From 9fddb8cdebd6164d401b693a7e5590a2974fb9e5 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Tue, 6 Oct 2015 04:32:09 +0200 Subject: [PATCH 09/10] spapr_iommu: Provide a function to switch a TCE table to allowing VFIO Message-id: <20151006153209.4849b61b@voom.fritz.box> Patchwork-id: 68079 O-Subject: Re: [RHEL7.2 qemu-kvm-rhev PATCHv4 09/10] spapr_iommu: Provide a function to switch a TCE table to allowing VFIO Bugzilla: 1259556 RH-Acked-by: Alex Williamson RH-Acked-by: Thomas Huth RH-Acked-by: Laurent Vivier 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 Upstream: Posted, revised, not merged Signed-off-by: David Gibson Signed-off-by: Miroslav Rezanina --- 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 af561e0..13d42d4 100644 --- a/hw/ppc/spapr_iommu.c +++ b/hw/ppc/spapr_iommu.c @@ -154,6 +154,38 @@ 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 acc61c3..da3e075 100644 --- a/include/hw/ppc/spapr.h +++ b/include/hw/ppc/spapr.h @@ -584,6 +584,8 @@ 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); -- 1.8.3.1