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Re: [Qemu-devel] [PATCH v3 03/15] exec-all.h: revert tb_page_addr_t to t
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [PATCH v3 03/15] exec-all.h: revert tb_page_addr_t to target_ulong |
Date: |
Mon, 3 Oct 2016 10:59:50 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 |
On 30/09/2016 23:30, Alex Bennée wrote:
> Commit b480d9b74 converted tb_page_addr_t to abi_ulong which while the
> right size imposes additional alignment restrictions on the type. This
> gets in the way of using atomic accesses on certain guest platforms
> which allow finer alignments. As tb_page_addr_t isn't actually visible
> to the guest we can revert the change.
>
> This is potentially less efficient for ILP32 style guests but it is the
> simpler change to make.
>
> Signed-off-by: Alex Bennée <address@hidden>
> ---
> include/exec/exec-all.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
> index 336a57c..c3596a6 100644
> --- a/include/exec/exec-all.h
> +++ b/include/exec/exec-all.h
> @@ -30,7 +30,7 @@
> addresses in userspace mode. Define tb_page_addr_t to be an appropriate
> type. */
> #if defined(CONFIG_USER_ONLY)
> -typedef abi_ulong tb_page_addr_t;
> +typedef target_ulong tb_page_addr_t;
> #else
> typedef ram_addr_t tb_page_addr_t;
> #endif
>
I think target_ulong is in general not accessible atomically, because we
still haven't dropped 64-on-32 support.
Paolo
- Re: [Qemu-devel] [PATCH v3 03/15] exec-all.h: revert tb_page_addr_t to target_ulong,
Paolo Bonzini <=