On 10/24/25 10:43 AM, Zhenzhong Duan wrote:
> In VFIO core, we call iommufd_backend_get_device_info() to return vendor
> specific hardware information data, but it's not good to extract this raw
> data in VFIO core.
>
> Introduce host_iommu_extract_quirks() to help extracting the raw data and
> return a bitmap in iommufd.c because it's the place defining
> iommufd_backend_get_device_info().
>
> The other choice is to put vendor data extracting code in vendor vIOMMU
> emulation file, but that will make those files mixed with vIOMMU
> emulation and host IOMMU extracting code, also need a new callback in
> PCIIOMMUOps. So we choose a simpler way as above.
up to now iommufd.c was arch independent. And on the other hand you
started to put iommufd specific info in intel_iommu.c so I am wondering
whether this is the good place to put this helper. Again, maybe consider
consider creating an intel_iommu_accel.c or something alike
Eric
>
> Suggested-by: Nicolin Chen <[email protected]>
> Signed-off-by: Zhenzhong Duan <[email protected]>
> Reviewed-by: Nicolin Chen <[email protected]>
> ---
> include/hw/iommu.h | 5 +++++
> include/system/host_iommu_device.h | 15 +++++++++++++++
> backends/iommufd.c | 13 +++++++++++++
> 3 files changed, 33 insertions(+)
>
> diff --git a/include/hw/iommu.h b/include/hw/iommu.h
> index 9b8bb94fc2..6d61410703 100644
> --- a/include/hw/iommu.h
> +++ b/include/hw/iommu.h
> @@ -22,4 +22,9 @@ enum viommu_flags {
> VIOMMU_FLAG_WANT_NESTING_PARENT = BIT_ULL(0),
> };
>
> +/* Host IOMMU quirks. Extracted from host IOMMU capabilities */
> +enum host_iommu_quirks {
> + HOST_IOMMU_QUIRK_NESTING_PARENT_BYPASS_RO = BIT_ULL(0),
> +};
> +
> #endif /* HW_IOMMU_H */
> diff --git a/include/system/host_iommu_device.h
> b/include/system/host_iommu_device.h
> index ab849a4a82..9ae7f4cc6d 100644
> --- a/include/system/host_iommu_device.h
> +++ b/include/system/host_iommu_device.h
> @@ -39,6 +39,21 @@ typedef struct HostIOMMUDeviceCaps {
> uint64_t hw_caps;
> VendorCaps vendor_caps;
> } HostIOMMUDeviceCaps;
> +
> +/**
> + * host_iommu_extract_quirk: Extract host IOMMU quirks
> + *
> + * This function converts @type specific hardware information data
> + * into a standard bitmap format.
> + *
> + * @type: IOMMU Hardware Info Types
> + *
> + * @VendorCaps: IOMMU @type specific hardware information data
> + *
> + * Returns: bitmap with each representing a host IOMMU quirk defined in
s/each/each bit
> + * enum host_iommu_quirks
> + */
> +uint64_t host_iommu_extract_quirks(uint32_t type, VendorCaps *caps);
> #endif
>
> #define TYPE_HOST_IOMMU_DEVICE "host-iommu-device"
> diff --git a/backends/iommufd.c b/backends/iommufd.c
> index 086bd67aea..61b991ec53 100644
> --- a/backends/iommufd.c
> +++ b/backends/iommufd.c
> @@ -19,6 +19,7 @@
> #include "migration/cpr.h"
> #include "monitor/monitor.h"
> #include "trace.h"
> +#include "hw/iommu.h"
> #include "hw/vfio/vfio-device.h"
> #include <sys/ioctl.h>
> #include <linux/iommufd.h>
> @@ -411,6 +412,18 @@ bool iommufd_backend_get_device_info(IOMMUFDBackend *be,
> uint32_t devid,
> return true;
> }
>
> +uint64_t host_iommu_extract_quirks(uint32_t type, VendorCaps *caps)
> +{
> + uint64_t quirks = 0;
> +
> + if (type == IOMMU_HW_INFO_TYPE_INTEL_VTD &&
> + caps->vtd.flags & IOMMU_HW_INFO_VTD_ERRATA_772415_SPR17) {
> + quirks |= HOST_IOMMU_QUIRK_NESTING_PARENT_BYPASS_RO;
> + }
> +
> + return quirks;
> +}
> +
> bool iommufd_backend_invalidate_cache(IOMMUFDBackend *be, uint32_t id,
> uint32_t data_type, uint32_t entry_len,
> uint32_t *entry_num, void *data,
