On Wed, Oct 5, 2022 at 1:11 AM Richard Henderson
<richard.hender...@linaro.org> wrote:
>
> Now that we have collected all of the page data into
> CPUTLBEntryFull, provide an interface to record that
> all in one go, instead of using 4 arguments.  This interface
> allows CPUTLBEntryFull to be extended without having to
> change the number of arguments.
>
> Reviewed-by: Alex Bennée <alex.ben...@linaro.org>
> Reviewed-by: Peter Maydell <peter.mayd...@linaro.org>
> Reviewed-by: Philippe Mathieu-Daudé <f4...@amsat.org>
> Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
> ---
>  include/exec/cpu-defs.h | 14 +++++++++++
>  include/exec/exec-all.h | 22 ++++++++++++++++++
>  accel/tcg/cputlb.c      | 51 ++++++++++++++++++++++++++---------------
>  3 files changed, 69 insertions(+), 18 deletions(-)
>
> diff --git a/include/exec/cpu-defs.h b/include/exec/cpu-defs.h
> index f70f54d850..5e12cc1854 100644
> --- a/include/exec/cpu-defs.h
> +++ b/include/exec/cpu-defs.h
> @@ -148,7 +148,21 @@ typedef struct CPUTLBEntryFull {
>       *     + the offset within the target MemoryRegion (otherwise)
>       */
>      hwaddr xlat_section;
> +
> +    /*
> +     * @phys_addr contains the physical address in the address space
> +     * given by cpu_asidx_from_attrs(cpu, @attrs).
> +     */
> +    hwaddr phys_addr;
> +
> +    /* @attrs contains the memory transaction attributes for the page. */
>      MemTxAttrs attrs;
> +
> +    /* @prot contains the complete protections for the page. */
> +    uint8_t prot;
> +
> +    /* @lg_page_size contains the log2 of the page size. */
> +    uint8_t lg_page_size;
>  } CPUTLBEntryFull;
>
>  /*
> diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
> index d255d69bc1..b1b920a713 100644
> --- a/include/exec/exec-all.h
> +++ b/include/exec/exec-all.h
> @@ -257,6 +257,28 @@ void tlb_flush_range_by_mmuidx_all_cpus_synced(CPUState 
> *cpu,
>                                                 uint16_t idxmap,
>                                                 unsigned bits);
>
> +/**
> + * tlb_set_page_full:
> + * @cpu: CPU context
> + * @mmu_idx: mmu index of the tlb to modify
> + * @vaddr: virtual address of the entry to add
> + * @full: the details of the tlb entry
> + *
> + * Add an entry to @cpu tlb index @mmu_idx.  All of the fields of
> + * @full must be filled, except for xlat_section, and constitute
> + * the complete description of the translated page.
> + *
> + * This is generally called by the target tlb_fill function after
> + * having performed a successful page table walk to find the physical
> + * address and attributes for the translation.
> + *
> + * At most one entry for a given virtual address is permitted. Only a
> + * single TARGET_PAGE_SIZE region is mapped; @full->lg_page_size is only
> + * used by tlb_flush_page.
> + */
> +void tlb_set_page_full(CPUState *cpu, int mmu_idx, target_ulong vaddr,
> +                       CPUTLBEntryFull *full);
> +
>  /**
>   * tlb_set_page_with_attrs:
>   * @cpu: CPU to add this TLB entry for
> diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
> index e3ee4260bd..361078471b 100644
> --- a/accel/tcg/cputlb.c
> +++ b/accel/tcg/cputlb.c
> @@ -1095,16 +1095,16 @@ static void tlb_add_large_page(CPUArchState *env, int 
> mmu_idx,
>      env_tlb(env)->d[mmu_idx].large_page_mask = lp_mask;
>  }
>
> -/* Add a new TLB entry. At most one entry for a given virtual address
> +/*
> + * Add a new TLB entry. At most one entry for a given virtual address
>   * is permitted. Only a single TARGET_PAGE_SIZE region is mapped, the
>   * supplied size is only used by tlb_flush_page.
>   *
>   * Called from TCG-generated code, which is under an RCU read-side
>   * critical section.
>   */
> -void tlb_set_page_with_attrs(CPUState *cpu, target_ulong vaddr,
> -                             hwaddr paddr, MemTxAttrs attrs, int prot,
> -                             int mmu_idx, target_ulong size)
> +void tlb_set_page_full(CPUState *cpu, int mmu_idx,
> +                       target_ulong vaddr, CPUTLBEntryFull *full)
>  {
>      CPUArchState *env = cpu->env_ptr;
>      CPUTLB *tlb = env_tlb(env);
> @@ -1117,35 +1117,36 @@ void tlb_set_page_with_attrs(CPUState *cpu, 
> target_ulong vaddr,
>      CPUTLBEntry *te, tn;
>      hwaddr iotlb, xlat, sz, paddr_page;
>      target_ulong vaddr_page;
> -    int asidx = cpu_asidx_from_attrs(cpu, attrs);
> -    int wp_flags;
> +    int asidx, wp_flags, prot;
>      bool is_ram, is_romd;
>
>      assert_cpu_is_self(cpu);
>
> -    if (size <= TARGET_PAGE_SIZE) {
> +    if (full->lg_page_size <= TARGET_PAGE_BITS) {
>          sz = TARGET_PAGE_SIZE;
>      } else {
> -        tlb_add_large_page(env, mmu_idx, vaddr, size);
> -        sz = size;
> +        sz = (hwaddr)1 << full->lg_page_size;
> +        tlb_add_large_page(env, mmu_idx, vaddr, sz);
>      }
>      vaddr_page = vaddr & TARGET_PAGE_MASK;
> -    paddr_page = paddr & TARGET_PAGE_MASK;
> +    paddr_page = full->phys_addr & TARGET_PAGE_MASK;
>
> +    prot = full->prot;
> +    asidx = cpu_asidx_from_attrs(cpu, full->attrs);
>      section = address_space_translate_for_iotlb(cpu, asidx, paddr_page,
> -                                                &xlat, &sz, attrs, &prot);
> +                                                &xlat, &sz, full->attrs, 
> &prot);
>      assert(sz >= TARGET_PAGE_SIZE);
>
>      tlb_debug("vaddr=" TARGET_FMT_lx " paddr=0x" TARGET_FMT_plx
>                " prot=%x idx=%d\n",
> -              vaddr, paddr, prot, mmu_idx);
> +              vaddr, full->phys_addr, prot, mmu_idx);
>
>      address = vaddr_page;
> -    if (size < TARGET_PAGE_SIZE) {
> +    if (full->lg_page_size < TARGET_PAGE_BITS) {
>          /* Repeat the MMU check and TLB fill on every access.  */
>          address |= TLB_INVALID_MASK;
>      }
> -    if (attrs.byte_swap) {
> +    if (full->attrs.byte_swap) {
>          address |= TLB_BSWAP;
>      }
>
> @@ -1236,8 +1237,10 @@ void tlb_set_page_with_attrs(CPUState *cpu, 
> target_ulong vaddr,
>       * subtract here is that of the page base, and not the same as the
>       * vaddr we add back in io_readx()/io_writex()/get_page_addr_code().
>       */
> +    desc->fulltlb[index] = *full;
>      desc->fulltlb[index].xlat_section = iotlb - vaddr_page;
> -    desc->fulltlb[index].attrs = attrs;
> +    desc->fulltlb[index].phys_addr = paddr_page;
> +    desc->fulltlb[index].prot = prot;
>
>      /* Now calculate the new entry */
>      tn.addend = addend - vaddr_page;
> @@ -1272,9 +1275,21 @@ void tlb_set_page_with_attrs(CPUState *cpu, 
> target_ulong vaddr,
>      qemu_spin_unlock(&tlb->c.lock);
>  }
>
> -/* Add a new TLB entry, but without specifying the memory
> - * transaction attributes to be used.
> - */
> +void tlb_set_page_with_attrs(CPUState *cpu, target_ulong vaddr,
> +                             hwaddr paddr, MemTxAttrs attrs, int prot,
> +                             int mmu_idx, target_ulong size)
> +{
> +    CPUTLBEntryFull full = {
> +        .phys_addr = paddr,
> +        .attrs = attrs,
> +        .prot = prot,
> +        .lg_page_size = ctz64(size)
> +    };
> +
> +    assert(is_power_of_2(size));

I'm hitting this assert with embedded RISC-V machines using PMP

What's happening is that I'm going through riscv_cpu_tlb_fill() for a
single stage machine mode (no MMU) lookup. This calls
get_physical_address_pmp(), which then calls pmp_is_range_in_tlb() to
determine the tlb size.

That ends up in pmp_get_tlb_size() with

pmp_sa: 0x10004abc
pmp_ea: 0x1000ffff
tlb_sa: 0x10004000
tlb_ea: 0x10004fff

So we take the:

    if (pmp_sa >= tlb_sa && pmp_sa <= tlb_ea && pmp_ea >= tlb_ea) {
        return tlb_ea - pmp_sa + 1;
    }

path and return 1348 (0x544) for the tlb size, which isn't a multiple of 2.

Any ideas of what to do here?

Alistair

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