From 20498df62df3a162b1001122fb25c4d6de22ce5e Mon Sep 17 00:00:00 2001
From: Paul Mackerras <paulus@ozlabs.org>
Date: Mon, 8 Oct 2018 16:31:13 +1100
Subject: [PATCH] KVM: PPC: Book3S HV: Add one-reg interface to virtual PTCR
 register

This adds a one-reg register identifier which can be used to read and
set the virtual PTCR for the guest.  This register identifies the
address and size of the virtual partition table for the guest, which
contains information about the nested guests under this guest.

Migrating this value is the only extra requirement for migrating a
guest which has nested guests (assuming of course that the destination
host supports nested virtualization in the kvm-hv module).

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 Documentation/virtual/kvm/api.txt   | 1 +
 arch/powerpc/include/uapi/asm/kvm.h | 1 +
 arch/powerpc/kvm/book3s_hv.c        | 6 ++++++
 3 files changed, 8 insertions(+)

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index c664064f76fb6..017d851b6c56f 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -1922,6 +1922,7 @@ registers, find a list below:
   PPC   | KVM_REG_PPC_TIDR              | 64
   PPC   | KVM_REG_PPC_PSSCR             | 64
   PPC   | KVM_REG_PPC_DEC_EXPIRY        | 64
+  PPC   | KVM_REG_PPC_PTCR              | 64
   PPC   | KVM_REG_PPC_TM_GPR0           | 64
           ...
   PPC   | KVM_REG_PPC_TM_GPR31          | 64
diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h
index 1b32b56a03d34..8c876c166ef27 100644
--- a/arch/powerpc/include/uapi/asm/kvm.h
+++ b/arch/powerpc/include/uapi/asm/kvm.h
@@ -634,6 +634,7 @@ struct kvm_ppc_cpu_char {
 
 #define KVM_REG_PPC_DEC_EXPIRY	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xbe)
 #define KVM_REG_PPC_ONLINE	(KVM_REG_PPC | KVM_REG_SIZE_U32 | 0xbf)
+#define KVM_REG_PPC_PTCR	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xc0)
 
 /* Transactional Memory checkpointed state:
  * This is all GPRs, all VSX regs and a subset of SPRs
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index c90deb5a52198..8458bbe2a9730 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1710,6 +1710,9 @@ static int kvmppc_get_one_reg_hv(struct kvm_vcpu *vcpu, u64 id,
 	case KVM_REG_PPC_ONLINE:
 		*val = get_reg_val(id, vcpu->arch.online);
 		break;
+	case KVM_REG_PPC_PTCR:
+		*val = get_reg_val(id, vcpu->kvm->arch.l1_ptcr);
+		break;
 	default:
 		r = -EINVAL;
 		break;
@@ -1941,6 +1944,9 @@ static int kvmppc_set_one_reg_hv(struct kvm_vcpu *vcpu, u64 id,
 			atomic_dec(&vcpu->arch.vcore->online_count);
 		vcpu->arch.online = i;
 		break;
+	case KVM_REG_PPC_PTCR:
+		vcpu->kvm->arch.l1_ptcr = set_reg_val(id, *val);
+		break;
 	default:
 		r = -EINVAL;
 		break;
-- 
2.39.5