block ais migration for machines <= 2.9

[Qemu-devel] block ais migration for machines <= 2.9

Posted by Christian Borntraeger 8 years, 1 month ago

Something like the following seems to do the tricks.
Needs proper patch description, review, full test with different kernel versions.....

diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index 1c7af39..2ff32ba 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -212,6 +212,7 @@ static void ccw_machine_class_init(ObjectClass *oc, void *data)
     s390mc->cpu_model_allowed = true;
     s390mc->css_migration_enabled = true;
     s390mc->gs_allowed = true;
+    s390mc->ais_allowed = true;
     mc->init = ccw_init;
     mc->reset = s390_machine_reset;
     mc->hot_add_cpu = s390_hot_add_cpu;
@@ -305,6 +306,11 @@ bool gs_allowed(void)
     return false;
 }
 
+bool ais_allowed(void)
+{
+    return get_machine_class()->ais_allowed;
+}
+
 static char *machine_get_loadparm(Object *obj, Error **errp)
 {
     S390CcwMachineState *ms = S390_CCW_MACHINE(obj);
@@ -533,6 +539,7 @@ static void ccw_machine_2_9_class_options(MachineClass *mc)
     S390CcwMachineClass *s390mc = S390_MACHINE_CLASS(mc);
 
     s390mc->gs_allowed = false;
+    s390mc->ais_allowed = false;
     ccw_machine_2_10_class_options(mc);
     SET_MACHINE_COMPAT(mc, CCW_COMPAT_2_9);
     s390mc->css_migration_enabled = false;
diff --git a/include/hw/s390x/s390-virtio-ccw.h b/include/hw/s390x/s390-virtio-ccw.h
index 41a9d28..bba8660 100644
--- a/include/hw/s390x/s390-virtio-ccw.h
+++ b/include/hw/s390x/s390-virtio-ccw.h
@@ -41,6 +41,7 @@ typedef struct S390CcwMachineClass {
     bool cpu_model_allowed;
     bool css_migration_enabled;
     bool gs_allowed;
+    bool ais_allowed;
 } S390CcwMachineClass;
 
 /* runtime-instrumentation allowed by the machine */
@@ -49,6 +50,8 @@ bool ri_allowed(void);
 bool cpu_model_allowed(void);
 /* guarded-storage allowed by the machine */
 bool gs_allowed(void);
+/* ais allowed by the machine */
+bool ais_allowed(void);
 
 /**
  * Returns true if (vmstate based) migration of the channel subsystem
diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
index c4c5791..531d474 100644
--- a/target/s390x/kvm.c
+++ b/target/s390x/kvm.c
@@ -309,7 +309,9 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
     }
 
     /* Try to enable AIS facility */
-    kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0);
+    if (ais_allowed()) {
+       kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0);
+    }
 
     qemu_mutex_init(&qemu_sigp_mutex);

Re: [Qemu-devel] block ais migration for machines <= 2.9

Posted by Cornelia Huck 8 years, 1 month ago

On Wed, 20 Sep 2017 14:53:07 +0200
Christian Borntraeger <borntraeger@de.ibm.com> wrote:

> Something like the following seems to do the tricks.
> Needs proper patch description, review, full test with different kernel versions.....

Looks sane.

Will you handle it?

> 
> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
> index 1c7af39..2ff32ba 100644
> --- a/hw/s390x/s390-virtio-ccw.c
> +++ b/hw/s390x/s390-virtio-ccw.c
> @@ -212,6 +212,7 @@ static void ccw_machine_class_init(ObjectClass *oc, void *data)
>      s390mc->cpu_model_allowed = true;
>      s390mc->css_migration_enabled = true;
>      s390mc->gs_allowed = true;
> +    s390mc->ais_allowed = true;
>      mc->init = ccw_init;
>      mc->reset = s390_machine_reset;
>      mc->hot_add_cpu = s390_hot_add_cpu;
> @@ -305,6 +306,11 @@ bool gs_allowed(void)
>      return false;
>  }
>  
> +bool ais_allowed(void)
> +{
> +    return get_machine_class()->ais_allowed;
> +}
> +
>  static char *machine_get_loadparm(Object *obj, Error **errp)
>  {
>      S390CcwMachineState *ms = S390_CCW_MACHINE(obj);
> @@ -533,6 +539,7 @@ static void ccw_machine_2_9_class_options(MachineClass *mc)
>      S390CcwMachineClass *s390mc = S390_MACHINE_CLASS(mc);
>  
>      s390mc->gs_allowed = false;
> +    s390mc->ais_allowed = false;
>      ccw_machine_2_10_class_options(mc);
>      SET_MACHINE_COMPAT(mc, CCW_COMPAT_2_9);
>      s390mc->css_migration_enabled = false;
> diff --git a/include/hw/s390x/s390-virtio-ccw.h b/include/hw/s390x/s390-virtio-ccw.h
> index 41a9d28..bba8660 100644
> --- a/include/hw/s390x/s390-virtio-ccw.h
> +++ b/include/hw/s390x/s390-virtio-ccw.h
> @@ -41,6 +41,7 @@ typedef struct S390CcwMachineClass {
>      bool cpu_model_allowed;
>      bool css_migration_enabled;
>      bool gs_allowed;
> +    bool ais_allowed;
>  } S390CcwMachineClass;
>  
>  /* runtime-instrumentation allowed by the machine */
> @@ -49,6 +50,8 @@ bool ri_allowed(void);
>  bool cpu_model_allowed(void);
>  /* guarded-storage allowed by the machine */
>  bool gs_allowed(void);
> +/* ais allowed by the machine */
> +bool ais_allowed(void);
>  
>  /**
>   * Returns true if (vmstate based) migration of the channel subsystem
> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
> index c4c5791..531d474 100644
> --- a/target/s390x/kvm.c
> +++ b/target/s390x/kvm.c
> @@ -309,7 +309,9 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
>      }
>  
>      /* Try to enable AIS facility */
> -    kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0);
> +    if (ais_allowed()) {
> +       kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0);
> +    }
>  
>      qemu_mutex_init(&qemu_sigp_mutex);
>

Re: [Qemu-devel] block ais migration for machines <= 2.9

Posted by Christian Borntraeger 8 years, 1 month ago


On 09/20/2017 02:59 PM, Cornelia Huck wrote:
> On Wed, 20 Sep 2017 14:53:07 +0200
> Christian Borntraeger <borntraeger@de.ibm.com> wrote:
> 
>> Something like the following seems to do the tricks.
>> Needs proper patch description, review, full test with different kernel versions.....
> 
> Looks sane.
> 
> Will you handle it?


Yes, I will do more testing etc and then send a proper version.

Re: [Qemu-devel] block ais migration for machines <= 2.9

Posted by Dr. David Alan Gilbert 8 years, 1 month ago

* Christian Borntraeger (borntraeger@de.ibm.com) wrote:
> Something like the following seems to do the tricks.
> Needs proper patch description, review, full test with different kernel versions.....

Without knowing anything about 'ais' - will this break migration from
2.10 -> 2.10+this fix?

Dave

> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
> index 1c7af39..2ff32ba 100644
> --- a/hw/s390x/s390-virtio-ccw.c
> +++ b/hw/s390x/s390-virtio-ccw.c
> @@ -212,6 +212,7 @@ static void ccw_machine_class_init(ObjectClass *oc, void *data)
>      s390mc->cpu_model_allowed = true;
>      s390mc->css_migration_enabled = true;
>      s390mc->gs_allowed = true;
> +    s390mc->ais_allowed = true;
>      mc->init = ccw_init;
>      mc->reset = s390_machine_reset;
>      mc->hot_add_cpu = s390_hot_add_cpu;
> @@ -305,6 +306,11 @@ bool gs_allowed(void)
>      return false;
>  }
>  
> +bool ais_allowed(void)
> +{
> +    return get_machine_class()->ais_allowed;
> +}
> +
>  static char *machine_get_loadparm(Object *obj, Error **errp)
>  {
>      S390CcwMachineState *ms = S390_CCW_MACHINE(obj);
> @@ -533,6 +539,7 @@ static void ccw_machine_2_9_class_options(MachineClass *mc)
>      S390CcwMachineClass *s390mc = S390_MACHINE_CLASS(mc);
>  
>      s390mc->gs_allowed = false;
> +    s390mc->ais_allowed = false;
>      ccw_machine_2_10_class_options(mc);
>      SET_MACHINE_COMPAT(mc, CCW_COMPAT_2_9);
>      s390mc->css_migration_enabled = false;
> diff --git a/include/hw/s390x/s390-virtio-ccw.h b/include/hw/s390x/s390-virtio-ccw.h
> index 41a9d28..bba8660 100644
> --- a/include/hw/s390x/s390-virtio-ccw.h
> +++ b/include/hw/s390x/s390-virtio-ccw.h
> @@ -41,6 +41,7 @@ typedef struct S390CcwMachineClass {
>      bool cpu_model_allowed;
>      bool css_migration_enabled;
>      bool gs_allowed;
> +    bool ais_allowed;
>  } S390CcwMachineClass;
>  
>  /* runtime-instrumentation allowed by the machine */
> @@ -49,6 +50,8 @@ bool ri_allowed(void);
>  bool cpu_model_allowed(void);
>  /* guarded-storage allowed by the machine */
>  bool gs_allowed(void);
> +/* ais allowed by the machine */
> +bool ais_allowed(void);
>  
>  /**
>   * Returns true if (vmstate based) migration of the channel subsystem
> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
> index c4c5791..531d474 100644
> --- a/target/s390x/kvm.c
> +++ b/target/s390x/kvm.c
> @@ -309,7 +309,9 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
>      }
>  
>      /* Try to enable AIS facility */
> -    kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0);
> +    if (ais_allowed()) {
> +       kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0);
> +    }
>  
>      qemu_mutex_init(&qemu_sigp_mutex);
> 
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Re: [Qemu-devel] block ais migration for machines <= 2.9

Posted by Yi Min Zhao 8 years, 1 month ago


在 2017/9/21 上午12:04, Dr. David Alan Gilbert 写道:
> * Christian Borntraeger (borntraeger@de.ibm.com) wrote:
>> Something like the following seems to do the tricks.
>> Needs proper patch description, review, full test with different kernel versions.....
> Without knowing anything about 'ais' - will this break migration from
> 2.10 -> 2.10+this fix?
I think it doesn't break. I will have a try later.
>
> Dave
>
>> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
>> index 1c7af39..2ff32ba 100644
>> --- a/hw/s390x/s390-virtio-ccw.c
>> +++ b/hw/s390x/s390-virtio-ccw.c
>> @@ -212,6 +212,7 @@ static void ccw_machine_class_init(ObjectClass *oc, void *data)
>>       s390mc->cpu_model_allowed = true;
>>       s390mc->css_migration_enabled = true;
>>       s390mc->gs_allowed = true;
>> +    s390mc->ais_allowed = true;
>>       mc->init = ccw_init;
>>       mc->reset = s390_machine_reset;
>>       mc->hot_add_cpu = s390_hot_add_cpu;
>> @@ -305,6 +306,11 @@ bool gs_allowed(void)
>>       return false;
>>   }
>>   
>> +bool ais_allowed(void)
>> +{
>> +    return get_machine_class()->ais_allowed;
>> +}
>> +
>>   static char *machine_get_loadparm(Object *obj, Error **errp)
>>   {
>>       S390CcwMachineState *ms = S390_CCW_MACHINE(obj);
>> @@ -533,6 +539,7 @@ static void ccw_machine_2_9_class_options(MachineClass *mc)
>>       S390CcwMachineClass *s390mc = S390_MACHINE_CLASS(mc);
>>   
>>       s390mc->gs_allowed = false;
>> +    s390mc->ais_allowed = false;
>>       ccw_machine_2_10_class_options(mc);
>>       SET_MACHINE_COMPAT(mc, CCW_COMPAT_2_9);
>>       s390mc->css_migration_enabled = false;
>> diff --git a/include/hw/s390x/s390-virtio-ccw.h b/include/hw/s390x/s390-virtio-ccw.h
>> index 41a9d28..bba8660 100644
>> --- a/include/hw/s390x/s390-virtio-ccw.h
>> +++ b/include/hw/s390x/s390-virtio-ccw.h
>> @@ -41,6 +41,7 @@ typedef struct S390CcwMachineClass {
>>       bool cpu_model_allowed;
>>       bool css_migration_enabled;
>>       bool gs_allowed;
>> +    bool ais_allowed;
>>   } S390CcwMachineClass;
>>   
>>   /* runtime-instrumentation allowed by the machine */
>> @@ -49,6 +50,8 @@ bool ri_allowed(void);
>>   bool cpu_model_allowed(void);
>>   /* guarded-storage allowed by the machine */
>>   bool gs_allowed(void);
>> +/* ais allowed by the machine */
>> +bool ais_allowed(void);
>>   
>>   /**
>>    * Returns true if (vmstate based) migration of the channel subsystem
>> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
>> index c4c5791..531d474 100644
>> --- a/target/s390x/kvm.c
>> +++ b/target/s390x/kvm.c
>> @@ -309,7 +309,9 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
>>       }
>>   
>>       /* Try to enable AIS facility */
>> -    kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0);
>> +    if (ais_allowed()) {
>> +       kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0);
>> +    }
>>   
>>       qemu_mutex_init(&qemu_sigp_mutex);
>>
>>
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
>
>

Re: [Qemu-devel] block ais migration for machines <= 2.9

Posted by Christian Borntraeger 8 years, 1 month ago

On 09/20/2017 06:04 PM, Dr. David Alan Gilbert wrote:
> * Christian Borntraeger (borntraeger@de.ibm.com) wrote:
>> Something like the following seems to do the tricks.
>> Needs proper patch description, review, full test with different kernel versions.....
> 
> Without knowing anything about 'ais' - will this break migration from
> 2.10 -> 2.10+this fix?

The problem only happens if the source system has kernel >= 4.12 thats why it
somehow missed my testing during the 2.10 freeze.

Now: "2.10" -> "2.10+this fix" will works fine for the 2.10 machine, but it does 
fail for the combination of qemu-2.10 with an older machine type like 2.8 and 2.9.

qemu-system-s390x: Failed to load s390-flic/ais:tmp
qemu-system-s390x: error while loading state for instance 0x0 of device 's390-flic'
qemu-system-s390x: load of migration failed: Function not implemented

We do run into an explicit check from hw/intc/s390_flic_kvm.c (see the return ENOSYS)

e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 443) static int kvm_flic_ais_post_load(void *opaque, int version_id)
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 444) {
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 445)     KVMS390FLICStateMigTmp *tmp = opaque;
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 446)     KVMS390FLICState *flic = tmp->parent;
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 447)     struct kvm_s390_ais_all ais = {
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 448)         .simm = tmp->simm,
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 449)         .nimm = tmp->nimm,
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 450)     };
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 451)     struct kvm_device_attr attr = {
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 452)         .group = KVM_DEV_FLIC_AISM_ALL,
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 453)         .addr = (uint64_t)&ais,
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 454)     };
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 455) 
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 456)     /* This can happen when the user mis-configures its guests in an
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 457)      * incompatible fashion or without a CPU model. For example using
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 458)      * qemu with -cpu host (which is not migration safe) and do a
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 459)      * migration from a host that has AIS to a host that has no AIS.
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 460)      * In that case the target system will reject the migration here.
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 461)      */
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 462)     if (!ais_needed(flic)) {
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 463)         return -ENOSYS;
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 464)     }
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 465) 
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 466)     return ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr) ? -errno : 0;
e7be8d49 (Yi Min Zhao       2017-05-16 18:58:44 +0800 467) }

So I think if we fix this we should definitely add this to 2.10.1 
to minimize the affected qemu versions. Not fixing it will break
migrations from 4.12/2.10 to older versions. 
 
> 
> Dave
> 
>> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
>> index 1c7af39..2ff32ba 100644
>> --- a/hw/s390x/s390-virtio-ccw.c
>> +++ b/hw/s390x/s390-virtio-ccw.c
>> @@ -212,6 +212,7 @@ static void ccw_machine_class_init(ObjectClass *oc, void *data)
>>      s390mc->cpu_model_allowed = true;
>>      s390mc->css_migration_enabled = true;
>>      s390mc->gs_allowed = true;
>> +    s390mc->ais_allowed = true;
>>      mc->init = ccw_init;
>>      mc->reset = s390_machine_reset;
>>      mc->hot_add_cpu = s390_hot_add_cpu;
>> @@ -305,6 +306,11 @@ bool gs_allowed(void)
>>      return false;
>>  }
>>  
>> +bool ais_allowed(void)
>> +{
>> +    return get_machine_class()->ais_allowed;
>> +}
>> +
>>  static char *machine_get_loadparm(Object *obj, Error **errp)
>>  {
>>      S390CcwMachineState *ms = S390_CCW_MACHINE(obj);
>> @@ -533,6 +539,7 @@ static void ccw_machine_2_9_class_options(MachineClass *mc)
>>      S390CcwMachineClass *s390mc = S390_MACHINE_CLASS(mc);
>>  
>>      s390mc->gs_allowed = false;
>> +    s390mc->ais_allowed = false;
>>      ccw_machine_2_10_class_options(mc);
>>      SET_MACHINE_COMPAT(mc, CCW_COMPAT_2_9);
>>      s390mc->css_migration_enabled = false;
>> diff --git a/include/hw/s390x/s390-virtio-ccw.h b/include/hw/s390x/s390-virtio-ccw.h
>> index 41a9d28..bba8660 100644
>> --- a/include/hw/s390x/s390-virtio-ccw.h
>> +++ b/include/hw/s390x/s390-virtio-ccw.h
>> @@ -41,6 +41,7 @@ typedef struct S390CcwMachineClass {
>>      bool cpu_model_allowed;
>>      bool css_migration_enabled;
>>      bool gs_allowed;
>> +    bool ais_allowed;
>>  } S390CcwMachineClass;
>>  
>>  /* runtime-instrumentation allowed by the machine */
>> @@ -49,6 +50,8 @@ bool ri_allowed(void);
>>  bool cpu_model_allowed(void);
>>  /* guarded-storage allowed by the machine */
>>  bool gs_allowed(void);
>> +/* ais allowed by the machine */
>> +bool ais_allowed(void);
>>  
>>  /**
>>   * Returns true if (vmstate based) migration of the channel subsystem
>> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
>> index c4c5791..531d474 100644
>> --- a/target/s390x/kvm.c
>> +++ b/target/s390x/kvm.c
>> @@ -309,7 +309,9 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
>>      }
>>  
>>      /* Try to enable AIS facility */
>> -    kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0);
>> +    if (ais_allowed()) {
>> +       kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0);
>> +    }
>>  
>>      qemu_mutex_init(&qemu_sigp_mutex);
>>
>>
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
>

Re: [Qemu-devel] block ais migration for machines <= 2.9

Posted by no-reply@patchew.org 8 years, 1 month ago

Hi,

This series seems to have some coding style problems. See output below for
more information:

Subject: [Qemu-devel] block ais migration for machines <= 2.9
Message-id: f6da1ec7-4845-fe78-b6b8-29a71d481458@de.ibm.com
Type: series

=== TEST SCRIPT BEGIN ===
#!/bin/bash

BASE=base
n=1
total=$(git log --oneline $BASE.. | wc -l)
failed=0

git config --local diff.renamelimit 0
git config --local diff.renames True

commits="$(git log --format=%H --reverse $BASE..)"
for c in $commits; do
    echo "Checking PATCH $n/$total: $(git log -n 1 --format=%s $c)..."
    if ! git show $c --format=email | ./scripts/checkpatch.pl --mailback -; then
        failed=1
        echo
    fi
    n=$((n+1))
done

exit $failed
=== TEST SCRIPT END ===

Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
Switched to a new branch 'test'
c0b3083c71 block ais migration for machines <= 2.9

=== OUTPUT BEGIN ===
Checking PATCH 1/1: block ais migration for machines <= 2.9...
ERROR: suspect code indent for conditional statements (4, 7)
#73: FILE: target/s390x/kvm.c:315:
+    if (ais_allowed()) {
+       kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0);

ERROR: Missing Signed-off-by: line(s)

total: 2 errors, 0 warnings, 50 lines checked

Your patch has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.

=== OUTPUT END ===

Test command exited with code: 1


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