[PATCH] bsd-user: Specify host page alignment if none specified

[PATCH] bsd-user: Specify host page alignment if none specified

[Warner Losh]

We're hitting an assert when we pass in alignment == 0 since that's not
a power of two. so pass in the ideal page size.

Signed-off-by: Warner Losh <imp@bsdimp.com>
---
 bsd-user/mmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/bsd-user/mmap.c b/bsd-user/mmap.c
index 74ed00b9fe3..e3ce4ab1fc7 100644
--- a/bsd-user/mmap.c
+++ b/bsd-user/mmap.c
@@ -260,7 +260,7 @@ static abi_ulong mmap_find_vma_aligned(abi_ulong start, abi_ulong size,
 
     if (reserved_va) {
         return mmap_find_vma_reserved(start, size,
-            (alignment != 0 ? 1 << alignment : 0));
+            (alignment != 0 ? 1 << alignment : qemu_host_page_size));
     }
 
     addr = start;
-- 
2.40.0

Re: [PATCH] bsd-user: Specify host page alignment if none specified

[Richard Henderson]

On 7/27/23 20:54, Warner Losh wrote:
> We're hitting an assert when we pass in alignment == 0 since that's not
> a power of two. so pass in the ideal page size.
> 
> Signed-off-by: Warner Losh <imp@bsdimp.com>
> ---
>   bsd-user/mmap.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~

> 
> diff --git a/bsd-user/mmap.c b/bsd-user/mmap.c
> index 74ed00b9fe3..e3ce4ab1fc7 100644
> --- a/bsd-user/mmap.c
> +++ b/bsd-user/mmap.c
> @@ -260,7 +260,7 @@ static abi_ulong mmap_find_vma_aligned(abi_ulong start, abi_ulong size,
>   
>       if (reserved_va) {
>           return mmap_find_vma_reserved(start, size,
> -            (alignment != 0 ? 1 << alignment : 0));
> +            (alignment != 0 ? 1 << alignment : qemu_host_page_size));
>       }
>   
>       addr = start;

Re: [PATCH] bsd-user: Specify host page alignment if none specified

[Richard Henderson]

On 7/28/23 06:34, Richard Henderson wrote:
> On 7/27/23 20:54, Warner Losh wrote:
>> We're hitting an assert when we pass in alignment == 0 since that's not
>> a power of two. so pass in the ideal page size.
>>
>> Signed-off-by: Warner Losh <imp@bsdimp.com>
>> ---
>>   bsd-user/mmap.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> 
> 
> r~
> 
>>
>> diff --git a/bsd-user/mmap.c b/bsd-user/mmap.c
>> index 74ed00b9fe3..e3ce4ab1fc7 100644
>> --- a/bsd-user/mmap.c
>> +++ b/bsd-user/mmap.c
>> @@ -260,7 +260,7 @@ static abi_ulong mmap_find_vma_aligned(abi_ulong start, abi_ulong size,
>>       if (reserved_va) {
>>           return mmap_find_vma_reserved(start, size,
>> -            (alignment != 0 ? 1 << alignment : 0));
>> +            (alignment != 0 ? 1 << alignment : qemu_host_page_size));

Actually, it probably should be MAX(qemu_host_page_size, TARGET_PAGE_SIZE).

Does freebsd currently support any hosts with a page size that is not 4k? It would have 
been true in the past, certainly, but perhaps they've all been deprecated and removed.


r~

Re: [PATCH] bsd-user: Specify host page alignment if none specified

[Warner Losh]

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On Fri, Jul 28, 2023 at 7:41 AM Richard Henderson <
richard.henderson@linaro.org> wrote:

> On 7/28/23 06:34, Richard Henderson wrote:
> > On 7/27/23 20:54, Warner Losh wrote:
> >> We're hitting an assert when we pass in alignment == 0 since that's not
> >> a power of two. so pass in the ideal page size.
> >>
> >> Signed-off-by: Warner Losh <imp@bsdimp.com>
> >> ---
> >>   bsd-user/mmap.c | 2 +-
> >>   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> >
> >
> > r~
> >
> >>
> >> diff --git a/bsd-user/mmap.c b/bsd-user/mmap.c
> >> index 74ed00b9fe3..e3ce4ab1fc7 100644
> >> --- a/bsd-user/mmap.c
> >> +++ b/bsd-user/mmap.c
> >> @@ -260,7 +260,7 @@ static abi_ulong mmap_find_vma_aligned(abi_ulong
> start, abi_ulong size,
> >>       if (reserved_va) {
> >>           return mmap_find_vma_reserved(start, size,
> >> -            (alignment != 0 ? 1 << alignment : 0));
> >> +            (alignment != 0 ? 1 << alignment : qemu_host_page_size));
>
> Actually, it probably should be MAX(qemu_host_page_size, TARGET_PAGE_SIZE).
>
> Does freebsd currently support any hosts with a page size that is not 4k?
> It would have
> been true in the past, certainly, but perhaps they've all been deprecated
> and removed.
>

arm64 supports 64k pages now too... I'll update the patch...

Warner

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