

Paolo

> +     ret = emulator_pio_in_emulated(&vcpu->arch.emulate_ctxt, size, port,
> +                                    &val, 1);
> +     if (ret) {
> +             kvm_register_write(vcpu, VCPU_REGS_RAX, val);
> +             return ret;
> +     }