[PATCH 5/8] KVM: PPC: e500: Add support for EPTCFG register

Mihai Caraman
2013-04-11T10:03:11Z

EPTCFG register defined by E.PT is accessed unconditionally by Linux guests
in the presence of MAV 2.0. Emulate it now.

Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
---
v3:
- Initialize EPTCFG to 0 since E.PT is not supported now

Documentation/virtual/kvm/api.txt | 1 +
arch/powerpc/include/asm/kvm_host.h | 1 +
arch/powerpc/include/uapi/asm/kvm.h | 1 +
arch/powerpc/kvm/e500_emulate.c | 9 +++++++++
arch/powerpc/kvm/e500_mmu.c | 12 ++++++++++++
5 files changed, 24 insertions(+), 0 deletions(-)

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index f045377..a1f2200 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -1807,6 +1807,7 @@ registers, find a list below:
PPC | KVM_REG_PPC_TLB1PS | 32
PPC | KVM_REG_PPC_TLB2PS | 32
PPC | KVM_REG_PPC_TLB3PS | 32
+ PPC | KVM_REG_PPC_EPTCFG | 32

ARM registers are mapped using the lower 32 bits. The upper 16 of that
is the register group type, or coprocessor number:
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 3b6cee3..8a48e68 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -504,6 +504,7 @@ struct kvm_vcpu_arch {
u32 tlbcfg[4];
u32 tlbps[4];
u32 mmucfg;
+ u32 eptcfg;
u32 epr;
u32 crit_save;
struct kvmppc_booke_debug_reg dbg_reg;
diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h
index 91341d9..7f4d191 100644
--- a/arch/powerpc/include/uapi/asm/kvm.h
+++ b/arch/powerpc/include/uapi/asm/kvm.h
@@ -446,5 +446,6 @@ struct kvm_get_htab_header {
#define KVM_REG_PPC_TLB1PS (KVM_REG_PPC | KVM_REG_SIZE_U32 | 0x98)
#define KVM_REG_PPC_TLB2PS (KVM_REG_PPC | KVM_REG_SIZE_U32 | 0x99)
#define KVM_REG_PPC_TLB3PS (KVM_REG_PPC | KVM_REG_SIZE_U32 | 0x9a)
+#define KVM_REG_PPC_EPTCFG (KVM_REG_PPC | KVM_REG_SIZE_U32 | 0x9b)

#endif /* __LINUX_KVM_POWERPC_H */
diff --git a/arch/powerpc/kvm/e500_emulate.c b/arch/powerpc/kvm/e500_emulate.c
index 12b8de2..b10a012 100644
--- a/arch/powerpc/kvm/e500_emulate.c
+++ b/arch/powerpc/kvm/e500_emulate.c
@@ -317,6 +317,15 @@ int kvmppc_core_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, ulong *spr_val)
case SPRN_MMUCFG:
*spr_val = vcpu->arch.mmucfg;
break;
+ case SPRN_EPTCFG:
+ if (!has_feature(vcpu, VCPU_FTR_MMU_V2))
+ return EMULATE_FAIL;
+ /*
+ * Legacy Linux guests access EPTCFG register even if the E.PT
+ * category is disabled in the VM. Give them a chance to live.
+ */
+ *spr_val = vcpu->arch.eptcfg;
+ break;

/* extra exceptions */
case SPRN_IVOR32:
diff --git a/arch/powerpc/kvm/e500_mmu.c b/arch/powerpc/kvm/e500_mmu.c
index a863dc1..1c1c5cb 100644
--- a/arch/powerpc/kvm/e500_mmu.c
+++ b/arch/powerpc/kvm/e500_mmu.c
@@ -624,6 +624,9 @@ int kvmppc_get_one_reg_e500_tlb(struct kvm_vcpu *vcpu, u64 id,
case KVM_REG_PPC_MMUCFG:
*val = get_reg_val(id, vcpu->arch.mmucfg);
break;
+ case KVM_REG_PPC_EPTCFG:
+ *val = get_reg_val(id, vcpu->arch.eptcfg);
+ break;
case KVM_REG_PPC_TLB0CFG:
case KVM_REG_PPC_TLB1CFG:
case KVM_REG_PPC_TLB2CFG:
@@ -678,6 +681,12 @@ int kvmppc_set_one_reg_e500_tlb(struct kvm_vcpu *vcpu, u64 id,
r = -EINVAL;
break;
}
+ case KVM_REG_PPC_EPTCFG: {
+ u32 reg = set_reg_val(id, *val);
+ if (reg != vcpu->arch.eptcfg)
+ r = -EINVAL;
+ break;
+ }
case KVM_REG_PPC_TLB0CFG:
case KVM_REG_PPC_TLB1CFG:
case KVM_REG_PPC_TLB2CFG:
@@ -875,6 +884,9 @@ static int vcpu_mmu_init(struct kvm_vcpu *vcpu,
if (has_feature(vcpu, VCPU_FTR_MMU_V2)) {
vcpu->arch.tlbps[0] = mfspr(SPRN_TLB0PS);
vcpu->arch.tlbps[1] = mfspr(SPRN_TLB1PS);
+
+ /* Guest mmu emulation currently doesn't handle E.PT */
+ vcpu->arch.eptcfg = 0;
}

return 0;
--
1.7.4.1