[RFC QEMU PATCH 10/10] cxl-mailbox-utils: Add support for VCS Get Virtual CXL Switch Info command.

[Joshua Lant <joshualant@gmail.com>]

Adds support for FMAPI command 0x5200, for more
information see CXL Specification v3.2 (7.6.7.2.1).

Signed-off-by: Joshua Lant <joshualant@gmail.com>
---
 hw/cxl/cxl-mailbox-utils.c | 84 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)

diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index cf6cb65eb6..825ef35179 100644
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -123,6 +123,7 @@ enum {
         #define GET_PHYSICAL_PORT_STATE     0x1
         #define PHYSICAL_PORT_CONTROL       0x2
     VIRTUAL_SWITCH = 0x52,
+        #define GET_VIRTUAL_SWITCH_INFO      0x0
         #define BIND_VPPB     0x1
         #define UNBIND_VPPB       0x2
     TUNNEL = 0x53,
@@ -825,6 +826,87 @@ static CXLRetCode cmd_physical_port_control(const struct cxl_cmd *cmd,
     }
 }
 
+/* CXL r3.2 Section 7.6.7.2.1: Get Virtual CXL Switch Info (Opcode 5200h) */
+static CXLRetCode cmd_get_virtual_switch_info(const struct cxl_cmd *cmd,
+                                            uint8_t *payload_in,
+                                            size_t len_in,
+                                            uint8_t *payload_out,
+                                            size_t *len_out,
+                                            CXLCCI *cci)
+{
+    struct cxl_fmapi_get_virtual_switch_info_req_pl {
+        uint8_t start_vppb;
+        uint8_t vppb_list_limit;
+        uint8_t number_of_vcs;
+        uint8_t vcs_id_list[];
+    } QEMU_PACKED *in = (void *)payload_in;
+    struct vppb_info {
+            uint8_t binding_status;
+            uint8_t bound_port_id;
+            uint8_t bound_ld_id;
+            uint8_t rsv1;
+    } QEMU_PACKED;
+    struct vcs_info_block {
+            uint8_t vcs_id;
+            uint8_t vcs_state;
+            uint8_t usp_id;
+            uint8_t num_vppbs;
+            struct vppb_info vppbs[];
+    } QEMU_PACKED;
+    struct cxl_fmapi_get_virtual_switch_info_rsp_pl {
+            uint8_t num_vcs;
+            uint8_t rsv1[3];
+            struct vcs_info_block vcs_info_list[];
+    } QEMU_PACKED *out = (void *)payload_out;
+
+    uint8_t num_vcs_ret = cci->vcs->num_usp_ppbs;
+    uint8_t num_vppbs_ret;
+    ssize_t len_out_tmp = *len_out;
+    len_out_tmp = sizeof(struct cxl_fmapi_get_virtual_switch_info_rsp_pl) +
+        (num_vcs_ret * sizeof(*out->vcs_info_list));
+    for(int i = 0; i < num_vcs_ret; i++) {
+        //num_vppbs_ret = get_num_vppbs_in_vcs(cci->d, i);
+        num_vppbs_ret = cci->vcs->usp_ppbs[i]->info->num_vppbs;
+        //vPPB List Entry Count=min(vPPB List Limit, Number of vPPBs).
+        len_out_tmp = (num_vppbs_ret <= VPPB_LIST_LIMIT) ?
+                len_out_tmp + (num_vppbs_ret * sizeof(struct vppb_info)) :
+                len_out_tmp + (VPPB_LIST_LIMIT * sizeof(struct vppb_info));
+    }
+    *len_out = len_out_tmp;
+
+    out->num_vcs = num_vcs_ret;
+    out->rsv1[0] = 0;
+    out->rsv1[1] = 0;
+    out->rsv1[2] = 0;
+
+    uint8_t *ptr = (uint8_t *)out->vcs_info_list;
+
+    for (int i = 0; i < num_vcs_ret; i++) {
+        CXLVCSInfoBlock *info = cci->vcs->usp_ppbs[i]->info;
+        uint8_t num_vppbs = info->num_vppbs;
+        uint8_t vppb_count = MIN(num_vppbs - in->start_vppb,
+                                 in->vppb_list_limit);
+
+        /* write fixed vcs_info_block header (4 bytes) */
+        *ptr++ = info->vcs_id;
+        *ptr++ = info->vcs_state;
+        *ptr++ = info->usp_id;
+        *ptr++ = num_vppbs;
+
+        /* write vppb entries for current vcs */
+        for (int j = in->start_vppb; j < in->start_vppb + vppb_count; j++) {
+            struct vppb_info *v = (struct vppb_info *)ptr;
+            v->binding_status = info->vppbs[j]->binding_status;
+            v->bound_port_id  = info->vppbs[j]->bound_port_id;
+            v->bound_ld_id    = info->vppbs[j]->bound_ld_id;
+            v->rsv1           = 0;
+            ptr += sizeof(struct vppb_info);
+        }
+    }
+
+    return CXL_MBOX_SUCCESS;
+}
+
 /* CXL r3.2 Section 7.6.7.2.2: Bind vPPB (Opcode 5201h) */
 static CXLRetCode cmd_bind_vppb(const struct cxl_cmd *cmd,
                                             uint8_t *payload_in,
@@ -4974,6 +5056,8 @@ static const struct cxl_cmd cxl_cmd_set_vcs_mctp[256][256] = {
         cmd_get_physical_port_state, ~0, 0 },
     [PHYSICAL_SWITCH][PHYSICAL_PORT_CONTROL] = { "SWITCH_PHYSICAL_PORT_CONTROL",
         cmd_physical_port_control, 2, 0 },
+    [VIRTUAL_SWITCH][GET_VIRTUAL_SWITCH_INFO] = { "GET_VIRTUAL_SWITCH_INFO",
+        cmd_get_virtual_switch_info, ~0, 0 },
     [VIRTUAL_SWITCH][BIND_VPPB] = { "BIND_VPPB",
         cmd_bind_vppb, ~0, 0 },
     [VIRTUAL_SWITCH][UNBIND_VPPB] = { "UNBIND_VPPB",
-- 
2.47.3