[PATCH v4 10/16] migration/multifd: Isolate ram pages packet data

Fabiano Rosas posted 16 patches 3 months ago
There is a newer version of this series
[PATCH v4 10/16] migration/multifd: Isolate ram pages packet data
Posted by Fabiano Rosas 3 months ago
While we cannot yet disentangle the multifd packet from page data, we
can make the code a bit cleaner by setting the page-related fields in
a separate function.

Signed-off-by: Fabiano Rosas <farosas@suse.de>
---
 migration/multifd.c    | 99 +++++++++++++++++++++++++-----------------
 migration/trace-events |  5 ++-
 2 files changed, 63 insertions(+), 41 deletions(-)

diff --git a/migration/multifd.c b/migration/multifd.c
index df8dfcc98f..d64fcdf4ac 100644
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -424,65 +424,61 @@ static int multifd_recv_initial_packet(QIOChannel *c, Error **errp)
     return msg.id;
 }
 
-void multifd_send_fill_packet(MultiFDSendParams *p)
+static void multifd_ram_fill_packet(MultiFDSendParams *p)
 {
     MultiFDPacket_t *packet = p->packet;
     MultiFDPages_t *pages = &p->data->u.ram;
-    uint64_t packet_num;
     uint32_t zero_num = pages->num - pages->normal_num;
-    int i;
 
-    packet->flags = cpu_to_be32(p->flags);
     packet->pages_alloc = cpu_to_be32(multifd_ram_page_count());
     packet->normal_pages = cpu_to_be32(pages->normal_num);
     packet->zero_pages = cpu_to_be32(zero_num);
-    packet->next_packet_size = cpu_to_be32(p->next_packet_size);
-
-    packet_num = qatomic_fetch_inc(&multifd_send_state->packet_num);
-    packet->packet_num = cpu_to_be64(packet_num);
 
     if (pages->block) {
         strncpy(packet->ramblock, pages->block->idstr, 256);
     }
 
-    for (i = 0; i < pages->num; i++) {
+    for (int i = 0; i < pages->num; i++) {
         /* there are architectures where ram_addr_t is 32 bit */
         uint64_t temp = pages->offset[i];
 
         packet->offset[i] = cpu_to_be64(temp);
     }
 
+    trace_multifd_send_ram_fill(p->id, pages->normal_num, zero_num);
+}
+
+void multifd_send_fill_packet(MultiFDSendParams *p)
+{
+    MultiFDPacket_t *packet = p->packet;
+    uint64_t packet_num;
+
+    memset(packet, 0, p->packet_len);
+
+    packet->magic = cpu_to_be32(MULTIFD_MAGIC);
+    packet->version = cpu_to_be32(MULTIFD_VERSION);
+
+    packet->flags = cpu_to_be32(p->flags);
+    packet->next_packet_size = cpu_to_be32(p->next_packet_size);
+
+    packet_num = qatomic_fetch_inc(&multifd_send_state->packet_num);
+    packet->packet_num = cpu_to_be64(packet_num);
+
     p->packets_sent++;
 
-    trace_multifd_send(p->id, packet_num, pages->normal_num, zero_num,
-                       p->flags, p->next_packet_size);
+    multifd_ram_fill_packet(p);
+
+    trace_multifd_send_fill(p->id, packet_num,
+                            p->flags, p->next_packet_size);
 }
 
-static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
+static int multifd_ram_unfill_packet(MultiFDRecvParams *p, Error **errp)
 {
     MultiFDPacket_t *packet = p->packet;
     uint32_t page_count = multifd_ram_page_count();
     uint32_t page_size = multifd_ram_page_size();
     int i;
 
-    packet->magic = be32_to_cpu(packet->magic);
-    if (packet->magic != MULTIFD_MAGIC) {
-        error_setg(errp, "multifd: received packet "
-                   "magic %x and expected magic %x",
-                   packet->magic, MULTIFD_MAGIC);
-        return -1;
-    }
-
-    packet->version = be32_to_cpu(packet->version);
-    if (packet->version != MULTIFD_VERSION) {
-        error_setg(errp, "multifd: received packet "
-                   "version %u and expected version %u",
-                   packet->version, MULTIFD_VERSION);
-        return -1;
-    }
-
-    p->flags = be32_to_cpu(packet->flags);
-
     packet->pages_alloc = be32_to_cpu(packet->pages_alloc);
     /*
      * If we received a packet that is 100 times bigger than expected
@@ -511,13 +507,6 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
         return -1;
     }
 
-    p->next_packet_size = be32_to_cpu(packet->next_packet_size);
-    p->packet_num = be64_to_cpu(packet->packet_num);
-    p->packets_recved++;
-
-    trace_multifd_recv(p->id, p->packet_num, p->normal_num, p->zero_num,
-                       p->flags, p->next_packet_size);
-
     if (p->normal_num == 0 && p->zero_num == 0) {
         return 0;
     }
@@ -559,6 +548,40 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
     return 0;
 }
 
+static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
+{
+    MultiFDPacket_t *packet = p->packet;
+    int ret = 0;
+
+    packet->magic = be32_to_cpu(packet->magic);
+    if (packet->magic != MULTIFD_MAGIC) {
+        error_setg(errp, "multifd: received packet "
+                   "magic %x and expected magic %x",
+                   packet->magic, MULTIFD_MAGIC);
+        return -1;
+    }
+
+    packet->version = be32_to_cpu(packet->version);
+    if (packet->version != MULTIFD_VERSION) {
+        error_setg(errp, "multifd: received packet "
+                   "version %u and expected version %u",
+                   packet->version, MULTIFD_VERSION);
+        return -1;
+    }
+
+    p->flags = be32_to_cpu(packet->flags);
+    p->next_packet_size = be32_to_cpu(packet->next_packet_size);
+    p->packet_num = be64_to_cpu(packet->packet_num);
+    p->packets_recved++;
+
+    ret = multifd_ram_unfill_packet(p, errp);
+
+    trace_multifd_recv_unfill(p->id, p->packet_num, p->flags,
+                              p->next_packet_size);
+
+    return ret;
+}
+
 static bool multifd_send_should_exit(void)
 {
     return qatomic_read(&multifd_send_state->exiting);
@@ -1203,8 +1226,6 @@ bool multifd_send_setup(void)
             p->packet_len = sizeof(MultiFDPacket_t)
                           + sizeof(uint64_t) * page_count;
             p->packet = g_malloc0(p->packet_len);
-            p->packet->magic = cpu_to_be32(MULTIFD_MAGIC);
-            p->packet->version = cpu_to_be32(MULTIFD_VERSION);
         }
         p->name = g_strdup_printf("mig/src/send_%d", i);
         p->write_flags = 0;
diff --git a/migration/trace-events b/migration/trace-events
index 0887cef912..c65902f042 100644
--- a/migration/trace-events
+++ b/migration/trace-events
@@ -128,7 +128,7 @@ postcopy_preempt_reset_channel(void) ""
 # multifd.c
 multifd_new_send_channel_async(uint8_t id) "channel %u"
 multifd_new_send_channel_async_error(uint8_t id, void *err) "channel=%u err=%p"
-multifd_recv(uint8_t id, uint64_t packet_num, uint32_t normal, uint32_t zero, uint32_t flags, uint32_t next_packet_size) "channel %u packet_num %" PRIu64 " normal pages %u zero pages %u flags 0x%x next packet size %u"
+multifd_recv_unfill(uint8_t id, uint64_t packet_num, uint32_t flags, uint32_t next_packet_size) "channel %u packet_num %" PRIu64 " flags 0x%x next packet size %u"
 multifd_recv_new_channel(uint8_t id) "channel %u"
 multifd_recv_sync_main(long packet_num) "packet num %ld"
 multifd_recv_sync_main_signal(uint8_t id) "channel %u"
@@ -136,7 +136,8 @@ multifd_recv_sync_main_wait(uint8_t id) "iter %u"
 multifd_recv_terminate_threads(bool error) "error %d"
 multifd_recv_thread_end(uint8_t id, uint64_t packets) "channel %u packets %" PRIu64
 multifd_recv_thread_start(uint8_t id) "%u"
-multifd_send(uint8_t id, uint64_t packet_num, uint32_t normal_pages, uint32_t zero_pages, uint32_t flags, uint32_t next_packet_size) "channel %u packet_num %" PRIu64 " normal pages %u zero pages %u flags 0x%x next packet size %u"
+multifd_send_fill(uint8_t id, uint64_t packet_num, uint32_t flags, uint32_t next_packet_size) "channel %u packet_num %" PRIu64 " flags 0x%x next packet size %u"
+multifd_send_ram_fill(uint8_t id, uint32_t normal, uint32_t zero) "channel %u normal pages %u zero pages %u"
 multifd_send_error(uint8_t id) "channel %u"
 multifd_send_sync_main(long packet_num) "packet num %ld"
 multifd_send_sync_main_signal(uint8_t id) "channel %u"
-- 
2.35.3
Re: [PATCH v4 10/16] migration/multifd: Isolate ram pages packet data
Posted by Peter Xu 2 months, 4 weeks ago
On Fri, Aug 23, 2024 at 02:39:05PM -0300, Fabiano Rosas wrote:
> While we cannot yet disentangle the multifd packet from page data, we
> can make the code a bit cleaner by setting the page-related fields in
> a separate function.
> 
> Signed-off-by: Fabiano Rosas <farosas@suse.de>

Reviewed-by: Peter Xu <peterx@redhat.com>

-- 
Peter Xu
Re: [PATCH v4 10/16] migration/multifd: Isolate ram pages packet data
Posted by Philippe Mathieu-Daudé 3 months ago
On 23/8/24 19:39, Fabiano Rosas wrote:
> While we cannot yet disentangle the multifd packet from page data, we
> can make the code a bit cleaner by setting the page-related fields in
> a separate function.
> 
> Signed-off-by: Fabiano Rosas <farosas@suse.de>
> ---
>   migration/multifd.c    | 99 +++++++++++++++++++++++++-----------------
>   migration/trace-events |  5 ++-
>   2 files changed, 63 insertions(+), 41 deletions(-)


> -static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
> +static int multifd_ram_unfill_packet(MultiFDRecvParams *p, Error **errp)
>   {
>       MultiFDPacket_t *packet = p->packet;
>       uint32_t page_count = multifd_ram_page_count();
>       uint32_t page_size = multifd_ram_page_size();
>       int i;
>   
> -    packet->magic = be32_to_cpu(packet->magic);
> -    if (packet->magic != MULTIFD_MAGIC) {
> -        error_setg(errp, "multifd: received packet "
> -                   "magic %x and expected magic %x",
> -                   packet->magic, MULTIFD_MAGIC);
> -        return -1;
> -    }
> -
> -    packet->version = be32_to_cpu(packet->version);
> -    if (packet->version != MULTIFD_VERSION) {
> -        error_setg(errp, "multifd: received packet "
> -                   "version %u and expected version %u",
> -                   packet->version, MULTIFD_VERSION);
> -        return -1;
> -    }
> -
> -    p->flags = be32_to_cpu(packet->flags);
> -
>       packet->pages_alloc = be32_to_cpu(packet->pages_alloc);
>       /*
>        * If we received a packet that is 100 times bigger than expected
> @@ -511,13 +507,6 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
>           return -1;
>       }
>   
> -    p->next_packet_size = be32_to_cpu(packet->next_packet_size);
> -    p->packet_num = be64_to_cpu(packet->packet_num);
> -    p->packets_recved++;
> -
> -    trace_multifd_recv(p->id, p->packet_num, p->normal_num, p->zero_num,
> -                       p->flags, p->next_packet_size);
> -
>       if (p->normal_num == 0 && p->zero_num == 0) {
>           return 0;
>       }
> @@ -559,6 +548,40 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
>       return 0;
>   }
>   
> +static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
> +{
> +    MultiFDPacket_t *packet = p->packet;
> +    int ret = 0;
> +
> +    packet->magic = be32_to_cpu(packet->magic);
> +    if (packet->magic != MULTIFD_MAGIC) {
> +        error_setg(errp, "multifd: received packet "
> +                   "magic %x and expected magic %x",
> +                   packet->magic, MULTIFD_MAGIC);
> +        return -1;
> +    }
> +
> +    packet->version = be32_to_cpu(packet->version);
> +    if (packet->version != MULTIFD_VERSION) {
> +        error_setg(errp, "multifd: received packet "
> +                   "version %u and expected version %u",
> +                   packet->version, MULTIFD_VERSION);
> +        return -1;
> +    }
> +
> +    p->flags = be32_to_cpu(packet->flags);
> +    p->next_packet_size = be32_to_cpu(packet->next_packet_size);
> +    p->packet_num = be64_to_cpu(packet->packet_num);
> +    p->packets_recved++;
> +
> +    ret = multifd_ram_unfill_packet(p, errp);

Pre-existing but since you modify this code, maybe cleaner to
"unfill" all packet fields, then check for sane magic/version
and return error, to not let a packet half-swapped. Otherwise:

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

> +
> +    trace_multifd_recv_unfill(p->id, p->packet_num, p->flags,
> +                              p->next_packet_size);
> +
> +    return ret;
> +}


Re: [PATCH v4 10/16] migration/multifd: Isolate ram pages packet data
Posted by Fabiano Rosas 2 months, 4 weeks ago
Philippe Mathieu-Daudé <philmd@linaro.org> writes:

> On 23/8/24 19:39, Fabiano Rosas wrote:
>> While we cannot yet disentangle the multifd packet from page data, we
>> can make the code a bit cleaner by setting the page-related fields in
>> a separate function.
>> 
>> Signed-off-by: Fabiano Rosas <farosas@suse.de>
>> ---
>>   migration/multifd.c    | 99 +++++++++++++++++++++++++-----------------
>>   migration/trace-events |  5 ++-
>>   2 files changed, 63 insertions(+), 41 deletions(-)
>
>
>> -static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
>> +static int multifd_ram_unfill_packet(MultiFDRecvParams *p, Error **errp)
>>   {
>>       MultiFDPacket_t *packet = p->packet;
>>       uint32_t page_count = multifd_ram_page_count();
>>       uint32_t page_size = multifd_ram_page_size();
>>       int i;
>>   
>> -    packet->magic = be32_to_cpu(packet->magic);
>> -    if (packet->magic != MULTIFD_MAGIC) {
>> -        error_setg(errp, "multifd: received packet "
>> -                   "magic %x and expected magic %x",
>> -                   packet->magic, MULTIFD_MAGIC);
>> -        return -1;
>> -    }
>> -
>> -    packet->version = be32_to_cpu(packet->version);
>> -    if (packet->version != MULTIFD_VERSION) {
>> -        error_setg(errp, "multifd: received packet "
>> -                   "version %u and expected version %u",
>> -                   packet->version, MULTIFD_VERSION);
>> -        return -1;
>> -    }
>> -
>> -    p->flags = be32_to_cpu(packet->flags);
>> -
>>       packet->pages_alloc = be32_to_cpu(packet->pages_alloc);
>>       /*
>>        * If we received a packet that is 100 times bigger than expected
>> @@ -511,13 +507,6 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
>>           return -1;
>>       }
>>   
>> -    p->next_packet_size = be32_to_cpu(packet->next_packet_size);
>> -    p->packet_num = be64_to_cpu(packet->packet_num);
>> -    p->packets_recved++;
>> -
>> -    trace_multifd_recv(p->id, p->packet_num, p->normal_num, p->zero_num,
>> -                       p->flags, p->next_packet_size);
>> -
>>       if (p->normal_num == 0 && p->zero_num == 0) {
>>           return 0;
>>       }
>> @@ -559,6 +548,40 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
>>       return 0;
>>   }
>>   
>> +static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
>> +{
>> +    MultiFDPacket_t *packet = p->packet;
>> +    int ret = 0;
>> +
>> +    packet->magic = be32_to_cpu(packet->magic);
>> +    if (packet->magic != MULTIFD_MAGIC) {
>> +        error_setg(errp, "multifd: received packet "
>> +                   "magic %x and expected magic %x",
>> +                   packet->magic, MULTIFD_MAGIC);
>> +        return -1;
>> +    }
>> +
>> +    packet->version = be32_to_cpu(packet->version);
>> +    if (packet->version != MULTIFD_VERSION) {
>> +        error_setg(errp, "multifd: received packet "
>> +                   "version %u and expected version %u",
>> +                   packet->version, MULTIFD_VERSION);
>> +        return -1;
>> +    }
>> +
>> +    p->flags = be32_to_cpu(packet->flags);
>> +    p->next_packet_size = be32_to_cpu(packet->next_packet_size);
>> +    p->packet_num = be64_to_cpu(packet->packet_num);
>> +    p->packets_recved++;
>> +
>> +    ret = multifd_ram_unfill_packet(p, errp);
>
> Pre-existing but since you modify this code, maybe cleaner to
> "unfill" all packet fields, then check for sane magic/version
> and return error, to not let a packet half-swapped. Otherwise:

I don't even see the point of byte-swapping the packet
in-place. Probably better to have all the swaps into the variables in
the unfill function and leave the packet unchanged. I'll add another
patch to the series.

>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>
>> +
>> +    trace_multifd_recv_unfill(p->id, p->packet_num, p->flags,
>> +                              p->next_packet_size);
>> +
>> +    return ret;
>> +}