[Qemu-devel] [PATCH 03/10] pseries: Clean up hash page table allocation error handling

[David Gibson <david@gibson.dropbear.id.au>]

The spapr_alloc_htab() and spapr_reset_htab() functions currently handle
all errors with error_setg(&error_abort, ...).

But really, the callers are really better placed to decide on the error
handling.  So, instead make the functions use the error propagation
infrastructure.

In the callers we change to &error_fatal instead of &error_abort, since
this can be triggered by a bad configuration or kernel error rather than
indicating a programming error in qemu.

While we're at it improve the messages themselves a bit, and clean up the
indentation a little.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 hw/ppc/spapr.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index b7fd09a..d28e349 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1016,7 +1016,7 @@ static void emulate_spapr_hypercall(PowerPCCPU *cpu)
 #define CLEAN_HPTE(_hpte)  ((*(uint64_t *)(_hpte)) &= tswap64(~HPTE64_V_HPTE_DIRTY))
 #define DIRTY_HPTE(_hpte)  ((*(uint64_t *)(_hpte)) |= tswap64(HPTE64_V_HPTE_DIRTY))
 
-static void spapr_alloc_htab(sPAPRMachineState *spapr)
+static void spapr_alloc_htab(sPAPRMachineState *spapr, Error **errp)
 {
     long shift;
     int index;
@@ -1031,7 +1031,8 @@ static void spapr_alloc_htab(sPAPRMachineState *spapr)
          * For HV KVM, host kernel will return -ENOMEM when requested
          * HTAB size can't be allocated.
          */
-        error_setg(&error_abort, "Failed to allocate HTAB of requested size, try with smaller maxmem");
+        error_setg_errno(errp, -shift,
+                         "Error allocating KVM hash page table, try smaller maxmem");
     } else if (shift > 0) {
         /*
          * Kernel handles htab, we don't need to allocate one
@@ -1040,7 +1041,10 @@ static void spapr_alloc_htab(sPAPRMachineState *spapr)
          * but we don't allow booting of such guests.
          */
         if (shift != spapr->htab_shift) {
-            error_setg(&error_abort, "Failed to allocate HTAB of requested size, try with smaller maxmem");
+            error_setg(errp,
+                "Small allocation for KVM hash page table (%ld < %"
+                PRIu32 "), try smaller maxmem",
+                shift, spapr->htab_shift);
         }
 
         spapr->htab_shift = shift;
@@ -1064,17 +1068,21 @@ static void spapr_alloc_htab(sPAPRMachineState *spapr)
  * If host kernel has allocated HTAB, KVM_PPC_ALLOCATE_HTAB ioctl is
  * used to clear HTAB. Otherwise QEMU-allocated HTAB is cleared manually.
  */
-static void spapr_reset_htab(sPAPRMachineState *spapr)
+static void spapr_reset_htab(sPAPRMachineState *spapr, Error **errp)
 {
     long shift;
     int index;
 
     shift = kvmppc_reset_htab(spapr->htab_shift);
     if (shift < 0) {
-        error_setg(&error_abort, "Failed to reset HTAB");
+        error_setg_errno(errp, -shift,
+                   "Error resetting KVM hash page table, try smaller maxmem");
     } else if (shift > 0) {
         if (shift != spapr->htab_shift) {
-            error_setg(&error_abort, "Requested HTAB allocation failed during reset");
+            error_setg(errp,
+                "Reduced size on reset of KVM hash page table (%ld < %"
+                PRIu32 "), try smaller maxmem",
+                shift, spapr->htab_shift);
         }
 
         /* Tell readers to update their file descriptor */
@@ -1145,7 +1153,7 @@ static void ppc_spapr_reset(void)
     foreach_dynamic_sysbus_device(find_unknown_sysbus_device, NULL);
 
     /* Reset the hash table & recalc the RMA */
-    spapr_reset_htab(spapr);
+    spapr_reset_htab(spapr, &error_fatal);
 
     qemu_devices_reset();
 
@@ -1792,7 +1800,7 @@ static void ppc_spapr_init(MachineState *machine)
         }
         spapr->htab_shift++;
     }
-    spapr_alloc_htab(spapr);
+    spapr_alloc_htab(spapr, &error_fatal);
 
     /* Set up Interrupt Controller before we create the VCPUs */
     spapr->icp = xics_system_init(machine,
-- 
2.5.0