Hi,
Could this patch go through?
If not please let me know so that I can fix.
Thank you!
Dayeol
On Sat, Oct 12, 2019, 11:30 AM Dayeol Lee <day...@berkeley.edu> wrote:
> No it doesn't mean that.
> But the following code will make the size TARGET_PAGE_SIZE - (page offset)
> if the address is not aligned.
>
> pmp_size = -(address | TARGET_PAGE_MASK)
>
>
> On Fri, Oct 11, 2019, 7:37 PM Jonathan Behrens <finte...@gmail.com> wrote:
>
>> How do you know that the access won't straddle a page boundary? Is there
>> a guarantee somewhere that size=0 means that the access is naturally
>> aligned?
>>
>> Jonathan
>>
>>
>> On Fri, Oct 11, 2019 at 7:14 PM Dayeol Lee <day...@berkeley.edu> wrote:
>>
>>> riscv_cpu_tlb_fill() uses the `size` parameter to check PMP violation
>>> using pmp_hart_has_privs().
>>> However, if the size is unknown (=0), the ending address will be
>>> `addr - 1` as it is `addr + size - 1` in `pmp_hart_has_privs()`.
>>> This always causes a false PMP violation on the starting address of the
>>> range, as `addr - 1` is not in the range.
>>>
>>> In order to fix, we just assume that all bytes from addr to the end of
>>> the page will be accessed if the size is unknown.
>>>
>>> Signed-off-by: Dayeol Lee <day...@berkeley.edu>
>>> Reviewed-by: Richard Henderson <richard.hender...@linaro.org>
>>> ---
>>> target/riscv/cpu_helper.c | 13 ++++++++++++-
>>> 1 file changed, 12 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
>>> index e32b6126af..7d9a22b601 100644
>>> --- a/target/riscv/cpu_helper.c
>>> +++ b/target/riscv/cpu_helper.c
>>> @@ -441,6 +441,7 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address,
>>> int size,
>>> CPURISCVState *env = &cpu->env;
>>> hwaddr pa = 0;
>>> int prot;
>>> + int pmp_size = 0;
>>> bool pmp_violation = false;
>>> int ret = TRANSLATE_FAIL;
>>> int mode = mmu_idx;
>>> @@ -460,9 +461,19 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr
>>> address, int size,
>>> "%s address=%" VADDR_PRIx " ret %d physical "
>>> TARGET_FMT_plx
>>> " prot %d\n", __func__, address, ret, pa, prot);
>>>
>>> + /*
>>> + * if size is unknown (0), assume that all bytes
>>> + * from addr to the end of the page will be accessed.
>>> + */
>>> + if (size == 0) {
>>> + pmp_size = -(address | TARGET_PAGE_MASK);
>>> + } else {
>>> + pmp_size = size;
>>> + }
>>> +
>>> if (riscv_feature(env, RISCV_FEATURE_PMP) &&
>>> (ret == TRANSLATE_SUCCESS) &&
>>> - !pmp_hart_has_privs(env, pa, size, 1 << access_type, mode)) {
>>> + !pmp_hart_has_privs(env, pa, pmp_size, 1 << access_type, mode))
>>> {
>>> ret = TRANSLATE_PMP_FAIL;
>>> }
>>> if (ret == TRANSLATE_PMP_FAIL) {
>>> --
>>> 2.20.1
>>>
>>>
>>>
