[PULL 51/63] hw/cxl/mbox: Add Information and Status / Identify command

["Michael S. Tsirkin" <mst@redhat.com>]

From: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Add this command that is only available via out of band CCIs. It replicates
information that can be discovered inband via PCI config space.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Message-Id: <20231023160806.13206-8-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/cxl/cxl-mailbox-utils.c | 55 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index 28ea02fcbe..6741698ee7 100644
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -11,6 +11,7 @@
 #include "hw/cxl/cxl.h"
 #include "hw/cxl/cxl_events.h"
 #include "hw/pci/pci.h"
+#include "hw/pci-bridge/cxl_upstream_port.h"
 #include "qemu/cutils.h"
 #include "qemu/log.h"
 #include "qemu/units.h"
@@ -44,6 +45,8 @@
  */
 
 enum {
+    INFOSTAT    = 0x00,
+        #define IS_IDENTIFY   0x1
     EVENTS      = 0x01,
         #define GET_RECORDS   0x0
         #define CLEAR_RECORDS   0x1
@@ -203,6 +206,57 @@ static CXLRetCode cmd_events_set_interrupt_policy(const struct cxl_cmd *cmd,
     return CXL_MBOX_SUCCESS;
 }
 
+/* CXL r3.0 section 8.2.9.1.1: Identify (Opcode 0001h) */
+static CXLRetCode cmd_infostat_identify(const struct cxl_cmd *cmd,
+                                        uint8_t *payload_in,
+                                        size_t len_in,
+                                        uint8_t *payload_out,
+                                        size_t *len_out,
+                                        CXLCCI *cci)
+{
+    PCIDeviceClass *class = PCI_DEVICE_GET_CLASS(cci->d);
+    struct {
+        uint16_t pcie_vid;
+        uint16_t pcie_did;
+        uint16_t pcie_subsys_vid;
+        uint16_t pcie_subsys_id;
+        uint64_t sn;
+    uint8_t max_message_size;
+        uint8_t component_type;
+    } QEMU_PACKED *is_identify;
+    QEMU_BUILD_BUG_ON(sizeof(*is_identify) != 18);
+
+    is_identify = (void *)payload_out;
+    memset(is_identify, 0, sizeof(*is_identify));
+    is_identify->pcie_vid = class->vendor_id;
+    is_identify->pcie_did = class->device_id;
+    if (object_dynamic_cast(OBJECT(cci->d), TYPE_CXL_USP)) {
+        is_identify->sn = CXL_USP(cci->d)->sn;
+        /* Subsystem info not defined for a USP */
+        is_identify->pcie_subsys_vid = 0;
+        is_identify->pcie_subsys_id = 0;
+        is_identify->component_type = 0x0; /* Switch */
+    } else if (object_dynamic_cast(OBJECT(cci->d), TYPE_CXL_TYPE3)) {
+        PCIDevice *pci_dev = PCI_DEVICE(cci->d);
+
+        is_identify->sn = CXL_TYPE3(cci->d)->sn;
+        /*
+         * We can't always use class->subsystem_vendor_id as
+         * it is not set if the defaults are used.
+         */
+        is_identify->pcie_subsys_vid =
+            pci_get_word(pci_dev->config + PCI_SUBSYSTEM_VENDOR_ID);
+        is_identify->pcie_subsys_id =
+            pci_get_word(pci_dev->config + PCI_SUBSYSTEM_ID);
+        is_identify->component_type = 0x3; /* Type 3 */
+    }
+
+    /* TODO: Allow this to vary across different CCIs */
+    is_identify->max_message_size = 9; /* 512 bytes - MCTP_CXL_MAILBOX_BYTES */
+    *len_out = sizeof(*is_identify);
+    return CXL_MBOX_SUCCESS;
+}
+
 /* 8.2.9.2.1 */
 static CXLRetCode cmd_firmware_update_get_info(const struct cxl_cmd *cmd,
                                                uint8_t *payload_in,
@@ -755,6 +809,7 @@ static const struct cxl_cmd cxl_cmd_set[256][256] = {
 };
 
 static const struct cxl_cmd cxl_cmd_set_sw[256][256] = {
+    [INFOSTAT][IS_IDENTIFY] = { "IDENTIFY", cmd_infostat_identify, 0, 0 },
     [TIMESTAMP][GET] = { "TIMESTAMP_GET", cmd_timestamp_get, 0, 0 },
     [TIMESTAMP][SET] = { "TIMESTAMP_SET", cmd_timestamp_set, 0,
                          IMMEDIATE_POLICY_CHANGE },
-- 
MST