On Thu, May 18, 2017 at 06:54:12PM -0300, Daniel Henrique Barboza wrote: > The LMB DRC release callback, spapr_lmb_release(), uses an opaque > parameter, a sPAPRDIMMState struct that stores the current LMBs that > are allocated to a DIMM (nr_lmbs). After each call to this callback, > the nr_lmbs is decremented by one and, when it reaches zero, the callback > proceeds with the qdev calls to hot unplug the LMB. > > Using drc->detach_cb_opaque is problematic because it can't be migrated in > the future DRC migration work. This patch makes the following changes to > eliminate the usage of this opaque callback inside spapr_lmb_release: > > - sPAPRDIMMState was moved from spapr.c and added to spapr.h. A new > attribute called 'addr' was added to it. This is used as an unique > identifier to associate a sPAPRDIMMState to a PCDIMM element. > > - sPAPRMachineState now hosts a new QTAILQ called 'pending_dimm_unplugs'. > This queue of sPAPRDIMMState elements will store the DIMM state of DIMMs > that are currently going under an unplug process. > > - spapr_lmb_release() will now retrieve the nr_lmbs value by getting the > correspondent sPAPRDIMMState. A helper function called spapr_dimm_get_address > was created to fetch the address of a PCDIMM device inside spapr_lmb_release. > When nr_lmbs reaches zero and the callback proceeds with the qdev hot unplug > calls, the sPAPRDIMMState struct is removed from spapr->pending_dimm_unplugs. > > After these changes, the opaque argument for spapr_lmb_release is now > unused and is passed as NULL inside spapr_del_lmbs. This and the other > opaque arguments can now be safely removed from the code. > > Signed-off-by: Daniel Henrique Barboza <danie...@linux.vnet.ibm.com> > --- > hw/ppc/spapr.c | 57 > +++++++++++++++++++++++++++++++++++++++++++++----- > include/hw/ppc/spapr.h | 4 ++++ > 2 files changed, 56 insertions(+), 5 deletions(-) > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index 0980d73..b05abe5 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -2050,6 +2050,7 @@ static void ppc_spapr_init(MachineState *machine) > msi_nonbroken = true; > > QLIST_INIT(&spapr->phbs); > + QTAILQ_INIT(&spapr->pending_dimm_unplugs); > > /* Allocate RMA if necessary */ > rma_alloc_size = kvmppc_alloc_rma(&rma); > @@ -2603,20 +2604,63 @@ out: > error_propagate(errp, local_err); > } > > -typedef struct sPAPRDIMMState { > +struct sPAPRDIMMState { > + uint64_t addr;
Since you're not trying to migrate this any more, you can index the list by an actual PCDIMMDevice *, rather than the base address. You're already passing the DeviceState * for the DIMM around, so this will actually remove the address parameter from some functions. I think that could actually be done as a preliminary cleanup. It also probably makes sense to merge spapr_del_lmbs() with spapr_memory_unplug_request(), they're both very small. > uint32_t nr_lmbs; > -} sPAPRDIMMState; > + QTAILQ_ENTRY(sPAPRDIMMState) next; > +}; > + > +static sPAPRDIMMState *spapr_pending_dimm_unplugs_find(sPAPRMachineState *s, > + uint64_t addr) > +{ > + sPAPRDIMMState *dimm_state = NULL; > + QTAILQ_FOREACH(dimm_state, &s->pending_dimm_unplugs, next) { > + if (dimm_state->addr == addr) { > + break; > + } > + } > + return dimm_state; > +} > + > +static void spapr_pending_dimm_unplugs_add(sPAPRMachineState *spapr, > + sPAPRDIMMState *dimm_state) > +{ > + g_assert(!spapr_pending_dimm_unplugs_find(spapr, dimm_state->addr)); > + QTAILQ_INSERT_HEAD(&spapr->pending_dimm_unplugs, dimm_state, next); > +} > + > +static void spapr_pending_dimm_unplugs_remove(sPAPRMachineState *spapr, > + sPAPRDIMMState *dimm_state) > +{ > + QTAILQ_REMOVE(&spapr->pending_dimm_unplugs, dimm_state, next); > + g_free(dimm_state); > +} > + > +static uint64_t spapr_dimm_get_address(PCDIMMDevice *dimm) > +{ > + Error *local_err = NULL; > + uint64_t addr; > + addr = object_property_get_int(OBJECT(dimm), PC_DIMM_ADDR_PROP, > + &local_err); > + if (local_err) { > + error_propagate(&error_abort, local_err); > + return 0; > + } > + return addr; > +} > > static void spapr_lmb_release(DeviceState *dev, void *opaque) > { > - sPAPRDIMMState *ds = (sPAPRDIMMState *)opaque; > HotplugHandler *hotplug_ctrl; > + uint64_t addr = spapr_dimm_get_address(PC_DIMM(dev)); > + sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine()); I prefer not to access the machine as a global when possible. I think it's preferable to pass down the spapr object from above - unplug_request() itself can get it from hotplug_dev. > + sPAPRDIMMState *ds = spapr_pending_dimm_unplugs_find(spapr, addr); > > if (--ds->nr_lmbs) { > return; > } > > - g_free(ds); > + spapr_pending_dimm_unplugs_remove(spapr, ds); > > /* > * Now that all the LMBs have been removed by the guest, call the > @@ -2633,17 +2677,20 @@ static void spapr_del_lmbs(DeviceState *dev, uint64_t > addr_start, uint64_t size, > sPAPRDRConnectorClass *drck; > uint32_t nr_lmbs = size / SPAPR_MEMORY_BLOCK_SIZE; > int i; > + sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine()); > sPAPRDIMMState *ds = g_malloc0(sizeof(sPAPRDIMMState)); > uint64_t addr = addr_start; > > ds->nr_lmbs = nr_lmbs; > + ds->addr = addr_start; > + spapr_pending_dimm_unplugs_add(spapr, ds); > for (i = 0; i < nr_lmbs; i++) { > drc = spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_LMB, > addr / SPAPR_MEMORY_BLOCK_SIZE); > g_assert(drc); > > drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc); > - drck->detach(drc, dev, spapr_lmb_release, ds, errp); > + drck->detach(drc, dev, spapr_lmb_release, NULL, errp); > addr += SPAPR_MEMORY_BLOCK_SIZE; > } > > diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h > index 5802f88..9823296 100644 > --- a/include/hw/ppc/spapr.h > +++ b/include/hw/ppc/spapr.h > @@ -32,6 +32,7 @@ struct sPAPRRTCState { > int64_t ns_offset; > }; > > +typedef struct sPAPRDIMMState sPAPRDIMMState; > typedef struct sPAPRMachineClass sPAPRMachineClass; > > #define TYPE_SPAPR_MACHINE "spapr-machine" > @@ -104,6 +105,9 @@ struct sPAPRMachineState { > /* RTAS state */ > QTAILQ_HEAD(, sPAPRConfigureConnectorState) ccs_list; > > + /* pending DIMM unplug queue */ Perhaps update this to mention that it's a cache which can be regenerated when necessary. > + QTAILQ_HEAD(, sPAPRDIMMState) pending_dimm_unplugs; > + > /*< public >*/ > char *kvm_type; > MemoryHotplugState hotplug_memory; -- 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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