Re: [PATCH] hw/nvme: fix missing check for PMR capability

[Keith Busch]

On Mon, Jun 07, 2021 at 11:47:57AM +0200, Klaus Jensen wrote:
> 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>

Looks good.

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 0bcaf7192f99..463772602c4e 100644
> --- a/hw/nvme/ctrl.c
> +++ b/hw/nvme/ctrl.c
> @@ -5583,6 +5583,10 @@ 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);
> -- 
> 2.31.1