[adding libvirt] On 06/27/2014 11:51 AM, Paolo Bonzini wrote:

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Da: "Alex Williamson" <alex.williamson@redhat.com> A: "Paolo Bonzini" <pbonzini@redhat.com> Cc: qemu-devel@nongnu.org, qemu-trivial@nongnu.org Inviato: Venerdì, 27 giugno 2014 18:34:59 Oggetto: Re: [PATCH for 2.1] vfio: use correct runstate

On Fri, 2014-06-27 at 16:32 +0200, Paolo Bonzini wrote:

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io-error is for block device errors; it should always be preceded by a BLOCK_IO_ERROR event.

Where does this requirement come from? I only see a loose association of IO_ERROR to disk in libvirt and none in QEMU.

See the RunState enum in qapi-schema.json:

## # @RunState # # An enumeration of VM run states. # # ... # # @internal-error: An internal error that prevents further guest execution # has occurred # # @io-error: the last IOP has failed and the device is configured to pause # on I/O errors # # @paused: guest has been paused via the 'stop' command

The point of io-error is that management can look at block devices, see if any have an error reported, and then resume execution (see documentation of rerror=stop and werror=stop/enospc). This is counter to the intentions you have in vfio.

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I think vfio wants to use RUN_STATE_INTERNAL_ERROR instead.

But that seems to put us into an "unknown" paused state in libvirt.

I think paused is incorrect, because (unlike RUN_STATE_IO_ERROR), you cannot resume from RUN_STATE_INTERNAL_ERROR except with a reset. QEMU enforces that, and this matches the error you are reporting:

error_report("%s(%04x:%02x:%02x.%x) Unrecoverable error detected. " "Please collect any data possible and then kill the guest", __func__, vdev->host.domain, vdev->host.bus, vdev->host.slot, vdev->host.function);

libvirt has a crashed state, I think that's what libvirt should call the internal-error runstate. IIRC on Xen you get to crashed when the processor raises an error on vmentry, for example.

Libvirt only knows about crashed/unknown, but one could add crashed/internal-error too.

Yes, we probably need to teach libvirt about this state. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org