| Message ID | 1499864265-144136-2-git-send-email-borntraeger@de.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, 12 Jul 2017 14:57:35 +0200 Christian Borntraeger <borntraeger@de.ibm.com> wrote: > From: Janosch Frank <frankja@linux.vnet.ibm.com> > > Let's keep track of cmma enablement and move the mem_path check into > the actual enablement. This now also warns users that do not use > cpu-models about disabled cmma when using huge pages. > > Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com> > Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> > --- > target/s390x/cpu.h | 1 + > target/s390x/kvm.c | 26 +++++++++++++++++--------- > 2 files changed, 18 insertions(+), 9 deletions(-) > @@ -177,6 +179,11 @@ int kvm_s390_set_mem_limit(KVMState *s, uint64_t new_limit, uint64_t *hw_limit) > return kvm_vm_ioctl(s, KVM_SET_DEVICE_ATTR, &attr); > } > > +int kvm_s390_cmma_active(void) > +{ > + return active_cmma; > +} This is rather "has cmma ever been enabled"... > + > static bool kvm_s390_cmma_available(void) > { > static bool initialized, value; > @@ -197,7 +204,7 @@ void kvm_s390_cmma_reset(void) > .attr = KVM_S390_VM_MEM_CLR_CMMA, > }; > > - if (mem_path || !kvm_s390_cmma_available()) { > + if (!kvm_s390_cmma_active()) { > return; > } ...as you don't clear it on reset, right? Confused me a bit at first, but Reviewed-by: Cornelia Huck <cohuck@redhat.com>
On 12.07.2017 15:49, Cornelia Huck wrote: > On Wed, 12 Jul 2017 14:57:35 +0200 > Christian Borntraeger <borntraeger@de.ibm.com> wrote: > >> From: Janosch Frank <frankja@linux.vnet.ibm.com> >> >> Let's keep track of cmma enablement and move the mem_path check into >> the actual enablement. This now also warns users that do not use >> cpu-models about disabled cmma when using huge pages. >> >> Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com> >> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> >> --- >> target/s390x/cpu.h | 1 + >> target/s390x/kvm.c | 26 +++++++++++++++++--------- >> 2 files changed, 18 insertions(+), 9 deletions(-) > >> @@ -177,6 +179,11 @@ int kvm_s390_set_mem_limit(KVMState *s, uint64_t new_limit, uint64_t *hw_limit) >> return kvm_vm_ioctl(s, KVM_SET_DEVICE_ATTR, &attr); >> } >> >> +int kvm_s390_cmma_active(void) >> +{ >> + return active_cmma; >> +} > > This is rather "has cmma ever been enabled"... > >> + >> static bool kvm_s390_cmma_available(void) >> { >> static bool initialized, value; >> @@ -197,7 +204,7 @@ void kvm_s390_cmma_reset(void) >> .attr = KVM_S390_VM_MEM_CLR_CMMA, >> }; >> >> - if (mem_path || !kvm_s390_cmma_available()) { >> + if (!kvm_s390_cmma_active()) { >> return; >> } > > ...as you don't clear it on reset, right? I guess you mean KVM_S390_VM_MEM_CLR_CMMA, yes that only manipulates/clears the PGSTE values but can not disable the cmma facility. Disabling that on a running VM would be "interesting" at best. > > Confused me a bit at first, but > > Reviewed-by: Cornelia Huck <cohuck@redhat.com> Thanks!
diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h index bdb9bdb..8ab75c0 100644 --- a/target/s390x/cpu.h +++ b/target/s390x/cpu.h @@ -1158,6 +1158,7 @@ int kvm_s390_assign_subch_ioeventfd(EventNotifier *notifier, uint32_t sch, int vq, bool assign); int kvm_s390_cpu_restart(S390CPU *cpu); int kvm_s390_get_memslot_count(KVMState *s); +int kvm_s390_cmma_active(void); void kvm_s390_cmma_reset(void); int kvm_s390_set_cpu_state(S390CPU *cpu, uint8_t cpu_state); void kvm_s390_reset_vcpu(S390CPU *cpu); diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c index a3d0019..7a2a7c0 100644 --- a/target/s390x/kvm.c +++ b/target/s390x/kvm.c @@ -140,6 +140,8 @@ static int cap_mem_op; static int cap_s390_irq; static int cap_ri; +static int active_cmma; + static void *legacy_s390_alloc(size_t size, uint64_t *align); static int kvm_s390_query_mem_limit(KVMState *s, uint64_t *memory_limit) @@ -177,6 +179,11 @@ int kvm_s390_set_mem_limit(KVMState *s, uint64_t new_limit, uint64_t *hw_limit) return kvm_vm_ioctl(s, KVM_SET_DEVICE_ATTR, &attr); } +int kvm_s390_cmma_active(void) +{ + return active_cmma; +} + static bool kvm_s390_cmma_available(void) { static bool initialized, value; @@ -197,7 +204,7 @@ void kvm_s390_cmma_reset(void) .attr = KVM_S390_VM_MEM_CLR_CMMA, }; - if (mem_path || !kvm_s390_cmma_available()) { + if (!kvm_s390_cmma_active()) { return; } @@ -213,7 +220,13 @@ static void kvm_s390_enable_cmma(void) .attr = KVM_S390_VM_MEM_ENABLE_CMMA, }; + if (mem_path) { + error_report("Warning: CMM will not be enabled because it is not " + "compatible to hugetlbfs."); + return; + } rc = kvm_vm_ioctl(kvm_state, KVM_SET_DEVICE_ATTR, &attr); + active_cmma = !rc; trace_kvm_enable_cmma(rc); } @@ -2641,7 +2654,7 @@ void kvm_s390_apply_cpu_model(const S390CPUModel *model, Error **errp) if (!model) { /* compatibility handling if cpu models are disabled */ - if (kvm_s390_cmma_available() && !mem_path) { + if (kvm_s390_cmma_available()) { kvm_s390_enable_cmma(); } return; @@ -2672,13 +2685,8 @@ void kvm_s390_apply_cpu_model(const S390CPUModel *model, Error **errp) error_setg(errp, "KVM: Error configuring CPU subfunctions: %d", rc); return; } - /* enable CMM via CMMA - disable on hugetlbfs */ + /* enable CMM via CMMA */ if (test_bit(S390_FEAT_CMM, model->features)) { - if (mem_path) { - error_report("Warning: CMM will not be enabled because it is not " - "compatible to hugetlbfs."); - } else { - kvm_s390_enable_cmma(); - } + kvm_s390_enable_cmma(); } }