nvme-pci: clear shadow doorbell memory on resets

The host memory doorbell and event buffers need to be initialized on
each reset so the driver doesn't observe stale values from the previous
instantiation.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Tested-by: John Levon <john.levon@nutanix.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index ed684874842ff0da4e0aa942a403918de0b69a81..6e05cfb4879fb7fd00cf7b4f90a9ba82e75d7905 100644 (file)
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -245,8 +245,15 @@ static int nvme_dbbuf_dma_alloc(struct nvme_dev *dev)
 {
        unsigned int mem_size = nvme_dbbuf_size(dev);
 
-       if (dev->dbbuf_dbs)
+       if (dev->dbbuf_dbs) {
+               /*
+                * Clear the dbbuf memory so the driver doesn't observe stale
+                * values from the previous instantiation.
+                */
+               memset(dev->dbbuf_dbs, 0, mem_size);
+               memset(dev->dbbuf_eis, 0, mem_size);
                return 0;
+       }
 
        dev->dbbuf_dbs = dma_alloc_coherent(dev->dev, mem_size,
                                            &dev->dbbuf_dbs_dma_addr,