Re: [Qemu-devel] [PATCH 04/14] Add MemTxAttrs to the IOTLB

[Paolo Bonzini <pbonzini@redhat.com>]

On 07/04/2015 22:09, Peter Maydell wrote:
> Add a MemTxAttrs field to the IOTLB, and allow target-specific
> code to set it via a new tlb_set_page_with_attrs() function;
> pass the attributes through to the device when making IO accesses.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  cputlb.c                | 18 +++++++++++++++---
>  include/exec/cpu-defs.h |  2 ++
>  include/exec/exec-all.h |  3 +++
>  softmmu_template.h      |  4 ++--
>  4 files changed, 22 insertions(+), 5 deletions(-)
> 
> diff --git a/cputlb.c b/cputlb.c
> index 5e1cb8f..7606548 100644
> --- a/cputlb.c
> +++ b/cputlb.c
> @@ -249,9 +249,9 @@ static void tlb_add_large_page(CPUArchState *env, target_ulong vaddr,
>   * Called from TCG-generated code, which is under an RCU read-side
>   * critical section.
>   */
> -void tlb_set_page(CPUState *cpu, target_ulong vaddr,
> -                  hwaddr paddr, int prot,
> -                  int mmu_idx, target_ulong size)
> +void tlb_set_page_with_attrs(CPUState *cpu, target_ulong vaddr,
> +                             hwaddr paddr, MemTxAttrs attrs, int prot,
> +                             int mmu_idx, target_ulong size)
>  {
>      CPUArchState *env = cpu->env_ptr;
>      MemoryRegionSection *section;
> @@ -302,6 +302,7 @@ void tlb_set_page(CPUState *cpu, target_ulong vaddr,
>  
>      /* refill the tlb */
>      env->iotlb[mmu_idx][index].addr = iotlb - vaddr;
> +    env->iotlb[mmu_idx][index].attrs = attrs;
>      te->addend = addend - vaddr;
>      if (prot & PAGE_READ) {
>          te->addr_read = address;
> @@ -331,6 +332,17 @@ void tlb_set_page(CPUState *cpu, target_ulong vaddr,
>      }
>  }
>  
> +/* Add a new TLB entry, but without specifying the memory
> + * transaction attributes to be used.
> + */
> +void tlb_set_page(CPUState *cpu, target_ulong vaddr,
> +                  hwaddr paddr, int prot,
> +                  int mmu_idx, target_ulong size)
> +{
> +    tlb_set_page_with_attrs(cpu, vaddr, paddr, MEMTXATTRS_UNSPECIFIED,
> +                            prot, mmu_idx, size);
> +}
> +
>  /* NOTE: this function can trigger an exception */
>  /* NOTE2: the returned address is not exactly the physical address: it
>   * is actually a ram_addr_t (in system mode; the user mode emulation
> diff --git a/include/exec/cpu-defs.h b/include/exec/cpu-defs.h
> index 7f88185..3f56546 100644
> --- a/include/exec/cpu-defs.h
> +++ b/include/exec/cpu-defs.h
> @@ -30,6 +30,7 @@
>  #ifndef CONFIG_USER_ONLY
>  #include "exec/hwaddr.h"
>  #endif
> +#include "exec/memattrs.h"
>  
>  #ifndef TARGET_LONG_BITS
>  #error TARGET_LONG_BITS must be defined before including this header
> @@ -109,6 +110,7 @@ QEMU_BUILD_BUG_ON(sizeof(CPUTLBEntry) != (1 << CPU_TLB_ENTRY_BITS));
>   */
>  typedef struct CPUIOTLBEntry {
>      hwaddr addr;
> +    MemTxAttrs attrs;
>  } CPUIOTLBEntry;
>  
>  #define CPU_COMMON_TLB \
> diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
> index ff1bc3e..b58cd47 100644
> --- a/include/exec/exec-all.h
> +++ b/include/exec/exec-all.h
> @@ -105,6 +105,9 @@ void tlb_flush(CPUState *cpu, int flush_global);
>  void tlb_set_page(CPUState *cpu, target_ulong vaddr,
>                    hwaddr paddr, int prot,
>                    int mmu_idx, target_ulong size);
> +void tlb_set_page_with_attrs(CPUState *cpu, target_ulong vaddr,
> +                             hwaddr paddr, MemTxAttrs attrs,
> +                             int prot, int mmu_idx, target_ulong size);
>  void tb_invalidate_phys_addr(AddressSpace *as, hwaddr addr);
>  #else
>  static inline void tlb_flush_page(CPUState *cpu, target_ulong addr)
> diff --git a/softmmu_template.h b/softmmu_template.h
> index 7a36550..7310a93 100644
> --- a/softmmu_template.h
> +++ b/softmmu_template.h
> @@ -159,7 +159,7 @@ static inline DATA_TYPE glue(io_read, SUFFIX)(CPUArchState *env,
>      }
>  
>      cpu->mem_io_vaddr = addr;
> -    io_mem_read(mr, physaddr, &val, 1 << SHIFT, MEMTXATTRS_UNSPECIFIED);
> +    io_mem_read(mr, physaddr, &val, 1 << SHIFT, iotlbentry->attrs);
>      return val;
>  }
>  #endif
> @@ -380,7 +380,7 @@ static inline void glue(io_write, SUFFIX)(CPUArchState *env,
>  
>      cpu->mem_io_vaddr = addr;
>      cpu->mem_io_pc = retaddr;
> -    io_mem_write(mr, physaddr, val, 1 << SHIFT, MEMTXATTRS_UNSPECIFIED);
> +    io_mem_write(mr, physaddr, val, 1 << SHIFT, iotlbentry->attrs);
>  }
>  
>  void helper_le_st_name(CPUArchState *env, target_ulong addr, DATA_TYPE val,
> 

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>