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accel/tcg: Simplify CPU_TLB_DYN_MAX_BITS

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Stop taking TARGET_VIRT_ADDR_SPACE_BITS into account.

Since we currently bound CPU_TLB_DYN_MAX_BITS to 22,
the new bound with a 4k page size is 20, which isn't
so different.

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2025-04-02 08:40:31 -07:00
parent 77ad412b32
commit 80e865668d
1 changed files with 1 additions and 20 deletions
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21
accel/tcg/tlb-bounds.h
View file

@ -7,26 +7,7 @@
#define ACCEL_TCG_TLB_BOUNDS_H
#define CPU_TLB_DYN_MIN_BITS 6
#define CPU_TLB_DYN_MAX_BITS (32 - TARGET_PAGE_BITS)
#define CPU_TLB_DYN_DEFAULT_BITS 8
# if HOST_LONG_BITS == 32
/* Make sure we do not require a double-word shift for the TLB load */
# define CPU_TLB_DYN_MAX_BITS (32 - TARGET_PAGE_BITS)
# else /* HOST_LONG_BITS == 64 */
/*
* Assuming TARGET_PAGE_BITS==12, with 2**22 entries we can cover 2**(22+12) ==
* 2**34 == 16G of address space. This is roughly what one would expect a
* TLB to cover in a modern (as of 2018) x86_64 CPU. For instance, Intel
* Skylake's Level-2 STLB has 16 1G entries.
* Also, make sure we do not size the TLB past the guest's address space.
*/
# ifdef TARGET_PAGE_BITS_VARY
# define CPU_TLB_DYN_MAX_BITS \
MIN(22, TARGET_VIRT_ADDR_SPACE_BITS - TARGET_PAGE_BITS)
# else
# define CPU_TLB_DYN_MAX_BITS \
MIN_CONST(22, TARGET_VIRT_ADDR_SPACE_BITS - TARGET_PAGE_BITS)
# endif
# endif
#endif /* ACCEL_TCG_TLB_BOUNDS_H */