KVM: PPC: Book3S PR: Expose TAR facility to guest
POWER8 implements a new register called TAR. This register has to be
enabled in FSCR and then from KVM's point of view is mere storage.
This patch enables the guest to use TAR.
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 232ec5f..29fbb55 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -449,7 +449,9 @@
ulong pc;
ulong ctr;
ulong lr;
+#ifdef CONFIG_PPC_BOOK3S
ulong tar;
+#endif
ulong xer;
u32 cr;
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index e2b86b5..93e1465 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -446,7 +446,9 @@
DEFINE(VCPU_XER, offsetof(struct kvm_vcpu, arch.xer));
DEFINE(VCPU_CTR, offsetof(struct kvm_vcpu, arch.ctr));
DEFINE(VCPU_LR, offsetof(struct kvm_vcpu, arch.lr));
+#ifdef CONFIG_PPC_BOOK3S
DEFINE(VCPU_TAR, offsetof(struct kvm_vcpu, arch.tar));
+#endif
DEFINE(VCPU_CR, offsetof(struct kvm_vcpu, arch.cr));
DEFINE(VCPU_PC, offsetof(struct kvm_vcpu, arch.pc));
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 79cfa2d..4046a1a 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -634,6 +634,9 @@
case KVM_REG_PPC_FSCR:
val = get_reg_val(reg->id, vcpu->arch.fscr);
break;
+ case KVM_REG_PPC_TAR:
+ val = get_reg_val(reg->id, vcpu->arch.tar);
+ break;
default:
r = -EINVAL;
break;
@@ -726,6 +729,9 @@
case KVM_REG_PPC_FSCR:
vcpu->arch.fscr = set_reg_val(reg->id, val);
break;
+ case KVM_REG_PPC_TAR:
+ vcpu->arch.tar = set_reg_val(reg->id, val);
+ break;
default:
r = -EINVAL;
break;
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 0092e12..ee1d8ee 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -891,9 +891,6 @@
case KVM_REG_PPC_BESCR:
*val = get_reg_val(id, vcpu->arch.bescr);
break;
- case KVM_REG_PPC_TAR:
- *val = get_reg_val(id, vcpu->arch.tar);
- break;
case KVM_REG_PPC_DPDES:
*val = get_reg_val(id, vcpu->arch.vcore->dpdes);
break;
@@ -1100,9 +1097,6 @@
case KVM_REG_PPC_BESCR:
vcpu->arch.bescr = set_reg_val(id, *val);
break;
- case KVM_REG_PPC_TAR:
- vcpu->arch.tar = set_reg_val(id, *val);
- break;
case KVM_REG_PPC_DPDES:
vcpu->arch.vcore->dpdes = set_reg_val(id, *val);
break;
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index ddc626e..7d27a95 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -90,6 +90,7 @@
#endif
kvmppc_giveup_ext(vcpu, MSR_FP | MSR_VEC | MSR_VSX);
+ kvmppc_giveup_fac(vcpu, FSCR_TAR_LG);
vcpu->cpu = -1;
}
@@ -625,6 +626,14 @@
/* Facility not available to the guest, ignore giveup request*/
return;
}
+
+ switch (fac) {
+ case FSCR_TAR_LG:
+ vcpu->arch.tar = mfspr(SPRN_TAR);
+ mtspr(SPRN_TAR, current->thread.tar);
+ vcpu->arch.shadow_fscr &= ~FSCR_TAR;
+ break;
+ }
#endif
}
@@ -794,6 +803,12 @@
}
switch (fac) {
+ case FSCR_TAR_LG:
+ /* TAR switching isn't lazy in Linux yet */
+ current->thread.tar = mfspr(SPRN_TAR);
+ mtspr(SPRN_TAR, vcpu->arch.tar);
+ vcpu->arch.shadow_fscr |= FSCR_TAR;
+ break;
default:
kvmppc_emulate_fac(vcpu, fac);
break;
@@ -1393,6 +1408,9 @@
/* Make sure we save the guest FPU/Altivec/VSX state */
kvmppc_giveup_ext(vcpu, MSR_FP | MSR_VEC | MSR_VSX);
+ /* Make sure we save the guest TAR/EBB/DSCR state */
+ kvmppc_giveup_fac(vcpu, FSCR_TAR_LG);
+
out:
vcpu->mode = OUTSIDE_GUEST_MODE;
return ret;