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[v10,1/5] hw/ppc/spapr.c: adding pending_dimm_unplugs to sPAPRMachineState

Message ID 20170518203548.14207-2-danielhb@linux.vnet.ibm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Daniel Henrique Barboza May 18, 2017, 8:35 p.m. UTC
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 <danielhb@linux.vnet.ibm.com>
---
 hw/ppc/spapr.c         | 57 +++++++++++++++++++++++++++++++++++++++++++++-----
 include/hw/ppc/spapr.h |  4 ++++
 2 files changed, 56 insertions(+), 5 deletions(-)
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Patch

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;
     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());
+    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 */
+    QTAILQ_HEAD(, sPAPRDIMMState) pending_dimm_unplugs;
+
     /*< public >*/
     char *kvm_type;
     MemoryHotplugState hotplug_memory;