diff options
| -rw-r--r-- | hw/pci/pci.c | 8 | ||||
| -rw-r--r-- | include/exec/memory.h | 14 | ||||
| -rw-r--r-- | include/hw/pci/pci_device.h | 3 | ||||
| -rw-r--r-- | system/memory.c | 5 | ||||
| -rw-r--r-- | system/physmem.c | 82 |
5 files changed, 76 insertions, 36 deletions
diff --git a/hw/pci/pci.c b/hw/pci/pci.c index fab86d0567..d2caf3ee8b 100644 --- a/hw/pci/pci.c +++ b/hw/pci/pci.c @@ -85,6 +85,8 @@ static Property pci_props[] = { QEMU_PCIE_ERR_UNC_MASK_BITNR, true), DEFINE_PROP_BIT("x-pcie-ari-nextfn-1", PCIDevice, cap_present, QEMU_PCIE_ARI_NEXTFN_1_BITNR, false), + DEFINE_PROP_SIZE32("x-max-bounce-buffer-size", PCIDevice, + max_bounce_buffer_size, DEFAULT_MAX_BOUNCE_BUFFER_SIZE), DEFINE_PROP_END_OF_LIST() }; @@ -1204,6 +1206,8 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, "bus master container", UINT64_MAX); address_space_init(&pci_dev->bus_master_as, &pci_dev->bus_master_container_region, pci_dev->name); + pci_dev->bus_master_as.max_bounce_buffer_size = + pci_dev->max_bounce_buffer_size; if (phase_check(PHASE_MACHINE_READY)) { pci_init_bus_master(pci_dev); @@ -2633,6 +2637,10 @@ static void pci_device_class_init(ObjectClass *klass, void *data) k->unrealize = pci_qdev_unrealize; k->bus_type = TYPE_PCI_BUS; device_class_set_props(k, pci_props); + object_class_property_set_description( + klass, "x-max-bounce-buffer-size", + "Maximum buffer size allocated for bounce buffers used for mapped " + "access to indirect DMA memory"); } static void pci_device_class_base_init(ObjectClass *klass, void *data) diff --git a/include/exec/memory.h b/include/exec/memory.h index 296fd068c0..e5e865d1a9 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -1084,13 +1084,7 @@ typedef struct AddressSpaceMapClient { QLIST_ENTRY(AddressSpaceMapClient) link; } AddressSpaceMapClient; -typedef struct { - MemoryRegion *mr; - void *buffer; - hwaddr addr; - hwaddr len; - bool in_use; -} BounceBuffer; +#define DEFAULT_MAX_BOUNCE_BUFFER_SIZE (4096) /** * struct AddressSpace: describes a mapping of addresses to #MemoryRegion objects @@ -1110,8 +1104,10 @@ struct AddressSpace { QTAILQ_HEAD(, MemoryListener) listeners; QTAILQ_ENTRY(AddressSpace) address_spaces_link; - /* Bounce buffer to use for this address space. */ - BounceBuffer bounce; + /* Maximum DMA bounce buffer size used for indirect memory map requests */ + size_t max_bounce_buffer_size; + /* Total size of bounce buffers currently allocated, atomically accessed */ + size_t bounce_buffer_size; /* List of callbacks to invoke when buffers free up */ QemuMutex map_client_list_lock; QLIST_HEAD(, AddressSpaceMapClient) map_client_list; diff --git a/include/hw/pci/pci_device.h b/include/hw/pci/pci_device.h index 15694f2489..91df40f989 100644 --- a/include/hw/pci/pci_device.h +++ b/include/hw/pci/pci_device.h @@ -167,6 +167,9 @@ struct PCIDevice { /* ID of standby device in net_failover pair */ char *failover_pair_id; uint32_t acpi_index; + + /* Maximum DMA bounce buffer size used for indirect memory map requests */ + uint32_t max_bounce_buffer_size; }; static inline int pci_intx(PCIDevice *pci_dev) diff --git a/system/memory.c b/system/memory.c index 5e6eb459d5..f6f6fee6d8 100644 --- a/system/memory.c +++ b/system/memory.c @@ -3148,7 +3148,8 @@ void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name) as->ioeventfds = NULL; QTAILQ_INIT(&as->listeners); QTAILQ_INSERT_TAIL(&address_spaces, as, address_spaces_link); - as->bounce.in_use = false; + as->max_bounce_buffer_size = DEFAULT_MAX_BOUNCE_BUFFER_SIZE; + as->bounce_buffer_size = 0; qemu_mutex_init(&as->map_client_list_lock); QLIST_INIT(&as->map_client_list); as->name = g_strdup(name ? name : "anonymous"); @@ -3158,7 +3159,7 @@ void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name) static void do_address_space_destroy(AddressSpace *as) { - assert(!qatomic_read(&as->bounce.in_use)); + assert(qatomic_read(&as->bounce_buffer_size) == 0); assert(QLIST_EMPTY(&as->map_client_list)); qemu_mutex_destroy(&as->map_client_list_lock); diff --git a/system/physmem.c b/system/physmem.c index 94600a33ec..971bfa0855 100644 --- a/system/physmem.c +++ b/system/physmem.c @@ -3095,6 +3095,20 @@ void cpu_flush_icache_range(hwaddr start, hwaddr len) NULL, len, FLUSH_CACHE); } +/* + * A magic value stored in the first 8 bytes of the bounce buffer struct. Used + * to detect illegal pointers passed to address_space_unmap. + */ +#define BOUNCE_BUFFER_MAGIC 0xb4017ceb4ffe12ed + +typedef struct { + uint64_t magic; + MemoryRegion *mr; + hwaddr addr; + size_t len; + uint8_t buffer[]; +} BounceBuffer; + static void address_space_unregister_map_client_do(AddressSpaceMapClient *client) { @@ -3120,9 +3134,9 @@ void address_space_register_map_client(AddressSpace *as, QEMUBH *bh) QEMU_LOCK_GUARD(&as->map_client_list_lock); client->bh = bh; QLIST_INSERT_HEAD(&as->map_client_list, client, link); - /* Write map_client_list before reading in_use. */ + /* Write map_client_list before reading bounce_buffer_size. */ smp_mb(); - if (!qatomic_read(&as->bounce.in_use)) { + if (qatomic_read(&as->bounce_buffer_size) < as->max_bounce_buffer_size) { address_space_notify_map_clients_locked(as); } } @@ -3251,28 +3265,40 @@ void *address_space_map(AddressSpace *as, mr = flatview_translate(fv, addr, &xlat, &l, is_write, attrs); if (!memory_access_is_direct(mr, is_write)) { - if (qatomic_xchg(&as->bounce.in_use, true)) { + size_t used = qatomic_read(&as->bounce_buffer_size); + for (;;) { + hwaddr alloc = MIN(as->max_bounce_buffer_size - used, l); + size_t new_size = used + alloc; + size_t actual = + qatomic_cmpxchg(&as->bounce_buffer_size, used, new_size); + if (actual == used) { + l = alloc; + break; + } + used = actual; + } + + if (l == 0) { *plen = 0; return NULL; } - /* Avoid unbounded allocations */ - l = MIN(l, TARGET_PAGE_SIZE); - as->bounce.buffer = qemu_memalign(TARGET_PAGE_SIZE, l); - as->bounce.addr = addr; - as->bounce.len = l; + BounceBuffer *bounce = g_malloc0(l + sizeof(BounceBuffer)); + bounce->magic = BOUNCE_BUFFER_MAGIC; memory_region_ref(mr); - as->bounce.mr = mr; + bounce->mr = mr; + bounce->addr = addr; + bounce->len = l; + if (!is_write) { flatview_read(fv, addr, MEMTXATTRS_UNSPECIFIED, - as->bounce.buffer, l); + bounce->buffer, l); } *plen = l; - return as->bounce.buffer; + return bounce->buffer; } - memory_region_ref(mr); *plen = flatview_extend_translation(fv, addr, len, mr, xlat, l, is_write, attrs); @@ -3287,12 +3313,11 @@ void *address_space_map(AddressSpace *as, void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len, bool is_write, hwaddr access_len) { - if (buffer != as->bounce.buffer) { - MemoryRegion *mr; - ram_addr_t addr1; + MemoryRegion *mr; + ram_addr_t addr1; - mr = memory_region_from_host(buffer, &addr1); - assert(mr != NULL); + mr = memory_region_from_host(buffer, &addr1); + if (mr != NULL) { if (is_write) { invalidate_and_set_dirty(mr, addr1, access_len); } @@ -3302,15 +3327,22 @@ void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len, memory_region_unref(mr); return; } + + + BounceBuffer *bounce = container_of(buffer, BounceBuffer, buffer); + assert(bounce->magic == BOUNCE_BUFFER_MAGIC); + if (is_write) { - address_space_write(as, as->bounce.addr, MEMTXATTRS_UNSPECIFIED, - as->bounce.buffer, access_len); - } - qemu_vfree(as->bounce.buffer); - as->bounce.buffer = NULL; - memory_region_unref(as->bounce.mr); - /* Clear in_use before reading map_client_list. */ - qatomic_set_mb(&as->bounce.in_use, false); + address_space_write(as, bounce->addr, MEMTXATTRS_UNSPECIFIED, + bounce->buffer, access_len); + } + + qatomic_sub(&as->bounce_buffer_size, bounce->len); + bounce->magic = ~BOUNCE_BUFFER_MAGIC; + memory_region_unref(bounce->mr); + g_free(bounce); + /* Write bounce_buffer_size before reading map_client_list. */ + smp_mb(); address_space_notify_map_clients(as); } |