On 05.06.14 14:08, Aneesh Kumar K.V wrote:
virtual time base register is a per VM, per cpu register that needs
to be saved and restored on vm exit and entry. Writing to VTB is not
allowed in the privileged mode.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/kvm_host.h | 1 +
arch/powerpc/include/asm/reg.h | 15 +++++++++++++++
arch/powerpc/include/asm/time.h | 9 +++++++++
arch/powerpc/kvm/book3s.c | 6 ++++++
arch/powerpc/kvm/book3s_emulate.c | 3 +++
arch/powerpc/kvm/book3s_hv.c | 6 ------
arch/powerpc/kvm/book3s_pr.c | 3 ++-
7 files changed, 36 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 4a58731a0a72..bd3caeaeebe1 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -505,6 +505,7 @@ struct kvm_vcpu_arch {
#endif
/* Time base value when we entered the guest */
u64 entry_tb;
+ u64 entry_vtb;
u32 tcr;
ulong tsr; /* we need to perform set/clr_bits() which requires ulong */
u32 ivor[64];
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 4852bcf270f3..3e7085d8af90 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -25,6 +25,7 @@
#ifdef CONFIG_8xx
#include <asm/reg_8xx.h>
#endif /* CONFIG_8xx */
+#include <asm/bug.h>
#define MSR_SF_LG 63 /* Enable 64 bit mode */
#define MSR_ISF_LG 61 /* Interrupt 64b mode valid on 630 */
@@ -1193,6 +1194,20 @@
: "r" ((unsigned long)(v)) \
: "memory")
+static inline unsigned long mfvtb (void)
+{
+#ifdef CONFIG_PPC_BOOK3S_64
+ if (cpu_has_feature(CPU_FTR_ARCH_207S))
+ return mfspr(SPRN_VTB);
+#endif
+ /*
+ * The above mfspr will be a no-op on anything before Power8
+ * That can result in random values returned. We need to
+ * capture that.
+ */
+ BUG();
+}
+
#ifdef __powerpc64__
#if defined(CONFIG_PPC_CELL) || defined(CONFIG_PPC_FSL_BOOK3E)
#define mftb() ({unsigned long rval; \
diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
index 1d428e6007ca..03cbada59d3a 100644
--- a/arch/powerpc/include/asm/time.h
+++ b/arch/powerpc/include/asm/time.h
@@ -102,6 +102,15 @@ static inline u64 get_rtc(void)
return (u64)hi * 1000000000 + lo;
}
+static inline u64 get_vtb(void)
+{
+#ifdef CONFIG_PPC_BOOK3S_64
+ if (cpu_has_feature(CPU_FTR_ARCH_207S))
+ return mfvtb();
+#endif
+ return 0;
+}
+
#ifdef CONFIG_PPC64
static inline u64 get_tb(void)
{
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 52c654dbd41a..ae43e4178ecd 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -646,6 +646,9 @@ int kvm_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
case KVM_REG_PPC_BESCR:
val = get_reg_val(reg->id, vcpu->arch.bescr);
break;
+ case KVM_REG_PPC_VTB:
+ val = get_reg_val(reg->id, vcpu->arch.vtb);
+ break;
default:
r = -EINVAL;
break;
@@ -750,6 +753,9 @@ int kvm_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
case KVM_REG_PPC_BESCR:
vcpu->arch.bescr = set_reg_val(reg->id, val);
break;
+ case KVM_REG_PPC_VTB:
+ vcpu->arch.vtb = set_reg_val(reg->id, val);
+ break;
default:
r = -EINVAL;
break;
diff --git a/arch/powerpc/kvm/book3s_emulate.c b/arch/powerpc/kvm/book3s_emulate.c
index 3565e775b61b..1bb16a59dcbc 100644
--- a/arch/powerpc/kvm/book3s_emulate.c
+++ b/arch/powerpc/kvm/book3s_emulate.c
@@ -577,6 +577,9 @@ int kvmppc_core_emulate_mfspr_pr(struct kvm_vcpu *vcpu, int sprn, ulong *spr_val
*/
*spr_val = vcpu->arch.spurr;
break;
+ case SPRN_VTB:
+ *spr_val = vcpu->arch.vtb;
Doesn't this mean that vtb can be the same 2 when the guest reads it 2
times in a row without getting preempted?
Alex
+ break;
case SPRN_GQR0:
case SPRN_GQR1:
case SPRN_GQR2:
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index aba05bbb3e74..f6ac58336b3f 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -897,9 +897,6 @@ static int kvmppc_get_one_reg_hv(struct kvm_vcpu *vcpu, u64 id,
case KVM_REG_PPC_IC:
*val = get_reg_val(id, vcpu->arch.ic);
break;
- case KVM_REG_PPC_VTB:
- *val = get_reg_val(id, vcpu->arch.vtb);
- break;
case KVM_REG_PPC_CSIGR:
*val = get_reg_val(id, vcpu->arch.csigr);
break;
@@ -1097,9 +1094,6 @@ static int kvmppc_set_one_reg_hv(struct kvm_vcpu *vcpu, u64 id,
case KVM_REG_PPC_IC:
vcpu->arch.ic = set_reg_val(id, *val);
break;
- case KVM_REG_PPC_VTB:
- vcpu->arch.vtb = set_reg_val(id, *val);
- break;
case KVM_REG_PPC_CSIGR:
vcpu->arch.csigr = set_reg_val(id, *val);
break;
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index ff15f8e31a27..96cdf89a8c86 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -125,6 +125,7 @@ void kvmppc_copy_to_svcpu(struct kvmppc_book3s_shadow_vcpu *svcpu,
* to find the guest purr and spurr value.
*/
vcpu->arch.entry_tb = get_tb();
+ vcpu->arch.entry_vtb = get_vtb();
svcpu->in_use = true;
}
@@ -176,7 +177,7 @@ void kvmppc_copy_from_svcpu(struct kvm_vcpu *vcpu,
*/
vcpu->arch.purr += get_tb() - vcpu->arch.entry_tb;
vcpu->arch.spurr += get_tb() - vcpu->arch.entry_tb;
-
+ vcpu->arch.vtb += get_vtb() - vcpu->arch.entry_vtb;
svcpu->in_use = false;
out:
--
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