[PATCH 0/1] e1000e: Fix tx/rx counters

[PATCH 0/1] e1000e: Fix tx/rx counters

[timothee.cocault]

This commit fixes a bug in the stats registers of the e1000* devices
reporting higher bandwidth usage.

I'm adding a bit of context for affected Googlers:

The e1000e is the default NIC used by libvirt for Windows VMs.
This bug creates huge slowdowns on BITS transfers (used for
Windows Update for example).
The task manager shows high usage of bandwidth (>2Gbps inbound),
and thus the BITS client throttles the speed (<1kbps).

A temporary fix is to switch to the rtl8139 device.

Timothée Cocault (1):
  e1000e: Fix tx/rx counters

 hw/net/e1000.c         | 5 ++---
 hw/net/e1000e_core.c   | 5 ++---
 hw/net/e1000x_common.c | 5 ++---
 hw/net/igb_core.c      | 5 ++---
 4 files changed, 8 insertions(+), 12 deletions(-)

[PATCH 1/1] e1000e: Fix tx/rx counters

[timothee.cocault]

The bytes and packets counter registers are cleared on read.

Copying the "total counter" registers to the "good counter" registers has
side effects.
If the "total" register is never read by the OS, it only gets incremented.
This leads to exponential growth of the "good" register.

This commit increments the counters individually to avoid this.

Signed-off-by: Timothée Cocault <timothee.cocault@gmail.com>
---
 hw/net/e1000.c         | 5 ++---
 hw/net/e1000e_core.c   | 5 ++---
 hw/net/e1000x_common.c | 5 ++---
 hw/net/igb_core.c      | 5 ++---
 4 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/hw/net/e1000.c b/hw/net/e1000.c
index 23d660619f..59bacb5d3b 100644
--- a/hw/net/e1000.c
+++ b/hw/net/e1000.c
@@ -637,9 +637,8 @@ xmit_seg(E1000State *s)
 
     e1000x_inc_reg_if_not_full(s->mac_reg, TPT);
     e1000x_grow_8reg_if_not_full(s->mac_reg, TOTL, s->tx.size + 4);
-    s->mac_reg[GPTC] = s->mac_reg[TPT];
-    s->mac_reg[GOTCL] = s->mac_reg[TOTL];
-    s->mac_reg[GOTCH] = s->mac_reg[TOTH];
+    e1000x_inc_reg_if_not_full(s->mac_reg, GPTC);
+    e1000x_grow_8reg_if_not_full(s->mac_reg, GOTCL, s->tx.size + 4);
 }
 
 static void
diff --git a/hw/net/e1000e_core.c b/hw/net/e1000e_core.c
index c0c09b6965..cfa3f55e96 100644
--- a/hw/net/e1000e_core.c
+++ b/hw/net/e1000e_core.c
@@ -711,9 +711,8 @@ e1000e_on_tx_done_update_stats(E1000ECore *core, struct NetTxPkt *tx_pkt)
         g_assert_not_reached();
     }
 
-    core->mac[GPTC] = core->mac[TPT];
-    core->mac[GOTCL] = core->mac[TOTL];
-    core->mac[GOTCH] = core->mac[TOTH];
+    e1000x_inc_reg_if_not_full(core->mac, GPTC);
+    e1000x_grow_8reg_if_not_full(core->mac, GOTCL, tot_len);
 }
 
 static void
diff --git a/hw/net/e1000x_common.c b/hw/net/e1000x_common.c
index b844af590a..4c8e7dcf70 100644
--- a/hw/net/e1000x_common.c
+++ b/hw/net/e1000x_common.c
@@ -220,15 +220,14 @@ e1000x_update_rx_total_stats(uint32_t *mac,
 
     e1000x_increase_size_stats(mac, PRCregs, data_fcs_size);
     e1000x_inc_reg_if_not_full(mac, TPR);
-    mac[GPRC] = mac[TPR];
+    e1000x_inc_reg_if_not_full(mac, GPRC);
     /* TOR - Total Octets Received:
     * This register includes bytes received in a packet from the <Destination
     * Address> field through the <CRC> field, inclusively.
     * Always include FCS length (4) in size.
     */
     e1000x_grow_8reg_if_not_full(mac, TORL, data_size + 4);
-    mac[GORCL] = mac[TORL];
-    mac[GORCH] = mac[TORH];
+    e1000x_grow_8reg_if_not_full(mac, GORCL, data_size + 4);
 }
 
 void
diff --git a/hw/net/igb_core.c b/hw/net/igb_core.c
index d733fed6cf..826e7a6cf1 100644
--- a/hw/net/igb_core.c
+++ b/hw/net/igb_core.c
@@ -538,9 +538,8 @@ igb_on_tx_done_update_stats(IGBCore *core, struct NetTxPkt *tx_pkt, int qn)
         g_assert_not_reached();
     }
 
-    core->mac[GPTC] = core->mac[TPT];
-    core->mac[GOTCL] = core->mac[TOTL];
-    core->mac[GOTCH] = core->mac[TOTH];
+    e1000x_inc_reg_if_not_full(core->mac, GPTC);
+    e1000x_grow_8reg_if_not_full(core->mac, GOTCL, tot_len);
 
     if (core->mac[MRQC] & 1) {
         uint16_t pool = qn % IGB_NUM_VM_POOLS;
-- 
2.40.0

Re: [PATCH 1/1] e1000e: Fix tx/rx counters

[Akihiko Odaki]

On 2023/04/11 0:27, timothee.cocault@gmail.com wrote:
> The bytes and packets counter registers are cleared on read.
> 
> Copying the "total counter" registers to the "good counter" registers has
> side effects.
> If the "total" register is never read by the OS, it only gets incremented.
> This leads to exponential growth of the "good" register.
> 
> This commit increments the counters individually to avoid this.
> 
> Signed-off-by: Timothée Cocault <timothee.cocault@gmail.com>

Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>

> ---
>   hw/net/e1000.c         | 5 ++---
>   hw/net/e1000e_core.c   | 5 ++---
>   hw/net/e1000x_common.c | 5 ++---
>   hw/net/igb_core.c      | 5 ++---
>   4 files changed, 8 insertions(+), 12 deletions(-)
> 
> diff --git a/hw/net/e1000.c b/hw/net/e1000.c
> index 23d660619f..59bacb5d3b 100644
> --- a/hw/net/e1000.c
> +++ b/hw/net/e1000.c
> @@ -637,9 +637,8 @@ xmit_seg(E1000State *s)
>   
>       e1000x_inc_reg_if_not_full(s->mac_reg, TPT);
>       e1000x_grow_8reg_if_not_full(s->mac_reg, TOTL, s->tx.size + 4);
> -    s->mac_reg[GPTC] = s->mac_reg[TPT];
> -    s->mac_reg[GOTCL] = s->mac_reg[TOTL];
> -    s->mac_reg[GOTCH] = s->mac_reg[TOTH];
> +    e1000x_inc_reg_if_not_full(s->mac_reg, GPTC);
> +    e1000x_grow_8reg_if_not_full(s->mac_reg, GOTCL, s->tx.size + 4);
>   }
>   
>   static void
> diff --git a/hw/net/e1000e_core.c b/hw/net/e1000e_core.c
> index c0c09b6965..cfa3f55e96 100644
> --- a/hw/net/e1000e_core.c
> +++ b/hw/net/e1000e_core.c
> @@ -711,9 +711,8 @@ e1000e_on_tx_done_update_stats(E1000ECore *core, struct NetTxPkt *tx_pkt)
>           g_assert_not_reached();
>       }
>   
> -    core->mac[GPTC] = core->mac[TPT];
> -    core->mac[GOTCL] = core->mac[TOTL];
> -    core->mac[GOTCH] = core->mac[TOTH];
> +    e1000x_inc_reg_if_not_full(core->mac, GPTC);
> +    e1000x_grow_8reg_if_not_full(core->mac, GOTCL, tot_len);
>   }
>   
>   static void
> diff --git a/hw/net/e1000x_common.c b/hw/net/e1000x_common.c
> index b844af590a..4c8e7dcf70 100644
> --- a/hw/net/e1000x_common.c
> +++ b/hw/net/e1000x_common.c
> @@ -220,15 +220,14 @@ e1000x_update_rx_total_stats(uint32_t *mac,
>   
>       e1000x_increase_size_stats(mac, PRCregs, data_fcs_size);
>       e1000x_inc_reg_if_not_full(mac, TPR);
> -    mac[GPRC] = mac[TPR];
> +    e1000x_inc_reg_if_not_full(mac, GPRC);
>       /* TOR - Total Octets Received:
>       * This register includes bytes received in a packet from the <Destination
>       * Address> field through the <CRC> field, inclusively.
>       * Always include FCS length (4) in size.
>       */
>       e1000x_grow_8reg_if_not_full(mac, TORL, data_size + 4);
> -    mac[GORCL] = mac[TORL];
> -    mac[GORCH] = mac[TORH];
> +    e1000x_grow_8reg_if_not_full(mac, GORCL, data_size + 4);
>   }
>   
>   void
> diff --git a/hw/net/igb_core.c b/hw/net/igb_core.c
> index d733fed6cf..826e7a6cf1 100644
> --- a/hw/net/igb_core.c
> +++ b/hw/net/igb_core.c
> @@ -538,9 +538,8 @@ igb_on_tx_done_update_stats(IGBCore *core, struct NetTxPkt *tx_pkt, int qn)
>           g_assert_not_reached();
>       }
>   
> -    core->mac[GPTC] = core->mac[TPT];
> -    core->mac[GOTCL] = core->mac[TOTL];
> -    core->mac[GOTCH] = core->mac[TOTH];
> +    e1000x_inc_reg_if_not_full(core->mac, GPTC);
> +    e1000x_grow_8reg_if_not_full(core->mac, GOTCL, tot_len);
>   
>       if (core->mac[MRQC] & 1) {
>           uint16_t pool = qn % IGB_NUM_VM_POOLS;

Re: [PATCH 1/1] e1000e: Fix tx/rx counters

[Jason Wang]

在 2023/4/10 23:33, Akihiko Odaki 写道:
> On 2023/04/11 0:27, timothee.cocault@gmail.com wrote:
>> The bytes and packets counter registers are cleared on read.
>>
>> Copying the "total counter" registers to the "good counter" registers 
>> has
>> side effects.
>> If the "total" register is never read by the OS, it only gets 
>> incremented.
>> This leads to exponential growth of the "good" register.
>>
>> This commit increments the counters individually to avoid this.
>>
>> Signed-off-by: Timothée Cocault <timothee.cocault@gmail.com>
>
> Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>


Queued.

Thanks


>
>> ---
>>   hw/net/e1000.c         | 5 ++---
>>   hw/net/e1000e_core.c   | 5 ++---
>>   hw/net/e1000x_common.c | 5 ++---
>>   hw/net/igb_core.c      | 5 ++---
>>   4 files changed, 8 insertions(+), 12 deletions(-)
>>
>> diff --git a/hw/net/e1000.c b/hw/net/e1000.c
>> index 23d660619f..59bacb5d3b 100644
>> --- a/hw/net/e1000.c
>> +++ b/hw/net/e1000.c
>> @@ -637,9 +637,8 @@ xmit_seg(E1000State *s)
>>         e1000x_inc_reg_if_not_full(s->mac_reg, TPT);
>>       e1000x_grow_8reg_if_not_full(s->mac_reg, TOTL, s->tx.size + 4);
>> -    s->mac_reg[GPTC] = s->mac_reg[TPT];
>> -    s->mac_reg[GOTCL] = s->mac_reg[TOTL];
>> -    s->mac_reg[GOTCH] = s->mac_reg[TOTH];
>> +    e1000x_inc_reg_if_not_full(s->mac_reg, GPTC);
>> +    e1000x_grow_8reg_if_not_full(s->mac_reg, GOTCL, s->tx.size + 4);
>>   }
>>     static void
>> diff --git a/hw/net/e1000e_core.c b/hw/net/e1000e_core.c
>> index c0c09b6965..cfa3f55e96 100644
>> --- a/hw/net/e1000e_core.c
>> +++ b/hw/net/e1000e_core.c
>> @@ -711,9 +711,8 @@ e1000e_on_tx_done_update_stats(E1000ECore *core, 
>> struct NetTxPkt *tx_pkt)
>>           g_assert_not_reached();
>>       }
>>   -    core->mac[GPTC] = core->mac[TPT];
>> -    core->mac[GOTCL] = core->mac[TOTL];
>> -    core->mac[GOTCH] = core->mac[TOTH];
>> +    e1000x_inc_reg_if_not_full(core->mac, GPTC);
>> +    e1000x_grow_8reg_if_not_full(core->mac, GOTCL, tot_len);
>>   }
>>     static void
>> diff --git a/hw/net/e1000x_common.c b/hw/net/e1000x_common.c
>> index b844af590a..4c8e7dcf70 100644
>> --- a/hw/net/e1000x_common.c
>> +++ b/hw/net/e1000x_common.c
>> @@ -220,15 +220,14 @@ e1000x_update_rx_total_stats(uint32_t *mac,
>>         e1000x_increase_size_stats(mac, PRCregs, data_fcs_size);
>>       e1000x_inc_reg_if_not_full(mac, TPR);
>> -    mac[GPRC] = mac[TPR];
>> +    e1000x_inc_reg_if_not_full(mac, GPRC);
>>       /* TOR - Total Octets Received:
>>       * This register includes bytes received in a packet from the 
>> <Destination
>>       * Address> field through the <CRC> field, inclusively.
>>       * Always include FCS length (4) in size.
>>       */
>>       e1000x_grow_8reg_if_not_full(mac, TORL, data_size + 4);
>> -    mac[GORCL] = mac[TORL];
>> -    mac[GORCH] = mac[TORH];
>> +    e1000x_grow_8reg_if_not_full(mac, GORCL, data_size + 4);
>>   }
>>     void
>> diff --git a/hw/net/igb_core.c b/hw/net/igb_core.c
>> index d733fed6cf..826e7a6cf1 100644
>> --- a/hw/net/igb_core.c
>> +++ b/hw/net/igb_core.c
>> @@ -538,9 +538,8 @@ igb_on_tx_done_update_stats(IGBCore *core, struct 
>> NetTxPkt *tx_pkt, int qn)
>>           g_assert_not_reached();
>>       }
>>   -    core->mac[GPTC] = core->mac[TPT];
>> -    core->mac[GOTCL] = core->mac[TOTL];
>> -    core->mac[GOTCH] = core->mac[TOTH];
>> +    e1000x_inc_reg_if_not_full(core->mac, GPTC);
>> +    e1000x_grow_8reg_if_not_full(core->mac, GOTCL, tot_len);
>>         if (core->mac[MRQC] & 1) {
>>           uint16_t pool = qn % IGB_NUM_VM_POOLS;
>

Re: [PATCH 1/1] e1000e: Fix tx/rx counters

[Michael Tokarev]

10.04.2023 18:27, timothee.cocault@gmail.com wrote:
> The bytes and packets counter registers are cleared on read.
> 
> Copying the "total counter" registers to the "good counter" registers has
> side effects.
> If the "total" register is never read by the OS, it only gets incremented.
> This leads to exponential growth of the "good" register.
> 
> This commit increments the counters individually to avoid this.

Smells like a -stable material, is it not?

Thanks,

/mjt

Re: [PATCH 1/1] e1000e: Fix tx/rx counters

[Jason Wang]

On Thu, May 11, 2023 at 2:54 AM Michael Tokarev <mjt@tls.msk.ru> wrote:
>
> 10.04.2023 18:27, timothee.cocault@gmail.com wrote:
> > The bytes and packets counter registers are cleared on read.
> >
> > Copying the "total counter" registers to the "good counter" registers has
> > side effects.
> > If the "total" register is never read by the OS, it only gets incremented.
> > This leads to exponential growth of the "good" register.
> >
> > This commit increments the counters individually to avoid this.
>
> Smells like a -stable material, is it not?

Yes, tagged for stable.

Thanks

>
> Thanks,
>
> /mjt
>