Dear Linux folks,


In QEMU 2.11 a disk is only detected by the AHCI driver and not by 
libata. On QEMU’s Standard PC (i440FX + PIIX, 1996), that causes an 
attached drive not to be detected as that machine doesn’t support AHCI.

Here is the output with the machine Standard PC (Q35 + ICH9, 2009), 
which does have AHCI support.

> $ qemu-system-x86_64 -enable-kvm -M q35 -m 1G -serial stdio -hda /dev/shm/qemu-debian.img -kernel bzImage -append "console=ttyS0,115200 console=tty0" -initrd initrd.cpio.xz
> WARNING: Image format was not specified for '/dev/shm/qemu-debian.img' and probing guessed raw.
>          Automatically detecting the format is dangerous for raw images, write operations on block 0 will be restricted.
>          Specify the 'raw' format explicitly to remove the restrictions.
> qemu-system-x86_64: warning: host doesn't support requested feature: CPUID.80000001H:ECX.svm [bit 2]
> [    0.000000] Linux version 4.17.0-rc4-heads+ (pmenzel@bohemianrhapsody.molgen.mpg.de) (gcc version 7.3.0 (GCC)) #1 SMP Sun May 13 10:11:43 CEST 2018
> [    0.000000] Command line: console=ttyS0,115200 console=tty0
> […]
> [    0.250239] SCSI subsystem initialized
> [    0.252012] libata version 3.00 loaded.
> […]
> [    0.633761] ahci 0000:00:1f.2: version 3.0
> [    0.635808] PCI Interrupt Link [LNKA] enabled at IRQ 10
> [    0.637935] PCI: setting IRQ 10 as level-triggered
> [    0.641276] ahci 0000:00:1f.2: AHCI 0001.0000 32 slots 6 ports 1.5 Gbps 0x3f impl SATA mode
> [    0.644598] ahci 0000:00:1f.2: flags: 64bit ncq only 
> [    0.647877] scsi host0: ahci
> [    0.649254] scsi host1: ahci
> [    0.650591] scsi host2: ahci
> [    0.652075] scsi host3: ahci
> [    0.653497] scsi host4: ahci
> [    0.654775] scsi host5: ahci
> [    0.656414] ata1: SATA max UDMA/133 abar m4096@0xfebb1000 port 0xfebb1100 irq 24
> [    0.659847] ata2: SATA max UDMA/133 abar m4096@0xfebb1000 port 0xfebb1180 irq 24
> [    0.664691] ata3: SATA max UDMA/133 abar m4096@0xfebb1000 port 0xfebb1200 irq 24
> [    0.667730] ata4: SATA max UDMA/133 abar m4096@0xfebb1000 port 0xfebb1280 irq 24
> [    0.670826] ata5: SATA max UDMA/133 abar m4096@0xfebb1000 port 0xfebb1300 irq 24
> [    0.674341] ata6: SATA max UDMA/133 abar m4096@0xfebb1000 port 0xfebb1380 irq 24
> [    0.678009] e1000: Intel(R) PRO/1000 Network Driver - version 7.3.21-k8-NAPI
> [    0.680694] e1000: Copyright (c) 1999-2006 Intel Corporation.
> [    0.683495] PCI Interrupt Link [LNKG] enabled at IRQ 11
> [    0.685429] PCI: setting IRQ 11 as level-triggered
> [    0.996760] ata6: SATA link down (SStatus 0 SControl 300)
> [    0.998724] ata5: SATA link down (SStatus 0 SControl 300)
> [    1.001077] ata4: SATA link down (SStatus 0 SControl 300)
> [    1.003553] ata3: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
> [    1.006047] ata3.00: ATAPI: QEMU DVD-ROM, 2.5+, max UDMA/100
> [    1.008241] ata3.00: applying bridge limits
> [    1.010322] ata2: SATA link down (SStatus 0 SControl 300)
> [    1.012609] ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
> [    1.014864] ata1.00: ATA-7: QEMU HARDDISK, 2.5+, max UDMA/100
> [    1.016994] ata1.00: 6291456 sectors, multi 16: LBA48 NCQ (depth 31/32)
> [    1.019254] ata1.00: applying bridge limits
> [    1.028470] ata3.00: configured for UDMA/100
> [    1.030279] ata1.00: configured for UDMA/100
> [    1.032075] scsi 0:0:0:0: Direct-Access     ATA      QEMU HARDDISK    2.5+ PQ: 0 ANSI: 5
> [    1.040151] sd 0:0:0:0: Attached scsi generic sg0 type 0
> [    1.041985] sd 0:0:0:0: [sda] 6291456 512-byte logical blocks: (3.22 GB/3.00 GiB)
> [    1.045002] sd 0:0:0:0: [sda] Write Protect is off
> [    1.046843] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00
> [    1.049064] scsi 2:0:0:0: CD-ROM            QEMU     QEMU DVD-ROM     2.5+ PQ: 0 ANSI: 5
> [    1.059073] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
> [    1.067126]  sda: sda1
> [    1.068217] sd 0:0:0:0: [sda] Attached SCSI disk
> [    1.074848] sr 2:0:0:0: [sr0] scsi3-mmc drive: 4x/4x cd/rw xa/form2 tray
> [    1.076830] cdrom: Uniform CD-ROM driver Revision: 3.20
> [    1.078760] sr 2:0:0:0: Attached scsi CD-ROM sr0
> [    1.085017] sr 2:0:0:0: Attached scsi generic sg1 type 5

The Debian disk image was built with grml-debootstrap.

     sudo grml-debootstrap --vmfile --vmsize 3G --target 
/dev/shm/qemu-debian.img -r sid

Is that a Linux or QEMU issue?


Kind regards,

Paul