diff options
Diffstat (limited to 'include/exec/cpu-defs.h')
| -rw-r--r-- | include/exec/cpu-defs.h | 71 |
1 files changed, 39 insertions, 32 deletions
diff --git a/include/exec/cpu-defs.h b/include/exec/cpu-defs.h index 6a60f94..8f2a848 100644 --- a/include/exec/cpu-defs.h +++ b/include/exec/cpu-defs.h @@ -67,37 +67,23 @@ typedef uint64_t target_ulong; #define CPU_TLB_ENTRY_BITS 5 #endif -/* TCG_TARGET_TLB_DISPLACEMENT_BITS is used in CPU_TLB_BITS to ensure that - * the TLB is not unnecessarily small, but still small enough for the - * TLB lookup instruction sequence used by the TCG target. - * - * TCG will have to generate an operand as large as the distance between - * env and the tlb_table[NB_MMU_MODES - 1][0].addend. For simplicity, - * the TCG targets just round everything up to the next power of two, and - * count bits. This works because: 1) the size of each TLB is a largish - * power of two, 2) and because the limit of the displacement is really close - * to a power of two, 3) the offset of tlb_table[0][0] inside env is smaller - * than the size of a TLB. - * - * For example, the maximum displacement 0xFFF0 on PPC and MIPS, but TCG - * just says "the displacement is 16 bits". TCG_TARGET_TLB_DISPLACEMENT_BITS - * then ensures that tlb_table at least 0x8000 bytes large ("not unnecessarily - * small": 2^15). The operand then will come up smaller than 0xFFF0 without - * any particular care, because the TLB for a single MMU mode is larger than - * 0x10000-0xFFF0=16 bytes. In the end, the maximum value of the operand - * could be something like 0xC000 (the offset of the last TLB table) plus - * 0x18 (the offset of the addend field in each TLB entry) plus the offset - * of tlb_table inside env (which is non-trivial but not huge). - */ -#define CPU_TLB_BITS \ - MIN(8, \ - TCG_TARGET_TLB_DISPLACEMENT_BITS - CPU_TLB_ENTRY_BITS - \ - (NB_MMU_MODES <= 1 ? 0 : \ - NB_MMU_MODES <= 2 ? 1 : \ - NB_MMU_MODES <= 4 ? 2 : \ - NB_MMU_MODES <= 8 ? 3 : 4)) +#define CPU_TLB_DYN_MIN_BITS 6 +#define CPU_TLB_DYN_DEFAULT_BITS 8 -#define CPU_TLB_SIZE (1 << CPU_TLB_BITS) +# 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. + */ +# define CPU_TLB_DYN_MAX_BITS \ + MIN(22, TARGET_VIRT_ADDR_SPACE_BITS - TARGET_PAGE_BITS) +# endif typedef struct CPUTLBEntry { /* bit TARGET_LONG_BITS to TARGET_PAGE_BITS : virtual address @@ -141,6 +127,18 @@ typedef struct CPUIOTLBEntry { MemTxAttrs attrs; } CPUIOTLBEntry; +/** + * struct CPUTLBWindow + * @begin_ns: host time (in ns) at the beginning of the time window + * @max_entries: maximum number of entries observed in the window + * + * See also: tlb_mmu_resize_locked() + */ +typedef struct CPUTLBWindow { + int64_t begin_ns; + size_t max_entries; +} CPUTLBWindow; + typedef struct CPUTLBDesc { /* * Describe a region covering all of the large pages allocated @@ -152,6 +150,8 @@ typedef struct CPUTLBDesc { target_ulong large_page_mask; /* The next index to use in the tlb victim table. */ size_t vindex; + CPUTLBWindow window; + size_t n_used_entries; } CPUTLBDesc; /* @@ -176,6 +176,13 @@ typedef struct CPUTLBCommon { size_t elide_flush_count; } CPUTLBCommon; +# define CPU_TLB \ + /* tlb_mask[i] contains (n_entries - 1) << CPU_TLB_ENTRY_BITS */ \ + uintptr_t tlb_mask[NB_MMU_MODES]; \ + CPUTLBEntry *tlb_table[NB_MMU_MODES]; +# define CPU_IOTLB \ + CPUIOTLBEntry *iotlb[NB_MMU_MODES]; + /* * The meaning of each of the MMU modes is defined in the target code. * Note that NB_MMU_MODES is not yet defined; we can only reference it @@ -184,9 +191,9 @@ typedef struct CPUTLBCommon { #define CPU_COMMON_TLB \ CPUTLBCommon tlb_c; \ CPUTLBDesc tlb_d[NB_MMU_MODES]; \ - CPUTLBEntry tlb_table[NB_MMU_MODES][CPU_TLB_SIZE]; \ + CPU_TLB \ CPUTLBEntry tlb_v_table[NB_MMU_MODES][CPU_VTLB_SIZE]; \ - CPUIOTLBEntry iotlb[NB_MMU_MODES][CPU_TLB_SIZE]; \ + CPU_IOTLB \ CPUIOTLBEntry iotlb_v[NB_MMU_MODES][CPU_VTLB_SIZE]; #else |