diff options
| author | Janosch Frank <frankja@linux.vnet.ibm.com> | 2016-05-10 16:03:42 +0300 |
|---|---|---|
| committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2016-06-10 13:07:12 +0300 |
| commit | 7d0a5e62411a9223512c6af2e4c08a2d7c00fa2e (patch) | |
| tree | 1c735ee1c90c691b0246c9bb07811030734d14e4 /arch/s390/kvm/kvm-s390.c | |
| parent | 95ca2cb57985b07f5b136405f80a5106f5b06641 (diff) | |
| download | linux-7d0a5e62411a9223512c6af2e4c08a2d7c00fa2e.tar.xz | |
KVM: s390: Limit sthyi execution
Store hypervisor information is a valid instruction not only in
supervisor state but also in problem state, i.e. the guest's
userspace. Its execution is not only computational and memory
intensive, but also has to get hold of the ipte lock to write to the
guest's memory.
This lock is not intended to be held often and long, especially not
from the untrusted guest userspace. Therefore we apply rate limiting
of sthyi executions per VM.
Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Acked-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Diffstat (limited to 'arch/s390/kvm/kvm-s390.c')
| -rw-r--r-- | arch/s390/kvm/kvm-s390.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 1c10254119b3..44297ff53b44 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -1151,6 +1151,8 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) rc = -ENOMEM; + ratelimit_state_init(&kvm->arch.sthyi_limit, 5 * HZ, 500); + kvm->arch.use_esca = 0; /* start with basic SCA */ rwlock_init(&kvm->arch.sca_lock); kvm->arch.sca = (struct bsca_block *) get_zeroed_page(GFP_KERNEL); |