On 2020-09-08 20:03, Philippe Mathieu-Daudé wrote:
> This driver uses the host page size to align its memory regions,
> but this size is not always compatible with the IOMMU. Add a
> check if the size matches, and bails out with listing the sizes
> the IOMMU supports.
>
> Example on Aarch64:
>
> $ qemu-system-aarch64 -M virt -drive
> if=none,id=nvme0,file=nvme://0006:90:00.0/1,format=raw
> qemu-system-aarch64: -drive
> if=none,id=nvme0,file=nvme://0006:90:00.0/1,format=raw: Unsupported IOMMU
> page size: 4 KiB
> Available page size:
> 64 KiB
> 512 MiB
>
> Suggested-by: Alex Williamson <alex.william...@redhat.com>
> Signed-off-by: Philippe Mathieu-Daudé <phi...@redhat.com>
> ---
> util/vfio-helpers.c | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c
> index 55b4107ce69..6d9ec7d365c 100644
> --- a/util/vfio-helpers.c
> +++ b/util/vfio-helpers.c
> @@ -11,6 +11,7 @@
> */
>
> #include "qemu/osdep.h"
> +#include "qemu/cutils.h"
> #include <sys/ioctl.h>
> #include <linux/vfio.h>
> #include "qapi/error.h"
> @@ -316,6 +317,25 @@ static int qemu_vfio_init_pci(QEMUVFIOState *s, const
> char *device,
> ret = -errno;
> goto fail;
> }
> + if (!(iommu_info.flags & VFIO_IOMMU_INFO_PGSIZES)) {
> + error_setg(errp, "Failed to get IOMMU page size info");
> + ret = -errno;
We don't have errno here, do we?
> + goto fail;
> + }
> + if (!extract64(iommu_info.iova_pgsizes,
> + ctz64(qemu_real_host_page_size), 1)) {
> + g_autofree char *host_page_size =
> size_to_str(qemu_real_host_page_size);
> + error_setg(errp, "Unsupported IOMMU page size: %s", host_page_size);
> + error_append_hint(errp, "Available page size:\n");
> + for (int i = 0; i < 64; i++) {
> + if (extract64(iommu_info.iova_pgsizes, i, 1)) {
> + g_autofree char *iova_pgsizes = size_to_str(1UL << i);
> + error_append_hint(errp, " %s\n", iova_pgsizes);
Interesting... Since it's printing page size which is fairly low level,
why not just plain (hex) numbers?
Fam
> + }
> + }
> + ret = -EINVAL;
> + goto fail;
> + }
>
> s->device = ioctl(s->group, VFIO_GROUP_GET_DEVICE_FD, device);
>
> --
> 2.26.2
>
>
