Re: [QEMU][PATCH v1 4/7] xen: let xen_ram_addr_from_mapcache() return -1 in case of not found entry

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Thu, 5 Oct 2023, Vikram Garhwal wrote:
> From: Juergen Gross <jgross@xxxxxxxx>
> 
> Today xen_ram_addr_from_mapcache() will either abort() or return 0 in
> case it can't find a matching entry for a pointer value. Both cases
> are bad, so change that to return an invalid address instead.
> 
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>

Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>


> ---
>  hw/xen/xen-mapcache.c | 12 +++---------
>  1 file changed, 3 insertions(+), 9 deletions(-)
> 
> diff --git a/hw/xen/xen-mapcache.c b/hw/xen/xen-mapcache.c
> index 8115c44c00..8a61c7dde6 100644
> --- a/hw/xen/xen-mapcache.c
> +++ b/hw/xen/xen-mapcache.c
> @@ -404,13 +404,8 @@ ram_addr_t xen_ram_addr_from_mapcache(void *ptr)
>          }
>      }
>      if (!found) {
> -        fprintf(stderr, "%s, could not find %p\n", __func__, ptr);
> -        QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) {
> -            DPRINTF("   "HWADDR_FMT_plx" -> %p is present\n", 
> reventry->paddr_index,
> -                    reventry->vaddr_req);
> -        }
> -        abort();
> -        return 0;
> +        mapcache_unlock();
> +        return RAM_ADDR_INVALID;
>      }
>  
>      entry = &mapcache->entry[paddr_index % mapcache->nr_buckets];
> @@ -418,8 +413,7 @@ ram_addr_t xen_ram_addr_from_mapcache(void *ptr)
>          entry = entry->next;
>      }
>      if (!entry) {
> -        DPRINTF("Trying to find address %p that is not in the mapcache!\n", 
> ptr);
> -        raddr = 0;
> +        raddr = RAM_ADDR_INVALID;
>      } else {
>          raddr = (reventry->paddr_index << MCACHE_BUCKET_SHIFT) +
>               ((unsigned long) ptr - (unsigned long) entry->vaddr_base);
> -- 
> 2.17.1
>