[PULL 19/41] KVM: PPC: Book3S PR: Expose TAR facility to guest

Alexander Graf
2014-05-30T12:43:04Z

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>
---
arch/powerpc/include/asm/kvm_host.h | 2 ++
arch/powerpc/kernel/asm-offsets.c | 2 ++
arch/powerpc/kvm/book3s.c | 6 ++++++
arch/powerpc/kvm/book3s_hv.c | 6 ------
arch/powerpc/kvm/book3s_pr.c | 18 ++++++++++++++++++
5 files changed, 28 insertions(+), 6 deletions(-)

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 @@ struct kvm_vcpu_arch {
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 @@ int main(void)
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 @@ int kvm_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
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 @@ int kvm_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
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 @@ static int kvmppc_get_one_reg_hv(struct kvm_vcpu *vcpu, u64 id,
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 @@ static int kvmppc_set_one_reg_hv(struct kvm_vcpu *vcpu, u64 id,
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 @@ static void kvmppc_core_vcpu_put_pr(struct kvm_vcpu *vcpu)
#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 @@ static void kvmppc_giveup_fac(struct kvm_vcpu *vcpu, ulong fac)
/* 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 @@ static int kvmppc_handle_fac(struct kvm_vcpu *vcpu, ulong fac)
}

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 @@ static int kvmppc_vcpu_run_pr(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
/* 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;
--
1.8.1.4