Commit 8607f5c3 authored by Jason Wang's avatar Jason Wang Committed by Michael S. Tsirkin
Browse files

virtio: convert to use DMA api 



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 when iommu platform (VIRTIO_F_IOMMU_PLATFORM) was enabled
  for this device.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Amit Shah <amit.shah@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: qemu-block@nongnu.org
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent a08aaff8

hw/block/virtio-blk.c

+1 −1
Original line number Diff line number Diff line
@@ -863,7 +863,7 @@ static int virtio_blk_load_device(VirtIODevice *vdev, QEMUFile *f, 
            }

        }



        req = qemu_get_virtqueue_element(f, sizeof(VirtIOBlockReq));

        req = qemu_get_virtqueue_element(vdev, f, sizeof(VirtIOBlockReq));

        virtio_blk_init_request(s, virtio_get_queue(vdev, vq_idx), req);

        req->next = s->rq;

        s->rq = req;

hw/char/virtio-serial-bus.c

+2 −1
Original line number Diff line number Diff line
@@ -732,6 +732,7 @@ static void virtio_serial_post_load_timer_cb(void *opaque) 
static int fetch_active_ports_list(QEMUFile *f,

                                   VirtIOSerial *s, uint32_t nr_active_ports)

{

    VirtIODevice *vdev = VIRTIO_DEVICE(s);

    uint32_t i;



    s->post_load = g_malloc0(sizeof(*s->post_load));
@@ -765,7 +766,7 @@ static int fetch_active_ports_list(QEMUFile *f, 
            qemu_get_be64s(f, &port->iov_offset);



            port->elem =

                qemu_get_virtqueue_element(f, sizeof(VirtQueueElement));

                qemu_get_virtqueue_element(vdev, f, sizeof(VirtQueueElement));



            /*

             *  Port was throttled on source machine.  Let's

hw/scsi/virtio-scsi.c

+3 −1
Original line number Diff line number Diff line
@@ -198,12 +198,14 @@ static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq) 
    SCSIBus *bus = sreq->bus;

    VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);

    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);

    VirtIODevice *vdev = VIRTIO_DEVICE(s);

    VirtIOSCSIReq *req;

    uint32_t n;



    qemu_get_be32s(f, &n);

    assert(n < vs->conf.num_queues);

    req = qemu_get_virtqueue_element(f, sizeof(VirtIOSCSIReq) + vs->cdb_size);

    req = qemu_get_virtqueue_element(vdev, f,

                                     sizeof(VirtIOSCSIReq) + vs->cdb_size);

    virtio_scsi_init_req(s, vs->cmd_vqs[n], req);



    if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,

hw/virtio/virtio-bus.c

+8 −0
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#include "hw/qdev.h"

#include "hw/virtio/virtio-bus.h"

#include "hw/virtio/virtio.h"

#include "exec/address-spaces.h"



/* #define DEBUG_VIRTIO_BUS */
@@ -61,6 +62,13 @@ void virtio_bus_device_plugged(VirtIODevice *vdev, Error **errp) 
    if (klass->device_plugged != NULL) {

        klass->device_plugged(qbus->parent, errp);

    }



    if (klass->get_dma_as != NULL &&

        virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM)) {

        vdev->dma_as = klass->get_dma_as(qbus->parent);

    } else {

        vdev->dma_as = &address_space_memory;

    }

}



/* Reset the virtio_bus */

hw/virtio/virtio-pci.c

+14 −0
Original line number Diff line number Diff line
@@ -1144,6 +1144,14 @@ 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)

{
@@ -1601,6 +1609,11 @@ static void virtio_pci_device_plugged(DeviceState *d, Error **errp) 
    }



    if (legacy) {

        if (virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM)) {

            error_setg(errp, "VIRTIO_F_IOMMU_PLATFORM was supported by"

                       "neither legacy nor transitional device.");

            return ;

        }

        /* legacy and transitional */

        pci_set_word(config + PCI_SUBSYSTEM_VENDOR_ID,

                     pci_get_word(config + PCI_VENDOR_ID));
@@ -2520,6 +2533,7 @@ static void virtio_pci_bus_class_init(ObjectClass *klass, void *data) 
    k->query_nvectors = virtio_pci_query_nvectors;

    k->ioeventfd_enabled = virtio_pci_ioeventfd_enabled;

    k->ioeventfd_assign = virtio_pci_ioeventfd_assign;

    k->get_dma_as = virtio_pci_get_dma_as;

}



static const TypeInfo virtio_pci_bus_info = {