On 6/12/26 03:43, Nathan Chen wrote:
From: Nathan Chen <[email protected]>
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 <[email protected]>
Signed-off-by: Nathan Chen <[email protected]>
---
include/system/host_iommu_device.h | 10 ++++++++++
backends/iommufd.c | 8 ++++++++
2 files changed, 18 insertions(+)
diff --git a/include/system/host_iommu_device.h
b/include/system/host_iommu_device.h
index f000301583..5615d6cb57 100644
--- a/include/system/host_iommu_device.h
+++ b/include/system/host_iommu_device.h
@@ -133,6 +133,16 @@ struct HostIOMMUDeviceClass {
* Returns: true on success, false on failure.
*/
bool (*get_pasid_info)(HostIOMMUDevice *hiod, PasidInfo *pasid_info);
+ /**
+ * @support_ats: Return whether ATS is supported for the device
+ * associated with @hiod host IOMMU device, checking if the
+ * IOMMU_HW_CAP_PCI_ATS_NOT_SUPPORTED capability bit is set.
IOMMU_HW_CAP_PCI_ATS_NOT_SUPPORTED is low level implementation detail,
which could differ on a future host IOMMU backend.
I would remove "checking if the IOMMU_HW_CAP_PCI_ATS_NOT_SUPPORTED
capability bit is set."
Something like this is more generic :
Returns true if ATS can be used by the device, false if the host IOMMU
reports it is unavailable.
Thanks,
C.
+ *
+ * @hiod: handle to the host IOMMU device
+ *
+ * Returns: true if ATS is supported, false otherwise
+ */
+ bool (*support_ats)(HostIOMMUDevice *hiod);
};
/*
diff --git a/backends/iommufd.c b/backends/iommufd.c
index 410b044370..7cc6767b4b 100644
--- a/backends/iommufd.c
+++ b/backends/iommufd.c
@@ -573,6 +573,13 @@ static int hiod_iommufd_get_cap(HostIOMMUDevice *hiod, int
cap, Error **errp)
}
}
+static bool hiod_iommufd_support_ats(HostIOMMUDevice *hiod)
+{
+ HostIOMMUDeviceCaps *caps = &hiod->caps;
+
+ return !(caps->hw_caps & IOMMU_HW_CAP_PCI_ATS_NOT_SUPPORTED);
+}
+
static bool hiod_iommufd_get_pasid_info(HostIOMMUDevice *hiod,
PasidInfo *pasid_info)
{
@@ -595,6 +602,7 @@ static void hiod_iommufd_class_init(ObjectClass *oc, const
void *data)
hiodc->get_cap = hiod_iommufd_get_cap;
hiodc->get_pasid_info = hiod_iommufd_get_pasid_info;
+ hiodc->support_ats = hiod_iommufd_support_ats;
};
static const TypeInfo types[] = {
