iommufd: Introduce handler for device ATS support
Introduce a support_ats() handler that returns whether ATS is supported for a device associated with a host IOMMU device, checking if the IOMMU_HW_CAP_PCI_ATS_NOT_SUPPORTED capability bit is set. Implement this handler in a new function for iommufd. Suggested-by: Shameer Kolothum <skolothumtho@nvidia.com> Reviewed-by: Cédric Le Goater <clg@redhat.com> Reviewed-by: Shameer Kolothum <skolothumtho@nvidia.com> Signed-off-by: Nathan Chen <nathanc@nvidia.com> Link: https://lore.kernel.org/qemu-devel/20260623204943.989903-2-nathanc@nvidia.com Signed-off-by: Cédric Le Goater <clg@redhat.com>
Nathan Chen committed
Jun 23, 2026 at 13:49 UTC
6befa5527418bcece6a81adb5e047bae43b733bf
2 files changed
+17
backends/iommufd.c
+8
@@ -638,6 +638,13 @@ static int hiod_iommufd_get_cap(HostIOMMUDevice *hiod, int cap, Error **errp)
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}
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}
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+static bool hiod_iommufd_support_ats(HostIOMMUDevice *hiod)
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+{
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+ HostIOMMUDeviceCaps *caps = &hiod->caps;
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+
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+ return !(caps->hw_caps & IOMMU_HW_CAP_PCI_ATS_NOT_SUPPORTED);
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+}
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+
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static bool hiod_iommufd_get_pasid_info(HostIOMMUDevice *hiod,
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PasidInfo *pasid_info)
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{
@@ -660,6 +667,7 @@ static void hiod_iommufd_class_init(ObjectClass *oc, const void *data)
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hiodc->get_cap = hiod_iommufd_get_cap;
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hiodc->get_pasid_info = hiod_iommufd_get_pasid_info;
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+ hiodc->support_ats = hiod_iommufd_support_ats;
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};
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static const TypeInfo types[] = {
include/system/host_iommu_device.h
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@@ -133,6 +133,15 @@ struct HostIOMMUDeviceClass {
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* Returns: true on success, false on failure.
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*/
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bool (*get_pasid_info)(HostIOMMUDevice *hiod, PasidInfo *pasid_info);
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+ /**
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+ * @support_ats: Returns true if ATS can be used by the device,
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+ * false if the host IOMMU reports it is unavailable.
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+ *
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+ * @hiod: handle to the host IOMMU device
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+ *
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+ * Returns: true if ATS is supported, false otherwise
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+ */
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+ bool (*support_ats)(HostIOMMUDevice *hiod);
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};
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/*