KVM: PPC: Add support for explicit HIOR setting

Until now, we always set HIOR based on the PVR, but this is just wrong.
Instead, we should be setting HIOR explicitly, so user space can decide
what the initial HIOR value is - just like on real hardware.

We keep the old PVR based way around for backwards compatibility, but
once user space uses the SET_ONE_REG based method, we drop the PVR logic.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>

6 files changed, 23 insertions, 2 deletions

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index e0c75dc..59a3826 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -1610,6 +1610,7 @@ registers, find a list below:
 
   Arch  |       Register        | Width (bits)
         |                       |
+  PPC   | KVM_REG_PPC_HIOR      | 64
 
 4.69 KVM_GET_ONE_REG
 
diff --git a/arch/powerpc/include/asm/kvm.h b/arch/powerpc/include/asm/kvm.h
index 663c57f..f41adcd 100644
--- a/arch/powerpc/include/asm/kvm.h
+++ b/arch/powerpc/include/asm/kvm.h
@@ -331,4 +331,6 @@ struct kvm_book3e_206_tlb_params {
 	__u32 reserved[8];
 };
 
+#define KVM_REG_PPC_HIOR	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0x1)
+
 #endif /* __LINUX_KVM_POWERPC_H */
diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index 3c3edee..aa795cc 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -90,6 +90,8 @@ struct kvmppc_vcpu_book3s {
 #endif
 	int context_id[SID_CONTEXTS];
 
+	bool hior_explicit;		/* HIOR is set by ioctl, not PVR */
+
 	struct hlist_head hpte_hash_pte[HPTEG_HASH_NUM_PTE];
 	struct hlist_head hpte_hash_pte_long[HPTEG_HASH_NUM_PTE_LONG];
 	struct hlist_head hpte_hash_vpte[HPTEG_HASH_NUM_VPTE];
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index c193625..00efda6 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -157,14 +157,16 @@ void kvmppc_set_pvr(struct kvm_vcpu *vcpu, u32 pvr)
 #ifdef CONFIG_PPC_BOOK3S_64
 	if ((pvr >= 0x330000) && (pvr < 0x70330000)) {
 		kvmppc_mmu_book3s_64_init(vcpu);
-		to_book3s(vcpu)->hior = 0xfff00000;
+		if (!to_book3s(vcpu)->hior_explicit)
+			to_book3s(vcpu)->hior = 0xfff00000;
 		to_book3s(vcpu)->msr_mask = 0xffffffffffffffffULL;
 		vcpu->arch.cpu_type = KVM_CPU_3S_64;
 	} else
 #endif
 	{
 		kvmppc_mmu_book3s_32_init(vcpu);
-		to_book3s(vcpu)->hior = 0;
+		if (!to_book3s(vcpu)->hior_explicit)
+			to_book3s(vcpu)->hior = 0;
 		to_book3s(vcpu)->msr_mask = 0xffffffffULL;
 		vcpu->arch.cpu_type = KVM_CPU_3S_32;
 	}
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 089c61b..5985209 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -212,6 +212,7 @@ int kvm_dev_ioctl_check_extension(long ext)
 	case KVM_CAP_PPC_BOOKE_SREGS:
 #else
 	case KVM_CAP_PPC_SEGSTATE:
+	case KVM_CAP_PPC_HIOR:
 	case KVM_CAP_PPC_PAPR:
 #endif
 	case KVM_CAP_PPC_UNSET_IRQ:
@@ -652,6 +653,11 @@ static int kvm_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu,
 	int r = -EINVAL;
 
 	switch (reg->id) {
+#ifdef CONFIG_PPC_BOOK3S
+	case KVM_REG_PPC_HIOR:
+		r = put_user(to_book3s(vcpu)->hior, (u64 __user *)reg->addr);
+		break;
+#endif
 	default:
 		break;
 	}
@@ -665,6 +671,13 @@ static int kvm_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu,
 	int r = -EINVAL;
 
 	switch (reg->id) {
+#ifdef CONFIG_PPC_BOOK3S
+	case KVM_ONE_REG_PPC_HIOR:
+		r = get_user(to_book3s(vcpu)->hior, (u64 __user *)reg->addr);
+		if (!r)
+			to_book3s(vcpu)->hior_explicit = true;
+		break;
+#endif
 	default:
 		break;
 	}
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 4f7a9fb..acbe429 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -580,6 +580,7 @@ struct kvm_ppc_pvinfo {
 #define KVM_CAP_PPC_SMT 64
 #define KVM_CAP_PPC_RMA	65
 #define KVM_CAP_MAX_VCPUS 66       /* returns max vcpus per vm */
+#define KVM_CAP_PPC_HIOR 67
 #define KVM_CAP_PPC_PAPR 68
 #define KVM_CAP_SW_TLB 69
 #define KVM_CAP_ONE_REG 70