On Wed, Sep 13, 2023 at 10:01:42AM +0200, Eric Auger wrote:
> The implementation populates the array of per IOMMUDevice
> host reserved regions.
>
> It is forbidden to have conflicting sets of host IOVA ranges
> to be applied onto the same IOMMU MR (implied by different
> host devices).
>
> Signed-off-by: Eric Auger <eric.au...@redhat.com>
>
> ---
>
> v1 -> v2:
> - Forbid conflicting sets of host resv regions
> ---
> include/hw/virtio/virtio-iommu.h | 2 ++
> hw/virtio/virtio-iommu.c | 48 ++++++++++++++++++++++++++++++++
> 2 files changed, 50 insertions(+)
>
> diff --git a/include/hw/virtio/virtio-iommu.h
> b/include/hw/virtio/virtio-iommu.h
> index 70b8ace34d..31b69c8261 100644
> --- a/include/hw/virtio/virtio-iommu.h
> +++ b/include/hw/virtio/virtio-iommu.h
> @@ -40,6 +40,8 @@ typedef struct IOMMUDevice {
> MemoryRegion root; /* The root container of the device */
> MemoryRegion bypass_mr; /* The alias of shared memory MR */
> GList *resv_regions;
> + Range *host_resv_regions;
> + uint32_t nr_host_resv_regions;
> } IOMMUDevice;
>
> typedef struct IOMMUPciBus {
> diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
> index ea359b586a..ed2df5116f 100644
> --- a/hw/virtio/virtio-iommu.c
> +++ b/hw/virtio/virtio-iommu.c
> @@ -20,6 +20,7 @@
> #include "qemu/osdep.h"
> #include "qemu/log.h"
> #include "qemu/iov.h"
> +#include "qemu/range.h"
> #include "exec/target_page.h"
> #include "hw/qdev-properties.h"
> #include "hw/virtio/virtio.h"
> @@ -1158,6 +1159,52 @@ static int
> virtio_iommu_set_page_size_mask(IOMMUMemoryRegion *mr,
> return 0;
> }
>
> +static int virtio_iommu_set_iova_ranges(IOMMUMemoryRegion *mr,
> + uint32_t nr_ranges,
> + struct Range *iova_ranges,
> + Error **errp)
> +{
> + IOMMUDevice *sdev = container_of(mr, IOMMUDevice, iommu_mr);
> + uint32_t nr_host_resv_regions;
> + Range *host_resv_regions;
> + int ret = -EINVAL;
> +
> + if (!nr_ranges) {
> + return 0;
> + }
> +
> + if (sdev->host_resv_regions) {
> + range_inverse_array(nr_ranges, iova_ranges,
> + &nr_host_resv_regions, &host_resv_regions,
> + 0, UINT64_MAX);
> + if (nr_host_resv_regions != sdev->nr_host_resv_regions) {
> + goto error;
> + }
> + for (int i = 0; i < nr_host_resv_regions; i++) {
> + Range *new = &host_resv_regions[i];
> + Range *existing = &sdev->host_resv_regions[i];
> +
> + if (!range_contains_range(existing, new)) {
> + goto error;
> + }
> + }
> + ret = 0;
> + goto out;
> + }
> +
> + range_inverse_array(nr_ranges, iova_ranges,
> + &sdev->nr_host_resv_regions,
> &sdev->host_resv_regions,
> + 0, UINT64_MAX);
Can set_iova_ranges() only be called for the first time before the guest
has had a chance to issue a probe request? Maybe we could add a
sanity-check that the guest hasn't issued a probe request yet, since we
can't notify about updated reserved regions.
I'm probably misremembering because I thought Linux set up IOMMU contexts
(including probe requests) before enabling DMA master in PCI which cause
QEMU VFIO to issue these calls. I'll double check.
Thanks,
Jean
> +
> + return 0;
> +error:
> + error_setg(errp, "IOMMU mr=%s Conflicting host reserved regions set!",
> + mr->parent_obj.name);
> +out:
> + g_free(host_resv_regions);
> + return ret;
> +}
> +
> static void virtio_iommu_system_reset(void *opaque)
> {
> VirtIOIOMMU *s = opaque;
> @@ -1453,6 +1500,7 @@ static void
> virtio_iommu_memory_region_class_init(ObjectClass *klass,
> imrc->replay = virtio_iommu_replay;
> imrc->notify_flag_changed = virtio_iommu_notify_flag_changed;
> imrc->iommu_set_page_size_mask = virtio_iommu_set_page_size_mask;
> + imrc->iommu_set_iova_ranges = virtio_iommu_set_iova_ranges;
> }
>
> static const TypeInfo virtio_iommu_info = {
> --
> 2.41.0
>
