Re: [PATCH v2 10/54] accel/tcg: Populate IntervalTree in tlb_set_page_full

[Pierrick Bouvier <pierrick.bouvier@linaro.org>]

On 11/14/24 08:00, Richard Henderson wrote:
> Add or replace an entry in the IntervalTree for each
> page installed into softmmu.  We do not yet use the
> tree for anything else.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   accel/tcg/cputlb.c | 34 ++++++++++++++++++++++++++++------
>   1 file changed, 28 insertions(+), 6 deletions(-)
> 
> diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
> index aa51fc1d26..ea6a5177de 100644
> --- a/accel/tcg/cputlb.c
> +++ b/accel/tcg/cputlb.c
> @@ -305,6 +305,17 @@ static void tlbfast_flush_locked(CPUTLBDesc *desc, CPUTLBDescFast *fast)
>       memset(fast->table, -1, sizeof_tlb(fast));
>   }
>   
> +static CPUTLBEntryTree *tlbtree_lookup_range(CPUTLBDesc *desc, vaddr s, vaddr l)
> +{
> +    IntervalTreeNode *i = interval_tree_iter_first(&desc->iroot, s, l);
> +    return i ? container_of(i, CPUTLBEntryTree, itree) : NULL;
> +}
> +
> +static CPUTLBEntryTree *tlbtree_lookup_addr(CPUTLBDesc *desc, vaddr addr)
> +{
> +    return tlbtree_lookup_range(desc, addr, addr);
> +}
> +
>   static void tlb_mmu_flush_locked(CPUTLBDesc *desc, CPUTLBDescFast *fast)
>   {
>       tlbfast_flush_locked(desc, fast);
> @@ -1072,7 +1083,8 @@ void tlb_set_page_full(CPUState *cpu, int mmu_idx,
>       MemoryRegionSection *section;
>       unsigned int index, read_flags, write_flags;
>       uintptr_t addend;
> -    CPUTLBEntry *te, tn;
> +    CPUTLBEntry *te;
> +    CPUTLBEntryTree *node;
>       hwaddr iotlb, xlat, sz, paddr_page;
>       vaddr addr_page;
>       int asidx, wp_flags, prot;
> @@ -1180,6 +1192,15 @@ void tlb_set_page_full(CPUState *cpu, int mmu_idx,
>           tlb_n_used_entries_dec(cpu, mmu_idx);
>       }
>   
> +    /* Replace an old IntervalTree entry, or create a new one. */
> +    node = tlbtree_lookup_addr(desc, addr_page);
> +    if (!node) {
> +        node = g_new(CPUTLBEntryTree, 1);
> +        node->itree.start = addr_page;
> +        node->itree.last = addr_page + TARGET_PAGE_SIZE - 1;
> +        interval_tree_insert(&node->itree, &desc->iroot);
> +    }
> +
>       /* refill the tlb */
>       /*
>        * When memory region is ram, iotlb contains a TARGET_PAGE_BITS
> @@ -1201,15 +1222,15 @@ void tlb_set_page_full(CPUState *cpu, int mmu_idx,
>       full->phys_addr = paddr_page;
>   
>       /* Now calculate the new entry */
> -    tn.addend = addend - addr_page;
> +    node->copy.addend = addend - addr_page;
>   
> -    tlb_set_compare(full, &tn, addr_page, read_flags,
> +    tlb_set_compare(full, &node->copy, addr_page, read_flags,
>                       MMU_INST_FETCH, prot & PAGE_EXEC);
>   
>       if (wp_flags & BP_MEM_READ) {
>           read_flags |= TLB_WATCHPOINT;
>       }
> -    tlb_set_compare(full, &tn, addr_page, read_flags,
> +    tlb_set_compare(full, &node->copy, addr_page, read_flags,
>                       MMU_DATA_LOAD, prot & PAGE_READ);
>   
>       if (prot & PAGE_WRITE_INV) {
> @@ -1218,10 +1239,11 @@ void tlb_set_page_full(CPUState *cpu, int mmu_idx,
>       if (wp_flags & BP_MEM_WRITE) {
>           write_flags |= TLB_WATCHPOINT;
>       }
> -    tlb_set_compare(full, &tn, addr_page, write_flags,
> +    tlb_set_compare(full, &node->copy, addr_page, write_flags,
>                       MMU_DATA_STORE, prot & PAGE_WRITE);
>   
> -    copy_tlb_helper_locked(te, &tn);
> +    node->full = *full;
> +    copy_tlb_helper_locked(te, &node->copy);
>       tlb_n_used_entries_inc(cpu, mmu_idx);
>       qemu_spin_unlock(&tlb->c.lock);
>   }

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>