Currently, all virtio devices bypass IOMMU completely. This is because address_space_memory is assumed and used during DMA emulation. This patch converts the virtio core API to use DMA API. This idea is
- introducing a new transport specific helper to query the dma address space. (only pci version is implemented). - query and use this address space during virtio device guest memory accessing With this virtiodevices will not bypass IOMMU anymore. Little tested with intel_iommu=on with virtio guest DMA series posted in https://lkml.org/lkml/2015/10/28/64. TODO: - Feature bit for this - Implement this for all transports Signed-off-by: Jason Wang <jasow...@redhat.com> --- hw/block/virtio-blk.c | 2 +- hw/char/virtio-serial-bus.c | 2 +- hw/scsi/virtio-scsi.c | 2 +- hw/virtio/virtio-pci.c | 9 +++++++++ hw/virtio/virtio.c | 36 +++++++++++++++++++-------------- include/hw/virtio/virtio-access.h | 42 +++++++++++++++++++++++++++++---------- include/hw/virtio/virtio-bus.h | 1 + include/hw/virtio/virtio.h | 2 +- 8 files changed, 67 insertions(+), 29 deletions(-) diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index e70fccf..5499480 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -846,7 +846,7 @@ static int virtio_blk_load_device(VirtIODevice *vdev, QEMUFile *f, req->next = s->rq; s->rq = req; - virtqueue_map(&req->elem); + virtqueue_map(vdev, &req->elem); } return 0; diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c index 497b0af..39e9ed2 100644 --- a/hw/char/virtio-serial-bus.c +++ b/hw/char/virtio-serial-bus.c @@ -705,7 +705,7 @@ static int fetch_active_ports_list(QEMUFile *f, int version_id, qemu_get_buffer(f, (unsigned char *)&port->elem, sizeof(port->elem)); - virtqueue_map(&port->elem); + virtqueue_map(&s->parent_obj, &port->elem); /* * Port was throttled on source machine. Let's diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c index 7655401..0734d27 100644 --- a/hw/scsi/virtio-scsi.c +++ b/hw/scsi/virtio-scsi.c @@ -206,7 +206,7 @@ static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq) req = virtio_scsi_init_req(s, vs->cmd_vqs[n]); qemu_get_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem)); - virtqueue_map(&req->elem); + virtqueue_map(&vs->parent_obj, &req->elem); if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size, sizeof(VirtIOSCSICmdResp) + vs->sense_size) < 0) { diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c index dd48562..876505d 100644 --- a/hw/virtio/virtio-pci.c +++ b/hw/virtio/virtio-pci.c @@ -1211,6 +1211,14 @@ static int virtio_pci_query_nvectors(DeviceState *d) return proxy->nvectors; } +static AddressSpace *virtio_pci_get_dma_as(DeviceState *d) +{ + VirtIOPCIProxy *proxy = VIRTIO_PCI(d); + PCIDevice *dev = &proxy->pci_dev; + + return pci_get_address_space(dev); +} + static int virtio_pci_add_mem_cap(VirtIOPCIProxy *proxy, struct virtio_pci_cap *cap) { @@ -2476,6 +2484,7 @@ static void virtio_pci_bus_class_init(ObjectClass *klass, void *data) k->device_plugged = virtio_pci_device_plugged; k->device_unplugged = virtio_pci_device_unplugged; k->query_nvectors = virtio_pci_query_nvectors; + k->get_dma_as = virtio_pci_get_dma_as; } static const TypeInfo virtio_pci_bus_info = { diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 1edef59..e09430d 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -21,6 +21,7 @@ #include "hw/virtio/virtio-bus.h" #include "migration/migration.h" #include "hw/virtio/virtio-access.h" +#include "sysemu/dma.h" /* * The alignment to use between consumer and producer parts of vring. @@ -247,6 +248,7 @@ int virtio_queue_empty(VirtQueue *vq) static void virtqueue_unmap_sg(VirtQueue *vq, const VirtQueueElement *elem, unsigned int len) { + AddressSpace *dma_as = virtio_get_dma_as(vq->vdev); unsigned int offset; int i; @@ -254,17 +256,17 @@ static void virtqueue_unmap_sg(VirtQueue *vq, const VirtQueueElement *elem, for (i = 0; i < elem->in_num; i++) { size_t size = MIN(len - offset, elem->in_sg[i].iov_len); - cpu_physical_memory_unmap(elem->in_sg[i].iov_base, - elem->in_sg[i].iov_len, - 1, size); + dma_memory_unmap(dma_as, elem->in_sg[i].iov_base, elem->in_sg[i].iov_len, + DMA_DIRECTION_FROM_DEVICE, size); offset += size; } for (i = 0; i < elem->out_num; i++) - cpu_physical_memory_unmap(elem->out_sg[i].iov_base, - elem->out_sg[i].iov_len, - 0, elem->out_sg[i].iov_len); + dma_memory_unmap(dma_as, elem->out_sg[i].iov_base, + elem->out_sg[i].iov_len, + DMA_DIRECTION_TO_DEVICE, + elem->out_sg[i].iov_len); } void virtqueue_discard(VirtQueue *vq, const VirtQueueElement *elem, @@ -448,9 +450,9 @@ int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes, return in_bytes <= in_total && out_bytes <= out_total; } -static void virtqueue_map_iovec(struct iovec *sg, hwaddr *addr, - unsigned int *num_sg, unsigned int max_size, - int is_write) +static void virtqueue_map_iovec(VirtIODevice *vdev, struct iovec *sg, + hwaddr *addr, unsigned int *num_sg, + unsigned int max_size, int is_write) { unsigned int i; hwaddr len; @@ -469,7 +471,10 @@ static void virtqueue_map_iovec(struct iovec *sg, hwaddr *addr, for (i = 0; i < *num_sg; i++) { len = sg[i].iov_len; - sg[i].iov_base = cpu_physical_memory_map(addr[i], &len, is_write); + sg[i].iov_base = dma_memory_map(virtio_get_dma_as(vdev), + addr[i], &len, is_write ? + DMA_DIRECTION_FROM_DEVICE : + DMA_DIRECTION_TO_DEVICE); if (!sg[i].iov_base) { error_report("virtio: error trying to map MMIO memory"); exit(1); @@ -491,13 +496,14 @@ static void virtqueue_map_iovec(struct iovec *sg, hwaddr *addr, } } -void virtqueue_map(VirtQueueElement *elem) +void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem) { - virtqueue_map_iovec(elem->in_sg, elem->in_addr, &elem->in_num, + virtqueue_map_iovec(vdev, elem->in_sg, elem->in_addr, &elem->in_num, MIN(ARRAY_SIZE(elem->in_sg), ARRAY_SIZE(elem->in_addr)), 1); - virtqueue_map_iovec(elem->out_sg, elem->out_addr, &elem->out_num, - MIN(ARRAY_SIZE(elem->out_sg), ARRAY_SIZE(elem->out_addr)), + virtqueue_map_iovec(vdev, elem->out_sg, elem->out_addr, &elem->out_num, + MIN(ARRAY_SIZE(elem->out_sg), + ARRAY_SIZE(elem->out_addr)), 0); } @@ -562,7 +568,7 @@ int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem) } while ((i = virtqueue_next_desc(vdev, desc_pa, i, max)) != max); /* Now map what we have collected */ - virtqueue_map(elem); + virtqueue_map(vdev, elem); elem->index = head; diff --git a/include/hw/virtio/virtio-access.h b/include/hw/virtio/virtio-access.h index 8aec843..cca7d2a 100644 --- a/include/hw/virtio/virtio-access.h +++ b/include/hw/virtio/virtio-access.h @@ -15,8 +15,20 @@ #ifndef _QEMU_VIRTIO_ACCESS_H #define _QEMU_VIRTIO_ACCESS_H #include "hw/virtio/virtio.h" +#include "hw/virtio/virtio-bus.h" #include "exec/address-spaces.h" +static inline AddressSpace *virtio_get_dma_as(VirtIODevice *vdev) +{ + BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); + VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); + + if (k->get_dma_as) { + return k->get_dma_as(qbus->parent); + } + return &address_space_memory; +} + static inline bool virtio_access_is_big_endian(VirtIODevice *vdev) { if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { @@ -47,45 +59,55 @@ static inline bool virtio_legacy_is_cross_endian(VirtIODevice *vdev) static inline uint16_t virtio_lduw_phys(VirtIODevice *vdev, hwaddr pa) { + AddressSpace *dma_as = virtio_get_dma_as(vdev); + if (virtio_access_is_big_endian(vdev)) { - return lduw_be_phys(&address_space_memory, pa); + return lduw_be_phys(dma_as, pa); } - return lduw_le_phys(&address_space_memory, pa); + return lduw_le_phys(dma_as, pa); } static inline uint32_t virtio_ldl_phys(VirtIODevice *vdev, hwaddr pa) { + AddressSpace *dma_as = virtio_get_dma_as(vdev); + if (virtio_access_is_big_endian(vdev)) { - return ldl_be_phys(&address_space_memory, pa); + return ldl_be_phys(dma_as, pa); } - return ldl_le_phys(&address_space_memory, pa); + return ldl_le_phys(dma_as, pa); } static inline uint64_t virtio_ldq_phys(VirtIODevice *vdev, hwaddr pa) { + AddressSpace *dma_as = virtio_get_dma_as(vdev); + if (virtio_access_is_big_endian(vdev)) { - return ldq_be_phys(&address_space_memory, pa); + return ldq_be_phys(dma_as, pa); } - return ldq_le_phys(&address_space_memory, pa); + return ldq_le_phys(dma_as, pa); } static inline void virtio_stw_phys(VirtIODevice *vdev, hwaddr pa, uint16_t value) { + AddressSpace *dma_as = virtio_get_dma_as(vdev); + if (virtio_access_is_big_endian(vdev)) { - stw_be_phys(&address_space_memory, pa, value); + stw_be_phys(dma_as, pa, value); } else { - stw_le_phys(&address_space_memory, pa, value); + stw_le_phys(dma_as, pa, value); } } static inline void virtio_stl_phys(VirtIODevice *vdev, hwaddr pa, uint32_t value) { + AddressSpace *dma_as = virtio_get_dma_as(vdev); + if (virtio_access_is_big_endian(vdev)) { - stl_be_phys(&address_space_memory, pa, value); + stl_be_phys(dma_as, pa, value); } else { - stl_le_phys(&address_space_memory, pa, value); + stl_le_phys(dma_as, pa, value); } } diff --git a/include/hw/virtio/virtio-bus.h b/include/hw/virtio/virtio-bus.h index 6c3d4cb..638735e 100644 --- a/include/hw/virtio/virtio-bus.h +++ b/include/hw/virtio/virtio-bus.h @@ -71,6 +71,7 @@ typedef struct VirtioBusClass { * Note that changing this will break migration for this transport. */ bool has_variable_vring_alignment; + AddressSpace *(*get_dma_as)(DeviceState *d); } VirtioBusClass; struct VirtioBusState { diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index 205fadf..7a8ef13 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virtio.h @@ -151,7 +151,7 @@ void virtqueue_discard(VirtQueue *vq, const VirtQueueElement *elem, void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem, unsigned int len, unsigned int idx); -void virtqueue_map(VirtQueueElement *elem); +void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem); int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem); int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes, unsigned int out_bytes); -- 2.5.0
