From c10325d6f9af84444120d8a6d1d59f41a282ae1b Mon Sep 17 00:00:00 2001 From: David Gibson Date: Thu, 1 Oct 2015 10:46:10 +1000 Subject: [PATCH] spapr_iommu: Provide a function to switch a TCE table to allowing VFIO Because of the way non-VFIO guest IOMMU operations are KVM accelerated, not all TCE tables (guest IOMMU contexts) can support VFIO devices. Currently, this is decided at creation time. To support hotplug of VFIO devices, we need to allow a TCE table which previously didn't allow VFIO devices to be switched so that it can. This patch adds an spapr_tce_set_need_vfio() function to do this, by reallocating the table in userspace if necessary. Currently this doesn't allow the KVM acceleration to be re-enabled if all the VFIO devices are removed. That's an optimization for another time. Signed-off-by: David Gibson Reviewed-by: Laurent Vivier --- hw/ppc/spapr_iommu.c | 32 ++++++++++++++++++++++++++++++++ include/hw/ppc/spapr.h | 2 ++ 2 files changed, 34 insertions(+) diff --git a/hw/ppc/spapr_iommu.c b/hw/ppc/spapr_iommu.c index 5166cde422..ed28565d8c 100644 --- a/hw/ppc/spapr_iommu.c +++ b/hw/ppc/spapr_iommu.c @@ -168,6 +168,38 @@ static int spapr_tce_table_realize(DeviceState *dev) return 0; } +void spapr_tce_set_need_vfio(sPAPRTCETable *tcet, bool need_vfio) +{ + size_t table_size = tcet->nb_table * sizeof(uint64_t); + void *newtable; + + if (need_vfio == tcet->need_vfio) { + /* Nothing to do */ + return; + } + + if (!need_vfio) { + /* FIXME: We don't support transition back to KVM accelerated + * TCEs yet */ + return; + } + + tcet->need_vfio = true; + + if (tcet->fd < 0) { + /* Table is already in userspace, nothing to be do */ + return; + } + + newtable = g_malloc(table_size); + memcpy(newtable, tcet->table, table_size); + + kvmppc_remove_spapr_tce(tcet->table, tcet->fd, tcet->nb_table); + + tcet->fd = -1; + tcet->table = newtable; +} + sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, uint32_t liobn, uint64_t bus_offset, uint32_t page_shift, diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h index 27d65d5f1d..5baa90683b 100644 --- a/include/hw/ppc/spapr.h +++ b/include/hw/ppc/spapr.h @@ -589,6 +589,8 @@ sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, uint32_t liobn, uint32_t page_shift, uint32_t nb_table, bool need_vfio); +void spapr_tce_set_need_vfio(sPAPRTCETable *tcet, 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); -- 2.39.5