From c8d6f66ae7d0ce5f3622c19e29a2333d28dc1e9a Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Mon, 17 Nov 2014 17:54:07 +0200 Subject: exec: cpu_physical_memory_set/clear_dirty_range Make cpu_physical_memory_set/clear_dirty_range behave symmetrically. To clear range for a given client type only, add cpu_physical_memory_clear_dirty_range_type. Signed-off-by: Michael S. Tsirkin Reviewed-by: Paolo Bonzini --- exec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'exec.c') diff --git a/exec.c b/exec.c index 963481a..a89aa6c 100644 --- a/exec.c +++ b/exec.c @@ -850,7 +850,7 @@ void cpu_physical_memory_reset_dirty(ram_addr_t start, ram_addr_t length, { if (length == 0) return; - cpu_physical_memory_clear_dirty_range(start, length, client); + cpu_physical_memory_clear_dirty_range_type(start, length, client); if (tcg_enabled()) { tlb_reset_dirty_range_all(start, length); -- cgit v1.1 From 9b8424d5735278ca382f11adc7c63072b632ab83 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Mon, 15 Dec 2014 22:55:32 +0200 Subject: exec: split length -> used_length/max_length This patch allows us to distinguish between two length values for each block: max_length - length of memory block that was allocated used_length - length of block used by QEMU/guest Currently, we set used_length - max_length, unconditionally. Follow-up patches allow used_length <= max_length. Signed-off-by: Michael S. Tsirkin Reviewed-by: Paolo Bonzini --- exec.c | 52 ++++++++++++++++++++++++++++------------------------ 1 file changed, 28 insertions(+), 24 deletions(-) (limited to 'exec.c') diff --git a/exec.c b/exec.c index a89aa6c..b69216a 100644 --- a/exec.c +++ b/exec.c @@ -812,11 +812,11 @@ static RAMBlock *qemu_get_ram_block(ram_addr_t addr) /* The list is protected by the iothread lock here. */ block = ram_list.mru_block; - if (block && addr - block->offset < block->length) { + if (block && addr - block->offset < block->max_length) { goto found; } QTAILQ_FOREACH(block, &ram_list.blocks, next) { - if (addr - block->offset < block->length) { + if (addr - block->offset < block->max_length) { goto found; } } @@ -1305,13 +1305,14 @@ static ram_addr_t ram_block_add(RAMBlock *new_block, Error **errp) /* This assumes the iothread lock is taken here too. */ qemu_mutex_lock_ramlist(); - new_block->offset = find_ram_offset(new_block->length); + new_block->offset = find_ram_offset(new_block->max_length); if (!new_block->host) { if (xen_enabled()) { - xen_ram_alloc(new_block->offset, new_block->length, new_block->mr); + xen_ram_alloc(new_block->offset, new_block->max_length, + new_block->mr); } else { - new_block->host = phys_mem_alloc(new_block->length, + new_block->host = phys_mem_alloc(new_block->max_length, &new_block->mr->align); if (!new_block->host) { error_setg_errno(errp, errno, @@ -1320,13 +1321,13 @@ static ram_addr_t ram_block_add(RAMBlock *new_block, Error **errp) qemu_mutex_unlock_ramlist(); return -1; } - memory_try_enable_merging(new_block->host, new_block->length); + memory_try_enable_merging(new_block->host, new_block->max_length); } } /* Keep the list sorted from biggest to smallest block. */ QTAILQ_FOREACH(block, &ram_list.blocks, next) { - if (block->length < new_block->length) { + if (block->max_length < new_block->max_length) { break; } } @@ -1350,14 +1351,15 @@ static ram_addr_t ram_block_add(RAMBlock *new_block, Error **errp) old_ram_size, new_ram_size); } } - cpu_physical_memory_set_dirty_range(new_block->offset, new_block->length); + cpu_physical_memory_set_dirty_range(new_block->offset, + new_block->used_length); - qemu_ram_setup_dump(new_block->host, new_block->length); - qemu_madvise(new_block->host, new_block->length, QEMU_MADV_HUGEPAGE); - qemu_madvise(new_block->host, new_block->length, QEMU_MADV_DONTFORK); + qemu_ram_setup_dump(new_block->host, new_block->max_length); + qemu_madvise(new_block->host, new_block->max_length, QEMU_MADV_HUGEPAGE); + qemu_madvise(new_block->host, new_block->max_length, QEMU_MADV_DONTFORK); if (kvm_enabled()) { - kvm_setup_guest_memory(new_block->host, new_block->length); + kvm_setup_guest_memory(new_block->host, new_block->max_length); } return new_block->offset; @@ -1391,7 +1393,8 @@ ram_addr_t qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr, size = TARGET_PAGE_ALIGN(size); new_block = g_malloc0(sizeof(*new_block)); new_block->mr = mr; - new_block->length = size; + new_block->used_length = size; + new_block->max_length = size; new_block->flags = share ? RAM_SHARED : 0; new_block->host = file_ram_alloc(new_block, size, mem_path, errp); @@ -1420,7 +1423,8 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host, size = TARGET_PAGE_ALIGN(size); new_block = g_malloc0(sizeof(*new_block)); new_block->mr = mr; - new_block->length = size; + new_block->used_length = size; + new_block->max_length = max_size; new_block->fd = -1; new_block->host = host; if (host) { @@ -1475,11 +1479,11 @@ void qemu_ram_free(ram_addr_t addr) xen_invalidate_map_cache_entry(block->host); #ifndef _WIN32 } else if (block->fd >= 0) { - munmap(block->host, block->length); + munmap(block->host, block->max_length); close(block->fd); #endif } else { - qemu_anon_ram_free(block->host, block->length); + qemu_anon_ram_free(block->host, block->max_length); } g_free(block); break; @@ -1499,7 +1503,7 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length) QTAILQ_FOREACH(block, &ram_list.blocks, next) { offset = addr - block->offset; - if (offset < block->length) { + if (offset < block->max_length) { vaddr = ramblock_ptr(block, offset); if (block->flags & RAM_PREALLOC) { ; @@ -1575,7 +1579,7 @@ void *qemu_get_ram_ptr(ram_addr_t addr) return xen_map_cache(addr, 0, 0); } else if (block->host == NULL) { block->host = - xen_map_cache(block->offset, block->length, 1); + xen_map_cache(block->offset, block->max_length, 1); } } return ramblock_ptr(block, addr - block->offset); @@ -1594,9 +1598,9 @@ static void *qemu_ram_ptr_length(ram_addr_t addr, hwaddr *size) RAMBlock *block; QTAILQ_FOREACH(block, &ram_list.blocks, next) { - if (addr - block->offset < block->length) { - if (addr - block->offset + *size > block->length) - *size = block->length - addr + block->offset; + if (addr - block->offset < block->max_length) { + if (addr - block->offset + *size > block->max_length) + *size = block->max_length - addr + block->offset; return ramblock_ptr(block, addr - block->offset); } } @@ -1619,7 +1623,7 @@ MemoryRegion *qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr) } block = ram_list.mru_block; - if (block && block->host && host - block->host < block->length) { + if (block && block->host && host - block->host < block->max_length) { goto found; } @@ -1628,7 +1632,7 @@ MemoryRegion *qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr) if (block->host == NULL) { continue; } - if (host - block->host < block->length) { + if (host - block->host < block->max_length) { goto found; } } @@ -2873,7 +2877,7 @@ void qemu_ram_foreach_block(RAMBlockIterFunc func, void *opaque) RAMBlock *block; QTAILQ_FOREACH(block, &ram_list.blocks, next) { - func(block->host, block->offset, block->length, opaque); + func(block->host, block->offset, block->used_length, opaque); } } #endif -- cgit v1.1 From 62be4e3a5041e84304aa23637da623a205c53ecc Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Wed, 12 Nov 2014 14:27:41 +0200 Subject: exec: qemu_ram_alloc_resizeable, qemu_ram_resize Add API to allocate "resizeable" RAM. This looks just like regular RAM generally, but has a special property that only a portion of it (used_length) is actually used, and migrated. This used_length size can change across reboots. Follow up patches will change used_length for such blocks at migration, making it easier to extend devices using such RAM (notably ACPI, but in the future thinkably other ROMs) without breaking migration compatibility or wasting ROM (guest) memory. Device is notified on resize, so it can adjust if necessary. qemu_ram_alloc_resizeable allocates this memory, qemu_ram_resize resizes it. Note: nothing prevents making all RAM resizeable in this way. However, reviewers felt that only enabling this selectively will make some class of errors easier to detect. Signed-off-by: Michael S. Tsirkin Reviewed-by: Paolo Bonzini --- exec.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 78 insertions(+), 4 deletions(-) (limited to 'exec.c') diff --git a/exec.c b/exec.c index b69216a..58ac6d6 100644 --- a/exec.c +++ b/exec.c @@ -75,6 +75,11 @@ static MemoryRegion io_mem_unassigned; /* RAM is mmap-ed with MAP_SHARED */ #define RAM_SHARED (1 << 1) +/* Only a portion of RAM (used_length) is actually used, and migrated. + * This used_length size can change across reboots. + */ +#define RAM_RESIZEABLE (1 << 2) + #endif struct CPUTailQ cpus = QTAILQ_HEAD_INITIALIZER(cpus); @@ -1186,7 +1191,7 @@ static ram_addr_t find_ram_offset(ram_addr_t size) QTAILQ_FOREACH(block, &ram_list.blocks, next) { ram_addr_t end, next = RAM_ADDR_MAX; - end = block->offset + block->length; + end = block->offset + block->max_length; QTAILQ_FOREACH(next_block, &ram_list.blocks, next) { if (next_block->offset >= end) { @@ -1214,7 +1219,7 @@ ram_addr_t last_ram_offset(void) ram_addr_t last = 0; QTAILQ_FOREACH(block, &ram_list.blocks, next) - last = MAX(last, block->offset + block->length); + last = MAX(last, block->offset + block->max_length); return last; } @@ -1296,6 +1301,49 @@ static int memory_try_enable_merging(void *addr, size_t len) return qemu_madvise(addr, len, QEMU_MADV_MERGEABLE); } +/* Only legal before guest might have detected the memory size: e.g. on + * incoming migration, or right after reset. + * + * As memory core doesn't know how is memory accessed, it is up to + * resize callback to update device state and/or add assertions to detect + * misuse, if necessary. + */ +int qemu_ram_resize(ram_addr_t base, ram_addr_t newsize, Error **errp) +{ + RAMBlock *block = find_ram_block(base); + + assert(block); + + if (block->used_length == newsize) { + return 0; + } + + if (!(block->flags & RAM_RESIZEABLE)) { + error_setg_errno(errp, EINVAL, + "Length mismatch: %s: 0x" RAM_ADDR_FMT + " in != 0x" RAM_ADDR_FMT, block->idstr, + newsize, block->used_length); + return -EINVAL; + } + + if (block->max_length < newsize) { + error_setg_errno(errp, EINVAL, + "Length too large: %s: 0x" RAM_ADDR_FMT + " > 0x" RAM_ADDR_FMT, block->idstr, + newsize, block->max_length); + return -EINVAL; + } + + cpu_physical_memory_clear_dirty_range(block->offset, block->used_length); + block->used_length = newsize; + cpu_physical_memory_set_dirty_range(block->offset, block->used_length); + memory_region_set_size(block->mr, newsize); + if (block->resized) { + block->resized(block->idstr, newsize, block->host); + } + return 0; +} + static ram_addr_t ram_block_add(RAMBlock *new_block, Error **errp) { RAMBlock *block; @@ -1413,7 +1461,12 @@ ram_addr_t qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr, } #endif -ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host, +static +ram_addr_t qemu_ram_alloc_internal(ram_addr_t size, ram_addr_t max_size, + void (*resized)(const char*, + uint64_t length, + void *host), + void *host, bool resizeable, MemoryRegion *mr, Error **errp) { RAMBlock *new_block; @@ -1421,15 +1474,21 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host, Error *local_err = NULL; size = TARGET_PAGE_ALIGN(size); + max_size = TARGET_PAGE_ALIGN(max_size); new_block = g_malloc0(sizeof(*new_block)); new_block->mr = mr; + new_block->resized = resized; new_block->used_length = size; new_block->max_length = max_size; + assert(max_size >= size); new_block->fd = -1; new_block->host = host; if (host) { new_block->flags |= RAM_PREALLOC; } + if (resizeable) { + new_block->flags |= RAM_RESIZEABLE; + } addr = ram_block_add(new_block, &local_err); if (local_err) { g_free(new_block); @@ -1439,9 +1498,24 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host, return addr; } +ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host, + MemoryRegion *mr, Error **errp) +{ + return qemu_ram_alloc_internal(size, size, NULL, host, false, mr, errp); +} + ram_addr_t qemu_ram_alloc(ram_addr_t size, MemoryRegion *mr, Error **errp) { - return qemu_ram_alloc_from_ptr(size, NULL, mr, errp); + return qemu_ram_alloc_internal(size, size, NULL, NULL, false, mr, errp); +} + +ram_addr_t qemu_ram_alloc_resizeable(ram_addr_t size, ram_addr_t maxsz, + void (*resized)(const char*, + uint64_t length, + void *host), + MemoryRegion *mr, Error **errp) +{ + return qemu_ram_alloc_internal(size, maxsz, resized, NULL, true, mr, errp); } void qemu_ram_free_from_ptr(ram_addr_t addr) -- cgit v1.1