spapr/xive: rework the mapping the KVM memory regions

Today, the interrupt device is fully initialized at reset when the CAS
negotiation process has completed. Depending on the KVM capabilities,
the SpaprXive memory regions (ESB, TIMA) are initialized with a host
MMIO backend or a QEMU emulated backend. This results in a complex
initialization sequence partially done at realize and later at reset,
and some memory region leaks.

To simplify this sequence and to remove of the late initialization of
the emulated device which is required to be done only once, we
introduce new memory regions specific for KVM. These regions are
mapped as overlaps on top of the emulated device to make use of the
host MMIOs. Also provide proper cleanups of these regions when the
XIVE KVM device is destroyed to fix the leaks.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190614165920.12670-2-clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

include/hw/ppc/spapr_xive.h

@@ -42,6 +42,7 @@ typedef struct SpaprXive {
     /* KVM support */
     int           fd;
     void          *tm_mmap;
+    MemoryRegion  tm_mmio_kvm;
     VMChangeStateEntry *change;
 } SpaprXive;
 
@@ -66,7 +67,6 @@ void spapr_xive_map_mmio(SpaprXive *xive);
 
 int spapr_xive_end_to_target(uint8_t end_blk, uint32_t end_idx,
                              uint32_t *out_server, uint8_t *out_prio);
-void spapr_xive_init(SpaprXive *xive, Error **errp);
 
 /*
  * KVM XIVE device helpers

include/hw/ppc/xive.h

@@ -197,6 +197,7 @@ typedef struct XiveSource {
 
     /* KVM support */
     void            *esb_mmap;
+    MemoryRegion    esb_mmio_kvm;
 
     XiveNotifier    *xive;
 } XiveSource;