Re: [Qemu-devel] [PATCH] ahci: map memory via device's address space instead of address_space_memory

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Jul 03, 2014 at 04:26:27PM +0800, Le Tan wrote:
> In map_page() in hw/ide/ahci.c, replace cpu_physical_memory_map() and
> cpu_physical_memory_unmap() with dma_memory_map() and dma_memory_unmap(),
> because ahci devices should not access memory directly but via their address
> space. Add an AddressSpace parameter to map_page(). In order to call
> map_page(), we should pass the AHCIState.as as the AddressSpace argument.
> 
> Signed-off-by: Le Tan <tamlokveer@gmail.com>

Makes sense
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>


> ---
>  hw/ide/ahci.c |   21 +++++++++++----------
>  1 file changed, 11 insertions(+), 10 deletions(-)
> 
> diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
> index 9bae22e..7bb0a03 100644
> --- a/hw/ide/ahci.c
> +++ b/hw/ide/ahci.c
> @@ -175,17 +175,18 @@ static void ahci_trigger_irq(AHCIState *s, AHCIDevice *d,
>      ahci_check_irq(s);
>  }
>  
> -static void map_page(uint8_t **ptr, uint64_t addr, uint32_t wanted)
> +static void map_page(AddressSpace *as, uint8_t **ptr, uint64_t addr,
> +                     uint32_t wanted)
>  {
>      hwaddr len = wanted;
>  
>      if (*ptr) {
> -        cpu_physical_memory_unmap(*ptr, len, 1, len);
> +        dma_memory_unmap(as, *ptr, len, DMA_DIRECTION_FROM_DEVICE, len);
>      }
>  
> -    *ptr = cpu_physical_memory_map(addr, &len, 1);
> +    *ptr = dma_memory_map(as, addr, &len, DMA_DIRECTION_FROM_DEVICE);
>      if (len < wanted) {
> -        cpu_physical_memory_unmap(*ptr, len, 1, len);
> +        dma_memory_unmap(as, *ptr, len, DMA_DIRECTION_FROM_DEVICE, len);
>          *ptr = NULL;
>      }
>  }
> @@ -198,24 +199,24 @@ static void  ahci_port_write(AHCIState *s, int port, int offset, uint32_t val)
>      switch (offset) {
>          case PORT_LST_ADDR:
>              pr->lst_addr = val;
> -            map_page(&s->dev[port].lst,
> +            map_page(s->as, &s->dev[port].lst,
>                       ((uint64_t)pr->lst_addr_hi << 32) | pr->lst_addr, 1024);
>              s->dev[port].cur_cmd = NULL;
>              break;
>          case PORT_LST_ADDR_HI:
>              pr->lst_addr_hi = val;
> -            map_page(&s->dev[port].lst,
> +            map_page(s->as, &s->dev[port].lst,
>                       ((uint64_t)pr->lst_addr_hi << 32) | pr->lst_addr, 1024);
>              s->dev[port].cur_cmd = NULL;
>              break;
>          case PORT_FIS_ADDR:
>              pr->fis_addr = val;
> -            map_page(&s->dev[port].res_fis,
> +            map_page(s->as, &s->dev[port].res_fis,
>                       ((uint64_t)pr->fis_addr_hi << 32) | pr->fis_addr, 256);
>              break;
>          case PORT_FIS_ADDR_HI:
>              pr->fis_addr_hi = val;
> -            map_page(&s->dev[port].res_fis,
> +            map_page(s->as, &s->dev[port].res_fis,
>                       ((uint64_t)pr->fis_addr_hi << 32) | pr->fis_addr, 256);
>              break;
>          case PORT_IRQ_STAT:
> @@ -1260,9 +1261,9 @@ static int ahci_state_post_load(void *opaque, int version_id)
>          ad = &s->dev[i];
>          AHCIPortRegs *pr = &ad->port_regs;
>  
> -        map_page(&ad->lst,
> +        map_page(s->as, &ad->lst,
>                   ((uint64_t)pr->lst_addr_hi << 32) | pr->lst_addr, 1024);
> -        map_page(&ad->res_fis,
> +        map_page(s->as, &ad->res_fis,
>                   ((uint64_t)pr->fis_addr_hi << 32) | pr->fis_addr, 256);
>          /*
>           * All pending i/o should be flushed out on a migrate. However,
> -- 
> 1.7.9.5