xen-hvm: Clean up xen_ram_alloc() error handling

xen_ram_alloc() dies with hw_error() on error, even though its caller
ram_block_add() handles errors just fine.  Add an Error **errp
parameter and use it.

Leave case RUN_STATE_INMIGRATE alone, because that looks like some
kind of warning.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

exec.c

@@ -1474,6 +1474,7 @@ static ram_addr_t ram_block_add(RAMBlock *new_block, Error **errp)
     RAMBlock *block;
     RAMBlock *last_block = NULL;
     ram_addr_t old_ram_size, new_ram_size;
+    Error *err = NULL;
 
     old_ram_size = last_ram_offset() >> TARGET_PAGE_BITS;
 
@@ -1483,7 +1484,12 @@ static ram_addr_t ram_block_add(RAMBlock *new_block, Error **errp)
     if (!new_block->host) {
         if (xen_enabled()) {
             xen_ram_alloc(new_block->offset, new_block->max_length,
-                          new_block->mr);
+                          new_block->mr, &err);
+            if (err) {
+                error_propagate(errp, err);
+                qemu_mutex_unlock_ramlist();
+                return -1;
+            }
         } else {
             new_block->host = phys_mem_alloc(new_block->max_length,
                                              &new_block->mr->align);

include/hw/xen/xen.h

@@ -41,7 +41,7 @@ void xenstore_store_pv_console_info(int i, struct CharDriverState *chr);
 #if defined(NEED_CPU_H) && !defined(CONFIG_USER_ONLY)
 void xen_hvm_init(PCMachineState *pcms, MemoryRegion **ram_memory);
 void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size,
-                   struct MemoryRegion *mr);
+                   struct MemoryRegion *mr, Error **errp);
 void xen_modified_memory(ram_addr_t start, ram_addr_t length);
 #endif
 

xen-hvm-stub.c

@@ -30,7 +30,8 @@ void xen_hvm_inject_msi(uint64_t addr, uint32_t data)
 {
 }
 
-void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, MemoryRegion *mr)
+void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, MemoryRegion *mr,
+                   Error **errp)
 {
 }
 

xen-hvm.c

@@ -239,9 +239,9 @@ static void xen_ram_init(PCMachineState *pcms,
     }
 }
 
-void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, MemoryRegion *mr)
+void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, MemoryRegion *mr,
+                   Error **errp)
 {
-    /* FIXME caller ram_block_add() wants error_setg() on failure */
     unsigned long nr_pfn;
     xen_pfn_t *pfn_list;
     int i;
@@ -268,7 +268,8 @@ void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, MemoryRegion *mr)
     }
 
     if (xc_domain_populate_physmap_exact(xen_xc, xen_domid, nr_pfn, 0, 0, pfn_list)) {
-        hw_error("xen: failed to populate ram at " RAM_ADDR_FMT, ram_addr);
+        error_setg(errp, "xen: failed to populate ram at " RAM_ADDR_FMT,
+                   ram_addr);
     }
 
     g_free(pfn_list);