hw/cxl/mbox: Wire up interrupts for background completion

Notify when the background operation is done. Note that for now background
commands are only supported on the main Type 3 mailbox.

Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20231023160806.13206-13-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

3 files changed, 24 insertions, 18 deletions

diff --git a/hw/cxl/cxl-device-utils.c b/hw/cxl/cxl-device-utils.c
index 51466a626b..61a3c4dc2e 100644
--- a/hw/cxl/cxl-device-utils.c
+++ b/hw/cxl/cxl-device-utils.c
@@ -357,10 +357,18 @@ static void device_reg_init_common(CXLDeviceState *cxl_dstate)
 
 static void mailbox_reg_init_common(CXLDeviceState *cxl_dstate)
 {
-    /* 2048 payload size, with no interrupt */
+    const uint8_t msi_n = 9;
+
+    /* 2048 payload size */
     ARRAY_FIELD_DP32(cxl_dstate->mbox_reg_state32, CXL_DEV_MAILBOX_CAP,
                      PAYLOAD_SIZE, CXL_MAILBOX_PAYLOAD_SHIFT);
     cxl_dstate->payload_size = CXL_MAILBOX_MAX_PAYLOAD_SIZE;
+    /* irq support */
+    ARRAY_FIELD_DP32(cxl_dstate->mbox_reg_state32, CXL_DEV_MAILBOX_CAP,
+                     BG_INT_CAP, 1);
+    ARRAY_FIELD_DP32(cxl_dstate->mbox_reg_state32, CXL_DEV_MAILBOX_CAP,
+                     MSI_N, msi_n);
+    cxl_dstate->mbox_msi_n = msi_n;
 }
 
 static void memdev_reg_init_common(CXLDeviceState *cxl_dstate) { }
diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index f1226f8f39..f3fd97deb5 100644
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -8,6 +8,8 @@
  */
 
 #include "qemu/osdep.h"
+#include "hw/pci/msi.h"
+#include "hw/pci/msix.h"
 #include "hw/cxl/cxl.h"
 #include "hw/cxl/cxl_events.h"
 #include "hw/pci/pci.h"
@@ -1076,28 +1078,16 @@ int cxl_process_cci_message(CXLCCI *cci, uint8_t set, uint8_t cmd,
 static void bg_timercb(void *opaque)
 {
     CXLCCI *cci = opaque;
-    CXLDeviceState *cxl_dstate = &CXL_TYPE3(cci->d)->cxl_dstate;
-    uint64_t bg_status_reg = 0;
     uint64_t now = qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL);
     uint64_t total_time = cci->bg.starttime + cci->bg.runtime;
 
     assert(cci->bg.runtime > 0);
-    bg_status_reg = FIELD_DP64(bg_status_reg, CXL_DEV_BG_CMD_STS,
-                               OP, cci->bg.opcode);
 
     if (now >= total_time) { /* we are done */
-        uint64_t status_reg;
         uint16_t ret = CXL_MBOX_SUCCESS;
 
         cci->bg.complete_pct = 100;
-        /* Clear bg */
-        status_reg = FIELD_DP64(0, CXL_DEV_MAILBOX_STS, BG_OP, 0);
-        cxl_dstate->mbox_reg_state64[R_CXL_DEV_MAILBOX_STS] = status_reg;
-
-        bg_status_reg = FIELD_DP64(bg_status_reg, CXL_DEV_BG_CMD_STS,
-                                   RET_CODE, ret);
-
-        /* TODO add ad-hoc cmd succesful completion handling */
+        cci->bg.ret_code = ret;
 
         qemu_log("Background command %04xh finished: %s\n",
                  cci->bg.opcode,
@@ -1108,14 +1098,21 @@ static void bg_timercb(void *opaque)
         timer_mod(cci->bg.timer, now + CXL_MBOX_BG_UPDATE_FREQ);
     }
 
-    bg_status_reg = FIELD_DP64(bg_status_reg, CXL_DEV_BG_CMD_STS,
-                               PERCENTAGE_COMP, cci->bg.complete_pct);
-    cxl_dstate->mbox_reg_state64[R_CXL_DEV_BG_CMD_STS] = bg_status_reg;
-
     if (cci->bg.complete_pct == 100) {
+        /* TODO: generalize to switch CCI */
+        CXLType3Dev *ct3d = CXL_TYPE3(cci->d);
+        CXLDeviceState *cxl_dstate = &ct3d->cxl_dstate;
+        PCIDevice *pdev = PCI_DEVICE(cci->d);
+
         cci->bg.starttime = 0;
         /* registers are updated, allow new bg-capable cmds */
         cci->bg.runtime = 0;
+
+        if (msix_enabled(pdev)) {
+            msix_notify(pdev, cxl_dstate->mbox_msi_n);
+        } else if (msi_enabled(pdev)) {
+            msi_notify(pdev, cxl_dstate->mbox_msi_n);
+        }
     }
 }
 
diff --git a/include/hw/cxl/cxl_device.h b/include/hw/cxl/cxl_device.h
index 124ff969ec..2a813cdddd 100644
--- a/include/hw/cxl/cxl_device.h
+++ b/include/hw/cxl/cxl_device.h
@@ -193,6 +193,7 @@ typedef struct cxl_device_state {
     struct {
         MemoryRegion mailbox;
         uint16_t payload_size;
+        uint8_t mbox_msi_n;
         union {
             uint8_t mbox_reg_state[CXL_MAILBOX_REGISTERS_LENGTH];
             uint16_t mbox_reg_state16[CXL_MAILBOX_REGISTERS_LENGTH / 2];