Commit 8eb29f1b authored by Peter Maydell's avatar Peter Maydell
Browse files

Merge remote-tracking branch 'remotes/awilliam/tags/vfio-updates-20190221.0' into staging 



VFIO updates 2019-02-21

 - Workaround kernel overflow bug in vfio type1 DMA unmap
   (Alex Williamson)

 - Refactor vfio container initialization (Eric Auger)

# gpg: Signature made Fri 22 Feb 2019 05:21:07 GMT
# gpg:                using RSA key 239B9B6E3BB08B22
# gpg: Good signature from "Alex Williamson <alex.williamson@redhat.com>" [full]
# gpg:                 aka "Alex Williamson <alex@shazbot.org>" [full]
# gpg:                 aka "Alex Williamson <alwillia@redhat.com>" [full]
# gpg:                 aka "Alex Williamson <alex.l.williamson@gmail.com>" [full]
# Primary key fingerprint: 42F6 C04E 540B D1A9 9E7B  8A90 239B 9B6E 3BB0 8B22

* remotes/awilliam/tags/vfio-updates-20190221.0:
  hw/vfio/common: Refactor container initialization
  vfio/common: Work around kernel overflow bug in DMA unmap

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
parents a05838cb 2b6326c0

hw/vfio/common.c

+89 −45
Original line number Diff line number Diff line
@@ -220,7 +220,25 @@ static int vfio_dma_unmap(VFIOContainer *container, 
        .size = size,

    };



    if (ioctl(container->fd, VFIO_IOMMU_UNMAP_DMA, &unmap)) {

    while (ioctl(container->fd, VFIO_IOMMU_UNMAP_DMA, &unmap)) {

        /*

         * The type1 backend has an off-by-one bug in the kernel (71a7d3d78e3c

         * v4.15) where an overflow in its wrap-around check prevents us from

         * unmapping the last page of the address space.  Test for the error

         * condition and re-try the unmap excluding the last page.  The

         * expectation is that we've never mapped the last page anyway and this

         * unmap request comes via vIOMMU support which also makes it unlikely

         * that this page is used.  This bug was introduced well after type1 v2

         * support was introduced, so we shouldn't need to test for v1.  A fix

         * is queued for kernel v5.0 so this workaround can be removed once

         * affected kernels are sufficiently deprecated.

         */

        if (errno == EINVAL && unmap.size && !(unmap.iova + unmap.size) &&

            container->iommu_type == VFIO_TYPE1v2_IOMMU) {

            trace_vfio_dma_unmap_overflow_workaround();

            unmap.size -= 1ULL << ctz64(container->pgsizes);

            continue;

        }

        error_report("VFIO_UNMAP_DMA: %d", -errno);

        return -errno;

    }
@@ -1036,6 +1054,60 @@ static void vfio_put_address_space(VFIOAddressSpace *space) 
    }

}



/*

 * vfio_get_iommu_type - selects the richest iommu_type (v2 first)

 */

static int vfio_get_iommu_type(VFIOContainer *container,

                               Error **errp)

{

    int iommu_types[] = { VFIO_TYPE1v2_IOMMU, VFIO_TYPE1_IOMMU,

                          VFIO_SPAPR_TCE_v2_IOMMU, VFIO_SPAPR_TCE_IOMMU };

    int i;



    for (i = 0; i < ARRAY_SIZE(iommu_types); i++) {

        if (ioctl(container->fd, VFIO_CHECK_EXTENSION, iommu_types[i])) {

            return iommu_types[i];

        }

    }

    error_setg(errp, "No available IOMMU models");

    return -EINVAL;

}



static int vfio_init_container(VFIOContainer *container, int group_fd,

                               Error **errp)

{

    int iommu_type, ret;



    iommu_type = vfio_get_iommu_type(container, errp);

    if (iommu_type < 0) {

        return iommu_type;

    }



    ret = ioctl(group_fd, VFIO_GROUP_SET_CONTAINER, &container->fd);

    if (ret) {

        error_setg_errno(errp, errno, "Failed to set group container");

        return -errno;

    }



    while (ioctl(container->fd, VFIO_SET_IOMMU, iommu_type)) {

        if (iommu_type == VFIO_SPAPR_TCE_v2_IOMMU) {

            /*

             * On sPAPR, despite the IOMMU subdriver always advertises v1 and

             * v2, the running platform may not support v2 and there is no

             * way to guess it until an IOMMU group gets added to the container.

             * So in case it fails with v2, try v1 as a fallback.

             */

            iommu_type = VFIO_SPAPR_TCE_IOMMU;

            continue;

        }

        error_setg_errno(errp, errno, "Failed to set iommu for container");

        return -errno;

    }



    container->iommu_type = iommu_type;

    return 0;

}



static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,

                                  Error **errp)

{
@@ -1101,25 +1173,17 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as, 
    container->fd = fd;

    QLIST_INIT(&container->giommu_list);

    QLIST_INIT(&container->hostwin_list);

    if (ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1_IOMMU) ||

        ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1v2_IOMMU)) {

        bool v2 = !!ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1v2_IOMMU);

        struct vfio_iommu_type1_info info;



        ret = ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &fd);

    ret = vfio_init_container(container, group->fd, errp);

    if (ret) {

            error_setg_errno(errp, errno, "failed to set group container");

            ret = -errno;

        goto free_container_exit;

    }



        container->iommu_type = v2 ? VFIO_TYPE1v2_IOMMU : VFIO_TYPE1_IOMMU;

        ret = ioctl(fd, VFIO_SET_IOMMU, container->iommu_type);

        if (ret) {

            error_setg_errno(errp, errno, "failed to set iommu for container");

            ret = -errno;

            goto free_container_exit;

        }

    switch (container->iommu_type) {

    case VFIO_TYPE1v2_IOMMU:

    case VFIO_TYPE1_IOMMU:

    {

        struct vfio_iommu_type1_info info;



        /*

         * FIXME: This assumes that a Type1 IOMMU can map any 64-bit
@@ -1137,30 +1201,13 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as, 
        }

        vfio_host_win_add(container, 0, (hwaddr)-1, info.iova_pgsizes);

        container->pgsizes = info.iova_pgsizes;

    } 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) {

            error_setg_errno(errp, errno, "failed to set group container");

            ret = -errno;

            goto free_container_exit;

        }

        container->iommu_type =

            v2 ? VFIO_SPAPR_TCE_v2_IOMMU : VFIO_SPAPR_TCE_IOMMU;

        ret = ioctl(fd, VFIO_SET_IOMMU, container->iommu_type);

        if (ret) {

            container->iommu_type = VFIO_SPAPR_TCE_IOMMU;

            v2 = false;

            ret = ioctl(fd, VFIO_SET_IOMMU, container->iommu_type);

        }

        if (ret) {

            error_setg_errno(errp, errno, "failed to set iommu for container");

            ret = -errno;

            goto free_container_exit;

        break;

    }

    case VFIO_SPAPR_TCE_v2_IOMMU:

    case VFIO_SPAPR_TCE_IOMMU:

    {

        struct vfio_iommu_spapr_tce_info info;

        bool v2 = container->iommu_type == VFIO_SPAPR_TCE_v2_IOMMU;



        /*

         * The host kernel code implementing VFIO_IOMMU_DISABLE is called
@@ -1222,10 +1269,7 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as, 
                              info.dma32_window_size - 1,

                              0x1000);

        }

    } else {

        error_setg(errp, "No available IOMMU models");

        ret = -EINVAL;

        goto free_container_exit;

    }

    }



    vfio_kvm_device_add_group(group);

hw/vfio/trace-events

+1 −0
Original line number Diff line number Diff line
@@ -110,6 +110,7 @@ vfio_region_mmaps_set_enabled(const char *name, bool enabled) "Region %s mmaps e 
vfio_region_sparse_mmap_header(const char *name, int index, int nr_areas) "Device %s region %d: %d sparse mmap entries"

vfio_region_sparse_mmap_entry(int i, unsigned long start, unsigned long end) "sparse entry %d [0x%lx - 0x%lx]"

vfio_get_dev_region(const char *name, int index, uint32_t type, uint32_t subtype) "%s index %d, %08x/%0x8"

vfio_dma_unmap_overflow_workaround(void) ""



# hw/vfio/platform.c

vfio_platform_base_device_init(char *name, int groupid) "%s belongs to group #%d"