From: Mattias Nissler <mnissler@rivosinc.com>
To: jag.raman@oracle.com, peterx@redhat.com, stefanha@redhat.com,
qemu-devel@nongnu.org
Cc: "Marcel Apfelbaum" <marcel.apfelbaum@gmail.com>,
"Philippe Mathieu-Daudé" <philmd@linaro.org>,
john.levon@nutanix.com, "David Hildenbrand" <david@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Elena Ufimtseva" <elena.ufimtseva@oracle.com>,
"Richard Henderson" <richard.henderson@linaro.org>,
"Mattias Nissler" <mnissler@rivosinc.com>,
"Jonathan Cameron" <Jonathan.Cameron@huawei.com>
Subject: [PATCH v10 3/7] system/physmem: Per-AddressSpace bounce buffering
Date: Tue, 7 May 2024 07:34:27 -0700 [thread overview]
Message-ID: <20240507143431.464382-4-mnissler@rivosinc.com> (raw)
In-Reply-To: <20240507143431.464382-1-mnissler@rivosinc.com>
Instead of using a single global bounce buffer, give each AddressSpace
its own bounce buffer. The MapClient callback mechanism moves to
AddressSpace accordingly.
This is in preparation for generalizing bounce buffer handling further
to allow multiple bounce buffers, with a total allocation limit
configured per AddressSpace.
Reviewed-by: Peter Xu <peterx@redhat.com>
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Mattias Nissler <mnissler@rivosinc.com>
Message-ID: <20240507094210.300566-2-mnissler@rivosinc.com>
[PMD: Split patch, part 2/2]
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Mattias Nissler <mnissler@rivosinc.com>
---
include/exec/memory.h | 19 +++++++++++
system/memory.c | 7 +++++
system/physmem.c | 73 ++++++++++++++++---------------------------
3 files changed, 53 insertions(+), 46 deletions(-)
diff --git a/include/exec/memory.h b/include/exec/memory.h
index e1e0c5a3de..d417d7f363 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -1112,6 +1112,19 @@ struct MemoryListener {
QTAILQ_ENTRY(MemoryListener) link_as;
};
+typedef struct AddressSpaceMapClient {
+ QEMUBH *bh;
+ QLIST_ENTRY(AddressSpaceMapClient) link;
+} AddressSpaceMapClient;
+
+typedef struct {
+ MemoryRegion *mr;
+ void *buffer;
+ hwaddr addr;
+ hwaddr len;
+ bool in_use;
+} BounceBuffer;
+
/**
* struct AddressSpace: describes a mapping of addresses to #MemoryRegion objects
*/
@@ -1129,6 +1142,12 @@ struct AddressSpace {
struct MemoryRegionIoeventfd *ioeventfds;
QTAILQ_HEAD(, MemoryListener) listeners;
QTAILQ_ENTRY(AddressSpace) address_spaces_link;
+
+ /* Bounce buffer to use for this address space. */
+ BounceBuffer bounce;
+ /* List of callbacks to invoke when buffers free up */
+ QemuMutex map_client_list_lock;
+ QLIST_HEAD(, AddressSpaceMapClient) map_client_list;
};
typedef struct AddressSpaceDispatch AddressSpaceDispatch;
diff --git a/system/memory.c b/system/memory.c
index 49f1cb2c38..642a449f8c 100644
--- a/system/memory.c
+++ b/system/memory.c
@@ -3174,6 +3174,9 @@ 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;
+ qemu_mutex_init(&as->map_client_list_lock);
+ QLIST_INIT(&as->map_client_list);
as->name = g_strdup(name ? name : "anonymous");
address_space_update_topology(as);
address_space_update_ioeventfds(as);
@@ -3181,6 +3184,10 @@ 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(QLIST_EMPTY(&as->map_client_list));
+ qemu_mutex_destroy(&as->map_client_list_lock);
+
assert(QTAILQ_EMPTY(&as->listeners));
flatview_unref(as->current_map);
diff --git a/system/physmem.c b/system/physmem.c
index 27e754ff57..62758202cf 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -3046,26 +3046,8 @@ void cpu_flush_icache_range(hwaddr start, hwaddr len)
NULL, len, FLUSH_CACHE);
}
-typedef struct {
- MemoryRegion *mr;
- void *buffer;
- hwaddr addr;
- hwaddr len;
- bool in_use;
-} BounceBuffer;
-
-static BounceBuffer bounce;
-
-typedef struct MapClient {
- QEMUBH *bh;
- QLIST_ENTRY(MapClient) link;
-} MapClient;
-
-QemuMutex map_client_list_lock;
-static QLIST_HEAD(, MapClient) map_client_list
- = QLIST_HEAD_INITIALIZER(map_client_list);
-
-static void address_space_unregister_map_client_do(MapClient *client)
+static void
+address_space_unregister_map_client_do(AddressSpaceMapClient *client)
{
QLIST_REMOVE(client, link);
g_free(client);
@@ -3073,10 +3055,10 @@ static void address_space_unregister_map_client_do(MapClient *client)
static void address_space_notify_map_clients_locked(AddressSpace *as)
{
- MapClient *client;
+ AddressSpaceMapClient *client;
- while (!QLIST_EMPTY(&map_client_list)) {
- client = QLIST_FIRST(&map_client_list);
+ while (!QLIST_EMPTY(&as->map_client_list)) {
+ client = QLIST_FIRST(&as->map_client_list);
qemu_bh_schedule(client->bh);
address_space_unregister_map_client_do(client);
}
@@ -3084,14 +3066,14 @@ static void address_space_notify_map_clients_locked(AddressSpace *as)
void address_space_register_map_client(AddressSpace *as, QEMUBH *bh)
{
- MapClient *client = g_malloc(sizeof(*client));
+ AddressSpaceMapClient *client = g_malloc(sizeof(*client));
- QEMU_LOCK_GUARD(&map_client_list_lock);
+ QEMU_LOCK_GUARD(&as->map_client_list_lock);
client->bh = bh;
- QLIST_INSERT_HEAD(&map_client_list, client, link);
+ QLIST_INSERT_HEAD(&as->map_client_list, client, link);
/* Write map_client_list before reading in_use. */
smp_mb();
- if (!qatomic_read(&bounce.in_use)) {
+ if (!qatomic_read(&as->bounce.in_use)) {
address_space_notify_map_clients_locked(as);
}
}
@@ -3109,15 +3091,14 @@ void cpu_exec_init_all(void)
finalize_target_page_bits();
io_mem_init();
memory_map_init();
- qemu_mutex_init(&map_client_list_lock);
}
void address_space_unregister_map_client(AddressSpace *as, QEMUBH *bh)
{
- MapClient *client;
+ AddressSpaceMapClient *client;
- QEMU_LOCK_GUARD(&map_client_list_lock);
- QLIST_FOREACH(client, &map_client_list, link) {
+ QEMU_LOCK_GUARD(&as->map_client_list_lock);
+ QLIST_FOREACH(client, &as->map_client_list, link) {
if (client->bh == bh) {
address_space_unregister_map_client_do(client);
break;
@@ -3127,7 +3108,7 @@ void address_space_unregister_map_client(AddressSpace *as, QEMUBH *bh)
static void address_space_notify_map_clients(AddressSpace *as)
{
- QEMU_LOCK_GUARD(&map_client_list_lock);
+ QEMU_LOCK_GUARD(&as->map_client_list_lock);
address_space_notify_map_clients_locked(as);
}
@@ -3219,25 +3200,25 @@ 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(&bounce.in_use, true)) {
+ if (qatomic_xchg(&as->bounce.in_use, true)) {
*plen = 0;
return NULL;
}
/* Avoid unbounded allocations */
l = MIN(l, TARGET_PAGE_SIZE);
- bounce.buffer = qemu_memalign(TARGET_PAGE_SIZE, l);
- bounce.addr = addr;
- bounce.len = l;
+ as->bounce.buffer = qemu_memalign(TARGET_PAGE_SIZE, l);
+ as->bounce.addr = addr;
+ as->bounce.len = l;
memory_region_ref(mr);
- bounce.mr = mr;
+ as->bounce.mr = mr;
if (!is_write) {
flatview_read(fv, addr, MEMTXATTRS_UNSPECIFIED,
- bounce.buffer, l);
+ as->bounce.buffer, l);
}
*plen = l;
- return bounce.buffer;
+ return as->bounce.buffer;
}
@@ -3255,7 +3236,7 @@ void *address_space_map(AddressSpace *as,
void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len,
bool is_write, hwaddr access_len)
{
- if (buffer != bounce.buffer) {
+ if (buffer != as->bounce.buffer) {
MemoryRegion *mr;
ram_addr_t addr1;
@@ -3271,14 +3252,14 @@ void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len,
return;
}
if (is_write) {
- address_space_write(as, bounce.addr, MEMTXATTRS_UNSPECIFIED,
- bounce.buffer, access_len);
+ address_space_write(as, as->bounce.addr, MEMTXATTRS_UNSPECIFIED,
+ as->bounce.buffer, access_len);
}
- qemu_vfree(bounce.buffer);
- bounce.buffer = NULL;
- memory_region_unref(bounce.mr);
+ 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(&bounce.in_use, false);
+ qatomic_set_mb(&as->bounce.in_use, false);
address_space_notify_map_clients(as);
}
--
2.43.2
next prev parent reply other threads:[~2024-05-07 14:35 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-07 14:34 [PATCH v10 0/7] Support message-based DMA in vfio-user server Mattias Nissler
2024-05-07 14:34 ` [PATCH v10 1/7] system/physmem: Replace qemu_mutex_lock() calls with QEMU_LOCK_GUARD Mattias Nissler
2024-05-07 20:02 ` Peter Xu
2024-05-07 14:34 ` [PATCH v10 2/7] system/physmem: Propagate AddressSpace to MapClient helpers Mattias Nissler
2024-05-07 14:34 ` Mattias Nissler [this message]
2024-05-07 14:34 ` [PATCH v10 4/7] softmmu: Support concurrent bounce buffers Mattias Nissler
2024-05-07 20:02 ` Peter Xu
2024-05-07 14:34 ` [PATCH v10 5/7] Update subprojects/libvfio-user Mattias Nissler
2024-05-07 14:34 ` [PATCH v10 6/7] vfio-user: Message-based DMA support Mattias Nissler
2024-05-07 14:34 ` [PATCH v10 7/7] vfio-user: Fix config space access byte order Mattias Nissler
2024-05-07 20:04 ` [PATCH v10 0/7] Support message-based DMA in vfio-user server Peter Xu
2024-05-08 21:16 ` Philippe Mathieu-Daudé
2024-05-08 21:21 ` Mattias Nissler
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