[PATCH 2/2] hw/cxl: Add the Get Supported Logs Sub-List cmd

[Davidlohr Bueso <dave@stgolabs.net>]

The spec is quite clear that system software should try using
this instead of the traditional GSL - albeit both qemu and driver
only have CEL. In addition make the already existing commands a
bit more generic for any addition of future logs.

As noted in the code, the spec is also not explicit about all
input scan range errors - for which qemu can return 0 entries but
still set the total number of entries available.

Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
---
 hw/cxl/cxl-mailbox-utils.c | 101 ++++++++++++++++++++++++++++++++++---
 1 file changed, 94 insertions(+), 7 deletions(-)

diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index 5152a83c6fdd..0110797b7b52 100644
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -64,6 +64,7 @@ enum {
     LOGS        = 0x04,
         #define GET_SUPPORTED 0x0
         #define GET_LOG       0x1
+        #define GET_SUPPORTED_SUBLIST  0x5
     IDENTIFY    = 0x40,
         #define MEMORY_DEVICE 0x0
     CCLS        = 0x41,
@@ -602,6 +603,11 @@ static CXLRetCode cmd_timestamp_set(const struct cxl_cmd *cmd,
     return CXL_MBOX_SUCCESS;
 }
 
+enum {
+    CXL_LOGS_CEL,
+    CXL_MAX_SUPPORTED_LOGS,
+};
+
 /* CXL 3.0 8.2.9.5.2.1 Command Effects Log (CEL) */
 static const QemuUUID cel_uuid = {
     .data = UUID(0x0da9c0b5, 0xbf41, 0x4b78, 0x8f, 0x79,
@@ -616,20 +622,28 @@ static CXLRetCode cmd_logs_get_supported(const struct cxl_cmd *cmd,
                                          size_t *len_out,
                                          CXLCCI *cci)
 {
+    uint16_t i;
     struct {
         uint16_t entries;
         uint8_t rsvd[6];
         struct {
             QemuUUID uuid;
             uint32_t size;
-        } log_entries[1];
+        } log_entries[CXL_MAX_SUPPORTED_LOGS];
     } QEMU_PACKED *supported_logs = (void *)payload_out;
     QEMU_BUILD_BUG_ON(sizeof(*supported_logs) != 0x1c);
 
-    supported_logs->entries = 1;
-    supported_logs->log_entries[0].uuid = cel_uuid;
-    supported_logs->log_entries[0].size = 4 * cci->cel_size;
-
+    supported_logs->entries = CXL_MAX_SUPPORTED_LOGS;
+    for (i = 0; i < CXL_MAX_SUPPORTED_LOGS; i++) { /* all */
+        switch (i) {
+        case CXL_LOGS_CEL:
+            supported_logs->log_entries[i].uuid = cel_uuid;
+            supported_logs->log_entries[i].size = 4 * cci->cel_size;
+            break;
+        default:
+            break;
+        }
+    }
     *len_out = sizeof(*supported_logs);
     return CXL_MBOX_SUCCESS;
 }
@@ -642,6 +656,8 @@ static CXLRetCode cmd_logs_get_log(const struct cxl_cmd *cmd,
                                    size_t *len_out,
                                    CXLCCI *cci)
 {
+    uint8_t i;
+    bool found = false;
     struct {
         QemuUUID uuid;
         uint32_t offset;
@@ -661,8 +677,15 @@ static CXLRetCode cmd_logs_get_log(const struct cxl_cmd *cmd,
         return CXL_MBOX_INVALID_INPUT;
     }
 
-    if (!qemu_uuid_is_equal(&get_log->uuid, &cel_uuid)) {
-        return CXL_MBOX_UNSUPPORTED;
+    for (i = 0; i < CXL_MAX_SUPPORTED_LOGS; i++) { /* all */
+        if (i == CXL_LOGS_CEL &&
+            qemu_uuid_is_equal(&get_log->uuid, &cel_uuid)) {
+                found = true;
+                break;
+        }
+    }
+    if (!found) {
+         return CXL_MBOX_UNSUPPORTED;
     }
 
     /* Store off everything to local variables so we can wipe out the payload */
@@ -673,6 +696,66 @@ static CXLRetCode cmd_logs_get_log(const struct cxl_cmd *cmd,
     return CXL_MBOX_SUCCESS;
 }
 
+/* CXL r3.0 8.2.9.5.6 */
+static CXLRetCode cmd_logs_get_supported_sublist(const struct cxl_cmd *cmd,
+                                                 uint8_t *payload_in,
+                                                 size_t len_in,
+                                                 uint8_t *payload_out,
+                                                 size_t *len_out,
+                                                 CXLCCI *cci)
+{
+    uint8_t i, entries, start;
+    struct inject_poison_pl {
+        uint8_t max_entries;
+        uint8_t start_idx;
+    } QEMU_PACKED *in = (void *)payload_in;
+    struct {
+        uint8_t entries;
+        uint8_t rsvd1;
+        uint16_t total_entries;
+        uint8_t start_idx;
+        uint8_t rsvd2[3];
+        struct {
+            QemuUUID uuid;
+            uint32_t size;
+        } log_entries[CXL_MAX_SUPPORTED_LOGS];
+    } QEMU_PACKED *supported_logs = (void *)payload_out;
+    QEMU_BUILD_BUG_ON(sizeof(*supported_logs) != 0x1c);
+
+    if (in->max_entries < 1) {
+        return CXL_MBOX_INVALID_INPUT;
+    }
+    /*
+     * XXX: Handle other bogus input by returning zero entries but
+     * setting the total_entries such that software user can
+     * get it right next time(?) CXL spec mentions nothing about
+     * handling this.
+     */
+    if (in->start_idx > CXL_MAX_SUPPORTED_LOGS - 1) {
+        start = 0;
+        entries = 0;
+    } else {
+        start = in->start_idx;
+        entries = MIN(CXL_MAX_SUPPORTED_LOGS - start, in->max_entries);
+    }
+    supported_logs->entries = entries;
+    supported_logs->total_entries = CXL_MAX_SUPPORTED_LOGS;
+    supported_logs->start_idx = start;
+    for (i = start; i < entries; i++) {
+        switch (i) {
+        case CXL_LOGS_CEL:
+            supported_logs->log_entries[i].uuid = cel_uuid;
+            supported_logs->log_entries[i].size = 4 * cci->cel_size;
+            break;
+        default:
+            break;
+        }
+    }
+
+    *len_out = sizeof(*supported_logs);
+    return CXL_MBOX_SUCCESS;
+}
+
 /* 8.2.9.5.1.1 */
 static CXLRetCode cmd_identify_memory_device(const struct cxl_cmd *cmd,
                                              uint8_t *payload_in,
@@ -1172,6 +1255,8 @@ static const struct cxl_cmd cxl_cmd_set[256][256] = {
     [TIMESTAMP][SET] = { "TIMESTAMP_SET", cmd_timestamp_set, 8, IMMEDIATE_POLICY_CHANGE },
     [LOGS][GET_SUPPORTED] = { "LOGS_GET_SUPPORTED", cmd_logs_get_supported, 0, 0 },
     [LOGS][GET_LOG] = { "LOGS_GET_LOG", cmd_logs_get_log, 0x18, 0 },
+    [LOGS][GET_SUPPORTED_SUBLIST] = { "LOGS_GET_SUPPORTED_SUBLIST",
+                                      cmd_logs_get_supported_sublist, 0x02, 0 },
     [IDENTIFY][MEMORY_DEVICE] = { "IDENTIFY_MEMORY_DEVICE",
         cmd_identify_memory_device, 0, 0 },
     [CCLS][GET_PARTITION_INFO] = { "CCLS_GET_PARTITION_INFO",
@@ -1203,6 +1288,8 @@ static const struct cxl_cmd cxl_cmd_set_sw[256][256] = {
     [TIMESTAMP][SET] = { "TIMESTAMP_SET", cmd_timestamp_set, 8, IMMEDIATE_POLICY_CHANGE },
     [LOGS][GET_SUPPORTED] = { "LOGS_GET_SUPPORTED", cmd_logs_get_supported, 0, 0 },
     [LOGS][GET_LOG] = { "LOGS_GET_LOG", cmd_logs_get_log, 0x18, 0 },
+    [LOGS][GET_SUPPORTED_SUBLIST] = { "LOGS_GET_SUPPORTED_SUBLIST",
+                                      cmd_logs_get_supported_sublist, 0x02, 0 },
     [PHYSICAL_SWITCH][IDENTIFY_SWITCH_DEVICE] = {"IDENTIFY_SWITCH_DEVICE",
         cmd_identify_switch_device, 0, 0x49 },
     [PHYSICAL_SWITCH][GET_PHYSICAL_PORT_STATE] = { "SWITCH_PHYSICAL_PORT_STATS",
-- 
2.41.0