From aca086ff27c3f67e81617e4b063d1126544a4f19 Mon Sep 17 00:00:00 2001 From: Ondrej Kozina Date: Fri, 6 Feb 2026 15:17:58 +0100 Subject: sed-opal: add IOC_OPAL_REACTIVATE_LSP. This adds the 'Reactivate' method as described in the "TCG Storage Opal SSC Feature Set: Single User Mode" document (ch. 3.1.1.1). The method enables switching an already active SED OPAL2 device, with appropriate firmware support for Single User Mode (SUM), to or from SUM. Signed-off-by: Ondrej Kozina Reviewed-and-tested-by: Milan Broz Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- include/uapi/linux/sed-opal.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/sed-opal.h b/include/uapi/linux/sed-opal.h index 9025dd5a4f0f..d03e590b6501 100644 --- a/include/uapi/linux/sed-opal.h +++ b/include/uapi/linux/sed-opal.h @@ -74,6 +74,19 @@ struct opal_lr_act { __u8 align[2]; /* Align to 8 byte boundary */ }; +struct opal_lr_react { + struct opal_key key; + struct opal_key new_admin_key; /* Set new Admin1 PIN if key_len is > 0 */ + __u8 num_lrs; /* + * Configure selected ranges (from lr[]) in SUM. + * If num_lrs > 0 the 'entire_table' must be 0 + */ + __u8 lr[OPAL_MAX_LRS]; + __u8 range_policy; /* Set RangeStartRangeLengthPolicy parameter */ + __u8 entire_table; /* Set all locking objects in SUM */ + __u8 align[4]; /* Align to 8 byte boundary */ +}; + struct opal_session_info { __u32 sum; __u32 who; @@ -216,5 +229,6 @@ struct opal_revert_lsp { #define IOC_OPAL_DISCOVERY _IOW('p', 239, struct opal_discovery) #define IOC_OPAL_REVERT_LSP _IOW('p', 240, struct opal_revert_lsp) #define IOC_OPAL_SET_SID_PW _IOW('p', 241, struct opal_new_pw) +#define IOC_OPAL_REACTIVATE_LSP _IOW('p', 242, struct opal_lr_react) #endif /* _UAPI_SED_OPAL_H */ -- cgit v1.2.3 From 8e3d34a7ce7386b01947dd649bd24775544e4d3e Mon Sep 17 00:00:00 2001 From: Ondrej Kozina Date: Fri, 6 Feb 2026 15:18:00 +0100 Subject: sed-opal: add IOC_OPAL_LR_SET_START_LEN ioctl. This ioctl is used to set up locking range start (offset) and locking range length attributes only. In Single User Mode (SUM), if the RangeStartRangeLengthPolicy parameter is set in the 'Reactivate' method, only Admin authority maintains the locking range length and start (offset) attributes of Locking objects set up for SUM. All other attributes from struct opal_user_lr_setup (RLE - read locking enabled, WLE - write locking enabled) shall remain in possession of the User authority associated with the Locking object set for SUM. Therefore, we need a separate function for setting up locking range start and locking range length because it may require two different authorities (and sessions) if the RangeStartRangeLengthPolicy attribute is set. With the IOC_OPAL_LR_SET_START_LEN ioctl, the opal_user_lr_setup members 'RLE' and 'WLE' of the ioctl argument are ignored. Signed-off-by: Ondrej Kozina Reviewed-and-tested-by: Milan Broz Signed-off-by: Jens Axboe --- include/uapi/linux/sed-opal.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/sed-opal.h b/include/uapi/linux/sed-opal.h index d03e590b6501..82de38f3fbeb 100644 --- a/include/uapi/linux/sed-opal.h +++ b/include/uapi/linux/sed-opal.h @@ -230,5 +230,6 @@ struct opal_revert_lsp { #define IOC_OPAL_REVERT_LSP _IOW('p', 240, struct opal_revert_lsp) #define IOC_OPAL_SET_SID_PW _IOW('p', 241, struct opal_new_pw) #define IOC_OPAL_REACTIVATE_LSP _IOW('p', 242, struct opal_lr_react) +#define IOC_OPAL_LR_SET_START_LEN _IOW('p', 243, struct opal_user_lr_setup) #endif /* _UAPI_SED_OPAL_H */ -- cgit v1.2.3 From a441a9d22433fea561de131e27fff41715c2d186 Mon Sep 17 00:00:00 2001 From: Ondrej Kozina Date: Fri, 6 Feb 2026 15:18:01 +0100 Subject: sed-opal: add IOC_OPAL_ENABLE_DISABLE_LR. This ioctl is used to set up RLE (read lock enabled) and WLE (write lock enabled) parameters of the Locking object. In Single User Mode (SUM), if the RangeStartRangeLengthPolicy parameter is set in the 'Reactivate' method, only Admin authority maintains the locking range length and start (offset) attributes of Locking objects set up for SUM. All other attributes from struct opal_user_lr_setup (RLE - read locking enabled, WLE - write locking enabled) shall remain in possession of the User authority associated with the Locking object set for SUM. With the IOC_OPAL_ENABLE_DISABLE_LR ioctl, the opal_user_lr_setup members 'range_start' and 'range_length' of the ioctl argument are ignored. Signed-off-by: Ondrej Kozina Reviewed-and-tested-by: Milan Broz Signed-off-by: Jens Axboe --- include/uapi/linux/sed-opal.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/sed-opal.h b/include/uapi/linux/sed-opal.h index 82de38f3fbeb..bde023ae2295 100644 --- a/include/uapi/linux/sed-opal.h +++ b/include/uapi/linux/sed-opal.h @@ -231,5 +231,6 @@ struct opal_revert_lsp { #define IOC_OPAL_SET_SID_PW _IOW('p', 241, struct opal_new_pw) #define IOC_OPAL_REACTIVATE_LSP _IOW('p', 242, struct opal_lr_react) #define IOC_OPAL_LR_SET_START_LEN _IOW('p', 243, struct opal_user_lr_setup) +#define IOC_OPAL_ENABLE_DISABLE_LR _IOW('p', 244, struct opal_user_lr_setup) #endif /* _UAPI_SED_OPAL_H */ -- cgit v1.2.3 From 0cc9293bccb234552b81c3ebc074f5839f019e01 Mon Sep 17 00:00:00 2001 From: Ondrej Kozina Date: Fri, 6 Feb 2026 15:18:03 +0100 Subject: sed-opal: add IOC_OPAL_GET_SUM_STATUS ioctl. This adds a function for retrieving the set of Locking objects enabled for Single User Mode (SUM) and the value of the RangeStartRangeLengthPolicy parameter. It retrieves data from the LockingInfo table, specifically the columns SingleUserModeRanges and RangeStartLengthPolicy, which were added according to the TCG Opal Feature Set: Single User Mode, as described in chapters 4.4.3.1 and 4.4.3.2. Signed-off-by: Ondrej Kozina Reviewed-and-tested-by: Milan Broz Signed-off-by: Jens Axboe --- include/uapi/linux/sed-opal.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/sed-opal.h b/include/uapi/linux/sed-opal.h index bde023ae2295..9830298ec51c 100644 --- a/include/uapi/linux/sed-opal.h +++ b/include/uapi/linux/sed-opal.h @@ -111,6 +111,18 @@ struct opal_lr_status { __u8 align[4]; }; +struct opal_sum_ranges { + /* + * Initiate Admin1 session if key_len > 0, + * use Anybody session otherwise. + */ + struct opal_key key; + __u8 num_lrs; + __u8 lr[OPAL_MAX_LRS]; + __u8 range_policy; + __u8 align[5]; /* Align to 8 byte boundary */ +}; + struct opal_lock_unlock { struct opal_session_info session; __u32 l_state; @@ -232,5 +244,6 @@ struct opal_revert_lsp { #define IOC_OPAL_REACTIVATE_LSP _IOW('p', 242, struct opal_lr_react) #define IOC_OPAL_LR_SET_START_LEN _IOW('p', 243, struct opal_user_lr_setup) #define IOC_OPAL_ENABLE_DISABLE_LR _IOW('p', 244, struct opal_user_lr_setup) +#define IOC_OPAL_GET_SUM_STATUS _IOW('p', 245, struct opal_sum_ranges) #endif /* _UAPI_SED_OPAL_H */ -- cgit v1.2.3 From 7da9261bab0a82bdbc4aafd2ad4bc3529b7cb772 Mon Sep 17 00:00:00 2001 From: Yang Xiuwei Date: Tue, 17 Mar 2026 15:22:24 +0800 Subject: bsg: add bsg_uring_cmd uapi structure Add the bsg_uring_cmd structure to the BSG UAPI header to support io_uring-based SCSI passthrough operations via IORING_OP_URING_CMD. Signed-off-by: Yang Xiuwei Reviewed-by: Bart Van Assche Link: https://patch.msgid.link/20260317072226.2598233-2-yangxiuwei@kylinos.cn Signed-off-by: Jens Axboe --- include/uapi/linux/bsg.h | 75 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/bsg.h b/include/uapi/linux/bsg.h index cd6302def5ed..6cff77f5b857 100644 --- a/include/uapi/linux/bsg.h +++ b/include/uapi/linux/bsg.h @@ -2,6 +2,9 @@ #ifndef _UAPIBSG_H #define _UAPIBSG_H +#ifdef __KERNEL__ +#include +#endif /* __KERNEL__ */ #include #define BSG_PROTOCOL_SCSI 0 @@ -63,5 +66,77 @@ struct sg_io_v4 { __u32 padding; }; +struct bsg_uring_cmd { + __u64 request; /* [i], [*i] command descriptor address */ + __u32 request_len; /* [i] command descriptor length in bytes */ + __u32 protocol; /* [i] protocol type (BSG_PROTOCOL_*) */ + __u32 subprotocol; /* [i] subprotocol type (BSG_SUB_PROTOCOL_*) */ + __u32 max_response_len; /* [i] response buffer size in bytes */ + + __u64 response; /* [i], [*o] response data address */ + __u64 dout_xferp; /* [i], [*i] */ + __u32 dout_xfer_len; /* [i] bytes to be transferred to device */ + __u32 dout_iovec_count; /* [i] 0 -> "flat" dout transfer else + * dout_xferp points to array of iovec + */ + __u64 din_xferp; /* [i], [*o] */ + __u32 din_xfer_len; /* [i] bytes to be transferred from device */ + __u32 din_iovec_count; /* [i] 0 -> "flat" din transfer */ + + __u32 timeout_ms; /* [i] timeout in milliseconds */ + __u8 reserved[12]; /* reserved for future extension */ +}; + +#ifdef __KERNEL__ +/* Must match IORING_OP_URING_CMD payload size (e.g. SQE128). */ +static_assert(sizeof(struct bsg_uring_cmd) == 80); +#endif /* __KERNEL__ */ + + +/* + * SCSI BSG io_uring completion (res2, 64-bit) + * + * When using BSG_PROTOCOL_SCSI + BSG_SUB_PROTOCOL_SCSI_CMD with + * IORING_OP_URING_CMD, the completion queue entry (CQE) contains: + * - result: errno (0 on success) + * - res2: packed SCSI status + * + * res2 bit layout: + * [0..7] device_status (SCSI status byte, e.g. CHECK_CONDITION) + * [8..15] driver_status (e.g. DRIVER_SENSE when sense data is valid) + * [16..23] host_status (e.g. DID_OK, DID_TIME_OUT) + * [24..31] sense_len_wr (bytes of sense data written to response buffer) + * [32..63] resid_len (residual transfer length) + */ +static inline __u8 bsg_scsi_res2_device_status(__u64 res2) +{ + return res2 & 0xff; +} +static inline __u8 bsg_scsi_res2_driver_status(__u64 res2) +{ + return res2 >> 8; +} +static inline __u8 bsg_scsi_res2_host_status(__u64 res2) +{ + return res2 >> 16; +} +static inline __u8 bsg_scsi_res2_sense_len(__u64 res2) +{ + return res2 >> 24; +} +static inline __u32 bsg_scsi_res2_resid_len(__u64 res2) +{ + return res2 >> 32; +} +static inline __u64 bsg_scsi_res2_build(__u8 device_status, __u8 driver_status, + __u8 host_status, __u8 sense_len_wr, + __u32 resid_len) +{ + return ((__u64)(__u32)(resid_len) << 32) | + ((__u64)sense_len_wr << 24) | + ((__u64)host_status << 16) | + ((__u64)driver_status << 8) | + (__u64)device_status; +} #endif /* _UAPIBSG_H */ -- cgit v1.2.3 From 499d2d2f4cf9f16634db47b06dee9676611b897f Mon Sep 17 00:00:00 2001 From: Milan Broz Date: Tue, 10 Mar 2026 10:53:49 +0100 Subject: sed-opal: Add STACK_RESET command The TCG Opal device could enter a state where no new session can be created, blocking even Discovery or PSID reset. While a power cycle or waiting for the timeout should work, there is another possibility for recovery: using the Stack Reset command. The Stack Reset command is defined in the TCG Storage Architecture Core Specification and is mandatory for all Opal devices (see Section 3.3.6 of the Opal SSC specification). This patch implements the Stack Reset command. Sending it should clear all active sessions immediately, allowing subsequent commands to run successfully. While it is a TCG transport layer command, the Linux kernel implements only Opal ioctls, so it makes sense to use the IOC_OPAL ioctl interface. The Stack Reset takes no arguments; the response can be success or pending. If the command reports a pending state, userspace can try to repeat it; in this case, the code returns -EBUSY. Signed-off-by: Milan Broz Reviewed-by: Ondrej Kozina Link: https://patch.msgid.link/20260310095349.411287-1-gmazyland@gmail.com Signed-off-by: Jens Axboe --- include/uapi/linux/sed-opal.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/sed-opal.h b/include/uapi/linux/sed-opal.h index 9830298ec51c..ef4d3be6ca7f 100644 --- a/include/uapi/linux/sed-opal.h +++ b/include/uapi/linux/sed-opal.h @@ -245,5 +245,6 @@ struct opal_revert_lsp { #define IOC_OPAL_LR_SET_START_LEN _IOW('p', 243, struct opal_user_lr_setup) #define IOC_OPAL_ENABLE_DISABLE_LR _IOW('p', 244, struct opal_user_lr_setup) #define IOC_OPAL_GET_SUM_STATUS _IOW('p', 245, struct opal_sum_ranges) +#define IOC_OPAL_STACK_RESET _IO('p', 246) #endif /* _UAPI_SED_OPAL_H */ -- cgit v1.2.3 From 2fb0ded237bb55dae45bc076666b348fc948ac9e Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Tue, 31 Mar 2026 23:31:52 +0800 Subject: ublk: add UBLK_U_CMD_REG_BUF/UNREG_BUF control commands MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add control commands for registering and unregistering shared memory buffers for zero-copy I/O: - UBLK_U_CMD_REG_BUF (0x18): pins pages from userspace, inserts PFN ranges into a per-device maple tree for O(log n) lookup during I/O. Buffer pointers are tracked in a per-device xarray. Returns the assigned buffer index. - UBLK_U_CMD_UNREG_BUF (0x19): removes PFN entries and unpins pages. Queue freeze/unfreeze is handled internally so userspace need not quiesce the device during registration. Also adds: - UBLK_IO_F_SHMEM_ZC flag and addr encoding helpers in UAPI header (16-bit buffer index supporting up to 65536 buffers) - Data structures (ublk_buf, ublk_buf_range) and xarray/maple tree - __ublk_ctrl_reg_buf() helper for PFN insertion with error unwinding - __ublk_ctrl_unreg_buf() helper for cleanup reuse - ublk_support_shmem_zc() / ublk_dev_support_shmem_zc() stubs (returning false — feature not enabled yet) Signed-off-by: Ming Lei Link: https://patch.msgid.link/20260331153207.3635125-2-ming.lei@redhat.com [axboe: fixup ublk_buf_reg -> ublk_shmem_buf_reg errors, comments] Signed-off-by: Jens Axboe --- include/uapi/linux/ublk_cmd.h | 72 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h index a88876756805..5b71c19d3b9c 100644 --- a/include/uapi/linux/ublk_cmd.h +++ b/include/uapi/linux/ublk_cmd.h @@ -57,6 +57,44 @@ _IOWR('u', 0x16, struct ublksrv_ctrl_cmd) #define UBLK_U_CMD_TRY_STOP_DEV \ _IOWR('u', 0x17, struct ublksrv_ctrl_cmd) +/* + * Register a shared memory buffer for zero-copy I/O. + * Input: ctrl_cmd.addr points to struct ublk_shmem_buf_reg (buffer VA + size) + * ctrl_cmd.len = sizeof(struct ublk_shmem_buf_reg) + * Result: >= 0 is the assigned buffer index, < 0 is error + * + * The kernel pins pages from the calling process's address space + * and inserts PFN ranges into a per-device maple tree. When a block + * request's pages match registered pages, the driver sets + * UBLK_IO_F_SHMEM_ZC and encodes the buffer index + offset in addr, + * allowing the server to access the data via its own mapping of the + * same shared memory — true zero copy. + * + * The memory can be backed by memfd, hugetlbfs, or any GUP-compatible + * shared mapping. Queue freeze is handled internally. + * + * The buffer VA and size are passed via a user buffer (not inline in + * ctrl_cmd) so that unprivileged devices can prepend the device path + * to ctrl_cmd.addr without corrupting the VA. + */ +#define UBLK_U_CMD_REG_BUF \ + _IOWR('u', 0x18, struct ublksrv_ctrl_cmd) +/* + * Unregister a shared memory buffer. + * Input: ctrl_cmd.data[0] = buffer index + */ +#define UBLK_U_CMD_UNREG_BUF \ + _IOWR('u', 0x19, struct ublksrv_ctrl_cmd) + +/* Parameter buffer for UBLK_U_CMD_REG_BUF, pointed to by ctrl_cmd.addr */ +struct ublk_shmem_buf_reg { + __u64 addr; /* userspace virtual address of shared memory */ + __u32 len; /* buffer size in bytes (page-aligned, max 4GB) */ + __u32 flags; +}; + +/* Pin pages without FOLL_WRITE; usable with write-sealed memfd */ +#define UBLK_SHMEM_BUF_READ_ONLY (1U << 0) /* * 64bits are enough now, and it should be easy to extend in case of * running out of feature flags @@ -370,6 +408,7 @@ /* Disable automatic partition scanning when device is started */ #define UBLK_F_NO_AUTO_PART_SCAN (1ULL << 18) + /* device state */ #define UBLK_S_DEV_DEAD 0 #define UBLK_S_DEV_LIVE 1 @@ -469,6 +508,12 @@ struct ublksrv_ctrl_dev_info { #define UBLK_IO_F_NEED_REG_BUF (1U << 17) /* Request has an integrity data buffer */ #define UBLK_IO_F_INTEGRITY (1UL << 18) +/* + * I/O buffer is in a registered shared memory buffer. When set, the addr + * field in ublksrv_io_desc encodes buffer index and byte offset instead + * of a userspace virtual address. + */ +#define UBLK_IO_F_SHMEM_ZC (1U << 19) /* * io cmd is described by this structure, and stored in share memory, indexed @@ -743,4 +788,31 @@ struct ublk_params { struct ublk_param_integrity integrity; }; +/* + * Shared memory zero-copy addr encoding for UBLK_IO_F_SHMEM_ZC. + * + * When UBLK_IO_F_SHMEM_ZC is set, ublksrv_io_desc.addr is encoded as: + * bits [0:31] = byte offset within the buffer (up to 4GB) + * bits [32:47] = buffer index (up to 65536) + * bits [48:63] = reserved (must be zero) + */ +#define UBLK_SHMEM_ZC_OFF_MASK 0xffffffffULL +#define UBLK_SHMEM_ZC_IDX_OFF 32 +#define UBLK_SHMEM_ZC_IDX_MASK 0xffffULL + +static inline __u64 ublk_shmem_zc_addr(__u16 index, __u32 offset) +{ + return ((__u64)index << UBLK_SHMEM_ZC_IDX_OFF) | offset; +} + +static inline __u16 ublk_shmem_zc_index(__u64 addr) +{ + return (addr >> UBLK_SHMEM_ZC_IDX_OFF) & UBLK_SHMEM_ZC_IDX_MASK; +} + +static inline __u32 ublk_shmem_zc_offset(__u64 addr) +{ + return (__u32)(addr & UBLK_SHMEM_ZC_OFF_MASK); +} + #endif -- cgit v1.2.3 From 08677040a91199175149d1fd465c02e3b3fc768a Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Tue, 31 Mar 2026 23:31:54 +0800 Subject: ublk: enable UBLK_F_SHMEM_ZC feature flag Add UBLK_F_SHMEM_ZC (1ULL << 19) to the UAPI header and UBLK_F_ALL. Switch ublk_support_shmem_zc() and ublk_dev_support_shmem_zc() from returning false to checking the actual flag, enabling the shared memory zero-copy feature for devices that request it. Signed-off-by: Ming Lei Link: https://patch.msgid.link/20260331153207.3635125-4-ming.lei@redhat.com [axboe: ublk_buf_reg -> ublk_shmem_buf_reg errors] Signed-off-by: Jens Axboe --- include/uapi/linux/ublk_cmd.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h index 5b71c19d3b9c..a7078b798791 100644 --- a/include/uapi/linux/ublk_cmd.h +++ b/include/uapi/linux/ublk_cmd.h @@ -408,6 +408,13 @@ struct ublk_shmem_buf_reg { /* Disable automatic partition scanning when device is started */ #define UBLK_F_NO_AUTO_PART_SCAN (1ULL << 18) +/* + * Enable shared memory zero copy. When enabled, the server can register + * shared memory buffers via UBLK_U_CMD_REG_BUF. If a block request's + * pages match a registered buffer, UBLK_IO_F_SHMEM_ZC is set and addr + * encodes the buffer index + offset instead of a userspace buffer address. + */ +#define UBLK_F_SHMEM_ZC (1ULL << 19) /* device state */ #define UBLK_S_DEV_DEAD 0 -- cgit v1.2.3 From 23b3b6f0b584b70a427d5bb826d320151890d7da Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 9 Apr 2026 21:30:13 +0800 Subject: ublk: widen ublk_shmem_buf_reg.len to __u64 for 4GB buffer support The __u32 len field cannot represent a 4GB buffer (0x100000000 overflows to 0). Change it to __u64 so buffers up to 4GB can be registered. Add a reserved field for alignment and validate it is zero. The kernel enforces a default max of 4GB (UBLK_SHMEM_BUF_SIZE_MAX) which may be increased in future. Signed-off-by: Ming Lei Link: https://patch.msgid.link/20260409133020.3780098-2-tom.leiming@gmail.com Signed-off-by: Jens Axboe --- include/uapi/linux/ublk_cmd.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h index a7078b798791..6991370a72ce 100644 --- a/include/uapi/linux/ublk_cmd.h +++ b/include/uapi/linux/ublk_cmd.h @@ -89,8 +89,9 @@ /* Parameter buffer for UBLK_U_CMD_REG_BUF, pointed to by ctrl_cmd.addr */ struct ublk_shmem_buf_reg { __u64 addr; /* userspace virtual address of shared memory */ - __u32 len; /* buffer size in bytes (page-aligned, max 4GB) */ + __u64 len; /* buffer size in bytes, page-aligned, default max 4GB */ __u32 flags; + __u32 reserved; }; /* Pin pages without FOLL_WRITE; usable with write-sealed memfd */ -- cgit v1.2.3