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>

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index c664064f76fb60ccc434988266776697660d0a5f..017d851b6c56f52689d477776912ea6641da15f3 100644 (file)
--- 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 1b32b56a03d34ce2a5f0b7f79c621f87d8c89dbf..8c876c166ef27b2c6fa754781fdbb103f2addc54 100644 (file)
--- 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 c90deb5a521980d1beecd583693c6111f083e83c..8458bbe2a97308e3e88ce99c1950329797538b69 100644 (file)
--- 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;