[Sound-open-firmware] Issues with using qemu emulator

[Tomasz Duszynski]

Hi,

I heard about SOF some time ago but did not have time to take a
closer look until now. I decided to start with Qemu and stumbled upon
some problems. Would be great if someone could take a look at attached
logs.

Here's component stack I have at the moment:

1. Linux: branch topic/sof-dev,
	  commit 3c39107 ASoC: topology: Check return value for soc_tplg_pcm_create()
2. SOF: branch sof-dev,
        commit c7d0149 pipeline: fix tasks initialization commit
3. Qemu: branch sof-v4.2
	 commit 8b66b81 qemu: io-bridge: remind users to start DSP first.

I am starting VMs using provided helper scripts i.e xtensa-host.sh
and x86-host.sh (run in that sequence).

Here's what ./xtensa-host.sh shows:

[tdu at home:~/workspace/sof/qemu]$ ./xtensa-host.sh byt
./xtensa-softmmu/qemu-system-xtensa -cpu baytrail -M adsp_byt -nographic -S
bridge-io: qemu-bridge-iram-mem fd 9 region 1 at 0x7fa5d8fd2000 allocated 81920 bytes
bridge-io: qemu-bridge-dram-mem fd 10 region 2 at 0x7fa5c988e000 allocated 163840 bytes
bridge-io: qemu-bridge-dmac0-io fd 11 region 3 at 0x7fa5d900f000 allocated 4096 bytes
bridge-io: qemu-bridge-dmac1-io fd 12 region 4 at 0x7fa5d8fd1000 allocated 4096 bytes
bridge-io: qemu-bridge-ssp0-io fd 13 region 5 at 0x7fa5d8fd0000 allocated 4096 bytes
bridge-io: qemu-bridge-ssp1-io fd 14 region 6 at 0x7fa5d8fcf000 allocated 4096 bytes
bridge-io: qemu-bridge-ssp2-io fd 15 region 7 at 0x7fa5d8fce000 allocated 4096 bytes
bridge-io: qemu-bridge-shim-io fd 16 region 8 at 0x7fa5d8fcd000 allocated 4096 bytes
bridge-io: qemu-bridge-mbox-io fd 17 region 9 at 0x7fa5d8fcc000 allocated 4096 bytes
bridge-io-mq: added /qemu-io-parent-byt
bridge-io-mq: added /qemu-io-child-byt
 ** Baytrail Xtensa HiFi2 EP DSP initialised.
 ** Waiting for host to load firmware...
bridge-io: 0 messages are currently on child queue.
QEMU 4.1.93 monitor - type 'help' for more information
(qemu) bridge-io: msg recv 0 type 1 size 20 msg 32
msg: id 0 msg 32 size 20 type 1
bridge-io: msg recv 1 type 1 size 20 msg 32
msg: id 1 msg 32 size 20 type 1
bridge-io: msg recv 2 type 1 size 20 msg 32
msg: id 2 msg 32 size 20 type 1
cpu: running
irq: SHIM_IMRLPESC masking 0 mask 0 active 0
irq: SC send busy interrupt 0xc2
irq: SHIM_IMRLPESC masking 1 mask 1 active 0
irq: SHIM_IMRLPESC masking 0 mask 0 active 0
irq: SC send busy interrupt 0xc5
irq: SHIM_IMRLPESC masking 1 mask 1 active 0
irq: SHIM_IMRLPESC masking 0 mask 0 active 0
IRQ: from DMAC 0 status 0 block 0 tfr 0
IRQ: from DMAC 0 status 0 block 0 tfr 0
irq: IMRD masking 0 mask 0 active 0
irq: PIMR masking 0 mask 38 active 0
IRQ: from DMAC 1 status 0 block 0 tfr 0
IRQ: from DMAC 1 status 0 block 0 tfr 0
irq: send busy interrupt 0x80000000
bridge-io: msg send: 0 type 2 msg 64 size 16 ret 0
bridge-io: msg recv 3 type 2 size 16 msg 64
msg: id 3 msg 64 size 16 type 2
IRQ: from HOST status 1 mask 0 active 1 cmd 0
irq: IMRD masking 1 mask 1 active 0
irq: IMRD masking 1 mask 0 active 1
bridge-io: msg recv 4 type 2 size 16 msg 64
msg: id 4 msg 64 size 16 type 2
IRQ: from HOST status 2 mask 0 active 2 cmd 0
irq: IMRD masking 2 mask 2 active 0
dma: 0:0: start SAR 0xd8f7000 DAR 0xff30c338 size 0x28
DMA req: src 0xd8f7000 dest 0xff30c338 size 0x28
bridge-io: msg send: 1 type 5 msg 96 size 56 ret 0
bridge-io: msg recv 5 type 5 size 56 msg 97
msg: id 5 msg 97 size 56 type 5
bridge-io: qemu-bridge-dmac:0.0 fd 20 region 16 at 0x7fa5d8fcb000 allocated 40 bytes
IRQ: from DMAC 0 status 2 block 1 tfr 0
IRQ: DMAC 0 set
DMA req complete: src 0xd8f7000 dest 0xff30c338 size 0x38
bridge-io: msg send: 2 type 5 msg 98 size 56 ret 0
IRQ: from DMAC 0 status 3 block 1 tfr 1
IRQ: from DMAC 0 status 3 block 1 tfr 1
IRQ: from DMAC 0 status 3 block 1 tfr 1
irq: send done interrupt 0x40000000
bridge-io: msg send: 3 type 2 msg 64 size 16 ret 0
irq: IMRD masking 2 mask 0 active 2
bridge-io: msg recv 6 type 2 size 16 msg 64
msg: id 6 msg 64 size 16 type 2
IRQ: from HOST status 2 mask 0 active 2 cmd 0
irq: IMRD masking 2 mask 2 active 0
irq: send done interrupt 0x40000000
bridge-io: msg send: 4 type 2 msg 64 size 16 ret 0
irq: IMRD masking 2 mask 0 active 2
dma: 1:0: start SAR 0xff31c800 DAR 0x0 size 0x83c
DMA req: src 0xff31c800 dest 0x0 size 0x83c
bridge-io: msg send: 5 type 5 msg 96 size 56 ret 0
bridge-io: msg recv 7 type 5 size 56 msg 97
msg: id 7 msg 97 size 56 type 5
error: can't create SHM size 0x83c for DMAC 1 chan 0

While the companion x86-host.sh shows:

[tdu at home:~/workspace/sof/qemu]$ ./x86-host.sh byt
bridge-io: qemu-bridge-iram-mem fd 19 region 1 at 0x7f09d9cb7000 allocated 81920 bytes
bridge-io: qemu-bridge-dram-mem fd 20 region 2 at 0x7f09cbfd8000 allocated 163840 bytes
bridge-io: qemu-bridge-pci-io fd 21 region 3 at 0x7f09e93d1000 allocated 4096 bytes
bridge-io: qemu-bridge-shim-io fd 22 region 4 at 0x7f09e93d0000 allocated 4096 bytes
bridge-io: qemu-bridge-mbox-io fd 23 region 5 at 0x7f09e93cf000 allocated 4096 bytes
bridge-io-mq: added /qemu-io-parent-byt
bridge-io-mq: added /qemu-io-child-byt
bridge-io: 0 messages are currently on parent queue.
bridge-io: msg send: 0 type 1 msg 32 size 20 ret 0
bridge-io: msg send: 1 type 1 msg 32 size 20 ret 0
bridge-io: msg send: 2 type 1 msg 32 size 20 ret 0
bridge-io: msg recv 0 type 2 size 16 msg 64
msg: id 0 msg 64 size 16 type 2
DSP IRQ: status 2 mask 0 active 2 cmd 70028800
irq: masking 0 mask 0 active 0
irq: send done interrupt 0x40000000
bridge-io: msg send: 3 type 2 msg 64 size 16 ret 0
irq: masking 1 mask 0 active 2
irq: send busy interrupt 0x80000000
bridge-io: msg send: 4 type 2 msg 64 size 16 ret 0
bridge-io: msg recv 1 type 5 size 56 msg 96
msg: id 1 msg 96 size 56 type 5
bridge-io: qemu-bridge-(null) fd 31 region 16 at 0x7f09d9c9e000 allocated 40 bytes
bridge-io: msg send: 5 type 5 msg 97 size 56 ret 0
bridge-io: msg recv 2 type 5 size 56 msg 98
msg: id 2 msg 98 size 56 type 5
bridge-io: msg recv 3 type 2 size 16 msg 64
msg: id 3 msg 64 size 16 type 2
DSP IRQ: status 1 mask 0 active 1 cmd 70028800
irq: masking 2 mask 0 active 0
irq: masking 0 mask 0 active 1
irq: send busy interrupt 0x80000000
bridge-io: msg send: 6 type 2 msg 64 size 16 ret 0
bridge-io: msg recv 4 type 2 size 16 msg 64
msg: id 4 msg 64 size 16 type 2
DSP IRQ: status 1 mask 0 active 1 cmd 70028800
bridge-io: msg recv 5 type 5 size 56 msg 96
msg: id 5 msg 96 size 56 type 5
error: cant alloc dma SHM -16
bridge-io: msg send: 7 type 5 msg 97 size 56 ret 0
irq: masking 2 mask 0 active 0
irq: masking 0 mask 0 active 1

So if I am not mistaken setup fails because some shared memory region
cannot be allocated. Below a callstack leading to error present in logs.

hw/dma/dw-dma-core.c:

dw_dma_msg()
  dma_M2M_do_transfer()
    qemu_io_register_shm() <-- ADSP_IO_SHM_DMA(1, 0) region
      if (_iob.shm[region].fd)
        return -EBUSY;

Now, if one goes back to xtensa logs it turns out that code wants
region ADSP_IO_SHM_DMA(1, 0) which evaluates to 32. This means we are
touching memory outside _iob.shm[] array (which has 32 entries).

Any thoughts?