On 6/10/25 17:39, Steve Sistare wrote:
Define the change process ioctl
Signed-off-by: Steve Sistare
Reviewed-by: Cédric Le Goater
Thanks,
C.
---
include/system/iommufd.h | 3 +++
backends/iommufd.c | 24
backends/trace-events| 1 +
3 files changed, 28 insertions(+)
diff --git a/include/system/iommufd.h b/include/system/iommufd.h
index 2d24d93..db5f2c7 100644
--- a/include/system/iommufd.h
+++ b/include/system/iommufd.h
@@ -69,6 +69,9 @@ bool iommufd_backend_invalidate_cache(IOMMUFDBackend *be,
uint32_t id,
uint32_t *entry_num, void *data,
Error **errp);
+bool iommufd_change_process_capable(IOMMUFDBackend *be);
+bool iommufd_change_process(IOMMUFDBackend *be, Error **errp);
+
#define TYPE_HOST_IOMMU_DEVICE_IOMMUFD TYPE_HOST_IOMMU_DEVICE "-iommufd"
OBJECT_DECLARE_TYPE(HostIOMMUDeviceIOMMUFD, HostIOMMUDeviceIOMMUFDClass,
HOST_IOMMU_DEVICE_IOMMUFD)
diff --git a/backends/iommufd.c b/backends/iommufd.c
index 3a2ecc7..87f81a0 100644
--- a/backends/iommufd.c
+++ b/backends/iommufd.c
@@ -73,6 +73,30 @@ static void iommufd_backend_class_init(ObjectClass *oc,
const void *data)
object_class_property_add_str(oc, "fd", NULL, iommufd_backend_set_fd);
}
+bool iommufd_change_process_capable(IOMMUFDBackend *be)
+{
+struct iommu_ioas_change_process args = {.size = sizeof(args)};
+
+/*
+ * Call IOMMU_IOAS_CHANGE_PROCESS to verify it is a recognized ioctl.
+ * This is a no-op if the process has not changed since DMA was mapped.
+ */
+return !ioctl(be->fd, IOMMU_IOAS_CHANGE_PROCESS, &args);
+}
+
+bool iommufd_change_process(IOMMUFDBackend *be, Error **errp)
+{
+struct iommu_ioas_change_process args = {.size = sizeof(args)};
+bool ret = !ioctl(be->fd, IOMMU_IOAS_CHANGE_PROCESS, &args);
+
+if (!ret) {
+error_setg_errno(errp, errno, "IOMMU_IOAS_CHANGE_PROCESS fd %d failed",
+ be->fd);
+}
+trace_iommufd_change_process(be->fd, ret);
+return ret;
+}
+
bool iommufd_backend_connect(IOMMUFDBackend *be, Error **errp)
{
int fd;
diff --git a/backends/trace-events b/backends/trace-events
index e5f3e70..56132d3 100644
--- a/backends/trace-events
+++ b/backends/trace-events
@@ -7,6 +7,7 @@ dbus_vmstate_loading(const char *id) "id: %s"
dbus_vmstate_saving(const char *id) "id: %s"
# iommufd.c
+iommufd_change_process(int fd, bool ret) "fd=%d (%d)"
iommufd_backend_connect(int fd, bool owned, uint32_t users) "fd=%d owned=%d
users=%d"
iommufd_backend_disconnect(int fd, uint32_t users) "fd=%d users=%d"
iommu_backend_set_fd(int fd) "pre-opened /dev/iommu fd=%d"
