spapr_iommu: Rename vfio_accel parameter

The vfio_accel parameter used when creating a new TCE table (guest IOMMU
context) has a confusing name.  What it really means is whether we need the
TCE table created to be able to support VFIO devices.

VFIO is relevant, because when available we use in-kernel acceleration of
the TCE table, but that may not work with VFIO devices because updates to
the table are handled in kernel, bypass qemu and so don't hit qemu's
infrastructure for keeping the VFIO host IOMMU state in sync with the guest
IOMMU state.

Rename the parameter to "need_vfio" throughout.  This is a cosmetic change,
with no impact on the logic.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>

hw/ppc/spapr_iommu.c

@@ -146,7 +146,7 @@ static int spapr_tce_table_realize(DeviceState *dev)
         tcet->table = kvmppc_create_spapr_tce(tcet->liobn,
                                               window_size,
                                               &tcet->fd,
-                                              tcet->vfio_accel);
+                                              tcet->need_vfio);
     }
 
     if (!tcet->table) {
@@ -172,7 +172,7 @@ sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, uint32_t liobn,
                                    uint64_t bus_offset,
                                    uint32_t page_shift,
                                    uint32_t nb_table,
-                                   bool vfio_accel)
+                                   bool need_vfio)
 {
     sPAPRTCETable *tcet;
     char tmp[64];
@@ -192,7 +192,7 @@ sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, uint32_t liobn,
     tcet->bus_offset = bus_offset;
     tcet->page_shift = page_shift;
     tcet->nb_table = nb_table;
-    tcet->vfio_accel = vfio_accel;
+    tcet->need_vfio = need_vfio;
 
     snprintf(tmp, sizeof(tmp), "tce-table-%x", liobn);
     object_property_add_child(OBJECT(owner), tmp, OBJECT(tcet), NULL);

include/hw/ppc/spapr.h

@@ -563,7 +563,7 @@ struct sPAPRTCETable {
     uint32_t page_shift;
     uint64_t *table;
     bool bypass;
-    bool vfio_accel;
+    bool need_vfio;
     int fd;
     MemoryRegion iommu;
     struct VIOsPAPRDevice *vdev; /* for @bypass migration compatibility only */
@@ -588,7 +588,7 @@ sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, uint32_t liobn,
                                    uint64_t bus_offset,
                                    uint32_t page_shift,
                                    uint32_t nb_table,
-                                   bool vfio_accel);
+                                   bool need_vfio);
 MemoryRegion *spapr_tce_get_iommu(sPAPRTCETable *tcet);
 int spapr_dma_dt(void *fdt, int node_off, const char *propname,
                  uint32_t liobn, uint64_t window, uint32_t size);

target-ppc/kvm.c

@@ -2070,7 +2070,7 @@ bool kvmppc_spapr_use_multitce(void)
 }
 
 void *kvmppc_create_spapr_tce(uint32_t liobn, uint32_t window_size, int *pfd,
-                              bool vfio_accel)
+                              bool need_vfio)
 {
     struct kvm_create_spapr_tce args = {
         .liobn = liobn,
@@ -2084,7 +2084,7 @@ void *kvmppc_create_spapr_tce(uint32_t liobn, uint32_t window_size, int *pfd,
      * destroying the table, which the upper layers -will- do
      */
     *pfd = -1;
-    if (!cap_spapr_tce || (vfio_accel && !cap_spapr_vfio)) {
+    if (!cap_spapr_tce || (need_vfio && !cap_spapr_vfio)) {
         return NULL;
     }
 

target-ppc/kvm_ppc.h

@@ -36,7 +36,7 @@ int kvmppc_booke_watchdog_enable(PowerPCCPU *cpu);
 off_t kvmppc_alloc_rma(void **rma);
 bool kvmppc_spapr_use_multitce(void);
 void *kvmppc_create_spapr_tce(uint32_t liobn, uint32_t window_size, int *pfd,
-                              bool vfio_accel);
+                              bool need_vfio);
 int kvmppc_remove_spapr_tce(void *table, int pfd, uint32_t window_size);
 int kvmppc_reset_htab(int shift_hint);
 uint64_t kvmppc_rma_size(uint64_t current_size, unsigned int hash_shift);