Controllers have different capabilities and report them in the
CAP register. We are particularly interested by the page size
limits.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 block/nvme.c       | 10 ++++++++++
 block/trace-events |  1 +
 2 files changed, 11 insertions(+)

diff --git a/block/nvme.c b/block/nvme.c
index 11fba2d754d..fad727416ee 100644
--- a/block/nvme.c
+++ b/block/nvme.c
@@ -725,6 +725,16 @@ static int nvme_init(BlockDriverState *bs, const char *device, int namespace,
      * Initialization". */
 
     cap = le64_to_cpu(regs->cap);
+    trace_nvme_controller_capability("Maximum Queue Entries Supported",
+                                     NVME_CAP_MQES(cap));
+    trace_nvme_controller_capability("Contiguous Queues Required",
+                                     NVME_CAP_CQR(cap));
+    trace_nvme_controller_capability("Subsystem  Reset Supported",
+                                     NVME_CAP_NSSRS(cap));
+    trace_nvme_controller_capability("Memory Page Size Minimum",
+                                     NVME_CAP_MPSMIN(cap));
+    trace_nvme_controller_capability("Memory Page Size Maximum",
+                                     NVME_CAP_MPSMAX(cap));
     if (!NVME_CAP_CSS(cap)) {
         error_setg(errp, "Device doesn't support NVMe command set");
         ret = -EINVAL;
diff --git a/block/trace-events b/block/trace-events
index 6694c23e1c1..8a24d7a8650 100644
--- a/block/trace-events
+++ b/block/trace-events
@@ -134,6 +134,7 @@ qed_aio_write_postfill(void *s, void *acb, uint64_t start, size_t len, uint64_t
 qed_aio_write_main(void *s, void *acb, int ret, uint64_t offset, size_t len) "s %p acb %p ret %d offset %"PRIu64" len %zu"
 
 # nvme.c
+nvme_controller_capability(const char *desc, uint64_t value) "%s: %"PRIu64
 nvme_kick(void *s, unsigned q_index) "s %p q #%u"
 nvme_dma_flush_queue_wait(void *s) "s %p"
 nvme_error(int cmd_specific, int sq_head, int sqid, int cid, int status) "cmd_specific %d sq_head %d sqid %d cid %d status 0x%x"
-- 
2.26.2