[PATCH RFC v2 14/14] nvme: Add NVME_IOCTL_CDQ to create/delete migration CDQs
Joel Granados
joel.granados at kernel.org
Fri Jul 24 04:11:08 PDT 2026
Controller Data Queue (CDQ) creation and deletion executed for the
migratable controller id defined in mc_id. When an eventfd file
descriptor is passed in tpt_fd, the AEN tail pointer trigger event is
routed as an eventfd signal. When tpt_fd is <= 0, the routing is turned
off.
Signed-off-by: Joel Granados <joel.granados at kernel.org>
---
drivers/nvme/host/cdq.c | 23 ++++++++++++++++++---
drivers/nvme/host/cdq.h | 4 +++-
drivers/nvme/host/ioctl.c | 44 ++++++++++++++++++++++++++++++++++++++++-
include/uapi/linux/nvme_ioctl.h | 22 +++++++++++++++++++++
4 files changed, 88 insertions(+), 5 deletions(-)
diff --git a/drivers/nvme/host/cdq.c b/drivers/nvme/host/cdq.c
index f4aabf0a8817058a11e6c30dcea9554076861327..ac10c8d48864615f53da232a547cd5da72630ed1 100644
--- a/drivers/nvme/host/cdq.c
+++ b/drivers/nvme/host/cdq.c
@@ -511,6 +511,22 @@ void nvme_delete_cdq(struct cdq_nvme_queue *cdq)
}
EXPORT_SYMBOL_GPL(nvme_delete_cdq);
+int nvme_delete_cdq_mcid(struct nvme_ctrl *ctrl, u16 mc_id)
+{
+ struct cdq_nvme_queue *cdq;
+ unsigned long i;
+
+ xa_for_each(&ctrl->cdqs, i, cdq) {
+ if (cdq->mc_id == mc_id) {
+ nvme_delete_cdq(cdq);
+ return 0;
+ }
+ }
+
+ return -ENOENT;
+}
+EXPORT_SYMBOL_GPL(nvme_delete_cdq_mcid);
+
int nvme_handle_cdq_aen_tpevent(struct nvme_ctrl *ctrl, u32 event_param)
{
u16 cdq_id = event_param & NVME_FEAT_CDQ_ID_MASK;
@@ -556,11 +572,12 @@ static int nvme_submit_create_cdq_cmd(struct cdq_nvme_queue *cdq)
return ret;
}
-int nvme_create_cdq(struct nvme_ctrl *ctrl, const u32 entry_nr, const u16 mc_id, const int tpt_fd)
+int nvme_create_cdq(struct nvme_ctrl *ctrl, const u32 entry_nr, const u16 mc_id,
+ const int tpt_fd, int *cdq_fd)
{
u64 size_nbyte = (u64)entry_nr * NVME_CDQ_MQ_ENTRY_NRBYTES;
struct cdq_nvme_queue *cdq = NULL;
- int ret, cdq_fd;
+ int ret;
/* The backing size and the CDQSIZE field are both u32 (bytes). */
if (size_nbyte > U32_MAX)
@@ -598,7 +615,7 @@ int nvme_create_cdq(struct nvme_ctrl *ctrl, const u32 entry_nr, const u16 mc_id,
if (ret)
goto del_cmd;
- ret = nvme_create_cdqfd(cdq, &cdq_fd);
+ ret = nvme_create_cdqfd(cdq, cdq_fd);
if (ret)
goto del_xarray;
diff --git a/drivers/nvme/host/cdq.h b/drivers/nvme/host/cdq.h
index 2958c6b92b1312930414b8466690aa7c0eb57754..06a6224a6583dd2ec7463c62f9381e0edcb6718f 100644
--- a/drivers/nvme/host/cdq.h
+++ b/drivers/nvme/host/cdq.h
@@ -89,7 +89,9 @@ void nvme_free_cdq(struct kref *ref);
* - Calls nvme_free_cdq if there are no more refs
*/
void nvme_delete_cdq(struct cdq_nvme_queue *cdq);
-int nvme_create_cdq(struct nvme_ctrl *ctrl, const u32 entry_nr, const u16 mc_id, int tpt_fd);
+int nvme_delete_cdq_mcid(struct nvme_ctrl *ctrl, u16 mc_id);
+int nvme_create_cdq(struct nvme_ctrl *ctrl, const u32 entry_nr, const u16 mc_id,
+ int tpt_fd, int *cdq_fd);
static inline void nvme_cdq_get(struct cdq_nvme_queue *cdq)
{
diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index 8844bbd395159e544218db413e066cae6c24b2f1..c289a220cb18b39bef4edbd0a8daaa4b46f8b4d9 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -8,6 +8,7 @@
#include <linux/nvme_ioctl.h>
#include <linux/io_uring/cmd.h>
#include "nvme.h"
+#include "cdq.h"
enum {
NVME_IOCTL_VEC = (1 << 0),
@@ -538,9 +539,46 @@ static int nvme_uring_cmd_io(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
return ret;
}
+static int nvme_user_cdq(struct nvme_ctrl *ctrl, void __user *argp)
+{
+ struct nvme_cdq_cmd cmd;
+ u32 entry_nr;
+ int ret, cdq_fd;
+
+ if (copy_from_user(&cmd, argp, sizeof(cmd)))
+ return -EFAULT;
+
+ /* A zero size requests deletion of the CDQ created for this mc_id. */
+ if (cmd.size_nbyte == 0)
+ return nvme_delete_cdq_mcid(ctrl, cmd.mc_id);
+
+ if (cmd.size_nbyte % NVME_CDQ_MQ_ENTRY_NRBYTES)
+ return -EINVAL;
+
+ entry_nr = cmd.size_nbyte / NVME_CDQ_MQ_ENTRY_NRBYTES;
+
+ ret = nvme_create_cdq(ctrl, entry_nr, cmd.mc_id, cmd.tpt_fd, &cdq_fd);
+ if (ret)
+ goto err_out;
+
+ cmd.cdq_fd = cdq_fd;
+ if (copy_to_user(argp, &cmd, sizeof(cmd))) {
+ ret = -EFAULT;
+ goto err_out;
+ }
+
+ return 0;
+
+err_out:
+ nvme_delete_cdq_mcid(ctrl, cmd.mc_id);
+ return ret;
+
+}
+
static bool is_ctrl_ioctl(unsigned int cmd)
{
- if (cmd == NVME_IOCTL_ADMIN_CMD || cmd == NVME_IOCTL_ADMIN64_CMD)
+ if (cmd == NVME_IOCTL_ADMIN_CMD || cmd == NVME_IOCTL_ADMIN64_CMD ||
+ cmd == NVME_IOCTL_CDQ)
return true;
if (is_sed_ioctl(cmd))
return true;
@@ -555,6 +593,8 @@ static int nvme_ctrl_ioctl(struct nvme_ctrl *ctrl, unsigned int cmd,
return nvme_user_cmd(ctrl, NULL, argp, 0, open_for_write);
case NVME_IOCTL_ADMIN64_CMD:
return nvme_user_cmd64(ctrl, NULL, argp, 0, open_for_write);
+ case NVME_IOCTL_CDQ:
+ return nvme_user_cdq(ctrl, argp);
default:
return sed_ioctl(ctrl->opal_dev, cmd, argp);
}
@@ -873,6 +913,8 @@ long nvme_dev_ioctl(struct file *file, unsigned int cmd,
return -EACCES;
nvme_queue_scan(ctrl);
return 0;
+ case NVME_IOCTL_CDQ:
+ return nvme_user_cdq(ctrl, argp);
default:
return -ENOTTY;
}
diff --git a/include/uapi/linux/nvme_ioctl.h b/include/uapi/linux/nvme_ioctl.h
index 2f76cba6716637baff53e167a6141b68420d75c3..b3fbab48a903bfb10521ca44d08e61fd2b37bbbd 100644
--- a/include/uapi/linux/nvme_ioctl.h
+++ b/include/uapi/linux/nvme_ioctl.h
@@ -92,6 +92,27 @@ struct nvme_uring_cmd {
__u32 rsvd2;
};
+struct nvme_cdq_cmd {
+ /* Migratable controller id (filled by user space). */
+ __u16 mc_id;
+
+ /*
+ * CDQ size in bytes: (number of entries) * 32. Must be a multiple of
+ * 32. A size of 0 requests deletion of the CDQ created for mc_id.
+ */
+ __u32 size_nbyte;
+
+ /*
+ * Tail Pointer Trigger eventfd file descriptor, passed when creating
+ * the CDQ. A value <= 0 means there is no eventfd and AERs are not
+ * forwarded.
+ */
+ __s32 tpt_fd;
+
+ /* Returned by the kernel: the CDQ file descriptor. */
+ __s32 cdq_fd;
+};
+
#define nvme_admin_cmd nvme_passthru_cmd
#define NVME_IOCTL_ID _IO('N', 0x40)
@@ -104,6 +125,7 @@ struct nvme_uring_cmd {
#define NVME_IOCTL_ADMIN64_CMD _IOWR('N', 0x47, struct nvme_passthru_cmd64)
#define NVME_IOCTL_IO64_CMD _IOWR('N', 0x48, struct nvme_passthru_cmd64)
#define NVME_IOCTL_IO64_CMD_VEC _IOWR('N', 0x49, struct nvme_passthru_cmd64)
+#define NVME_IOCTL_CDQ _IOWR('N', 0x50, struct nvme_cdq_cmd)
/* io_uring async commands: */
#define NVME_URING_CMD_IO _IOWR('N', 0x80, struct nvme_uring_cmd)
--
2.50.1
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