From: "Jason J. Herne" <jjherne@xxxxxxxxxxxxxxxxxx>
Provide KVM_REG_S390_TOD and KVM_REG_S390_TOD_HIGH registers on s390 for
managing guest Time Of Day clock value.
KVM_REG_S390_TOD_HIGH is presently always set to 0. In the future it will
contain a high order expansion of the tod clock value after it overflows
the 64-bits of KVM_REG_S390_TOD.
Signed-off-by: Jason J. Herne <jjherne@xxxxxxxxxxxxxxxxxx>
---
arch/s390/include/uapi/asm/kvm.h | 2 ++
arch/s390/kvm/kvm-s390.c | 63 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 65 insertions(+)
diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h
index 48eda3a..5578832 100644
--- a/arch/s390/include/uapi/asm/kvm.h
+++ b/arch/s390/include/uapi/asm/kvm.h
@@ -138,4 +138,6 @@ struct kvm_sync_regs {
#define KVM_REG_S390_PFSELECT (KVM_REG_S390 | KVM_REG_SIZE_U64 | 0x7)
#define KVM_REG_S390_PP (KVM_REG_S390 | KVM_REG_SIZE_U64 | 0x8)
#define KVM_REG_S390_GBEA (KVM_REG_S390 | KVM_REG_SIZE_U64 | 0x9)
+#define KVM_REG_S390_TOD (KVM_REG_S390 | KVM_REG_SIZE_U64 | 0xA)
+#define KVM_REG_S390_TOD_HIGH (KVM_REG_S390 | KVM_REG_SIZE_U8 | 0xB)
#endif
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 55aade4..17e3d61 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -31,6 +31,7 @@
#include <asm/switch_to.h>
#include <asm/facility.h>
#include <asm/sclp.h>
+#include<asm/timex.h>
#include "kvm-s390.h"
#include "gaccess.h"
@@ -788,10 +789,48 @@ int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
return 0;
}
+static int kvm_s390_get_guest_tod(struct kvm_vcpu *vcpu, u64 *guest_tod)
+{
+ u64 host_tod;
+ int r;
+
+ r = store_tod_clock(&host_tod);
+ if (r)
+ return r;
+
+ *guest_tod = host_tod + vcpu->arch.sie_block->epoch;
+ return 0;
+}
+
+/*
+Set the guest's effective TOD clock to the given value. The guest's
+TOD clock is determined by the following formula: gtod = host_tod + epoch.
+NOTE: Even though the epoch value is associated with a vcpu, there is only
+one TOD clock and epoch value per guest. All vcpu's epoch values must be kept
+synchronized.
+*/
+static int kvm_s390_set_guest_tod(struct kvm_vcpu *vcpu, u64 guest_tod)
+{
+ struct kvm_vcpu *cur_vcpu;
+ unsigned int vcpu_idx;
+ u64 host_tod;
+ int r;
+
+ r = store_tod_clock(&host_tod);
+ if (r)
+ return r;
+
+ kvm_for_each_vcpu(vcpu_idx, cur_vcpu, vcpu->kvm) {
+ cur_vcpu->arch.sie_block->epoch = guest_tod - host_tod;
+ }
+ return 0;
+}
+
static int kvm_arch_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu,
struct kvm_one_reg *reg)
{
int r = -EINVAL;
+ u64 gtod;
switch (reg->id) {
case KVM_REG_S390_TODPR:
@@ -830,6 +869,15 @@ static int kvm_arch_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu,
r = put_user(vcpu->arch.sie_block->gbea,
(u64 __user *)reg->addr);
break;
+ case KVM_REG_S390_TOD:
+ r = kvm_s390_get_guest_tod(vcpu, >od);
+ if (r)
+ break;
+ r = put_user(gtod, (u64 __user *)reg->addr);
+ break;
+ case KVM_REG_S390_TOD_HIGH:
+ r = put_user(0, (u8 __user *)reg->addr);
+ break;
default:
break;
}
@@ -841,6 +889,8 @@ static int kvm_arch_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu,
struct kvm_one_reg *reg)
{
int r = -EINVAL;
+ u64 gtod;
+ u8 gtod_high;
switch (reg->id) {
case KVM_REG_S390_TODPR:
@@ -879,6 +929,19 @@ static int kvm_arch_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu,
r = get_user(vcpu->arch.sie_block->gbea,
(u64 __user *)reg->addr);
break;
+ case KVM_REG_S390_TOD:
+ r = get_user(gtod, (u64 __user *)reg->addr);
+ if (r)
+ break;
+ r = kvm_s390_set_guest_tod(vcpu, gtod);
+ break;
+ case KVM_REG_S390_TOD_HIGH:
+ r = get_user(gtod_high, (u8 __user *)reg->addr);
+ if (r)
+ break;
+ if (gtod_high != 0)
+ r = -EINVAL;
+ break;
default:
break;
}
--
1.8.3.2
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