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[libvirt] [PATCH v2 2/2] domain_conf: Relax SCSI addr used check

Michal Privoznik posted 2 patches 6 years, 5 months ago
[libvirt] [PATCH v2 2/2] domain_conf: Relax SCSI addr used check
Posted by Michal Privoznik 6 years, 5 months ago 
In domain_conf.c we have virDomainSCSIDriveAddressIsUsed()
function which returns true or false if given drive address is
already in use for given domain config or not. However, it also
takes a shortcut and returns true (meaning address in use) if the
unit number equals 7. This is because for some controllers this
is reserved address. The limitation comes mostly from vmware and
applies to lsilogic, buslogic, spapr-vscsi and vmpvscsi models.
On the other hand, we were not checking for the maximum unit
number (aka LUN number) which is also relevant and differs from
model to model.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
---
 src/conf/domain_conf.c | 53 ++++++++++++++++++++++++++++++++++++++----
 1 file changed, 48 insertions(+), 5 deletions(-)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 69c486f382..3e7603891f 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -4813,11 +4813,54 @@ bool
 virDomainSCSIDriveAddressIsUsed(const virDomainDef *def,
                                 const virDomainDeviceDriveAddress *addr)
 {
-    /* In current implementation, the maximum unit number of a controller
-     * is either 16 or 7 (narrow SCSI bus), and if the maximum unit number
-     * is 16, the controller itself is on unit 7 */
-    if (addr->unit == 7)
-        return true;
+    const virDomainControllerDef *cont;
+
+    cont = virDomainDeviceFindSCSIController(def, addr);
+    if (cont) {
+        int max = -1;
+        int reserved = -1;
+
+        /* Different controllers have different limits. These limits here are
+         * taken from QEMU source code, but nevertheless they should apply to
+         * other hypervisors too. */
+        switch ((virDomainControllerModelSCSI) cont->model) {
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VIRTIO_SCSI:
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VIRTIO_TRANSITIONAL:
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VIRTIO_NON_TRANSITIONAL:
+            max = 16383;
+            break;
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_IBMVSCSI:
+            max = 31;
+            reserved = 7;
+            break;
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LSISAS1068:
+            max = 1;
+            break;
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LSISAS1078:
+            max = 255;
+            break;
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LSILOGIC:
+            max = 0;
+            reserved = 7;
+            break;
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VMPVSCSI:
+            max = 0;
+            reserved = 7;
+            break;
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_BUSLOGIC:
+            reserved = 7;
+            break;
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_DEFAULT:
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_AUTO:
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LAST:
+            break;
+        }
+
+        if (max != -1 && addr->unit >= max)
+            return true;
+        if (reserved != -1 && addr->unit == reserved)
+            return true;
+    }
 
     if (virDomainDriveAddressIsUsedByDisk(def, VIR_DOMAIN_DISK_BUS_SCSI,
                                           addr) ||
-- 
2.21.0

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Re: [libvirt] [PATCH v2 2/2] domain_conf: Relax SCSI addr used check
Posted by Daniel P. Berrangé 6 years, 5 months ago 
On Wed, Sep 11, 2019 at 03:17:42PM +0200, Michal Privoznik wrote:
> In domain_conf.c we have virDomainSCSIDriveAddressIsUsed()
> function which returns true or false if given drive address is
> already in use for given domain config or not. However, it also
> takes a shortcut and returns true (meaning address in use) if the
> unit number equals 7. This is because for some controllers this
> is reserved address. The limitation comes mostly from vmware and
> applies to lsilogic, buslogic, spapr-vscsi and vmpvscsi models.
> On the other hand, we were not checking for the maximum unit
> number (aka LUN number) which is also relevant and differs from
> model to model.
> 
> Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
> ---
>  src/conf/domain_conf.c | 53 ++++++++++++++++++++++++++++++++++++++----
>  1 file changed, 48 insertions(+), 5 deletions(-)
> 
> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
> index 69c486f382..3e7603891f 100644
> --- a/src/conf/domain_conf.c
> +++ b/src/conf/domain_conf.c
> @@ -4813,11 +4813,54 @@ bool
>  virDomainSCSIDriveAddressIsUsed(const virDomainDef *def,
>                                  const virDomainDeviceDriveAddress *addr)
>  {
> -    /* In current implementation, the maximum unit number of a controller
> -     * is either 16 or 7 (narrow SCSI bus), and if the maximum unit number
> -     * is 16, the controller itself is on unit 7 */
> -    if (addr->unit == 7)
> -        return true;
> +    const virDomainControllerDef *cont;
> +
> +    cont = virDomainDeviceFindSCSIController(def, addr);
> +    if (cont) {
> +        int max = -1;
> +        int reserved = -1;
> +
> +        /* Different controllers have different limits. These limits here are
> +         * taken from QEMU source code, but nevertheless they should apply to
> +         * other hypervisors too. */
> +        switch ((virDomainControllerModelSCSI) cont->model) {
> +        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VIRTIO_SCSI:
> +        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VIRTIO_TRANSITIONAL:
> +        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VIRTIO_NON_TRANSITIONAL:
> +            max = 16383;
> +            break;
> +        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_IBMVSCSI:
> +            max = 31;
> +            reserved = 7;
> +            break;
> +        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LSISAS1068:
> +            max = 1;
> +            break;
> +        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LSISAS1078:
> +            max = 255;
> +            break;
> +        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LSILOGIC:
> +            max = 0;

        Surely this ^^^ means....

> +        if (max != -1 && addr->unit >= max)
> +            return true;

...this is always true and so we'll be unable to attach
a drive to any LUN at all.

> +        if (reserved != -1 && addr->unit == reserved)
> +            return true;
> +    }
>  
>      if (virDomainDriveAddressIsUsedByDisk(def, VIR_DOMAIN_DISK_BUS_SCSI,
>                                            addr) ||

Regards,
Daniel
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Re: [libvirt] [PATCH v2 2/2] domain_conf: Relax SCSI addr used check
Posted by Michal Privoznik 6 years, 5 months ago 
On 9/11/19 3:24 PM, Daniel P. Berrangé wrote:
> On Wed, Sep 11, 2019 at 03:17:42PM +0200, Michal Privoznik wrote:
>> In domain_conf.c we have virDomainSCSIDriveAddressIsUsed()
>> function which returns true or false if given drive address is
>> already in use for given domain config or not. However, it also
>> takes a shortcut and returns true (meaning address in use) if the
>> unit number equals 7. This is because for some controllers this
>> is reserved address. The limitation comes mostly from vmware and
>> applies to lsilogic, buslogic, spapr-vscsi and vmpvscsi models.
>> On the other hand, we were not checking for the maximum unit
>> number (aka LUN number) which is also relevant and differs from
>> model to model.
>>
>> Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
>> ---
>>   src/conf/domain_conf.c | 53 ++++++++++++++++++++++++++++++++++++++----
>>   1 file changed, 48 insertions(+), 5 deletions(-)
>>
>> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
>> index 69c486f382..3e7603891f 100644
>> --- a/src/conf/domain_conf.c
>> +++ b/src/conf/domain_conf.c
>> @@ -4813,11 +4813,54 @@ bool
>>   virDomainSCSIDriveAddressIsUsed(const virDomainDef *def,
>>                                   const virDomainDeviceDriveAddress *addr)
>>   {
>> -    /* In current implementation, the maximum unit number of a controller
>> -     * is either 16 or 7 (narrow SCSI bus), and if the maximum unit number
>> -     * is 16, the controller itself is on unit 7 */
>> -    if (addr->unit == 7)
>> -        return true;
>> +    const virDomainControllerDef *cont;
>> +
>> +    cont = virDomainDeviceFindSCSIController(def, addr);
>> +    if (cont) {
>> +        int max = -1;
>> +        int reserved = -1;
>> +
>> +        /* Different controllers have different limits. These limits here are
>> +         * taken from QEMU source code, but nevertheless they should apply to
>> +         * other hypervisors too. */
>> +        switch ((virDomainControllerModelSCSI) cont->model) {
>> +        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VIRTIO_SCSI:
>> +        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VIRTIO_TRANSITIONAL:
>> +        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VIRTIO_NON_TRANSITIONAL:
>> +            max = 16383;
>> +            break;
>> +        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_IBMVSCSI:
>> +            max = 31;
>> +            reserved = 7;
>> +            break;
>> +        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LSISAS1068:
>> +            max = 1;
>> +            break;
>> +        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LSISAS1078:
>> +            max = 255;
>> +            break;
>> +        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LSILOGIC:
>> +            max = 0;
> 
>          Surely this ^^^ means....
> 
>> +        if (max != -1 && addr->unit >= max)
>> +            return true;
> 
> ...this is always true and so we'll be unable to attach
> a drive to any LUN at all.

Ah, good catch. Looks like I've misread qemu's sorce code. Conside this squashed in:

diff --git i/src/conf/domain_conf.c w/src/conf/domain_conf.c
index 3e7603891f..31cff38ae3 100644
--- i/src/conf/domain_conf.c
+++ w/src/conf/domain_conf.c
@@ -4840,11 +4840,9 @@ virDomainSCSIDriveAddressIsUsed(const virDomainDef *def,
             max = 255;
             break;
         case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LSILOGIC:
-            max = 0;
             reserved = 7;
             break;
         case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VMPVSCSI:
-            max = 0;
             reserved = 7;
             break;
         case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_BUSLOGIC:


Michal

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Re: [libvirt] [PATCH v2 2/2] domain_conf: Relax SCSI addr used check
Posted by Daniel P. Berrangé 6 years, 3 months ago 
On Wed, Sep 11, 2019 at 05:16:31PM +0200, Michal Privoznik wrote:
> On 9/11/19 3:24 PM, Daniel P. Berrangé wrote:
> > On Wed, Sep 11, 2019 at 03:17:42PM +0200, Michal Privoznik wrote:
> >> In domain_conf.c we have virDomainSCSIDriveAddressIsUsed()
> >> function which returns true or false if given drive address is
> >> already in use for given domain config or not. However, it also
> >> takes a shortcut and returns true (meaning address in use) if the
> >> unit number equals 7. This is because for some controllers this
> >> is reserved address. The limitation comes mostly from vmware and
> >> applies to lsilogic, buslogic, spapr-vscsi and vmpvscsi models.
> >> On the other hand, we were not checking for the maximum unit
> >> number (aka LUN number) which is also relevant and differs from
> >> model to model.
> >>
> >> Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
> >> ---
> >>   src/conf/domain_conf.c | 53 ++++++++++++++++++++++++++++++++++++++----
> >>   1 file changed, 48 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
> >> index 69c486f382..3e7603891f 100644
> >> --- a/src/conf/domain_conf.c
> >> +++ b/src/conf/domain_conf.c
> >> @@ -4813,11 +4813,54 @@ bool
> >>   virDomainSCSIDriveAddressIsUsed(const virDomainDef *def,
> >>                                   const virDomainDeviceDriveAddress *addr)
> >>   {
> >> -    /* In current implementation, the maximum unit number of a controller
> >> -     * is either 16 or 7 (narrow SCSI bus), and if the maximum unit number
> >> -     * is 16, the controller itself is on unit 7 */
> >> -    if (addr->unit == 7)
> >> -        return true;
> >> +    const virDomainControllerDef *cont;
> >> +
> >> +    cont = virDomainDeviceFindSCSIController(def, addr);
> >> +    if (cont) {
> >> +        int max = -1;
> >> +        int reserved = -1;
> >> +
> >> +        /* Different controllers have different limits. These limits here are
> >> +         * taken from QEMU source code, but nevertheless they should apply to
> >> +         * other hypervisors too. */
> >> +        switch ((virDomainControllerModelSCSI) cont->model) {
> >> +        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VIRTIO_SCSI:
> >> +        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VIRTIO_TRANSITIONAL:
> >> +        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VIRTIO_NON_TRANSITIONAL:
> >> +            max = 16383;
> >> +            break;
> >> +        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_IBMVSCSI:
> >> +            max = 31;
> >> +            reserved = 7;
> >> +            break;
> >> +        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LSISAS1068:
> >> +            max = 1;
> >> +            break;
> >> +        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LSISAS1078:
> >> +            max = 255;
> >> +            break;
> >> +        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LSILOGIC:
> >> +            max = 0;
> > 
> >          Surely this ^^^ means....
> > 
> >> +        if (max != -1 && addr->unit >= max)
> >> +            return true;
> > 
> > ...this is always true and so we'll be unable to attach
> > a drive to any LUN at all.
> 
> Ah, good catch. Looks like I've misread qemu's sorce code. Conside this squashed in:
> 
> diff --git i/src/conf/domain_conf.c w/src/conf/domain_conf.c
> index 3e7603891f..31cff38ae3 100644
> --- i/src/conf/domain_conf.c
> +++ w/src/conf/domain_conf.c
> @@ -4840,11 +4840,9 @@ virDomainSCSIDriveAddressIsUsed(const virDomainDef *def,
>              max = 255;
>              break;
>          case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LSILOGIC:
> -            max = 0;
>              reserved = 7;
>              break;
>          case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VMPVSCSI:
> -            max = 0;
>              reserved = 7;
>              break;
>          case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_BUSLOGIC:

With that

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

Regards,
Daniel
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