Re: [PATCH v6 07/42] nvme: refactor nvme_addr_read

[Maxim Levitsky]

On Mon, 2020-03-16 at 07:28 -0700, Klaus Jensen wrote:
> From: Klaus Jensen <address@hidden>
> 
> Pull the controller memory buffer check to its own function. The check
> will be used on its own in later patches.
> 
> Signed-off-by: Klaus Jensen <address@hidden>
> Acked-by: Keith Busch <address@hidden>
> ---
>  hw/block/nvme.c | 16 ++++++++++++----
>  1 file changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/block/nvme.c b/hw/block/nvme.c
> index b38d7e548a60..08a83d449de3 100644
> --- a/hw/block/nvme.c
> +++ b/hw/block/nvme.c
> @@ -52,14 +52,22 @@
>  
>  static void nvme_process_sq(void *opaque);
>  
> +static inline bool nvme_addr_is_cmb(NvmeCtrl *n, hwaddr addr)
> +{
> +    hwaddr low = n->ctrl_mem.addr;
> +    hwaddr hi  = n->ctrl_mem.addr + int128_get64(n->ctrl_mem.size);
> +
> +    return addr >= low && addr < hi;
> +}
> +
>  static void nvme_addr_read(NvmeCtrl *n, hwaddr addr, void *buf, int size)
>  {
> -    if (n->cmbsz && addr >= n->ctrl_mem.addr &&
> -                addr < (n->ctrl_mem.addr + int128_get64(n->ctrl_mem.size))) {
> +    if (n->cmbsz && nvme_addr_is_cmb(n, addr)) {
>          memcpy(buf, (void *)&n->cmbuf[addr - n->ctrl_mem.addr], size);
> -    } else {
> -        pci_dma_read(&n->parent_obj, addr, buf, size);
> +        return;
>      }
> +
> +    pci_dma_read(&n->parent_obj, addr, buf, size);
>  }
>  
>  static int nvme_check_sqid(NvmeCtrl *n, uint16_t sqid)

Note that this patch still contains a bug that it removes the check against the 
accessed
size, which you fix in later patch.
I prefer to not add a bug in first place
However if you have a reason for this, I won't mind.

Best regards,
        Maxim Levitsky