Skip to content

Commit

Permalink
Browse files Browse the repository at this point in the history
accel/tcg: Add cluster number to TCG TB hash
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 <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 20190121152218.9592-4-peter.maydell@linaro.org
  • Loading branch information
pm215 committed Jan 29, 2019
1 parent 7ea7b9a commit f7b7860
Show file tree
Hide file tree
Showing 3 changed files with 9 additions and 1 deletion.
3 changes: 3 additions & 0 deletions accel/tcg/cpu-exec.c
Expand Up @@ -325,6 +325,9 @@ TranslationBlock *tb_htable_lookup(CPUState *cpu, target_ulong pc,
struct tb_desc desc;
uint32_t h;

cf_mask &= ~CF_CLUSTER_MASK;
cf_mask |= cpu->cluster_index << CF_CLUSTER_SHIFT;

desc.env = (CPUArchState *)cpu->env_ptr;
desc.cs_base = cs_base;
desc.flags = flags;
Expand Down
3 changes: 3 additions & 0 deletions accel/tcg/translate-all.c
Expand Up @@ -1688,6 +1688,9 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
cflags |= CF_NOCACHE | 1;
}

cflags &= ~CF_CLUSTER_MASK;
cflags |= cpu->cluster_index << CF_CLUSTER_SHIFT;

buffer_overflow:
tb = tb_alloc(pc);
if (unlikely(!tb)) {
Expand Down
4 changes: 3 additions & 1 deletion include/exec/exec-all.h
Expand Up @@ -351,9 +351,11 @@ struct TranslationBlock {
#define CF_USE_ICOUNT 0x00020000
#define CF_INVALID 0x00040000 /* TB is stale. Set with @jmp_lock held */
#define CF_PARALLEL 0x00080000 /* Generate code for a parallel context */
#define CF_CLUSTER_MASK 0xff000000 /* Top 8 bits are cluster ID */
#define CF_CLUSTER_SHIFT 24
/* cflags' mask for hashing/comparison */
#define CF_HASH_MASK \
(CF_COUNT_MASK | CF_LAST_IO | CF_USE_ICOUNT | CF_PARALLEL)
(CF_COUNT_MASK | CF_LAST_IO | CF_USE_ICOUNT | CF_PARALLEL | CF_CLUSTER_MASK)

/* Per-vCPU dynamic tracing state used to generate this TB */
uint32_t trace_vcpu_dstate;
Expand Down

0 comments on commit f7b7860

Please sign in to comment.