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| author | David Hildenbrand <dahi@linux.vnet.ibm.com> | 2015-09-29 16:27:24 +0200 |
|---|---|---|
| committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2015-10-13 15:50:34 +0200 |
| commit | 5a3d883a59b3fe8dc8775c7a79200a5b11a6761e (patch) | |
| tree | a1b60ce1821f86e3a6fc30e32ba3228d5525f6f6 /arch/s390/kvm/priv.c | |
| parent | 238293b14d9b1f5689e2aa68710000b0f25aa612 (diff) | |
| download | op-kernel-dev-5a3d883a59b3fe8dc8775c7a79200a5b11a6761e.zip op-kernel-dev-5a3d883a59b3fe8dc8775c7a79200a5b11a6761e.tar.gz | |
KVM: s390: switch to get_tod_clock() and fix STP sync races
Nobody except early.c makes use of store_tod_clock() to handle the
cc. So if we would get a cc != 0, we would be in more trouble.
Let's replace all users with get_tod_clock(). Returning a cc
on an ioctl sounded strange either way.
We can now also easily move the get_tod_clock() call into the
preempt_disable() section. This is in fact necessary to make the
STP sync work as expected. Otherwise the host TOD could change
and we would end up with a wrong epoch calculation.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Diffstat (limited to 'arch/s390/kvm/priv.c')
| -rw-r--r-- | arch/s390/kvm/priv.c | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 4d21dc4..b253de5 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -34,7 +34,7 @@ static int handle_set_clock(struct kvm_vcpu *vcpu) { struct kvm_vcpu *cpup; - s64 hostclk, val; + s64 val; int i, rc; ar_t ar; u64 op2; @@ -49,15 +49,11 @@ static int handle_set_clock(struct kvm_vcpu *vcpu) if (rc) return kvm_s390_inject_prog_cond(vcpu, rc); - if (store_tod_clock(&hostclk)) { - kvm_s390_set_psw_cc(vcpu, 3); - return 0; - } VCPU_EVENT(vcpu, 3, "SCK: setting guest TOD to 0x%llx", val); - val = (val - hostclk) & ~0x3fUL; mutex_lock(&vcpu->kvm->lock); preempt_disable(); + val = (val - get_tod_clock()) & ~0x3fUL; kvm_for_each_vcpu(i, cpup, vcpu->kvm) cpup->arch.sie_block->epoch = val; preempt_enable(); |
