On Mon, Jun 19, 2017 at 05:52:27PM -0500, Michael Roth wrote:
> Quoting David Gibson (2017-06-08 00:09:30)
> > There are substantial differences in the various paths through
> > set_isolation_state(), both for setting to ISOLATED versus UNISOLATED
> > state and for logical versus physical DRCs.
> >
> > So, split the set_isolation_state() method into isolate() and unisolate()
> > methods, and give it different implementations for the two DRC types.
> >
> > Factor some minimal common checks, including for valid indicator values
> > (which we weren't previously checking) into rtas_set_isolation_state().
> >
> > Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
> > ---
> > hw/ppc/spapr_drc.c | 145
> > ++++++++++++++++++++++++++++++++-------------
> > include/hw/ppc/spapr_drc.h | 6 +-
> > 2 files changed, 105 insertions(+), 46 deletions(-)
> >
> > diff --git a/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c
> > index 9e01d7b..90c0fde 100644
> > --- a/hw/ppc/spapr_drc.c
> > +++ b/hw/ppc/spapr_drc.c
> > @@ -46,30 +46,64 @@ uint32_t spapr_drc_index(sPAPRDRConnector *drc)
> > | (drc->id & DRC_INDEX_ID_MASK);
> > }
> >
> > -static uint32_t set_isolation_state(sPAPRDRConnector *drc,
> > - sPAPRDRIsolationState state)
> > +static uint32_t drc_isolate_physical(sPAPRDRConnector *drc)
> > {
> > - trace_spapr_drc_set_isolation_state(spapr_drc_index(drc), state);
> > -
> > /* if the guest is configuring a device attached to this DRC, we
> > * should reset the configuration state at this point since it may
> > * no longer be reliable (guest released device and needs to start
> > * over, or unplug occurred so the FDT is no longer valid)
> > */
> > - if (state == SPAPR_DR_ISOLATION_STATE_ISOLATED) {
> > - g_free(drc->ccs);
> > - drc->ccs = NULL;
> > - }
> > + g_free(drc->ccs);
> > + drc->ccs = NULL;
> >
> > - if (state == SPAPR_DR_ISOLATION_STATE_UNISOLATED) {
> > - /* cannot unisolate a non-existent resource, and, or resources
> > - * which are in an 'UNUSABLE' allocation state. (PAPR 2.7,
> > 13.5.3.5)
> > - */
> > - if (!drc->dev ||
> > - drc->allocation_state == SPAPR_DR_ALLOCATION_STATE_UNUSABLE) {
> > - return RTAS_OUT_NO_SUCH_INDICATOR;
> > + drc->isolation_state = SPAPR_DR_ISOLATION_STATE_ISOLATED;
> > +
> > + /* if we're awaiting release, but still in an unconfigured state,
> > + * it's likely the guest is still in the process of configuring
> > + * the device and is transitioning the devices to an ISOLATED
> > + * state as a part of that process. so we only complete the
> > + * removal when this transition happens for a device in a
> > + * configured state, as suggested by the state diagram from PAPR+
> > + * 2.7, 13.4
> > + */
> > + if (drc->awaiting_release) {
> > + uint32_t drc_index = spapr_drc_index(drc);
> > + if (drc->configured) {
> > + trace_spapr_drc_set_isolation_state_finalizing(drc_index);
> > + spapr_drc_detach(drc, DEVICE(drc->dev), NULL);
> > + } else {
> > + trace_spapr_drc_set_isolation_state_deferring(drc_index);
> > }
> > }
> > + drc->configured = false;
> > +
> > + return RTAS_OUT_SUCCESS;
> > +}
> > +
> > +static uint32_t drc_unisolate_physical(sPAPRDRConnector *drc)
> > +{
> > + /* cannot unisolate a non-existent resource, and, or resources
> > + * which are in an 'UNUSABLE' allocation state. (PAPR 2.7,
> > + * 13.5.3.5)
> > + */
> > + if (!drc->dev) {
> > + return RTAS_OUT_NO_SUCH_INDICATOR;
> > + }
> > +
> > + drc->isolation_state = SPAPR_DR_ISOLATION_STATE_UNISOLATED;
> > +
> > + return RTAS_OUT_SUCCESS;
> > +}
> > +
> > +static uint32_t drc_isolate_logical(sPAPRDRConnector *drc)
> > +{
> > + /* if the guest is configuring a device attached to this DRC, we
> > + * should reset the configuration state at this point since it may
> > + * no longer be reliable (guest released device and needs to start
> > + * over, or unplug occurred so the FDT is no longer valid)
> > + */
> > + g_free(drc->ccs);
> > + drc->ccs = NULL;
> >
> > /*
> > * Fail any requests to ISOLATE the LMB DRC if this LMB doesn't
> > @@ -81,35 +115,47 @@ static uint32_t set_isolation_state(sPAPRDRConnector
> > *drc,
> > * If the LMB being removed doesn't belong to a DIMM device that is
> > * actually being unplugged, fail the isolation request here.
> > */
> > - if (spapr_drc_type(drc) == SPAPR_DR_CONNECTOR_TYPE_LMB) {
> > - if ((state == SPAPR_DR_ISOLATION_STATE_ISOLATED) &&
> > - !drc->awaiting_release) {
> > - return RTAS_OUT_HW_ERROR;
> > - }
> > + if (spapr_drc_type(drc) == SPAPR_DR_CONNECTOR_TYPE_LMB
> > + && !drc->awaiting_release) {
> > + return RTAS_OUT_HW_ERROR;
> > }
> >
> > - drc->isolation_state = state;
> > + drc->isolation_state = SPAPR_DR_ISOLATION_STATE_ISOLATED;
> >
> > - if (drc->isolation_state == SPAPR_DR_ISOLATION_STATE_ISOLATED) {
> > - /* if we're awaiting release, but still in an unconfigured state,
> > - * it's likely the guest is still in the process of configuring
> > - * the device and is transitioning the devices to an ISOLATED
> > - * state as a part of that process. so we only complete the
> > - * removal when this transition happens for a device in a
> > - * configured state, as suggested by the state diagram from
> > - * PAPR+ 2.7, 13.4
> > - */
> > - if (drc->awaiting_release) {
> > - uint32_t drc_index = spapr_drc_index(drc);
> > - if (drc->configured) {
> > - trace_spapr_drc_set_isolation_state_finalizing(drc_index);
> > - spapr_drc_detach(drc, DEVICE(drc->dev), NULL);
> > - } else {
> > - trace_spapr_drc_set_isolation_state_deferring(drc_index);
> > - }
> > + /* if we're awaiting release, but still in an unconfigured state,
> > + * it's likely the guest is still in the process of configuring
> > + * the device and is transitioning the devices to an ISOLATED
> > + * state as a part of that process. so we only complete the
> > + * removal when this transition happens for a device in a
> > + * configured state, as suggested by the state diagram from PAPR+
> > + * 2.7, 13.4
> > + */
> > + if (drc->awaiting_release) {
> > + uint32_t drc_index = spapr_drc_index(drc);
> > + if (drc->configured) {
> > + trace_spapr_drc_set_isolation_state_finalizing(drc_index);
> > + spapr_drc_detach(drc, DEVICE(drc->dev), NULL);
> > + } else {
> > + trace_spapr_drc_set_isolation_state_deferring(drc_index);
>
> Not sure this is the right patch to do it, but this refactoring does make
> it more apparent that the if (drc->configured) checks should get pushed
> down into spapr_drc_detach() like the other deferral checks at some point.
>
> (There are 2 locations that do the detach without checking configured,
> but you switched out the one in reset() to use spapr_drc_release()
> already, and I don't think drc_set_unusable() without first going
> through drc_isolate_*() is a transition that PAPR would allow anyway)
Right, but no, I don't think this patch is the place to do it.
I'll see what this looks like once I've made other cleanups on my
queue.
--
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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