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Date: Wed, 29 Oct 2014 12:35:22 +0100
From: Paolo Bonzini <pbonzini@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH 05/17] scsi: Remove 'lun' argument
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To: Hannes Reinecke <hare@suse.de>, qemu-devel@nongnu.org
Cc: Alexander Graf <agraf@suse.de>, Nic Bellinger <nab@datera.com>, Andreas Faerber <afaerber@suse.de>



On 10/29/2014 12:13 PM, Hannes Reinecke wrote:
>> Passing a
>> > NULL SCSIDevice is hard though.
>> > 
> But still can happen even with the current code.
> Look at eg hw/scsi/esp.c:
> 
>     current_lun = scsi_device_find(&s->bus, 0, s->current_dev->id, lun);
>     s->current_req = scsi_req_new(current_lun, 0, buf, s);
>     datalen = scsi_req_enqueue(s->current_req);
> 
> If scsi_device_find() returns NULL we're done for.

That cannot happen:

    s->current_dev = scsi_device_find(&s->bus, 0, target, 0);
    if (!s->current_dev) {
        // No such drive
        s->rregs[ESP_RSTAT] = 0;
        s->rregs[ESP_RINTR] = INTR_DC;
        s->rregs[ESP_RSEQ] = SEQ_0;
        esp_raise_irq(s);
        return 0;
    }

This is in get_cmd, called by handle_satn and handle_s_without_atn
before do_busid_cmd.

Paolo