Re: [PATCH] accel/tcg: Drop PAGE_RESERVED for CONFIG_BSD

[Richard Henderson]

On 12/20/22 14:09, Warner Losh wrote:
> On Sat, Dec 17, 2022 at 11:48 AM Richard Henderson <richard.henderson@linaro.org 
> <mailto:richard.henderson@linaro.org>> wrote:
>
>     Make bsd-user match linux-user in not marking host pages
>     as reserved.  This isn't especially effective anyway, as
>     it doesn't take into account any heap memory that qemu
>     may allocate after startup.
>
>     Cc: Warner Losh <imp@bsdimp.com <mailto:imp@bsdimp.com>>
>     Signed-off-by: Richard Henderson <richard.henderson@linaro.org
>     <mailto:richard.henderson@linaro.org>>
>     ---
>
>     I started to simply fix up this code to match my user-only interval-tree
>     patch set, as L1_MAP_ADDR_SPACE_BITS gets removed from translate-all.c,
>     but then I decided to remove it all.
>
>
> I think this is fine. We already do a translation for addresses so marking this 
> as 'reserved'
> doesn't help that much. We need to map memory into a contiguous 
> guess-address-space,
> but the underlying host memory needn't be contiguous at all.
>
> I've not yet tested this, but would like to. What's your timeline on getting 
> this done?

ASAP.  I want to remove...

>     -                    if (h2g_valid(endaddr)) {
>     -                        endaddr = h2g(endaddr);
>     -                        page_set_flags(startaddr, endaddr, PAGE_RESERVED);
>     -                    } else {
>     -#if TARGET_ABI_BITS <= L1_MAP_ADDR_SPACE_BITS

L1_MAP_ADDR_SPACE_BITS.


r~