diff options
| author | Peter Maydell <peter.maydell@linaro.org> | 2016-10-24 16:26:49 +0100 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2016-10-24 16:26:49 +0100 |
| commit | 20bccb82ff3ea09bcb7c4ee226d3160cab15f7da (patch) | |
| tree | beb472fa034fe9e742c571f678982235695f29eb /include/exec | |
| parent | 66ec9f49399f0a9fa13ee77c472caba0de2773fc (diff) | |
cpu: Support a target CPU having a variable page size
Support target CPUs having a page size which isn't knownn
at compile time. To use this, the CPU implementation should:
* define TARGET_PAGE_BITS_VARY
* not define TARGET_PAGE_BITS
* define TARGET_PAGE_BITS_MIN to the smallest value it
might possibly want for TARGET_PAGE_BITS
* call set_preferred_target_page_bits() in its realize
function to indicate the actual preferred target page
size for the CPU (and report any error from it)
In CONFIG_USER_ONLY, the CPU implementation should continue
to define TARGET_PAGE_BITS appropriately for the guest
OS page size.
Machines which want to take advantage of having the page
size something larger than TARGET_PAGE_BITS_MIN must
set the MachineClass minimum_page_bits field to a value
which they guarantee will be no greater than the preferred
page size for any CPU they create.
Note that changing the target page size by setting
minimum_page_bits is a migration compatibility break
for that machine.
For debugging purposes, attempts to use TARGET_PAGE_SIZE
before it has been finally confirmed will assert.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'include/exec')
| -rw-r--r-- | include/exec/cpu-all.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h index b6a705982f..861260d3db 100644 --- a/include/exec/cpu-all.h +++ b/include/exec/cpu-all.h @@ -189,6 +189,15 @@ void address_space_stq(AddressSpace *as, hwaddr addr, uint64_t val, /* page related stuff */ +#ifdef TARGET_PAGE_BITS_VARY +extern bool target_page_bits_decided; +extern int target_page_bits; +#define TARGET_PAGE_BITS ({ assert(target_page_bits_decided); \ + target_page_bits; }) +#else +#define TARGET_PAGE_BITS_MIN TARGET_PAGE_BITS +#endif + #define TARGET_PAGE_SIZE (1 << TARGET_PAGE_BITS) #define TARGET_PAGE_MASK ~(TARGET_PAGE_SIZE - 1) #define TARGET_PAGE_ALIGN(addr) (((addr) + TARGET_PAGE_SIZE - 1) & TARGET_PAGE_MASK) |