Re: [PATCH v7 6/7] spapr: use DEVICE_UNPLUG_GUEST_ERROR to report unplug errors

[David Gibson <david@gibson.dropbear.id.au>]

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On Tue, Aug 24, 2021 at 09:48:34PM -0300, Daniel Henrique Barboza wrote:
> Linux Kernel 5.12 is now unisolating CPU DRCs in the device_removal
> error path, signalling that the hotunplug process wasn't successful.
> This allow us to send a DEVICE_UNPLUG_GUEST_ERROR in drc_unisolate_logical()
> to signal this error to the management layer.
> 
> We also have another error path in spapr_memory_unplug_rollback() for
> configured LMB DRCs. Kernels older than 5.13 will not unisolate the LMBs
> in the hotunplug error path, but it will reconfigure them. Let's send
> the DEVICE_UNPLUG_GUEST_ERROR event in that code path as well to cover the
> case of older kernels.
> 
> Reviewed-by: Greg Kurz <groug@kaod.org>
> Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

Acked-by: David Gibson <david@gibson.dropbear.id.au>

> ---
>  hw/ppc/spapr.c     | 10 +++++++++-
>  hw/ppc/spapr_drc.c |  9 +++++----
>  2 files changed, 14 insertions(+), 5 deletions(-)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 4f1ee90e9e..206c536d3a 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -29,6 +29,7 @@
>  #include "qemu/datadir.h"
>  #include "qapi/error.h"
>  #include "qapi/qapi-events-machine.h"
> +#include "qapi/qapi-events-qdev.h"
>  #include "qapi/visitor.h"
>  #include "sysemu/sysemu.h"
>  #include "sysemu/hostmem.h"
> @@ -3686,11 +3687,18 @@ void spapr_memory_unplug_rollback(SpaprMachineState *spapr, DeviceState *dev)
>  
>      /*
>       * Tell QAPI that something happened and the memory
> -     * hotunplug wasn't successful.
> +     * hotunplug wasn't successful. Keep sending
> +     * MEM_UNPLUG_ERROR even while sending
> +     * DEVICE_UNPLUG_GUEST_ERROR until the deprecation of
> +     * MEM_UNPLUG_ERROR is due.
>       */
>      qapi_error = g_strdup_printf("Memory hotunplug rejected by the guest "
>                                   "for device %s", dev->id);
> +
>      qapi_event_send_mem_unplug_error(dev->id ? : "", qapi_error);
> +
> +    qapi_event_send_device_unplug_guest_error(!!dev->id, dev->id,
> +                                              dev->canonical_path);
>  }
>  
>  /* Callback to be called during DRC release. */
> diff --git a/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c
> index a4d9496f76..f8ac0a10df 100644
> --- a/hw/ppc/spapr_drc.c
> +++ b/hw/ppc/spapr_drc.c
> @@ -17,6 +17,8 @@
>  #include "hw/ppc/spapr_drc.h"
>  #include "qom/object.h"
>  #include "migration/vmstate.h"
> +#include "qapi/error.h"
> +#include "qapi/qapi-events-qdev.h"
>  #include "qapi/visitor.h"
>  #include "qemu/error-report.h"
>  #include "hw/ppc/spapr.h" /* for RTAS return codes */
> @@ -173,10 +175,9 @@ static uint32_t drc_unisolate_logical(SpaprDrc *drc)
>                               "for device %s", drc->dev->id);
>              }
>  
> -            /*
> -             * TODO: send a QAPI DEVICE_UNPLUG_ERROR event when
> -             * it is implemented.
> -             */
> +            qapi_event_send_device_unplug_guest_error(!!drc->dev->id,
> +                                                      drc->dev->id,
> +                                                      drc->dev->canonical_path);
>          }
>  
>          return RTAS_OUT_SUCCESS; /* Nothing to do */

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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