On 02/07/2018 06:46 AM, David Hildenbrand wrote:
Right now, SET CLOCK called in the guest does not properly take care of
the epoch index, as the call goes via the old kvm_s390_set_tod_clock()
interface. So the epoch index is neither reset to 0, if required, nor
properly set to e.g. 0xff on negative values.
Fix this by providing a single kvm_s390_set_tod_clock() function. Move
Multiple-epoch facility handling into it.
Signed-off-by: David Hildenbrand<david@xxxxxxxxxx>
---
arch/s390/kvm/kvm-s390.c | 46 +++++++++++++++-------------------------------
arch/s390/kvm/kvm-s390.h | 5 ++---
arch/s390/kvm/priv.c | 9 +++++----
3 files changed, 22 insertions(+), 38 deletions(-)
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index ba4c7092335a..b514ee427077 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -902,12 +902,9 @@ static int kvm_s390_set_tod_ext(struct kvm *kvm, struct kvm_device_attr *attr)
if (copy_from_user(>od, (void __user *)attr->addr, sizeof(gtod)))
return -EFAULT;
- if (test_kvm_facility(kvm, 139))
- kvm_s390_set_tod_clock_ext(kvm, >od);
- else if (gtod.epoch_idx == 0)
- kvm_s390_set_tod_clock(kvm, gtod.tod);
- else
+ if (!test_kvm_facility(kvm, 139) && gtod.epoch_idx)
return -EINVAL;
+ kvm_s390_set_tod_clock(kvm, >od);
VM_EVENT(kvm, 3, "SET: TOD extension: 0x%x, TOD base: 0x%llx",
gtod.epoch_idx, gtod.tod);
@@ -932,13 +929,14 @@ static int kvm_s390_set_tod_high(struct kvm *kvm, struct kvm_device_attr *attr)
static int kvm_s390_set_tod_low(struct kvm *kvm, struct kvm_device_attr *attr)
{
- u64 gtod;
+ struct kvm_s390_vm_tod_clock gtod = { 0 };
- if (copy_from_user(>od, (void __user *)attr->addr, sizeof(gtod)))
+ if (copy_from_user(>od.tod, (void __user *)attr->addr,
+ sizeof(gtod.tod)))
return -EFAULT;
- kvm_s390_set_tod_clock(kvm, gtod);
- VM_EVENT(kvm, 3, "SET: TOD base: 0x%llx", gtod);
+ kvm_s390_set_tod_clock(kvm, >od);
+ VM_EVENT(kvm, 3, "SET: TOD base: 0x%llx", gtod.tod);
return 0;
}
@@ -3021,8 +3019,8 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu)
return 0;
}
-void kvm_s390_set_tod_clock_ext(struct kvm *kvm,
- const struct kvm_s390_vm_tod_clock *gtod)
+void kvm_s390_set_tod_clock(struct kvm *kvm,
+ const struct kvm_s390_vm_tod_clock *gtod)
Nit: off by one space --------^
{
struct kvm_vcpu *vcpu;
struct kvm_s390_tod_clock_ext htod;
@@ -3034,10 +3032,12 @@ void kvm_s390_set_tod_clock_ext(struct kvm *kvm,
get_tod_clock_ext((char *)&htod);
kvm->arch.epoch = gtod->tod - htod.tod;
- kvm->arch.epdx = gtod->epoch_idx - htod.epoch_idx;
-
- if (kvm->arch.epoch > gtod->tod)
- kvm->arch.epdx -= 1;
+ kvm->arch.epdx = 0;
+ if (test_kvm_facility(kvm, 139)) {
+ kvm->arch.epdx = gtod->epoch_idx - htod.epoch_idx;
+ if (kvm->arch.epoch > gtod->tod)
+ kvm->arch.epdx -= 1;
+ }
kvm_s390_vcpu_block_all(kvm);
kvm_for_each_vcpu(i, vcpu, kvm) {
@@ -3050,22 +3050,6 @@ void kvm_s390_set_tod_clock_ext(struct kvm *kvm,
mutex_unlock(&kvm->lock);
}
-void kvm_s390_set_tod_clock(struct kvm *kvm, u64 tod)
-{
- struct kvm_vcpu *vcpu;
- int i;
-
- mutex_lock(&kvm->lock);
- preempt_disable();
- kvm->arch.epoch = tod - get_tod_clock();
- kvm_s390_vcpu_block_all(kvm);
- kvm_for_each_vcpu(i, vcpu, kvm)
- vcpu->arch.sie_block->epoch = kvm->arch.epoch;
- kvm_s390_vcpu_unblock_all(kvm);
- preempt_enable();
- mutex_unlock(&kvm->lock);
-}
-
/**
* kvm_arch_fault_in_page - fault-in guest page if necessary
* @vcpu: The corresponding virtual cpu
diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index bd31b37b0e6f..19d719262765 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -283,9 +283,8 @@ int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu);
int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu);
/* implemented in kvm-s390.c */
-void kvm_s390_set_tod_clock_ext(struct kvm *kvm,
- const struct kvm_s390_vm_tod_clock *gtod);
-void kvm_s390_set_tod_clock(struct kvm *kvm, u64 tod);
+void kvm_s390_set_tod_clock(struct kvm *kvm,
+ const struct kvm_s390_vm_tod_clock *gtod);
Same nit here.
long kvm_arch_fault_in_page(struct kvm_vcpu *vcpu, gpa_t gpa, int writable);
int kvm_s390_store_status_unloaded(struct kvm_vcpu *vcpu, unsigned long addr);
int kvm_s390_vcpu_store_status(struct kvm_vcpu *vcpu, unsigned long addr);
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index c4c4e157c036..33505c32c48a 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -85,9 +85,10 @@ int kvm_s390_handle_e3(struct kvm_vcpu *vcpu)
/* Handle SCK (SET CLOCK) interception */
static int handle_set_clock(struct kvm_vcpu *vcpu)
{
+ struct kvm_s390_vm_tod_clock gtod = { 0 };
int rc;
u8 ar;
- u64 op2, val;
+ u64 op2;
vcpu->stat.instruction_sck++;
@@ -97,12 +98,12 @@ static int handle_set_clock(struct kvm_vcpu *vcpu)
op2 = kvm_s390_get_base_disp_s(vcpu, &ar);
if (op2 & 7) /* Operand must be on a doubleword boundary */
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
- rc = read_guest(vcpu, op2, ar, &val, sizeof(val));
+ rc = read_guest(vcpu, op2, ar, >od.tod, sizeof(gtod.tod));
if (rc)
return kvm_s390_inject_prog_cond(vcpu, rc);
- VCPU_EVENT(vcpu, 3, "SCK: setting guest TOD to 0x%llx", val);
- kvm_s390_set_tod_clock(vcpu->kvm, val);
+ VCPU_EVENT(vcpu, 3, "SCK: setting guest TOD to 0x%llx", gtod.tod);
+ kvm_s390_set_tod_clock(vcpu->kvm, >od);
kvm_s390_set_psw_cc(vcpu, 0);
return 0;
Set clock only concerns the left-most 64 bits of the TOD-Clock, right?
(thinking out
loud) I wonder if we need to also concern ourselves about the epoch
extension... but
perhaps current use cases of set clock do not warrant that?
--
- Collin L Walling
--
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