From 6886867e9880830d735d8ae6f6cc63ed9eb2be0c Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 21 Jul 2014 16:45:18 +0200 Subject: [PATCH] exec: fix migration with devices that use address_space_rw Devices that use address_space_rw to write large areas to memory (as opposed to address_space_map/unmap) were broken with respect to migration since fe680d0 (exec: Limit translation limiting in address_space_translate to xen, 2014-05-07). Such devices include IDE CD-ROMs. The reason is that invalidate_and_set_dirty (called by address_space_rw but not address_space_map/unmap) was only setting the dirty bit for the first page in the translation. To fix this, introduce cpu_physical_memory_set_dirty_range_nocode that is the same as cpu_physical_memory_set_dirty_range except it does not muck with the DIRTY_MEMORY_CODE bitmap. This function can be used if the caller invalidates translations with tb_invalidate_phys_page_range. There is another difference between cpu_physical_memory_set_dirty_range and cpu_physical_memory_set_dirty_flag; the former includes a call to xen_modified_memory. This is handled separately in invalidate_and_set_dirty, and is not needed in other callers of cpu_physical_memory_set_dirty_range_nocode, so leave it alone. Just one nit: now that invalidate_and_set_dirty takes care of handling multiple pages, there is no need for address_space_unmap to wrap it in a loop. In fact that loop would now be O(n^2). Reported-by: Dave Gilbert Reviewed-by: Michael S. Tsirkin Tested-by: Gerd Hoffmann Signed-off-by: Paolo Bonzini --- exec.c | 20 ++++---------------- include/exec/ram_addr.h | 11 +++++++++++ 2 files changed, 15 insertions(+), 16 deletions(-) diff --git a/exec.c b/exec.c index 5a2a25e851..765bd942eb 100644 --- a/exec.c +++ b/exec.c @@ -1568,8 +1568,7 @@ static void notdirty_mem_write(void *opaque, hwaddr ram_addr, default: abort(); } - cpu_physical_memory_set_dirty_flag(ram_addr, DIRTY_MEMORY_MIGRATION); - cpu_physical_memory_set_dirty_flag(ram_addr, DIRTY_MEMORY_VGA); + cpu_physical_memory_set_dirty_range_nocode(ram_addr, size); /* we remove the notdirty callback only if the code has been flushed */ if (!cpu_physical_memory_is_clean(ram_addr)) { @@ -1978,8 +1977,7 @@ static void invalidate_and_set_dirty(hwaddr addr, /* invalidate code */ tb_invalidate_phys_page_range(addr, addr + length, 0); /* set dirty bit */ - cpu_physical_memory_set_dirty_flag(addr, DIRTY_MEMORY_VGA); - cpu_physical_memory_set_dirty_flag(addr, DIRTY_MEMORY_MIGRATION); + cpu_physical_memory_set_dirty_range_nocode(addr, length); } xen_modified_memory(addr, length); } @@ -2335,15 +2333,7 @@ void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len, mr = qemu_ram_addr_from_host(buffer, &addr1); assert(mr != NULL); if (is_write) { - while (access_len) { - unsigned l; - l = TARGET_PAGE_SIZE; - if (l > access_len) - l = access_len; - invalidate_and_set_dirty(addr1, l); - addr1 += l; - access_len -= l; - } + invalidate_and_set_dirty(addr1, access_len); } if (xen_enabled()) { xen_invalidate_map_cache_entry(buffer); @@ -2581,9 +2571,7 @@ void stl_phys_notdirty(AddressSpace *as, hwaddr addr, uint32_t val) /* invalidate code */ tb_invalidate_phys_page_range(addr1, addr1 + 4, 0); /* set dirty bit */ - cpu_physical_memory_set_dirty_flag(addr1, - DIRTY_MEMORY_MIGRATION); - cpu_physical_memory_set_dirty_flag(addr1, DIRTY_MEMORY_VGA); + cpu_physical_memory_set_dirty_range_nocode(addr1, 4); } } } diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h index e9eb831ee3..6593be1310 100644 --- a/include/exec/ram_addr.h +++ b/include/exec/ram_addr.h @@ -71,6 +71,17 @@ static inline void cpu_physical_memory_set_dirty_flag(ram_addr_t addr, set_bit(addr >> TARGET_PAGE_BITS, ram_list.dirty_memory[client]); } +static inline void cpu_physical_memory_set_dirty_range_nocode(ram_addr_t start, + ram_addr_t length) +{ + unsigned long end, page; + + end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS; + page = start >> TARGET_PAGE_BITS; + bitmap_set(ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION], page, end - page); + bitmap_set(ram_list.dirty_memory[DIRTY_MEMORY_VGA], page, end - page); +} + static inline void cpu_physical_memory_set_dirty_range(ram_addr_t start, ram_addr_t length) {