[PATCH 2/4] hw/cxl/mbox: replace sanitize_running() with cxl_dev_media_disabled()

[Jonathan Cameron <Jonathan.Cameron@huawei.com>]

From: Hyeonggon Yoo <42.hyeyoo@gmail.com>

The spec states that reads/writes should have no effect and a part of
commands should be ignored when the media is disabled, not when the
sanitize command is running.

Introduce cxl_dev_media_disabled() to check if the media is disabled and
replace sanitize_running() with it.

Make sure that the media has been correctly disabled during sanitation
by adding an assert to __toggle_media(). Now, enabling when already
enabled or vice versa results in an assert() failure.

Suggested-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Link: https://lore.kernel.org/r/20231222090051.3265307-4-42.hyeyoo@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

---
Fix added to ensure the state sanity check only applies on type3 devices
---
 include/hw/cxl/cxl_device.h | 10 +++++-----
 hw/cxl/cxl-mailbox-utils.c  | 29 +++++++++++++++++------------
 hw/mem/cxl_type3.c          |  4 ++--
 3 files changed, 24 insertions(+), 19 deletions(-)

diff --git a/include/hw/cxl/cxl_device.h b/include/hw/cxl/cxl_device.h
index b5beb7f90e..42a622197e 100644
--- a/include/hw/cxl/cxl_device.h
+++ b/include/hw/cxl/cxl_device.h
@@ -397,14 +397,14 @@ static inline void __toggle_media(CXLDeviceState *cxl_dstate, int val)
 #define cxl_dev_enable_media(cxlds)                     \
         do { __toggle_media((cxlds), 0x1); } while (0)
 
-static inline bool scan_media_running(CXLCCI *cci)
+static inline bool cxl_dev_media_disabled(CXLDeviceState *cxl_dstate)
 {
-    return !!cci->bg.runtime && cci->bg.opcode == 0x4304;
+    uint64_t dev_status_reg = cxl_dstate->mbox_reg_state64[R_CXL_MEM_DEV_STS];
+    return FIELD_EX64(dev_status_reg, CXL_MEM_DEV_STS, MEDIA_STATUS) == 0x3;
 }
-
-static inline bool sanitize_running(CXLCCI *cci)
+static inline bool scan_media_running(CXLCCI *cci)
 {
-    return !!cci->bg.runtime && cci->bg.opcode == 0x4400;
+    return !!cci->bg.runtime && cci->bg.opcode == 0x4304;
 }
 
 typedef struct CXLError {
diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index 6a60f81794..adeb71071c 100644
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -2115,6 +2115,7 @@ int cxl_process_cci_message(CXLCCI *cci, uint8_t set, uint8_t cmd,
     int ret;
     const struct cxl_cmd *cxl_cmd;
     opcode_handler h;
+    CXLDeviceState *cxl_dstate;
 
     *len_out = 0;
     cxl_cmd = &cci->cxl_cmd_set[set][cmd];
@@ -2135,18 +2136,22 @@ int cxl_process_cci_message(CXLCCI *cci, uint8_t set, uint8_t cmd,
         return CXL_MBOX_BUSY;
     }
 
-    /* forbid any selected commands while overwriting */
-    if (sanitize_running(cci)) {
-        if (h == cmd_events_get_records ||
-            h == cmd_ccls_get_partition_info ||
-            h == cmd_ccls_set_lsa ||
-            h == cmd_ccls_get_lsa ||
-            h == cmd_logs_get_log ||
-            h == cmd_media_get_poison_list ||
-            h == cmd_media_inject_poison ||
-            h == cmd_media_clear_poison ||
-            h == cmd_sanitize_overwrite) {
-            return CXL_MBOX_MEDIA_DISABLED;
+    /* forbid any selected commands while the media is disabled */
+    if (object_dynamic_cast(OBJECT(cci->d), TYPE_CXL_TYPE3)) {
+        cxl_dstate = &CXL_TYPE3(cci->d)->cxl_dstate;
+
+        if (cxl_dev_media_disabled(cxl_dstate)) {
+            if (h == cmd_events_get_records ||
+                h == cmd_ccls_get_partition_info ||
+                h == cmd_ccls_set_lsa ||
+                h == cmd_ccls_get_lsa ||
+                h == cmd_logs_get_log ||
+                h == cmd_media_get_poison_list ||
+                h == cmd_media_inject_poison ||
+                h == cmd_media_clear_poison ||
+                h == cmd_sanitize_overwrite) {
+                return CXL_MBOX_MEDIA_DISABLED;
+            }
         }
     }
 
diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
index 62956a0403..925c88ac5d 100644
--- a/hw/mem/cxl_type3.c
+++ b/hw/mem/cxl_type3.c
@@ -1127,7 +1127,7 @@ MemTxResult cxl_type3_read(PCIDevice *d, hwaddr host_addr, uint64_t *data,
         return MEMTX_ERROR;
     }
 
-    if (sanitize_running(&ct3d->cci)) {
+    if (cxl_dev_media_disabled(&ct3d->cxl_dstate)) {
         qemu_guest_getrandom_nofail(data, size);
         return MEMTX_OK;
     }
@@ -1149,7 +1149,7 @@ MemTxResult cxl_type3_write(PCIDevice *d, hwaddr host_addr, uint64_t data,
         return MEMTX_ERROR;
     }
 
-    if (sanitize_running(&ct3d->cci)) {
+    if (cxl_dev_media_disabled(&ct3d->cxl_dstate)) {
         return MEMTX_OK;
     }
 
-- 
2.43.0