From 1f4e496e1fc2eb6c8bf377a0f9695930c380bfd3 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Tue, 22 Nov 2016 12:04:52 +0100 Subject: [PATCH] exec: introduce MemoryRegionCache Device models often have to perform multiple access to a single memory region that is known in advance, but would to use "DMA-style" functions instead of address_space_map/unmap. This can happen for example when the data has to undergo endianness conversion. Introduce a new data structure to cache the result of address_space_translate without forcing usage of a host address like address_space_map does. Signed-off-by: Paolo Bonzini --- exec.c | 76 ++++++++++++++++++++ include/exec/cpu-all.h | 23 ++++++ include/exec/memory.h | 151 ++++++++++++++++++++++++++++++++++++++++ include/qemu/typedefs.h | 1 + 4 files changed, 251 insertions(+) diff --git a/exec.c b/exec.c index d4b36568f1..8d4bb0e8c1 100644 --- a/exec.c +++ b/exec.c @@ -3077,6 +3077,82 @@ void cpu_physical_memory_unmap(void *buffer, hwaddr len, #define RCU_READ_UNLOCK(...) rcu_read_unlock() #include "memory_ldst.inc.c" +int64_t address_space_cache_init(MemoryRegionCache *cache, + AddressSpace *as, + hwaddr addr, + hwaddr len, + bool is_write) +{ + hwaddr l, xlat; + MemoryRegion *mr; + void *ptr; + + assert(len > 0); + + l = len; + mr = address_space_translate(as, addr, &xlat, &l, is_write); + if (!memory_access_is_direct(mr, is_write)) { + return -EINVAL; + } + + l = address_space_extend_translation(as, addr, len, mr, xlat, l, is_write); + ptr = qemu_ram_ptr_length(mr->ram_block, xlat, &l); + + cache->xlat = xlat; + cache->is_write = is_write; + cache->mr = mr; + cache->ptr = ptr; + cache->len = l; + memory_region_ref(cache->mr); + + return l; +} + +void address_space_cache_invalidate(MemoryRegionCache *cache, + hwaddr addr, + hwaddr access_len) +{ + assert(cache->is_write); + invalidate_and_set_dirty(cache->mr, addr + cache->xlat, access_len); +} + +void address_space_cache_destroy(MemoryRegionCache *cache) +{ + if (!cache->mr) { + return; + } + + if (xen_enabled()) { + xen_invalidate_map_cache_entry(cache->ptr); + } + memory_region_unref(cache->mr); +} + +/* Called from RCU critical section. This function has the same + * semantics as address_space_translate, but it only works on a + * predefined range of a MemoryRegion that was mapped with + * address_space_cache_init. + */ +static inline MemoryRegion *address_space_translate_cached( + MemoryRegionCache *cache, hwaddr addr, hwaddr *xlat, + hwaddr *plen, bool is_write) +{ + assert(addr < cache->len && *plen <= cache->len - addr); + *xlat = addr + cache->xlat; + return cache->mr; +} + +#define ARG1_DECL MemoryRegionCache *cache +#define ARG1 cache +#define SUFFIX _cached +#define TRANSLATE(...) address_space_translate_cached(cache, __VA_ARGS__) +#define IS_DIRECT(mr, is_write) true +#define MAP_RAM(mr, ofs) (cache->ptr + (ofs - cache->xlat)) +#define INVALIDATE(mr, ofs, len) ((void)0) +#define RCU_READ_LOCK() ((void)0) +#define RCU_READ_UNLOCK() ((void)0) +#include "memory_ldst.inc.c" + /* virtual memory access for debug (includes writing to ROM) */ int cpu_memory_rw_debug(CPUState *cpu, target_ulong addr, uint8_t *buf, int len, int is_write) diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h index e9004e5798..ffe43d5654 100644 --- a/include/exec/cpu-all.h +++ b/include/exec/cpu-all.h @@ -186,6 +186,29 @@ void address_space_stl(AddressSpace *as, hwaddr addr, uint32_t val, MemTxAttrs attrs, MemTxResult *result); void address_space_stq(AddressSpace *as, hwaddr addr, uint64_t val, MemTxAttrs attrs, MemTxResult *result); + +uint32_t lduw_phys_cached(MemoryRegionCache *cache, hwaddr addr); +uint32_t ldl_phys_cached(MemoryRegionCache *cache, hwaddr addr); +uint64_t ldq_phys_cached(MemoryRegionCache *cache, hwaddr addr); +void stl_phys_notdirty_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val); +void stw_phys_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val); +void stl_phys_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val); +void stq_phys_cached(MemoryRegionCache *cache, hwaddr addr, uint64_t val); + +uint32_t address_space_lduw_cached(MemoryRegionCache *cache, hwaddr addr, + MemTxAttrs attrs, MemTxResult *result); +uint32_t address_space_ldl_cached(MemoryRegionCache *cache, hwaddr addr, + MemTxAttrs attrs, MemTxResult *result); +uint64_t address_space_ldq_cached(MemoryRegionCache *cache, hwaddr addr, + MemTxAttrs attrs, MemTxResult *result); +void address_space_stl_notdirty_cached(MemoryRegionCache *cache, hwaddr addr, + uint32_t val, MemTxAttrs attrs, MemTxResult *result); +void address_space_stw_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val, + MemTxAttrs attrs, MemTxResult *result); +void address_space_stl_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val, + MemTxAttrs attrs, MemTxResult *result); +void address_space_stq_cached(MemoryRegionCache *cache, hwaddr addr, uint64_t val, + MemTxAttrs attrs, MemTxResult *result); #endif /* page related stuff */ diff --git a/include/exec/memory.h b/include/exec/memory.h index f35b6125ab..64560f61b4 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -1419,6 +1419,125 @@ void stl_be_phys(AddressSpace *as, hwaddr addr, uint32_t val); void stq_le_phys(AddressSpace *as, hwaddr addr, uint64_t val); void stq_be_phys(AddressSpace *as, hwaddr addr, uint64_t val); +struct MemoryRegionCache { + hwaddr xlat; + void *ptr; + hwaddr len; + MemoryRegion *mr; + bool is_write; +}; + +/* address_space_cache_init: prepare for repeated access to a physical + * memory region + * + * @cache: #MemoryRegionCache to be filled + * @as: #AddressSpace to be accessed + * @addr: address within that address space + * @len: length of buffer + * @is_write: indicates the transfer direction + * + * Will only work with RAM, and may map a subset of the requested range by + * returning a value that is less than @len. On failure, return a negative + * errno value. + * + * Because it only works with RAM, this function can be used for + * read-modify-write operations. In this case, is_write should be %true. + * + * Note that addresses passed to the address_space_*_cached functions + * are relative to @addr. + */ +int64_t address_space_cache_init(MemoryRegionCache *cache, + AddressSpace *as, + hwaddr addr, + hwaddr len, + bool is_write); + +/** + * address_space_cache_invalidate: complete a write to a #MemoryRegionCache + * + * @cache: The #MemoryRegionCache to operate on. + * @addr: The first physical address that was written, relative to the + * address that was passed to @address_space_cache_init. + * @access_len: The number of bytes that were written starting at @addr. + */ +void address_space_cache_invalidate(MemoryRegionCache *cache, + hwaddr addr, + hwaddr access_len); + +/** + * address_space_cache_destroy: free a #MemoryRegionCache + * + * @cache: The #MemoryRegionCache whose memory should be released. + */ +void address_space_cache_destroy(MemoryRegionCache *cache); + +/* address_space_ld*_cached: load from a cached #MemoryRegion + * address_space_st*_cached: store into a cached #MemoryRegion + * + * These functions perform a load or store of the byte, word, + * longword or quad to the specified address. The address is + * a physical address in the AddressSpace, but it must lie within + * a #MemoryRegion that was mapped with address_space_cache_init. + * + * The _le suffixed functions treat the data as little endian; + * _be indicates big endian; no suffix indicates "same endianness + * as guest CPU". + * + * The "guest CPU endianness" accessors are deprecated for use outside + * target-* code; devices should be CPU-agnostic and use either the LE + * or the BE accessors. + * + * @cache: previously initialized #MemoryRegionCache to be accessed + * @addr: address within the address space + * @val: data value, for stores + * @attrs: memory transaction attributes + * @result: location to write the success/failure of the transaction; + * if NULL, this information is discarded + */ +uint32_t address_space_ldub_cached(MemoryRegionCache *cache, hwaddr addr, + MemTxAttrs attrs, MemTxResult *result); +uint32_t address_space_lduw_le_cached(MemoryRegionCache *cache, hwaddr addr, + MemTxAttrs attrs, MemTxResult *result); +uint32_t address_space_lduw_be_cached(MemoryRegionCache *cache, hwaddr addr, + MemTxAttrs attrs, MemTxResult *result); +uint32_t address_space_ldl_le_cached(MemoryRegionCache *cache, hwaddr addr, + MemTxAttrs attrs, MemTxResult *result); +uint32_t address_space_ldl_be_cached(MemoryRegionCache *cache, hwaddr addr, + MemTxAttrs attrs, MemTxResult *result); +uint64_t address_space_ldq_le_cached(MemoryRegionCache *cache, hwaddr addr, + MemTxAttrs attrs, MemTxResult *result); +uint64_t address_space_ldq_be_cached(MemoryRegionCache *cache, hwaddr addr, + MemTxAttrs attrs, MemTxResult *result); +void address_space_stb_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val, + MemTxAttrs attrs, MemTxResult *result); +void address_space_stw_le_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val, + MemTxAttrs attrs, MemTxResult *result); +void address_space_stw_be_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val, + MemTxAttrs attrs, MemTxResult *result); +void address_space_stl_le_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val, + MemTxAttrs attrs, MemTxResult *result); +void address_space_stl_be_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val, + MemTxAttrs attrs, MemTxResult *result); +void address_space_stq_le_cached(MemoryRegionCache *cache, hwaddr addr, uint64_t val, + MemTxAttrs attrs, MemTxResult *result); +void address_space_stq_be_cached(MemoryRegionCache *cache, hwaddr addr, uint64_t val, + MemTxAttrs attrs, MemTxResult *result); + +uint32_t ldub_phys_cached(MemoryRegionCache *cache, hwaddr addr); +uint32_t lduw_le_phys_cached(MemoryRegionCache *cache, hwaddr addr); +uint32_t lduw_be_phys_cached(MemoryRegionCache *cache, hwaddr addr); +uint32_t ldl_le_phys_cached(MemoryRegionCache *cache, hwaddr addr); +uint32_t ldl_be_phys_cached(MemoryRegionCache *cache, hwaddr addr); +uint64_t ldq_le_phys_cached(MemoryRegionCache *cache, hwaddr addr); +uint64_t ldq_be_phys_cached(MemoryRegionCache *cache, hwaddr addr); +void stb_phys_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val); +void stw_le_phys_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val); +void stw_be_phys_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val); +void stl_le_phys_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val); +void stl_be_phys_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val); +void stq_le_phys_cached(MemoryRegionCache *cache, hwaddr addr, uint64_t val); +void stq_be_phys_cached(MemoryRegionCache *cache, hwaddr addr, uint64_t val); + /* address_space_translate: translate an address range into an address space * into a MemoryRegion and an address range into that section. Should be * called from an RCU critical section, to avoid that the last reference @@ -1544,6 +1663,38 @@ MemTxResult address_space_read(AddressSpace *as, hwaddr addr, MemTxAttrs attrs, return result; } +/** + * address_space_read_cached: read from a cached RAM region + * + * @cache: Cached region to be addressed + * @addr: address relative to the base of the RAM region + * @buf: buffer with the data transferred + * @len: length of the data transferred + */ +static inline void +address_space_read_cached(MemoryRegionCache *cache, hwaddr addr, + void *buf, int len) +{ + assert(addr < cache->len && len <= cache->len - addr); + memcpy(buf, cache->ptr + addr, len); +} + +/** + * address_space_write_cached: write to a cached RAM region + * + * @cache: Cached region to be addressed + * @addr: address relative to the base of the RAM region + * @buf: buffer with the data transferred + * @len: length of the data transferred + */ +static inline void +address_space_write_cached(MemoryRegionCache *cache, hwaddr addr, + void *buf, int len) +{ + assert(addr < cache->len && len <= cache->len - addr); + memcpy(cache->ptr + addr, buf, len); +} + #endif #endif diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h index 1b8c30a7a0..9a8bcbde36 100644 --- a/include/qemu/typedefs.h +++ b/include/qemu/typedefs.h @@ -45,6 +45,7 @@ typedef struct MachineState MachineState; typedef struct MemoryListener MemoryListener; typedef struct MemoryMappingList MemoryMappingList; typedef struct MemoryRegion MemoryRegion; +typedef struct MemoryRegionCache MemoryRegionCache; typedef struct MemoryRegionSection MemoryRegionSection; typedef struct MigrationIncomingState MigrationIncomingState; typedef struct MigrationParams MigrationParams;