[PATCH 2/2] KVM: PPC: Book3S HV: H_SVM_INIT_START must call UV_RETURN

[Ram Pai]

On Fri, Mar 20, 2020 at 11:26:43AM +0100, Laurent Dufour wrote:
> When the call to UV_REGISTER_MEM_SLOT is failing, for instance because
> there is not enough free secured memory, the Hypervisor (HV) has to call
			   secure memory,

> UV_RETURN to report the error to the Ultravisor (UV). Then the UV will call
> H_SVM_INIT_ABORT to abort the securing phase and go back to the calling VM.
> 
> If the kvm->arch.secure_guest is not set, in the return path rfid is called
> but there is no valid context to get back to the SVM since the Hcall has
> been routed by the Ultravisor.
> 
> Move the setting of kvm->arch.secure_guest earlier in
> kvmppc_h_svm_init_start() so in the return path, UV_RETURN will be called
> instead of rfid.
> 
> Cc: Bharata B Rao <bharata at linux.ibm.com>
> Cc: Paul Mackerras <paulus at ozlabs.org>
> Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
> Cc: Michael Ellerman <mpe at ellerman.id.au>
> Signed-off-by: Laurent Dufour <ldufour at linux.ibm.com>

Reviewed-by: Ram Pai <linuxram at us.ibm.com>