From a8955ac9aa33e2d3edb4ea948d74cf52fc9771a2 Mon Sep 17 00:00:00 2001 From: Brijesh Singh Date: Thu, 15 Feb 2018 09:03:19 -0600 Subject: [PATCH] exec: add ram_debug_ops support Currently, the guest memory access for the debug purpose is performed using the memcpy(). Lets extend the 'struct MemoryRegion' to include ram_debug_ops callbacks. The ram_debug_ops can be used to override memcpy() with something else. The feature can be used by encrypted guest -- which can register callbacks to override memcpy() with memory encryption/decryption APIs. a typical usage: mem_read(uint8_t *dst, uint8_t *src, uint32_t len, MemTxAttrs *attrs); mem_write(uint8_t *dst, uint8_t *src, uint32_t len, MemTxAttrs *attrs); MemoryRegionRAMReadWriteOps ops; ops.read = mem_read; ops.write = mem_write; memory_region_init_ram(mem, NULL, "memory", size, NULL); memory_region_set_ram_debug_ops(mem, ops); Cc: Paolo Bonzini Cc: Peter Crosthwaite Cc: Richard Henderson Signed-off-by: Brijesh Singh [BR: FATE#322124] Signed-off-by: Bruce Rogers --- exec.c | 43 ++++++++++++++++++++++++++++++++----------- include/exec/memory.h | 30 +++++++++++++++++++++++++++++- 2 files changed, 61 insertions(+), 12 deletions(-) diff --git a/exec.c b/exec.c index 1ca0f9e0ab..fe49807f58 100644 --- a/exec.c +++ b/exec.c @@ -2983,7 +2983,11 @@ static MemTxResult flatview_write_continue(FlatView *fv, hwaddr addr, } else { /* RAM case */ ptr = qemu_ram_ptr_length(mr->ram_block, addr1, &l, false); - memcpy(ptr, buf, l); + if (attrs.debug && mr->ram_debug_ops) { + mr->ram_debug_ops->write(ptr, buf, l, attrs); + } else { + memcpy(ptr, buf, l); + } invalidate_and_set_dirty(mr, addr1, l); } @@ -3081,7 +3085,11 @@ MemTxResult flatview_read_continue(FlatView *fv, hwaddr addr, } else { /* RAM case */ ptr = qemu_ram_ptr_length(mr->ram_block, addr1, &l, false); - memcpy(buf, ptr, l); + if (attrs.debug && mr->ram_debug_ops) { + mr->ram_debug_ops->read(buf, ptr, l, attrs); + } else { + memcpy(buf, ptr, l); + } } if (release_lock) { @@ -3155,7 +3163,8 @@ enum write_rom_type { }; static inline void cpu_physical_memory_write_rom_internal(AddressSpace *as, - hwaddr addr, const uint8_t *buf, int len, enum write_rom_type type) + hwaddr addr, const uint8_t *buf, int len, MemTxAttrs attrs, + enum write_rom_type type) { hwaddr l; uint8_t *ptr; @@ -3175,7 +3184,11 @@ static inline void cpu_physical_memory_write_rom_internal(AddressSpace *as, ptr = qemu_map_ram_ptr(mr->ram_block, addr1); switch (type) { case WRITE_DATA: - memcpy(ptr, buf, l); + if (mr->ram_debug_ops) { + mr->ram_debug_ops->write(ptr, buf, l, attrs); + } else { + memcpy(ptr, buf, l); + } invalidate_and_set_dirty(mr, addr1, l); break; case FLUSH_CACHE: @@ -3194,7 +3207,9 @@ static inline void cpu_physical_memory_write_rom_internal(AddressSpace *as, void cpu_physical_memory_write_rom(AddressSpace *as, hwaddr addr, const uint8_t *buf, int len) { - cpu_physical_memory_write_rom_internal(as, addr, buf, len, WRITE_DATA); + cpu_physical_memory_write_rom_internal(as, addr, buf, len, + MEMTXATTRS_UNSPECIFIED, + WRITE_DATA); } void cpu_flush_icache_range(hwaddr start, int len) @@ -3209,8 +3224,9 @@ void cpu_flush_icache_range(hwaddr start, int len) return; } - cpu_physical_memory_write_rom_internal(&address_space_memory, - start, NULL, len, FLUSH_CACHE); + cpu_physical_memory_write_rom_internal(&address_space_memory, start, NULL, + len, MEMTXATTRS_UNSPECIFIED, + FLUSH_CACHE); } typedef struct { @@ -3525,6 +3541,10 @@ int cpu_memory_rw_debug(CPUState *cpu, target_ulong addr, page = addr & TARGET_PAGE_MASK; phys_addr = cpu_get_phys_page_attrs_debug(cpu, page, &attrs); asidx = cpu_asidx_from_attrs(cpu, attrs); + + /* set debug attrs to indicate memory access is from the debugger */ + attrs.debug = 1; + /* if no physical page mapped, return an error */ if (phys_addr == -1) return -1; @@ -3533,13 +3553,14 @@ int cpu_memory_rw_debug(CPUState *cpu, target_ulong addr, l = len; phys_addr += (addr & ~TARGET_PAGE_MASK); if (is_write) { - cpu_physical_memory_write_rom(cpu->cpu_ases[asidx].as, - phys_addr, buf, l); + cpu_physical_memory_write_rom_internal(cpu->cpu_ases[asidx].as, + phys_addr, buf, l, attrs, + WRITE_DATA); } else { address_space_rw(cpu->cpu_ases[asidx].as, phys_addr, - MEMTXATTRS_UNSPECIFIED, - buf, l, 0); + attrs, buf, l, 0); } + len -= l; buf += l; addr += l; diff --git a/include/exec/memory.h b/include/exec/memory.h index 5ed4042f87..8d3b99cba8 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -215,6 +215,18 @@ typedef struct IOMMUMemoryRegionClass { typedef struct CoalescedMemoryRange CoalescedMemoryRange; typedef struct MemoryRegionIoeventfd MemoryRegionIoeventfd; +/* Memory Region RAM debug callback */ +typedef struct MemoryRegionRAMReadWriteOps MemoryRegionRAMReadWriteOps; + +struct MemoryRegionRAMReadWriteOps { + /* Write data into guest memory */ + int (*write) (uint8_t *dest, const uint8_t *src, + uint32_t len, MemTxAttrs attrs); + /* Read data from guest memory */ + int (*read) (uint8_t *dest, const uint8_t *src, + uint32_t len, MemTxAttrs attrs); +}; + struct MemoryRegion { Object parent_obj; @@ -254,6 +266,7 @@ struct MemoryRegion { const char *name; unsigned ioeventfd_nb; MemoryRegionIoeventfd *ioeventfds; + const MemoryRegionRAMReadWriteOps *ram_debug_ops; }; struct IOMMUMemoryRegion { @@ -620,6 +633,21 @@ void memory_region_init_rom_device_nomigrate(MemoryRegion *mr, uint64_t size, Error **errp); +/** + * memory_region_set_ram_debug_ops: Set debug access ops for a given memory + * region. + * + * @mr: the #MemoryRegion to be initialized + * @ops: a function that will be used for when accessing @target region during + * debug + */ +static inline void +memory_region_set_ram_debug_ops(MemoryRegion *mr, + const MemoryRegionRAMReadWriteOps *ops) +{ + mr->ram_debug_ops = ops; +} + /** * memory_region_init_reservation: Initialize a memory region that reserves * I/O space. @@ -1928,7 +1956,7 @@ MemTxResult flatview_read(FlatView *fv, hwaddr addr, MemTxAttrs attrs, void *ptr; MemoryRegion *mr; - if (__builtin_constant_p(len)) { + if (__builtin_constant_p(len) && !attrs.debug) { if (len) { rcu_read_lock(); l = len;