| Message ID | 20210416210941.381119-2-danielhb413@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | pSeries: handle hotunplug errors in drc_unisolate_logical() | expand |
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 */
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 */
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 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> --- hw/ppc/spapr_drc.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+)