The 00:07.0 refers to the iscsi disk. The seabios debug info is as follows:
init virtio-scsi
phys_alloc zone=0x7ffbfe78 size=4096 align=1000 ret=7ffa7000 (detail=0x7ffa9390)
/7ffa7000\ Start thread
|7ffa7000| found virtio-scsi at 00:07.0
|7ffa7000| phys_alloc zone=0x7ffbfe84 size=55 align=10 ret=7ffdffc0 (detail=0x7ffa8760)
|7ffa7000| pci dev 00:07.0 virtio cap at 0x84 type 5 [pci cfg access]
|7ffa7000| pci dev 00:07.0 virtio cap at 0x70 type 2 bar 4 at 0xfea00000 off +0x3000 [mmio]
|7ffa7000| pci dev 00:07.0 virtio cap at 0x60 type 4 bar 4 at 0xfea00000 off +0x2000 [mmio]
|7ffa7000| pci dev 00:07.0 virtio cap at 0x50 type 3 bar 4 at 0xfea00000 off +0x1000 [mmio]
|7ffa7000| pci dev 00:07.0 virtio cap at 0x40 type 1 bar 4 at 0xfea00000 off +0x0000 [mmio]
|7ffa7000| pci dev 00:07.0 using modern (1.0) virtio mode
|7ffa7000| vp write fea00014 (1) <- 0x0
|7ffa7000| vp read fea01000 (1) -> 0x0
|7ffa7000| vp write fea00014 (1) <- 0x3
|7ffa7000| vp write fea00000 (4) <- 0x0
|7ffa7000| vp read fea00004 (4) -> 0x30000006
|7ffa7000| vp write fea00000 (4) <- 0x1
|7ffa7000| vp read fea00004 (4) -> 0x1
|7ffa7000| vp write fea00008 (4) <- 0x0
|7ffa7000| vp write fea0000c (4) <- 0x0
|7ffa7000| vp write fea00008 (4) <- 0x1
|7ffa7000| vp write fea0000c (4) <- 0x1
|7ffa7000| vp write fea00014 (1) <- 0xb
|7ffa7000| vp read fea00014 (1) -> 0xb
|7ffa7000| WARNING - Unable to allocate resource at vp_find_vq:301!
|7ffa7000| fail to find vq for virtio-scsi 00:07.0
|7ffa7000| vp write fea00014 (1) <- 0x0
|7ffa7000| vp read fea01000 (1) -> 0x0
|7ffa7000| phys_free 7ffdffc0 (detail=0x7ffa8760)
\7ffa7000/ End thread
phys_free 7ffa7000 (detail=0x7ffa9390)