From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:32943) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1axql7-000706-WB for qemu-devel@nongnu.org; Wed, 04 May 2016 02:58:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1axqkv-0006sT-1f for qemu-devel@nongnu.org; Wed, 04 May 2016 02:58:04 -0400 Received: from e23smtp01.au.ibm.com ([202.81.31.143]:47360) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1axqku-0006nl-E4 for qemu-devel@nongnu.org; Wed, 04 May 2016 02:57:56 -0400 Received: from localhost by e23smtp01.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 4 May 2016 16:57:37 +1000 From: Alexey Kardashevskiy Date: Wed, 4 May 2016 16:52:26 +1000 Message-Id: <1462344751-28281-15-git-send-email-aik@ozlabs.ru> In-Reply-To: <1462344751-28281-1-git-send-email-aik@ozlabs.ru> References: <1462344751-28281-1-git-send-email-aik@ozlabs.ru> Subject: [Qemu-devel] [PATCH qemu v16 14/19] vfio: spapr: Add DMA memory preregistering (SPAPR IOMMU v2) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Alexey Kardashevskiy , qemu-ppc@nongnu.org, Alexander Graf , David Gibson , Alex Williamson , Paolo Bonzini This makes use of the new "memory registering" feature. The idea is to provide the userspace ability to notify the host kernel about pages which are going to be used for DMA. Having this information, the host kernel can pin them all once per user process, do locked pages accounting (once) and not spent time on doing that in real time with possible failures which cannot be handled nicely in some cases. This adds a prereg memory listener which listens on address_space_memory and notifies a VFIO container about memory which needs to be pinned/unpinned. VFIO MMIO regions (i.e. "skip dump" regions) are skipped. As there is no per-IOMMU-type release() callback anymore, this stores the IOMMU type in the container so vfio_listener_release() can determine if it needs to unregister @prereg_listener. The feature is only enabled for SPAPR IOMMU v2. The host kernel changes are required. Since v2 does not need/support VFIO_IOMMU_ENABLE, this does not call it when v2 is detected and enabled. This enforces guest RAM blocks to be host page size aligned; however this is not new as KVM already requires memory slots to be host page size aligned. Signed-off-by: Alexey Kardashevskiy --- Changes: v16: * switched to 64bit math everywhere as there is no chance to see region_add on RAM blocks even remotely close to 1<<64bytes. v15: * banned unaligned sections * added an vfio_prereg_gpa_to_ua() helper v14: * s/free_container_exit/listener_release_exit/g * added "if memory_region_is_iommu()" to vfio_prereg_listener_skipped_section --- hw/vfio/Makefile.objs | 1 + hw/vfio/common.c | 38 +++++++++--- hw/vfio/prereg.c | 137 ++++++++++++++++++++++++++++++++++++++++++ include/hw/vfio/vfio-common.h | 4 ++ trace-events | 2 + 5 files changed, 172 insertions(+), 10 deletions(-) create mode 100644 hw/vfio/prereg.c diff --git a/hw/vfio/Makefile.objs b/hw/vfio/Makefile.objs index ceddbb8..5800e0e 100644 --- a/hw/vfio/Makefile.objs +++ b/hw/vfio/Makefile.objs @@ -4,4 +4,5 @@ obj-$(CONFIG_PCI) += pci.o pci-quirks.o obj-$(CONFIG_SOFTMMU) += platform.o obj-$(CONFIG_SOFTMMU) += calxeda-xgmac.o obj-$(CONFIG_SOFTMMU) += amd-xgbe.o +obj-$(CONFIG_SOFTMMU) += prereg.o endif diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 2050040..496eb82 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -501,6 +501,9 @@ static const MemoryListener vfio_memory_listener = { static void vfio_listener_release(VFIOContainer *container) { memory_listener_unregister(&container->listener); + if (container->iommu_type == VFIO_SPAPR_TCE_v2_IOMMU) { + memory_listener_unregister(&container->prereg_listener); + } } int vfio_region_setup(Object *obj, VFIODevice *vbasedev, VFIORegion *region, @@ -808,8 +811,8 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as) goto free_container_exit; } - ret = ioctl(fd, VFIO_SET_IOMMU, - v2 ? VFIO_TYPE1v2_IOMMU : VFIO_TYPE1_IOMMU); + container->iommu_type = v2 ? VFIO_TYPE1v2_IOMMU : VFIO_TYPE1_IOMMU; + ret = ioctl(fd, VFIO_SET_IOMMU, container->iommu_type); if (ret) { error_report("vfio: failed to set iommu for container: %m"); ret = -errno; @@ -834,8 +837,10 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as) if ((ret == 0) && (info.flags & VFIO_IOMMU_INFO_PGSIZES)) { container->iova_pgsizes = info.iova_pgsizes; } - } else if (ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_SPAPR_TCE_IOMMU)) { + } else if (ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_SPAPR_TCE_IOMMU) || + ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_SPAPR_TCE_v2_IOMMU)) { struct vfio_iommu_spapr_tce_info info; + bool v2 = !!ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_SPAPR_TCE_v2_IOMMU); ret = ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &fd); if (ret) { @@ -843,7 +848,9 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as) ret = -errno; goto free_container_exit; } - ret = ioctl(fd, VFIO_SET_IOMMU, VFIO_SPAPR_TCE_IOMMU); + container->iommu_type = + v2 ? VFIO_SPAPR_TCE_v2_IOMMU : VFIO_SPAPR_TCE_IOMMU; + ret = ioctl(fd, VFIO_SET_IOMMU, container->iommu_type); if (ret) { error_report("vfio: failed to set iommu for container: %m"); ret = -errno; @@ -855,11 +862,22 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as) * when container fd is closed so we do not call it explicitly * in this file. */ - ret = ioctl(fd, VFIO_IOMMU_ENABLE); - if (ret) { - error_report("vfio: failed to enable container: %m"); - ret = -errno; - goto free_container_exit; + if (!v2) { + ret = ioctl(fd, VFIO_IOMMU_ENABLE); + if (ret) { + error_report("vfio: failed to enable container: %m"); + ret = -errno; + goto free_container_exit; + } + } else { + container->prereg_listener = vfio_prereg_listener; + + memory_listener_register(&container->prereg_listener, + &address_space_memory); + if (container->error) { + error_report("vfio: RAM memory listener initialization failed for container"); + goto listener_release_exit; + } } /* @@ -872,7 +890,7 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as) if (ret) { error_report("vfio: VFIO_IOMMU_SPAPR_TCE_GET_INFO failed: %m"); ret = -errno; - goto free_container_exit; + goto listener_release_exit; } container->min_iova = info.dma32_window_start; container->max_iova = container->min_iova + info.dma32_window_size - 1; diff --git a/hw/vfio/prereg.c b/hw/vfio/prereg.c new file mode 100644 index 0000000..d0e4728 --- /dev/null +++ b/hw/vfio/prereg.c @@ -0,0 +1,137 @@ +/* + * DMA memory preregistration + * + * Authors: + * Alexey Kardashevskiy + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + */ + +#include "qemu/osdep.h" +#include +#include + +#include "hw/vfio/vfio-common.h" +#include "hw/hw.h" +#include "qemu/error-report.h" +#include "trace.h" + +static bool vfio_prereg_listener_skipped_section(MemoryRegionSection *section) +{ + if (memory_region_is_iommu(section->mr)) { + error_report("Cannot possibly preregister IOMMU memory"); + return true; + } + + return !memory_region_is_ram(section->mr) || + memory_region_is_skip_dump(section->mr); +} + +static void *vfio_prereg_gpa_to_ua(MemoryRegionSection *section, hwaddr gpa) +{ + return memory_region_get_ram_ptr(section->mr) + + section->offset_within_region + + (gpa - section->offset_within_address_space); +} + +static void vfio_prereg_listener_region_add(MemoryListener *listener, + MemoryRegionSection *section) +{ + VFIOContainer *container = container_of(listener, VFIOContainer, + prereg_listener); + const hwaddr gpa = section->offset_within_address_space; + hwaddr end; + int ret; + hwaddr page_mask = qemu_real_host_page_mask; + struct vfio_iommu_spapr_register_memory reg = { + .argsz = sizeof(reg), + .flags = 0, + }; + + if (vfio_prereg_listener_skipped_section(section)) { + trace_vfio_listener_region_add_skip( + section->offset_within_address_space, + section->offset_within_address_space + + int128_get64(int128_sub(section->size, int128_one()))); + return; + } + + if (unlikely((section->offset_within_address_space & ~page_mask) || + (section->offset_within_region & ~page_mask) || + (int128_get64(section->size) & ~page_mask))) { + error_report("%s received unaligned region", __func__); + return; + } + + end = section->offset_within_address_space + int128_get64(section->size); + g_assert(gpa < end); + + memory_region_ref(section->mr); + + reg.vaddr = (__u64) vfio_prereg_gpa_to_ua(section, gpa); + reg.size = end - gpa; + + ret = ioctl(container->fd, VFIO_IOMMU_SPAPR_REGISTER_MEMORY, ®); + trace_vfio_ram_register(reg.vaddr, reg.size, ret ? -errno : 0); + if (ret) { + /* + * On the initfn path, store the first error in the container so we + * can gracefully fail. Runtime, there's not much we can do other + * than throw a hardware error. + */ + if (!container->initialized) { + if (!container->error) { + container->error = ret; + } + } else { + hw_error("vfio: Memory registering failed, unable to continue"); + } + } +} + +static void vfio_prereg_listener_region_del(MemoryListener *listener, + MemoryRegionSection *section) +{ + VFIOContainer *container = container_of(listener, VFIOContainer, + prereg_listener); + const hwaddr gpa = section->offset_within_address_space; + hwaddr end; + int ret; + hwaddr page_mask = qemu_real_host_page_mask; + struct vfio_iommu_spapr_register_memory reg = { + .argsz = sizeof(reg), + .flags = 0, + }; + + if (vfio_prereg_listener_skipped_section(section)) { + trace_vfio_listener_region_del_skip( + section->offset_within_address_space, + section->offset_within_address_space + + int128_get64(int128_sub(section->size, int128_one()))); + return; + } + + if (unlikely((section->offset_within_address_space & ~page_mask) || + (section->offset_within_region & ~page_mask) || + (int128_get64(section->size) & ~page_mask))) { + error_report("%s received unaligned region", __func__); + return; + } + + end = section->offset_within_address_space + int128_get64(section->size); + if (gpa >= end) { + return; + } + + reg.vaddr = (__u64) vfio_prereg_gpa_to_ua(section, gpa); + reg.size = end - gpa; + + ret = ioctl(container->fd, VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY, ®); + trace_vfio_ram_unregister(reg.vaddr, reg.size, ret ? -errno : 0); +} + +const MemoryListener vfio_prereg_listener = { + .region_add = vfio_prereg_listener_region_add, + .region_del = vfio_prereg_listener_region_del, +}; diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h index c9b6622..c72e45a 100644 --- a/include/hw/vfio/vfio-common.h +++ b/include/hw/vfio/vfio-common.h @@ -73,6 +73,8 @@ typedef struct VFIOContainer { VFIOAddressSpace *space; int fd; /* /dev/vfio/vfio, empowered by the attached groups */ MemoryListener listener; + MemoryListener prereg_listener; + unsigned iommu_type; int error; bool initialized; /* @@ -156,4 +158,6 @@ extern QLIST_HEAD(vfio_as_head, VFIOAddressSpace) vfio_address_spaces; int vfio_get_region_info(VFIODevice *vbasedev, int index, struct vfio_region_info **info); #endif +extern const MemoryListener vfio_prereg_listener; + #endif /* !HW_VFIO_VFIO_COMMON_H */ diff --git a/trace-events b/trace-events index dd50005..d0d8615 100644 --- a/trace-events +++ b/trace-events @@ -1737,6 +1737,8 @@ vfio_region_mmap(const char *name, unsigned long offset, unsigned long end) "Reg vfio_region_exit(const char *name, int index) "Device %s, region %d" vfio_region_finalize(const char *name, int index) "Device %s, region %d" vfio_region_mmaps_set_enabled(const char *name, bool enabled) "Region %s mmaps enabled: %d" +vfio_ram_register(uint64_t va, uint64_t size, int ret) "va=%"PRIx64" size=%"PRIx64" ret=%d" +vfio_ram_unregister(uint64_t va, uint64_t size, int ret) "va=%"PRIx64" size=%"PRIx64" ret=%d" # hw/vfio/platform.c vfio_platform_base_device_init(char *name, int groupid) "%s belongs to group #%d" -- 2.5.0.rc3