diff options
| -rw-r--r-- | include/exec/cpu-common.h | 1 | ||||
| -rw-r--r-- | include/exec/memory.h | 15 | ||||
| -rw-r--r-- | include/exec/ram_addr.h | 3 | ||||
| -rw-r--r-- | include/qemu/osdep.h | 9 | ||||
| -rw-r--r-- | migration/ram.c | 3 | ||||
| -rw-r--r-- | softmmu/physmem.c | 15 | ||||
| -rw-r--r-- | util/mmap-alloc.c | 7 | ||||
| -rw-r--r-- | util/oslib-posix.c | 6 | ||||
| -rw-r--r-- | util/oslib-win32.c | 13 |
9 files changed, 59 insertions, 13 deletions
diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h index ccabed4003..039d422bf4 100644 --- a/include/exec/cpu-common.h +++ b/include/exec/cpu-common.h @@ -59,6 +59,7 @@ ram_addr_t qemu_ram_get_offset(RAMBlock *rb); ram_addr_t qemu_ram_get_used_length(RAMBlock *rb); ram_addr_t qemu_ram_get_max_length(RAMBlock *rb); bool qemu_ram_is_shared(RAMBlock *rb); +bool qemu_ram_is_noreserve(RAMBlock *rb); bool qemu_ram_is_uf_zeroable(RAMBlock *rb); void qemu_ram_set_uf_zeroable(RAMBlock *rb); bool qemu_ram_is_migratable(RAMBlock *rb); diff --git a/include/exec/memory.h b/include/exec/memory.h index b1f8fa1df0..b116f7c64e 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -155,6 +155,13 @@ typedef struct IOMMUTLBEvent { */ #define RAM_UF_WRITEPROTECT (1 << 6) +/* + * RAM is mmap-ed with MAP_NORESERVE. When set, reserving swap space (or huge + * pages if applicable) is skipped: will bail out if not supported. When not + * set, the OS will do the reservation, if supported for the memory type. + */ +#define RAM_NORESERVE (1 << 7) + static inline void iommu_notifier_init(IOMMUNotifier *n, IOMMUNotify fn, IOMMUNotifierFlag flags, hwaddr start, hwaddr end, @@ -949,7 +956,7 @@ void memory_region_init_ram_nomigrate(MemoryRegion *mr, * @name: Region name, becomes part of RAMBlock name used in migration stream * must be unique within any device * @size: size of the region. - * @ram_flags: RamBlock flags. Supported flags: RAM_SHARED. + * @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_NORESERVE. * @errp: pointer to Error*, to store an error if it happens. * * Note that this function does not do anything to cause the data in the @@ -1005,7 +1012,8 @@ void memory_region_init_resizeable_ram(MemoryRegion *mr, * @size: size of the region. * @align: alignment of the region base address; if 0, the default alignment * (getpagesize()) will be used. - * @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM. + * @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM, + * RAM_NORESERVE, * @path: the path in which to allocate the RAM. * @readonly: true to open @path for reading, false for read/write. * @errp: pointer to Error*, to store an error if it happens. @@ -1031,7 +1039,8 @@ void memory_region_init_ram_from_file(MemoryRegion *mr, * @owner: the object that tracks the region's reference count * @name: the name of the region. * @size: size of the region. - * @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM. + * @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM, + * RAM_NORESERVE. * @fd: the fd to mmap. * @offset: offset within the file referenced by fd * @errp: pointer to Error*, to store an error if it happens. diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h index 6d4513f8e2..551876bed0 100644 --- a/include/exec/ram_addr.h +++ b/include/exec/ram_addr.h @@ -104,7 +104,8 @@ long qemu_maxrampagesize(void); * Parameters: * @size: the size in bytes of the ram block * @mr: the memory region where the ram block is - * @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM. + * @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM, + * RAM_NORESERVE. * @mem_path or @fd: specify the backing file or device * @readonly: true to open @path for reading, false for read/write. * @errp: pointer to Error*, to store an error if it happens diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h index 37a38c4af3..c2c7fe5c47 100644 --- a/include/qemu/osdep.h +++ b/include/qemu/osdep.h @@ -362,7 +362,8 @@ extern "C" { int qemu_daemon(int nochdir, int noclose); void *qemu_try_memalign(size_t alignment, size_t size); void *qemu_memalign(size_t alignment, size_t size); -void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared); +void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared, + bool noreserve); void qemu_vfree(void *ptr); void qemu_anon_ram_free(void *ptr, size_t size); @@ -383,6 +384,12 @@ void qemu_anon_ram_free(void *ptr, size_t size); */ #define QEMU_MAP_SYNC (1 << 2) +/* + * Use MAP_NORESERVE to skip reservation of swap space (or huge pages if + * applicable). Bail out if not supported/effective. + */ +#define QEMU_MAP_NORESERVE (1 << 3) + #define QEMU_MADV_INVALID -1 diff --git a/migration/ram.c b/migration/ram.c index 60ea913c54..723af67c2e 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -3343,8 +3343,7 @@ int colo_init_ram_cache(void) WITH_RCU_READ_LOCK_GUARD() { RAMBLOCK_FOREACH_NOT_IGNORED(block) { block->colo_cache = qemu_anon_ram_alloc(block->used_length, - NULL, - false); + NULL, false, false); if (!block->colo_cache) { error_report("%s: Can't alloc memory for COLO cache of block %s," "size 0x" RAM_ADDR_FMT, __func__, block->idstr, diff --git a/softmmu/physmem.c b/softmmu/physmem.c index a110aa67fd..11ea8e19a6 100644 --- a/softmmu/physmem.c +++ b/softmmu/physmem.c @@ -1591,6 +1591,7 @@ static void *file_ram_alloc(RAMBlock *block, qemu_map_flags = readonly ? QEMU_MAP_READONLY : 0; qemu_map_flags |= (block->flags & RAM_SHARED) ? QEMU_MAP_SHARED : 0; qemu_map_flags |= (block->flags & RAM_PMEM) ? QEMU_MAP_SYNC : 0; + qemu_map_flags |= (block->flags & RAM_NORESERVE) ? QEMU_MAP_NORESERVE : 0; area = qemu_ram_mmap(fd, memory, block->mr->align, qemu_map_flags, offset); if (area == MAP_FAILED) { error_setg_errno(errp, errno, @@ -1716,6 +1717,11 @@ bool qemu_ram_is_shared(RAMBlock *rb) return rb->flags & RAM_SHARED; } +bool qemu_ram_is_noreserve(RAMBlock *rb) +{ + return rb->flags & RAM_NORESERVE; +} + /* Note: Only set at the start of postcopy */ bool qemu_ram_is_uf_zeroable(RAMBlock *rb) { @@ -1950,6 +1956,7 @@ static void dirty_memory_extend(ram_addr_t old_ram_size, static void ram_block_add(RAMBlock *new_block, Error **errp) { + const bool noreserve = qemu_ram_is_noreserve(new_block); const bool shared = qemu_ram_is_shared(new_block); RAMBlock *block; RAMBlock *last_block = NULL; @@ -1973,7 +1980,7 @@ static void ram_block_add(RAMBlock *new_block, Error **errp) } else { new_block->host = qemu_anon_ram_alloc(new_block->max_length, &new_block->mr->align, - shared); + shared, noreserve); if (!new_block->host) { error_setg_errno(errp, errno, "cannot set up guest memory '%s'", @@ -2045,7 +2052,7 @@ RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr, int64_t file_size, file_align; /* Just support these ram flags by now. */ - assert((ram_flags & ~(RAM_SHARED | RAM_PMEM)) == 0); + assert((ram_flags & ~(RAM_SHARED | RAM_PMEM | RAM_NORESERVE)) == 0); if (xen_enabled()) { error_setg(errp, "-mem-path not supported with Xen"); @@ -2137,6 +2144,8 @@ RAMBlock *qemu_ram_alloc_internal(ram_addr_t size, ram_addr_t max_size, Error *local_err = NULL; assert((ram_flags & ~(RAM_SHARED | RAM_RESIZEABLE | RAM_PREALLOC)) == 0); + assert((ram_flags & ~(RAM_SHARED | RAM_RESIZEABLE | RAM_PREALLOC | + RAM_NORESERVE)) == 0); assert(!host ^ (ram_flags & RAM_PREALLOC)); size = HOST_PAGE_ALIGN(size); @@ -2170,7 +2179,7 @@ RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host, RAMBlock *qemu_ram_alloc(ram_addr_t size, uint32_t ram_flags, MemoryRegion *mr, Error **errp) { - assert((ram_flags & ~RAM_SHARED) == 0); + assert((ram_flags & ~(RAM_SHARED | RAM_NORESERVE)) == 0); return qemu_ram_alloc_internal(size, size, NULL, NULL, ram_flags, mr, errp); } diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c index 1ddc0e2a1e..d0cf4aaee5 100644 --- a/util/mmap-alloc.c +++ b/util/mmap-alloc.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "qemu/mmap-alloc.h" #include "qemu/host-utils.h" +#include "qemu/error-report.h" #define HUGETLBFS_MAGIC 0x958458f6 @@ -121,6 +122,7 @@ static void *mmap_reserve(size_t size, int fd) static void *mmap_activate(void *ptr, size_t size, int fd, uint32_t qemu_map_flags, off_t map_offset) { + const bool noreserve = qemu_map_flags & QEMU_MAP_NORESERVE; const bool readonly = qemu_map_flags & QEMU_MAP_READONLY; const bool shared = qemu_map_flags & QEMU_MAP_SHARED; const bool sync = qemu_map_flags & QEMU_MAP_SYNC; @@ -129,6 +131,11 @@ static void *mmap_activate(void *ptr, size_t size, int fd, int flags = MAP_FIXED; void *activated_ptr; + if (noreserve) { + error_report("Skipping reservation of swap space is not supported"); + return MAP_FAILED; + } + flags |= fd == -1 ? MAP_ANONYMOUS : 0; flags |= shared ? MAP_SHARED : MAP_PRIVATE; if (shared && sync) { diff --git a/util/oslib-posix.c b/util/oslib-posix.c index 0dd7784a88..e8bdb02e1d 100644 --- a/util/oslib-posix.c +++ b/util/oslib-posix.c @@ -227,9 +227,11 @@ void *qemu_memalign(size_t alignment, size_t size) } /* alloc shared memory pages */ -void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment, bool shared) +void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment, bool shared, + bool noreserve) { - const uint32_t qemu_map_flags = shared ? QEMU_MAP_SHARED : 0; + const uint32_t qemu_map_flags = (shared ? QEMU_MAP_SHARED : 0) | + (noreserve ? QEMU_MAP_NORESERVE : 0); size_t align = QEMU_VMALLOC_ALIGN; void *ptr = qemu_ram_mmap(-1, size, align, qemu_map_flags, 0); diff --git a/util/oslib-win32.c b/util/oslib-win32.c index ca99356fdf..ee3a3692d8 100644 --- a/util/oslib-win32.c +++ b/util/oslib-win32.c @@ -38,6 +38,7 @@ #include "trace.h" #include "qemu/sockets.h" #include "qemu/cutils.h" +#include "qemu/error-report.h" #include <malloc.h> /* this must come after including "trace.h" */ @@ -76,10 +77,20 @@ static int get_allocation_granularity(void) return system_info.dwAllocationGranularity; } -void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared) +void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared, + bool noreserve) { void *ptr; + if (noreserve) { + /* + * We need a MEM_COMMIT before accessing any memory in a MEM_RESERVE + * area; we cannot easily mimic POSIX MAP_NORESERVE semantics. + */ + error_report("Skipping reservation of swap space is not supported."); + return NULL; + } + ptr = VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_READWRITE); trace_qemu_anon_ram_alloc(size, ptr); |