On 4/29/19 7:25 PM, Peter Maydell wrote:
> On Wed, 3 Apr 2019 at 04:49, Richard Henderson
> <richard.hender...@linaro.org> wrote:
>>
>> This hook will replace the (user-only mode specific) handle_mmu_fault
>> hook, and the (system mode specific) tlb_fill function.
>>
>> The handle_mmu_fault hook was written as if there was a valid
>> way to recover from an mmu fault, and had 3 possible return states.
>> In reality, the only valid action is to raise an exception,
>> return to the main loop, and delver the SIGSEGV to the guest.
>
> "deliver"
>
> You might also mention here that all of the implementations
> of handle_mmu_fault for guest architectures which support
> linux-user do in fact only ever return 1.
>
>>
>> Using the hook for system mode requires that all targets be converted,
>> so for now the hook is (optionally) used only from user-only mode.
>>
>> Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
>> ---
>> include/qom/cpu.h | 9 +++++++++
>> accel/tcg/user-exec.c | 42 ++++++++++++++----------------------------
>> 2 files changed, 23 insertions(+), 28 deletions(-)
>>
>> diff --git a/include/qom/cpu.h b/include/qom/cpu.h
>> index 1d6099e5d4..7e96a0aed3 100644
>> --- a/include/qom/cpu.h
>> +++ b/include/qom/cpu.h
>> @@ -119,6 +119,12 @@ struct TranslationBlock;
>> * will need to do more. If this hook is not implemented then the
>> * default is to call @set_pc(tb->pc).
>> * @handle_mmu_fault: Callback for handling an MMU fault.
>> + * @tlb_fill: Callback for handling a softmmu tlb miss or user-only
>> + * address fault. For system mode, if the access is valid, call
>> + * tlb_set_page and return true; if the access is invalid, and
>> + * probe is true, return false; otherwise raise an exception and
>> + * do not return. For user-only mode, always raise an exception
>> + * and do not return.
>> * @get_phys_page_debug: Callback for obtaining a physical address.
>> * @get_phys_page_attrs_debug: Callback for obtaining a physical address
>> and the
>> * associated memory transaction attributes to use for the access.
>> @@ -194,6 +200,9 @@ typedef struct CPUClass {
>> void (*synchronize_from_tb)(CPUState *cpu, struct TranslationBlock *tb);
>> int (*handle_mmu_fault)(CPUState *cpu, vaddr address, int size, int rw,
>> int mmu_index);
>> + bool (*tlb_fill)(CPUState *cpu, vaddr address, int size,
>> + MMUAccessType access_type, int mmu_idx,
>> + bool probe, uintptr_t retaddr);
>> hwaddr (*get_phys_page_debug)(CPUState *cpu, vaddr addr);
>> hwaddr (*get_phys_page_attrs_debug)(CPUState *cpu, vaddr addr,
>> MemTxAttrs *attrs);
>> diff --git a/accel/tcg/user-exec.c b/accel/tcg/user-exec.c
>> index fa9380a380..f13c0b2b67 100644
>> --- a/accel/tcg/user-exec.c
>> +++ b/accel/tcg/user-exec.c
>> @@ -65,6 +65,7 @@ static inline int handle_cpu_signal(uintptr_t pc,
>> siginfo_t *info,
>> CPUClass *cc;
>> int ret;
>> unsigned long address = (unsigned long)info->si_addr;
>> + MMUAccessType access_type;
>>
>> /* We must handle PC addresses from two different sources:
>> * a call return address and a signal frame address.
>> @@ -151,40 +152,25 @@ static inline int handle_cpu_signal(uintptr_t pc,
>> siginfo_t *info,
>> #if TARGET_LONG_BITS == 32 && HOST_LONG_BITS == 64
>> g_assert(h2g_valid(address));
>> #endif
>> -
>> - /* Convert forcefully to guest address space, invalid addresses
>> - are still valid segv ones */
>
> This comment is still valid so I don't think it should be deleted.
>
>> address = h2g_nocheck(address);
>
> Otherwise
>
> Reviewed-by: Peter Maydell <peter.mayd...@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com>
