From: Klaus Jensen <k.jensen@samsung.com>

Qiang Liu reported that an access on an unknown address is triggered in
memory_region_set_enabled because a check on CAP.PMRS is missing for the
PMRCTL register write when no PMR is configured.

Cc: qemu-stable@nongnu.org
Fixes: 75c3c9de961d ("hw/block/nvme: disable PMR at boot up")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/362
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
---
 hw/nvme/ctrl.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c
index dd2b4fa127cc..5c6c7d3455c3 100644
--- a/hw/nvme/ctrl.c
+++ b/hw/nvme/ctrl.c
@@ -5860,6 +5860,10 @@ static void nvme_write_bar(NvmeCtrl *n, hwaddr offset, uint64_t data,
                        "invalid write to PMRCAP register, ignored");
         return;
     case 0xe04: /* PMRCTL */
+        if (!NVME_CAP_PMRS(n->bar.cap)) {
+            return;
+        }
+
         n->bar.pmrctl = data;
         if (NVME_PMRCTL_EN(data)) {
             memory_region_set_enabled(&n->pmr.dev->mr, true);
-- 
2.32.0