Re: [Qemu-devel] [PATCH v2 3/4] accel/tcg: Add cluster number to TCG TB hash

[Richard Henderson]

On 1/14/19 10:56 PM, Peter Maydell wrote:
> Include the cluster number in the hash we use to look
> up TBs. This is important because a TB that is valid
> for one cluster at a given physical address and set
> of CPU flags is not necessarily valid for another:
> the two clusters may have different views of physical
> memory, or may have different CPU features (eg FPU
> present or absent).
> 
> We put the cluster number in the high 8 bits of the
> TB cflags. This gives us up to 256 clusters, which should
> be enough for anybody. If we ever need more, or need
> more bits in cflags for other purposes, we could make
> tb_hash_func() take more data (and expand qemu_xxhash7()
> to qemu_xxhash8()).
> 
> Signed-off-by: Peter Maydell <address@hidden>
> ---
> v1->v2: move the setting of the cluster index in
> cf_mask in tb_htable_lookup() up to before we
> set desc.cf_mask from it...
> ---
>  include/exec/exec-all.h   | 4 +++-
>  accel/tcg/cpu-exec.c      | 3 +++
>  accel/tcg/translate-all.c | 3 +++
>  3 files changed, 9 insertions(+), 1 deletion(-)

Reviewed-by: Richard Henderson <address@hidden>


r~