[PATCH v3 2/4] net/gve: introduce extended adminq command

Jasper Tran O'Leary
2026-03-04T01:49:34Z

From: Vee Agarwal <veethebee@google.com>

Flow steering adminq commands are too large to fit into a normal adminq
command buffer which accepts at most 56 bytes. As a result, introduce
extended adminq commands which permit larger command buffers using
indirection. Namely, extended command operations point to inner command
buffers allocated at a specified DMA address. As specified with the
device, all extended commands will use inner opcodes larger than 0xFF.

Signed-off-by: Vee Agarwal <veethebee@google.com>
Signed-off-by: Jasper Tran O'Leary <jtranoleary@google.com>
Reviewed-by: Joshua Washington <joshwash@google.com>
---
drivers/net/gve/base/gve_adminq.c | 30 ++++++++++++++++++++++++++++++
drivers/net/gve/base/gve_adminq.h | 16 ++++++++++++++++
2 files changed, 46 insertions(+)

diff --git a/drivers/net/gve/base/gve_adminq.c b/drivers/net/gve/base/gve_adminq.c
index 64b9468..0cc6d44 100644
--- a/drivers/net/gve/base/gve_adminq.c
+++ b/drivers/net/gve/base/gve_adminq.c
@@ -438,6 +438,8 @@ static int gve_adminq_issue_cmd(struct gve_priv *priv,

memcpy(cmd, cmd_orig, sizeof(*cmd_orig));
opcode = be32_to_cpu(READ_ONCE32(cmd->opcode));
+ if (opcode == GVE_ADMINQ_EXTENDED_COMMAND)
+ opcode = be32_to_cpu(READ_ONCE32(cmd->extended_command.inner_opcode));

switch (opcode) {
case GVE_ADMINQ_DESCRIBE_DEVICE:
@@ -516,6 +518,34 @@ static int gve_adminq_execute_cmd(struct gve_priv *priv,
return gve_adminq_kick_and_wait(priv);
}

+static int gve_adminq_execute_extended_cmd(struct gve_priv *priv, u32 opcode,
+ size_t cmd_size, void *cmd_orig)
+{
+ union gve_adminq_command cmd;
+ struct gve_dma_mem inner_cmd_dma_mem;
+ void *inner_cmd;
+ int err;
+
+ inner_cmd = gve_alloc_dma_mem(&inner_cmd_dma_mem, cmd_size);
+ if (!inner_cmd)
+ return -ENOMEM;
+
+ memcpy(inner_cmd, cmd_orig, cmd_size);
+
+ memset(&cmd, 0, sizeof(cmd));
+ cmd.opcode = cpu_to_be32(GVE_ADMINQ_EXTENDED_COMMAND);
+ cmd.extended_command = (struct gve_adminq_extended_command) {
+ .inner_opcode = cpu_to_be32(opcode),
+ .inner_length = cpu_to_be32(cmd_size),
+ .inner_command_addr = cpu_to_be64(inner_cmd_dma_mem.pa),
+ };
+
+ err = gve_adminq_execute_cmd(priv, &cmd);
+
+ gve_free_dma_mem(&inner_cmd_dma_mem);
+ return err;
+}
+
/* The device specifies that the management vector can either be the first irq
* or the last irq. ntfy_blk_msix_base_idx indicates the first irq assigned to
* the ntfy blks. It if is 0 then the management vector is last, if it is 1 then
diff --git a/drivers/net/gve/base/gve_adminq.h b/drivers/net/gve/base/gve_adminq.h
index e237353..f52658e 100644
--- a/drivers/net/gve/base/gve_adminq.h
+++ b/drivers/net/gve/base/gve_adminq.h
@@ -25,8 +25,15 @@ enum gve_adminq_opcodes {
GVE_ADMINQ_REPORT_LINK_SPEED = 0xD,
GVE_ADMINQ_GET_PTYPE_MAP = 0xE,
GVE_ADMINQ_VERIFY_DRIVER_COMPATIBILITY = 0xF,
+ /* For commands that are larger than 56 bytes */
+ GVE_ADMINQ_EXTENDED_COMMAND = 0xFF,
};

+/* The normal adminq command is restricted to be 56 bytes at maximum. For the
+ * longer adminq command, it is wrapped by GVE_ADMINQ_EXTENDED_COMMAND with
+ * inner opcode of gve_adminq_extended_cmd_opcodes specified. The inner command
+ * is written in the dma memory allocated by GVE_ADMINQ_EXTENDED_COMMAND.
+ */
/* Admin queue status codes */
enum gve_adminq_statuses {
GVE_ADMINQ_COMMAND_UNSET = 0x0,
@@ -194,6 +201,14 @@ enum gve_driver_capbility {
#define GVE_DRIVER_CAPABILITY_FLAGS3 0x0
#define GVE_DRIVER_CAPABILITY_FLAGS4 0x0

+struct gve_adminq_extended_command {
+ __be32 inner_opcode;
+ __be32 inner_length;
+ __be64 inner_command_addr;
+};
+
+GVE_CHECK_STRUCT_LEN(16, gve_adminq_extended_command);
+
struct gve_driver_info {
u8 os_type; /* 0x05 = DPDK */
u8 driver_major;
@@ -440,6 +455,7 @@ union gve_adminq_command {
struct gve_adminq_get_ptype_map get_ptype_map;
struct gve_adminq_verify_driver_compatibility
verify_driver_compatibility;
+ struct gve_adminq_extended_command extended_command;
};
};
u8 reserved[64];
--
2.53.0.473.g4a7958ca14-goog