On Tue, Jul 30, 2019 at 3:04 PM Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
>
> On 29/07/19 13:57, Anup Patel wrote:
> > void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
> > {
> > - /* TODO: */
> > + struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
> > +
> > + csr_write(CSR_HIDELEG, csr->hideleg);
> > + csr_write(CSR_HEDELEG, csr->hedeleg);
>
> Writing HIDELEG and HEDELEG here seems either wrong or inefficient to me.
>
> I don't remember the spec well enough, but there are two cases:
>
> 1) either they only matter while the guest runs and then you can set
> them in kvm_arch_hardware_enable. KVM common code takes care of doing
> this on all CPUs for you.
This is a good suggestion. I will use kvm_arch_hardware_enable() for
programming HIDELEG and HEDELEG CSRs.
>
> 2) or they also matter while the host runs and then you need to set them
> in vcpu_switch.S.
They don't matter in HS-mode so we don't need to access them in
vcpu_switch.S
Regards,
Anup
