[RFC PATCH 11/22] ublk: bpf: enable ublk-bpf

[Ming Lei <tom.leiming@gmail.com>]

Add feature flag of UBLK_F_BPF, meantime pass bpf struct_ops prog
id via ublk parameter from userspace.

ublk-bpf needs to copy data between ublk request pages and userspace
buffer any more, so let ublk_need_map_io() return false for UBLK_F_BPF
too.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
---
 drivers/block/ublk/bpf.c      |  3 +--
 drivers/block/ublk/main.c     | 15 ++++++++++++++-
 drivers/block/ublk/ublk.h     | 10 ++++++----
 include/uapi/linux/ublk_cmd.h | 14 +++++++++++++-
 4 files changed, 34 insertions(+), 8 deletions(-)

diff --git a/drivers/block/ublk/bpf.c b/drivers/block/ublk/bpf.c
index 4179b7f61e92..ef1546a7ccda 100644
--- a/drivers/block/ublk/bpf.c
+++ b/drivers/block/ublk/bpf.c
@@ -79,8 +79,7 @@ int ublk_bpf_attach(struct ublk_device *ub)
 	if (!ublk_dev_support_bpf(ub))
 		return 0;
 
-	/* todo: ublk device need to provide struct_ops prog id */
-	ub->prog.prog_id = 0;
+	ub->prog.prog_id = ub->params.bpf.ops_id;
 	ub->prog.ops = &ublk_prog_consumer_ops;
 
 	return ublk_bpf_prog_attach(&ub->prog);
diff --git a/drivers/block/ublk/main.c b/drivers/block/ublk/main.c
index 0b136bc5247f..3c2ed9bf924d 100644
--- a/drivers/block/ublk/main.c
+++ b/drivers/block/ublk/main.c
@@ -416,6 +416,19 @@ static int ublk_validate_params(const struct ublk_device *ub)
 	else if (ublk_dev_is_zoned(ub))
 		return -EINVAL;
 
+	if (ub->params.types & UBLK_PARAM_TYPE_BPF) {
+		const struct ublk_param_bpf *p = &ub->params.bpf;
+
+		if (!ublk_dev_support_bpf(ub))
+			return -EINVAL;
+
+		if (!(p->flags & UBLK_BPF_HAS_OPS_ID))
+			return -EINVAL;
+	} else {
+		if (ublk_dev_support_bpf(ub))
+			return -EINVAL;
+	}
+
 	return 0;
 }
 
@@ -434,7 +447,7 @@ static inline bool ublk_support_user_copy(const struct ublk_queue *ubq)
 
 static inline bool ublk_need_map_io(const struct ublk_queue *ubq)
 {
-	return !ublk_support_user_copy(ubq);
+	return !(ublk_support_user_copy(ubq) || ublk_support_bpf(ubq));
 }
 
 static inline bool ublk_need_req_ref(const struct ublk_queue *ubq)
diff --git a/drivers/block/ublk/ublk.h b/drivers/block/ublk/ublk.h
index 7579b0032a3c..8343e70bd723 100644
--- a/drivers/block/ublk/ublk.h
+++ b/drivers/block/ublk/ublk.h
@@ -24,7 +24,8 @@
 		| UBLK_F_CMD_IOCTL_ENCODE \
 		| UBLK_F_USER_COPY \
 		| UBLK_F_ZONED \
-		| UBLK_F_USER_RECOVERY_FAIL_IO)
+		| UBLK_F_USER_RECOVERY_FAIL_IO \
+		| UBLK_F_BPF)
 
 #define UBLK_F_ALL_RECOVERY_FLAGS (UBLK_F_USER_RECOVERY \
 		| UBLK_F_USER_RECOVERY_REISSUE \
@@ -33,7 +34,8 @@
 /* All UBLK_PARAM_TYPE_* should be included here */
 #define UBLK_PARAM_TYPE_ALL                                \
 	(UBLK_PARAM_TYPE_BASIC | UBLK_PARAM_TYPE_DISCARD | \
-	 UBLK_PARAM_TYPE_DEVT | UBLK_PARAM_TYPE_ZONED)
+	 UBLK_PARAM_TYPE_DEVT | UBLK_PARAM_TYPE_ZONED | \
+	 UBLK_PARAM_TYPE_BPF)
 
 enum {
 	UBLK_BPF_IO_PREP	= 0,
@@ -193,12 +195,12 @@ static inline struct ublksrv_io_desc *ublk_get_iod(struct ublk_queue *ubq,
 
 static inline bool ublk_support_bpf(const struct ublk_queue *ubq)
 {
-	return false;
+	return ubq->flags & UBLK_F_BPF;
 }
 
 static inline bool ublk_dev_support_bpf(const struct ublk_device *ub)
 {
-	return false;
+	return ub->dev_info.flags & UBLK_F_BPF;
 }
 
 struct ublk_device *ublk_get_device(struct ublk_device *ub);
diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h
index a8bc98bb69fc..27cf14e65cbc 100644
--- a/include/uapi/linux/ublk_cmd.h
+++ b/include/uapi/linux/ublk_cmd.h
@@ -207,6 +207,9 @@
  */
 #define UBLK_F_USER_RECOVERY_FAIL_IO (1ULL << 9)
 
+/* ublk IO is handled by bpf prog */
+#define UBLK_F_BPF		(1ULL << 10)
+
 /* device state */
 #define UBLK_S_DEV_DEAD	0
 #define UBLK_S_DEV_LIVE	1
@@ -401,6 +404,13 @@ struct ublk_param_zoned {
 	__u8	reserved[20];
 };
 
+struct ublk_param_bpf {
+#define UBLK_BPF_HAS_OPS_ID            (1 << 0)
+	__u8	flags;
+	__u8	ops_id;
+	__u8	reserved[6];
+};
+
 struct ublk_params {
 	/*
 	 * Total length of parameters, userspace has to set 'len' for both
@@ -413,12 +423,14 @@ struct ublk_params {
 #define UBLK_PARAM_TYPE_DISCARD         (1 << 1)
 #define UBLK_PARAM_TYPE_DEVT            (1 << 2)
 #define UBLK_PARAM_TYPE_ZONED           (1 << 3)
+#define UBLK_PARAM_TYPE_BPF             (1 << 4)
 	__u32	types;			/* types of parameter included */
 
 	struct ublk_param_basic		basic;
 	struct ublk_param_discard	discard;
 	struct ublk_param_devt		devt;
-	struct ublk_param_zoned	zoned;
+	struct ublk_param_zoned		zoned;
+	struct ublk_param_bpf		bpf;
 };
 
 #endif
-- 
2.47.0