On 07/21/2017 03:57 AM, David Gibson wrote:
In case unplugs_find() founds a DIMM state (the condition this patch is trying to fix), ds is returned as NULL. This is working because unplug_request() does not use the return value of unplugs_add() and because recover() is only called if find() returns NULL. Still notOn Fri, Jul 21, 2017 at 10:21:06AM +0530, Bharata B Rao wrote:Commit 0cffce56 (hw/ppc/spapr.c: adding pending_dimm_unplugs to sPAPRMachineState) introduced a new way to track pending LMBs of DIMM device that is marked for removal. Since this commit we can hit the assert in spapr_pending_dimm_unplugs_add() in the following situation: - DIMM device removal fails as the guest doesn't allow the removal. - Subsequent attempt to remove the same DIMM would hit the assert as the corresponding sPAPRDIMMState is still part of the pending_dimm_unplugs list. Fix this by removing the assert and conditionally adding the sPAPRDIMMState to pending_dimm_unplugs list only when it is not already present. Fixes: 0cffce56ae3501c5783d779f97993ce478acf856 Signed-off-by: Bharata B Rao <bhar...@linux.vnet.ibm.com>Applied to ppc-for-2.10.--- Changes in v2: - sPAPRDIMMState is now allocated within spapr_pending_dimm_unplugs_add() itself (David Gibson) - spapr_recover_pending_dimm_state() should never return a NULL sPAPRDIMMState, added an assert for the same. hw/ppc/spapr.c | 37 +++++++++++++++++++++---------------- 1 file changed, 21 insertions(+), 16 deletions(-) diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index 1cb09e7..2465b27 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -2850,11 +2850,25 @@ static sPAPRDIMMState *spapr_pending_dimm_unplugs_find(sPAPRMachineState *s, return dimm_state; }-static void spapr_pending_dimm_unplugs_add(sPAPRMachineState *spapr,- sPAPRDIMMState *dimm_state) +static sPAPRDIMMState *spapr_pending_dimm_unplugs_add(sPAPRMachineState *spapr, + uint32_t nr_lmbs, + PCDIMMDevice *dimm) { - g_assert(!spapr_pending_dimm_unplugs_find(spapr, dimm_state->dimm)); - QTAILQ_INSERT_HEAD(&spapr->pending_dimm_unplugs, dimm_state, next); + sPAPRDIMMState *ds = NULL; + + /* + * If this request is for a DIMM whose removal had failed earlier + * (due to guest's refusal to remove the LMBs), we would have this + * dimm already in the pending_dimm_unplugs list. In that + * case don't add again. + */ + if (!spapr_pending_dimm_unplugs_find(spapr, dimm)) { + ds = g_malloc0(sizeof(sPAPRDIMMState)); + ds->nr_lmbs = nr_lmbs; + ds->dimm = dimm; + QTAILQ_INSERT_HEAD(&spapr->pending_dimm_unplugs, ds, next); + } + return ds;
so pretty. What makes sense here is something like: ds = spapr_pending_dimm_unplugs_find(spapr, dimm); if (!ds) { (...) } return ds;I think this is not worth sending a v3, David can amend it in the tree. After amending feel
free to add my Reviewed-by: Daniel Barboza <danie...@linux.vnet.ibm.com>
}static void spapr_pending_dimm_unplugs_remove(sPAPRMachineState *spapr,@@ -2875,7 +2889,6 @@ static sPAPRDIMMState *spapr_recover_pending_dimm_state(sPAPRMachineState *ms, uint32_t avail_lmbs = 0; uint64_t addr_start, addr; int i; - sPAPRDIMMState *ds;addr_start = object_property_get_int(OBJECT(dimm), PC_DIMM_ADDR_PROP,&error_abort); @@ -2891,11 +2904,7 @@ static sPAPRDIMMState *spapr_recover_pending_dimm_state(sPAPRMachineState *ms, addr += SPAPR_MEMORY_BLOCK_SIZE; }- ds = g_malloc0(sizeof(sPAPRDIMMState));- ds->nr_lmbs = avail_lmbs; - ds->dimm = dimm; - spapr_pending_dimm_unplugs_add(ms, ds); - return ds; + return spapr_pending_dimm_unplugs_add(ms, avail_lmbs, dimm); }/* Callback to be called during DRC release. */@@ -2911,6 +2920,7 @@ void spapr_lmb_release(DeviceState *dev) * during the unplug process. In this case recover it. */ if (ds == NULL) { ds = spapr_recover_pending_dimm_state(spapr, PC_DIMM(dev)); + g_assert(ds); /* The DRC being examined by the caller at least must be counted */ g_assert(ds->nr_lmbs); } @@ -2942,18 +2952,13 @@ static void spapr_memory_unplug_request(HotplugHandler *hotplug_dev, uint64_t addr_start, addr; int i; sPAPRDRConnector *drc; - sPAPRDIMMState *ds; - addr_start = object_property_get_uint(OBJECT(dimm), PC_DIMM_ADDR_PROP, &local_err); if (local_err) { goto out; }- ds = g_malloc0(sizeof(sPAPRDIMMState));- ds->nr_lmbs = nr_lmbs; - ds->dimm = dimm; - spapr_pending_dimm_unplugs_add(spapr, ds); + spapr_pending_dimm_unplugs_add(spapr, nr_lmbs, dimm);addr = addr_start;for (i = 0; i < nr_lmbs; i++) {