bhyve supports passing disk serial number using the "ser=<SN>"
option, so update bhyveBuildAHCIControllerArgStr() to set it
from the "serial" element.

Closes: https://gitlab.com/libvirt/libvirt/-/work_items/901
Signed-off-by: Roman Bogorodskiy <bogorodskiy@gmail.com>
---
 src/bhyve/bhyve_command.c                                      | 3 +++
 .../x86_64/bhyvexml2argv-sata-rotation-rate.args               | 2 +-
 .../x86_64/bhyvexml2argv-sata-rotation-rate.xml                | 3 +++
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/bhyve/bhyve_command.c b/src/bhyve/bhyve_command.c
index a4f9c8823b..f0c3cf03c5 100644
--- a/src/bhyve/bhyve_command.c
+++ b/src/bhyve/bhyve_command.c
@@ -333,6 +333,9 @@ bhyveBuildAHCIControllerArgStr(const virDomainDef *def,
         if (disk->rotation_rate)
             virBufferAsprintf(&device, ",nmrr=%u", disk->rotation_rate);
 
+        if (disk->serial)
+            virBufferAsprintf(&device, ",ser=%s", disk->serial);
+
         virBufferAddBuffer(&buf, &device);
     }
 
diff --git a/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-sata-rotation-rate.args b/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-sata-rotation-rate.args
index 2cf40953e8..3ae510e2ed 100644
--- a/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-sata-rotation-rate.args
+++ b/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-sata-rotation-rate.args
@@ -5,6 +5,6 @@ bhyve \
 -H \
 -P \
 -s 0:0,hostbridge \
--s 2:0,ahci,hd:/tmp/freebsd1.img,nmrr=7200,hd:/tmp/freebsd2.img,nmrr=5400,hd:/tmp/freebsd3.img,nmrr=1 \
+-s 2:0,ahci,hd:/tmp/freebsd1.img,nmrr=7200,ser=BHYVE-SER01-0001,hd:/tmp/freebsd2.img,nmrr=5400,ser=BHYVE-SER02-0004,hd:/tmp/freebsd3.img,nmrr=1,ser=BHYVE-SER03-1234 \
 -s 3:0,virtio-net,faketapdev,mac=52:54:00:b9:94:02 \
 bhyve
diff --git a/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-sata-rotation-rate.xml b/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-sata-rotation-rate.xml
index a0d80cb908..ed6da8e317 100644
--- a/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-sata-rotation-rate.xml
+++ b/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-sata-rotation-rate.xml
@@ -8,16 +8,19 @@
   </os>
   <devices>
     <disk type='file'>
+      <serial>BHYVE-SER01-0001</serial>
       <driver name='file' type='raw'/>
       <source file='/tmp/freebsd1.img'/>
       <target dev='hda' bus='sata' rotation_rate='7200'/>
     </disk>
     <disk type='file'>
+      <serial>BHYVE-SER02-0004</serial>
       <driver name='file' type='raw'/>
       <source file='/tmp/freebsd2.img'/>
       <target dev='hdb' bus='sata' rotation_rate='5400'/>
     </disk>
     <disk type='file'>
+      <serial>BHYVE-SER03-1234</serial>
       <driver name='file' type='raw'/>
       <source file='/tmp/freebsd3.img'/>
       <target dev='hdc' bus='sata' rotation_rate='1'/>
-- 
2.52.0

On Fri, Jul 31, 2026 at 19:52:03 +0200, Roman Bogorodskiy wrote:
> bhyve supports passing disk serial number using the "ser=<SN>"
> option, so update bhyveBuildAHCIControllerArgStr() to set it
> from the "serial" element.
> 
> Closes: https://gitlab.com/libvirt/libvirt/-/work_items/901
> Signed-off-by: Roman Bogorodskiy <bogorodskiy@gmail.com>
> ---
>  src/bhyve/bhyve_command.c                                      | 3 +++
>  .../x86_64/bhyvexml2argv-sata-rotation-rate.args               | 2 +-
>  .../x86_64/bhyvexml2argv-sata-rotation-rate.xml                | 3 +++
>  3 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/src/bhyve/bhyve_command.c b/src/bhyve/bhyve_command.c
> index a4f9c8823b..f0c3cf03c5 100644
> --- a/src/bhyve/bhyve_command.c
> +++ b/src/bhyve/bhyve_command.c
> @@ -333,6 +333,9 @@ bhyveBuildAHCIControllerArgStr(const virDomainDef *def,
>          if (disk->rotation_rate)
>              virBufferAsprintf(&device, ",nmrr=%u", disk->rotation_rate);
>  
> +        if (disk->serial)
> +            virBufferAsprintf(&device, ",ser=%s", disk->serial);

Note that libvirt doesn't enforce any length limits for 'serial' value.

In qemu it gets silently truncated to the size that qemu supports (which
may or may not conform to the "physical"/protocol specification limits.

We had trouble with that in the past when qemu changed the truncation.

How does bhyve behave here?

  Peter Krempa wrote:

> On Fri, Jul 31, 2026 at 19:52:03 +0200, Roman Bogorodskiy wrote:
> > bhyve supports passing disk serial number using the "ser=<SN>"
> > option, so update bhyveBuildAHCIControllerArgStr() to set it
> > from the "serial" element.
> > 
> > Closes: https://gitlab.com/libvirt/libvirt/-/work_items/901
> > Signed-off-by: Roman Bogorodskiy <bogorodskiy@gmail.com>
> > ---
> >  src/bhyve/bhyve_command.c                                      | 3 +++
> >  .../x86_64/bhyvexml2argv-sata-rotation-rate.args               | 2 +-
> >  .../x86_64/bhyvexml2argv-sata-rotation-rate.xml                | 3 +++
> >  3 files changed, 7 insertions(+), 1 deletion(-)
> > 
> > diff --git a/src/bhyve/bhyve_command.c b/src/bhyve/bhyve_command.c
> > index a4f9c8823b..f0c3cf03c5 100644
> > --- a/src/bhyve/bhyve_command.c
> > +++ b/src/bhyve/bhyve_command.c
> > @@ -333,6 +333,9 @@ bhyveBuildAHCIControllerArgStr(const virDomainDef *def,
> >          if (disk->rotation_rate)
> >              virBufferAsprintf(&device, ",nmrr=%u", disk->rotation_rate);
> >  
> > +        if (disk->serial)
> > +            virBufferAsprintf(&device, ",ser=%s", disk->serial);
> 
> Note that libvirt doesn't enforce any length limits for 'serial' value.
> 
> In qemu it gets silently truncated to the size that qemu supports (which
> may or may not conform to the "physical"/protocol specification limits.
> 
> We had trouble with that in the past when qemu changed the truncation.
> 
> How does bhyve behave here?

Bhyve mentions 20 character limits for both AHCI and NVMe. It also
silently truncates the user provided value to this 20 char limit.

It does not _seem_ that this limit is going to change for AHCI and NVMe.