Re: [PATCH v8 07/11] i386/pc: handle unitialized mr in pc_get_cxl_range_end()

[Igor Mammedov]

On Fri, 15 Jul 2022 18:16:24 +0100
Joao Martins <joao.m.martins@oracle.com> wrote:

> Remove pc_get_cxl_range_end() dependency on the CXL memory region,
> and replace with one that does not require the CXL host_mr to determine
> the start of CXL start.
> 
> This in preparation to allow pc_pci_hole64_start() to be called early
> in pc_memory_init(), handle CXL memory region end when its underlying
> memory region isn't yet initialized.
> 
> Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
> Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
> ---
>  hw/i386/pc.c | 18 ++++++++----------
>  1 file changed, 8 insertions(+), 10 deletions(-)
> 
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 3fdcab4bb4f3..c654be6cf0bd 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -843,17 +843,15 @@ static uint64_t pc_get_cxl_range_start(PCMachineState 
> *pcms)
>  
>  static uint64_t pc_get_cxl_range_end(PCMachineState *pcms)
>  {
> -    uint64_t start = 0;
> +    uint64_t start = pc_get_cxl_range_start(pcms) + MiB;
                                                     ^^^^^
why it's here?

>  
> -    if (pcms->cxl_devices_state.host_mr.addr) {
> -        start = pcms->cxl_devices_state.host_mr.addr +
> -            memory_region_size(&pcms->cxl_devices_state.host_mr);
> -        if (pcms->cxl_devices_state.fixed_windows) {
> -            GList *it;
> -            for (it = pcms->cxl_devices_state.fixed_windows; it; it = 
> it->next) {
> -                CXLFixedWindow *fw = it->data;
> -                start = fw->mr.addr + memory_region_size(&fw->mr);
> -            }
> +    if (pcms->cxl_devices_state.fixed_windows) {
> +        GList *it;
> +
> +        start = ROUND_UP(start, 256 * MiB);

and also this unexplained alignment.

> +        for (it = pcms->cxl_devices_state.fixed_windows; it; it = it->next) {
> +            CXLFixedWindow *fw = it->data;
> +            start += fw->size;
>          }
>      }
>