[Qemu-devel] [PATCH qemu v13 13/16] spapr_iommu: Remove need_vfio flag from sPAPRTCETable

[Alexey Kardashevskiy]

sPAPRTCETable has a need_vfio flag which is passed to
kvmppc_create_spapr_tce() and controls whether to create a guest view
table in KVM as this depends on the host kernel ability to accelerate
H_PUT_TCE for VFIO devices. We would set this flag at the moment
when sPAPRTCETable is created in spapr_tce_new_table() and
use when the table is allocated in spapr_tce_table_realize().

Now we explicitly enable/disable DMA windows via spapr_tce_table_enable()
and spapr_tce_table_disable() and can pass this flag directly without
caching it in sPAPRTCETable.

This removes the flag. This should cause no behavioural change.

Signed-off-by: Alexey Kardashevskiy <address@hidden>
---
 hw/ppc/spapr_iommu.c   | 13 +++++--------
 include/hw/ppc/spapr.h |  1 -
 2 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/hw/ppc/spapr_iommu.c b/hw/ppc/spapr_iommu.c
index 4c52cf4..8aa2238 100644
--- a/hw/ppc/spapr_iommu.c
+++ b/hw/ppc/spapr_iommu.c
@@ -210,8 +210,9 @@ void spapr_tce_set_need_vfio(sPAPRTCETable *tcet, bool 
need_vfio)
 {
     size_t table_size = tcet->nb_table * sizeof(uint64_t);
     void *newtable;
+    bool tcet_can_vfio = tcet->fd < 0;
 
-    if (need_vfio == tcet->need_vfio) {
+    if (need_vfio == tcet_can_vfio) {
         /* Nothing to do */
         return;
     }
@@ -222,8 +223,6 @@ void spapr_tce_set_need_vfio(sPAPRTCETable *tcet, bool 
need_vfio)
         return;
     }
 
-    tcet->need_vfio = true;
-
     if (tcet->fd < 0) {
         /* Table is already in userspace, nothing to be do */
         return;
@@ -261,7 +260,7 @@ sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, 
uint32_t liobn)
     return tcet;
 }
 
-static void spapr_tce_table_do_enable(sPAPRTCETable *tcet)
+static void spapr_tce_table_do_enable(sPAPRTCETable *tcet, bool need_vfio)
 {
     if (!tcet->nb_table) {
         return;
@@ -271,7 +270,7 @@ static void spapr_tce_table_do_enable(sPAPRTCETable *tcet)
                                         tcet->page_shift,
                                         tcet->nb_table,
                                         &tcet->fd,
-                                        tcet->need_vfio);
+                                        need_vfio);
 
     memory_region_set_size(&tcet->iommu,
                            (uint64_t)tcet->nb_table << tcet->page_shift);
@@ -291,9 +290,8 @@ void spapr_tce_table_enable(sPAPRTCETable *tcet,
     tcet->bus_offset = bus_offset;
     tcet->page_shift = page_shift;
     tcet->nb_table = nb_table;
-    tcet->need_vfio = need_vfio;
 
-    spapr_tce_table_do_enable(tcet);
+    spapr_tce_table_do_enable(tcet, need_vfio);
 }
 
 void spapr_tce_table_disable(sPAPRTCETable *tcet)
@@ -312,7 +310,6 @@ void spapr_tce_table_disable(sPAPRTCETable *tcet)
     tcet->bus_offset = 0;
     tcet->page_shift = 0;
     tcet->nb_table = 0;
-    tcet->need_vfio = false;
 }
 
 static void spapr_tce_table_unrealize(DeviceState *dev, Error **errp)
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 5d2f8f4..505cb3a 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -546,7 +546,6 @@ struct sPAPRTCETable {
     uint32_t page_shift;
     uint64_t *table;
     bool bypass;
-    bool need_vfio;
     int fd;
     MemoryRegion root, iommu;
     struct VIOsPAPRDevice *vdev; /* for @bypass migration compatibility only */
-- 
2.5.0.rc3