Laurent Dufour <lduf...@linux.ibm.com> writes: > 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 > 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 <bhar...@linux.ibm.com> > Cc: Paul Mackerras <pau...@ozlabs.org> > Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org> > Cc: Michael Ellerman <m...@ellerman.id.au> > Signed-off-by: Laurent Dufour <lduf...@linux.ibm.com> > ---
I tested this along with the code that rejects the secure transition when it is not enabled in KVM. I have also forced a KVM_PPC_SVM_OFF (via system_reset) right after setting kvm->arch.secure_guest and nothing bad happened. Tested-by: Fabiano Rosas <faro...@linux.ibm.com> > arch/powerpc/kvm/book3s_hv_uvmem.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c > b/arch/powerpc/kvm/book3s_hv_uvmem.c > index 79b1202b1c62..68dff151315c 100644 > --- a/arch/powerpc/kvm/book3s_hv_uvmem.c > +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c > @@ -209,6 +209,8 @@ unsigned long kvmppc_h_svm_init_start(struct kvm *kvm) > int ret = H_SUCCESS; > int srcu_idx; > > + kvm->arch.secure_guest = KVMPPC_SECURE_INIT_START; > + > if (!kvmppc_uvmem_bitmap) > return H_UNSUPPORTED; > > @@ -233,7 +235,6 @@ unsigned long kvmppc_h_svm_init_start(struct kvm *kvm) > goto out; > } > } > - kvm->arch.secure_guest |= KVMPPC_SECURE_INIT_START; > out: > srcu_read_unlock(&kvm->srcu, srcu_idx); > return ret;
