[PATCH v3 8/9] KVM: PPC: Ultravisor: Enter a secure guest

[Paul Mackerras]

On Thu, Jun 06, 2019 at 02:36:13PM -0300, Claudio Carvalho wrote:
> From: Sukadev Bhattiprolu <sukadev at linux.vnet.ibm.com>
> 
> To enter a secure guest, we have to go through the ultravisor, therefore
> we do a ucall when we are entering a secure guest.
> 
> This change is needed for any sort of entry to the secure guest from the
> hypervisor, whether it is a return from an hcall, a return from a
> hypervisor interrupt, or the first time that a secure guest vCPU is run.
> 
> If we are returning from an hcall, the results are already in the
> appropriate registers (R3:12), except for R6,7, which need to be
> restored before doing the ucall (UV_RETURN).
> 
> Have fast_guest_return check the kvm_arch.secure_guest field so that a
> new CPU enters UV when started (in response to a RTAS start-cpu call).
> 
> Thanks to input from Paul Mackerras, Ram Pai and Mike Anderson.
> 
> Signed-off-by: Sukadev Bhattiprolu <sukadev at linux.vnet.ibm.com>
> [Pass SRR1 in r11 for UV_RETURN, fix kvmppc_msr_interrupt to preserve
>  the MSR_S bit]
> Signed-off-by: Paul Mackerras <paulus at ozlabs.org>
> [Fix UV_RETURN token number and arch.secure_guest check]
> Signed-off-by: Ram Pai <linuxram at us.ibm.com>
> [Update commit message and ret_to_ultra comment]
> Signed-off-by: Claudio Carvalho <cclaudio at linux.ibm.com>

Acked-by: Paul Mackerras <paulus at ozlabs.org>

Paul.