spapr_pci: (Mostly) remove spapr-pci-vfio-host-bridge

Now that the regular spapr-pci-host-bridge can handle EEH, there are only
two things that spapr-pci-vfio-host-bridge does differently:
    1. automatically sizes its DMA window to match the host IOMMU
    2. checks if the attached VFIO container is backed by the
       VFIO_SPAPR_TCE_IOMMU type on the host

(1) is not particularly useful, since the default window used by the
regular host bridge will work with the host IOMMU configuration on all
current systems anyway.

Plus, automatically changing guest visible configuration (such as the DMA
window) based on host settings is generally a bad idea.  It's not
definitively broken, since spapr-pci-vfio-host-bridge is only supposed to
support VFIO devices which can't be migrated anyway, but still.

(2) is not really useful, because if a guest tries to configure EEH on a
different host IOMMU, the first call will fail and that will be that.

It's possible there are scripts or tools out there which expect
spapr-pci-vfio-host-bridge, so we don't remove it entirely.  This patch
reduces it to just a stub for backwards compatibility.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>

1 files changed, 17 insertions, 44 deletions

diff --git a/hw/ppc/spapr_pci_vfio.c b/hw/ppc/spapr_pci_vfio.c
index 16a4a8f5e0..9e15924f50 100644
--- a/hw/ppc/spapr_pci_vfio.c
+++ b/hw/ppc/spapr_pci_vfio.c
@@ -23,54 +23,29 @@
 #include "hw/pci/msix.h"
 #include "linux/vfio.h"
 #include "hw/vfio/vfio.h"
+#include "qemu/error-report.h"
 
-static Property spapr_phb_vfio_properties[] = {
-    DEFINE_PROP_INT32("iommu", sPAPRPHBVFIOState, iommugroupid, -1),
-    DEFINE_PROP_END_OF_LIST(),
-};
+#define TYPE_SPAPR_PCI_VFIO_HOST_BRIDGE "spapr-pci-vfio-host-bridge"
 
-static void spapr_phb_vfio_finish_realize(sPAPRPHBState *sphb, Error **errp)
-{
-    sPAPRPHBVFIOState *svphb = SPAPR_PCI_VFIO_HOST_BRIDGE(sphb);
-    struct vfio_iommu_spapr_tce_info info = { .argsz = sizeof(info) };
-    int ret;
-    sPAPRTCETable *tcet;
-    uint32_t liobn = svphb->phb.dma_liobn;
+#define SPAPR_PCI_VFIO_HOST_BRIDGE(obj) \
+    OBJECT_CHECK(sPAPRPHBVFIOState, (obj), TYPE_SPAPR_PCI_VFIO_HOST_BRIDGE)
 
-    if (svphb->iommugroupid == -1) {
-        error_setg(errp, "Wrong IOMMU group ID %d", svphb->iommugroupid);
-        return;
-    }
+typedef struct sPAPRPHBVFIOState sPAPRPHBVFIOState;
 
-    ret = vfio_container_ioctl(&svphb->phb.iommu_as, svphb->iommugroupid,
-                               VFIO_CHECK_EXTENSION,
-                               (void *) VFIO_SPAPR_TCE_IOMMU);
-    if (ret != 1) {
-        error_setg_errno(errp, -ret,
-                         "spapr-vfio: SPAPR extension is not supported");
-        return;
-    }
+struct sPAPRPHBVFIOState {
+    sPAPRPHBState phb;
 
-    ret = vfio_container_ioctl(&svphb->phb.iommu_as, svphb->iommugroupid,
-                               VFIO_IOMMU_SPAPR_TCE_GET_INFO, &info);
-    if (ret) {
-        error_setg_errno(errp, -ret,
-                         "spapr-vfio: get info from container failed");
-        return;
-    }
+    int32_t iommugroupid;
+};
 
-    tcet = spapr_tce_new_table(DEVICE(sphb), liobn, info.dma32_window_start,
-                               SPAPR_TCE_PAGE_SHIFT,
-                               info.dma32_window_size >> SPAPR_TCE_PAGE_SHIFT,
-                               true);
-    if (!tcet) {
-        error_setg(errp, "spapr-vfio: failed to create VFIO TCE table");
-        return;
-    }
+static Property spapr_phb_vfio_properties[] = {
+    DEFINE_PROP_INT32("iommu", sPAPRPHBVFIOState, iommugroupid, -1),
+    DEFINE_PROP_END_OF_LIST(),
+};
 
-    /* Register default 32bit DMA window */
-    memory_region_add_subregion(&sphb->iommu_root, tcet->bus_offset,
-                                spapr_tce_get_iommu(tcet));
+static void spapr_phb_vfio_instance_init(Object *obj)
+{
+    error_report("spapr-pci-vfio-host-bridge is deprecated");
 }
 
 bool spapr_phb_eeh_available(sPAPRPHBState *sphb)
@@ -241,18 +216,16 @@ int spapr_phb_vfio_eeh_configure(sPAPRPHBState *sphb)
 static void spapr_phb_vfio_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
-    sPAPRPHBClass *spc = SPAPR_PCI_HOST_BRIDGE_CLASS(klass);
 
     dc->props = spapr_phb_vfio_properties;
-    spc->finish_realize = spapr_phb_vfio_finish_realize;
 }
 
 static const TypeInfo spapr_phb_vfio_info = {
     .name          = TYPE_SPAPR_PCI_VFIO_HOST_BRIDGE,
     .parent        = TYPE_SPAPR_PCI_HOST_BRIDGE,
     .instance_size = sizeof(sPAPRPHBVFIOState),
+    .instance_init = spapr_phb_vfio_instance_init,
     .class_init    = spapr_phb_vfio_class_init,
-    .class_size    = sizeof(sPAPRPHBClass),
 };
 
 static void spapr_pci_vfio_register_types(void)