| Message ID | 20190114115637.6335-4-peter.maydell@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | tcg: support heterogenous CPU clusters | expand |
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 <peter.maydell@linaro.org> > --- > 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 <richard.henderson@linaro.org> r~
diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h index 815e5b1e838..aa7b81aaf01 100644 --- a/include/exec/exec-all.h +++ b/include/exec/exec-all.h @@ -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; diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c index 870027d4359..6c4a33262f5 100644 --- a/accel/tcg/cpu-exec.c +++ b/accel/tcg/cpu-exec.c @@ -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; diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index 639f0b27287..ba27f5acc8c 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -1692,6 +1692,9 @@ 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)) {
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> --- 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(-) -- 2.20.1