[PATCH] hw/block/nvme: add smart_critical_warning property

[zhenwei pi]

There is a very low probability that hitting physical NVMe disk
hardware critical warning case, it's hard to write & test a monitor
agent service.

For debugging purposes, add a new 'smart_critical_warning' property
to emulate this situation.

Test with this patch:
1, append 'smart_critical_warning=16' for nvme parameters.
2, run smartctl in guest
 #smartctl -H -l error /dev/nvme0n1

  === START OF SMART DATA SECTION ===
  SMART overall-health self-assessment test result: FAILED!
  - volatile memory backup device has failed

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
---
 hw/block/nvme.c | 4 ++++
 hw/block/nvme.h | 1 +
 2 files changed, 5 insertions(+)

diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index 27d2c72716..2f0bcac91c 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -1215,6 +1215,8 @@ static uint16_t nvme_smart_info(NvmeCtrl *n, uint8_t rae, 
uint32_t buf_len,
 
     trans_len = MIN(sizeof(smart) - off, buf_len);
 
+    smart.critical_warning = n->params.smart_critical_warning;
+
     smart.data_units_read[0] = cpu_to_le64(DIV_ROUND_UP(stats.units_read,
                                                         1000));
     smart.data_units_written[0] = cpu_to_le64(DIV_ROUND_UP(stats.units_written,
@@ -2824,6 +2826,8 @@ static Property nvme_props[] = {
     DEFINE_PROP_UINT32("aer_max_queued", NvmeCtrl, params.aer_max_queued, 64),
     DEFINE_PROP_UINT8("mdts", NvmeCtrl, params.mdts, 7),
     DEFINE_PROP_BOOL("use-intel-id", NvmeCtrl, params.use_intel_id, false),
+    DEFINE_PROP_UINT8("smart_critical_warning", NvmeCtrl,
+                      params.smart_critical_warning, 0),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/hw/block/nvme.h b/hw/block/nvme.h
index e080a2318a..76684f5ac0 100644
--- a/hw/block/nvme.h
+++ b/hw/block/nvme.h
@@ -16,6 +16,7 @@ typedef struct NvmeParams {
     uint32_t aer_max_queued;
     uint8_t  mdts;
     bool     use_intel_id;
+    uint8_t  smart_critical_warning;
 } NvmeParams;
 
 typedef struct NvmeAsyncEvent {
-- 
2.25.1