[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH 1/1] spapr_drc.c: handle hotunplug errors in drc_unisolate_lo
From: |
David Gibson |
Subject: |
Re: [PATCH 1/1] spapr_drc.c: handle hotunplug errors in drc_unisolate_logical() |
Date: |
Mon, 19 Apr 2021 14:08:46 +1000 |
On Fri, Apr 16, 2021 at 06:09:41PM -0300, Daniel Henrique Barboza wrote:
> The Linux kernel will call set-indicator to move a DRC to 'unisolate' in
> the case a device removal fails. Setting a DRC that is already
Only issue I have with this patch is that this isn't quite accurate
yet. Can you reword this to include some of the rationale from the
cover letters about how a previous no-op is a safe choice to allow
guest->hv error signalling and that we expect the Linux kernel to use
it at some point.
> unisolated or configured to 'unisolate' is a no-op for the current
> hypervisors that supports pSeries guests, namely QEMU and phyp, and is
> being used to signal hotunplug errors if the hypervisor has the code for
> it.
>
> This patch changes drc_unisolate_logical() to implement in the pSeries
> machine. For CPUs it's a simple matter of setting drc->unplug_requested
> to 'false', while for LMBs the process is similar to the rollback that
> is done in rtas_ibm_configure_connector(). Although at this moment the
> Linux kernel is only reporting CPU removal errors, let's get the code
> ready to handle LMBs as well.
>
> Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Otherwise,
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> ---
> hw/ppc/spapr_drc.c | 23 +++++++++++++++++++++++
> 1 file changed, 23 insertions(+)
>
> diff --git a/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c
> index 9e16505fa1..6918e0c9d1 100644
> --- a/hw/ppc/spapr_drc.c
> +++ b/hw/ppc/spapr_drc.c
> @@ -151,9 +151,32 @@ static uint32_t drc_isolate_logical(SpaprDrc *drc)
>
> static uint32_t drc_unisolate_logical(SpaprDrc *drc)
> {
> + SpaprMachineState *spapr = NULL;
> +
> switch (drc->state) {
> case SPAPR_DRC_STATE_LOGICAL_UNISOLATE:
> case SPAPR_DRC_STATE_LOGICAL_CONFIGURED:
> + /*
> + * Unisolating a logical DRC that was marked for unplug
> + * means that the kernel is refusing the removal.
> + */
> + if (drc->unplug_requested && drc->dev) {
> + if (spapr_drc_type(drc) == SPAPR_DR_CONNECTOR_TYPE_LMB) {
> + spapr = SPAPR_MACHINE(qdev_get_machine());
> +
> + spapr_memory_unplug_rollback(spapr, drc->dev);
> + }
> +
> + drc->unplug_requested = false;
> + error_report("Device hotunplug rejected by the guest "
> + "for device %s", drc->dev->id);
> +
> + /*
> + * TODO: send a QAPI DEVICE_UNPLUG_ERROR event when
> + * it is implemented.
> + */
> + }
> +
> return RTAS_OUT_SUCCESS; /* Nothing to do */
> case SPAPR_DRC_STATE_LOGICAL_AVAILABLE:
> break; /* see below */
--
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
signature.asc
Description: PGP signature