Re: [PATCH v5 06/26] nvme: refactor nvme_addr_read

[Maxim Levitsky]

On Tue, 2020-02-04 at 10:51 +0100, Klaus Jensen wrote:
> 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>
> ---
>  hw/block/nvme.c | 18 +++++++++++++-----
>  1 file changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/hw/block/nvme.c b/hw/block/nvme.c
> index 9abf74da20f2..ba5089df9ece 100644
> --- a/hw/block/nvme.c
> +++ b/hw/block/nvme.c
> @@ -54,14 +54,22 @@
>  
>  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))) {
> -        memcpy(buf, (void *)&n->cmbuf[addr - n->ctrl_mem.addr], size);
> -    } else {
> -        pci_dma_read(&n->parent_obj, addr, buf, size);
> +    if (n->cmbsz && nvme_addr_is_cmb(n, addr)) {
> +        memcpy(buf, (void *) &n->cmbuf[addr - n->ctrl_mem.addr], size);
Nitpick:
I am not an expert on qemu coding style but I suspect that there is extra space 
after that (void *).

Also note that in following patches you fix a serious bug in this function that 
it doesn't
check that the whole range is in CMB but only that the start of the area is.
I would move it here, or even to a separate patch.

> +        return;
>      }
> +
> +    pci_dma_read(&n->parent_obj, addr, buf, size);
>  }
>  
>  static int nvme_check_sqid(NvmeCtrl *n, uint16_t sqid)

Best regards,
        Maxim Levitsky