On 6/25/20 9:34 AM, Peter Maydell wrote:
> On Fri, 5 Jun 2020 at 05:17, Richard Henderson
> <[email protected]> wrote:
>>
>> This is the only use of guest_addr_valid that does not begin
>> with a guest address, but a host address being transformed to
>> a guest address.
>>
>> We will shortly adjust guest_addr_valid to handle guest memory
>> tags, and the host address should not be subjected to that.
>>
>> Move h2g_valid adjacent to the other h2g macros.
>>
>> Signed-off-by: Richard Henderson <[email protected]>
>> ---
>> include/exec/cpu_ldst.h | 5 +++--
>> 1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/include/exec/cpu_ldst.h b/include/exec/cpu_ldst.h
>> index c14a48f65e..3930362e20 100644
>> --- a/include/exec/cpu_ldst.h
>> +++ b/include/exec/cpu_ldst.h
>> @@ -77,15 +77,16 @@ typedef uint64_t abi_ptr;
>> #else
>> #define guest_addr_valid(x) ((x) <= GUEST_ADDR_MAX)
>> #endif
>> -#define h2g_valid(x) guest_addr_valid((unsigned long)(x) - guest_base)
>>
>> static inline int guest_range_valid(unsigned long start, unsigned long len)
>> {
>> return len - 1 <= GUEST_ADDR_MAX && start <= GUEST_ADDR_MAX - len + 1;
>> }
>>
>> +#define h2g_valid(x) ((uintptr_t)(x) - guest_base <= GUEST_ADDR_MAX)
>
> The old implementation returns true for
> HOST_LONG_BITS <= TARGET_VIRT_ADDR_SPACE_BITS
> (because there's a different definition of guest_addr_valid() there)
> but this one does a range check even in that case.
It's part and parcel with patch 1, wherein we are in fact attempting to limit
the guest address space to GUEST_ADDR_MAX.
That's why I put patch 1 first, so the behaviour change happens there.
>> #define h2g_nocheck(x) ({ \
>> - unsigned long __ret = (unsigned long)(x) - guest_base; \
>> + uintptr_t __ret = (uintptr_t)(x) - guest_base; \
>> (abi_ptr)__ret; \
>> })
>
> Why the type change? This seems unrelated.
Dropped. Though at some point we should purge unsigned long, as there is
always a clearer type to use.
r~
