[Qemu-devel] [PATCH 1/2] rtl8139: add vlan tag insertion

[Qemu-devel] [PATCH 1/2] rtl8139: add vlan tag insertion

[Benjamin Poirier]

Add support to the emulated hardware to add vlan tags in packets going
from the guest to the network.

Signed-off-by: Benjamin Poirier <benjamin.poirier@polymtl.ca>
Cc: Igor V. Kovalenko <igor.v.kovalenko@gmail.com>
---
 hw/rtl8139.c |   46 +++++++++++++++++++++++++++++++++++-----------
 1 files changed, 35 insertions(+), 11 deletions(-)

diff --git a/hw/rtl8139.c b/hw/rtl8139.c
index d92981d..ac294da 100644
--- a/hw/rtl8139.c
+++ b/hw/rtl8139.c
@@ -47,6 +47,8 @@
  *                                  Darwin)
  */
 
+#include <net/ethernet.h>
+
 #include "hw.h"
 #include "pci.h"
 #include "qemu-timer.h"
@@ -58,6 +60,10 @@
 
 #define PCI_FREQUENCY 33000000L
 
+/* bytes in VLAN tag */
+#define VLAN_TCI_LEN 2
+#define VLAN_HDR_LEN (ETHER_TYPE_LEN + VLAN_TCI_LEN)
+
 /* debug RTL8139 card C+ mode only */
 //#define DEBUG_RTL8139CP 1
 
@@ -1913,7 +1919,6 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s)
 
     cpu_physical_memory_read(cplus_tx_ring_desc,    (uint8_t *)&val, 4);
     txdw0 = le32_to_cpu(val);
-    /* TODO: implement VLAN tagging support, VLAN tag data is read to txdw1 */
     cpu_physical_memory_read(cplus_tx_ring_desc+4,  (uint8_t *)&val, 4);
     txdw1 = le32_to_cpu(val);
     cpu_physical_memory_read(cplus_tx_ring_desc+8,  (uint8_t *)&val, 4);
@@ -1925,9 +1930,6 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s)
            descriptor,
            txdw0, txdw1, txbufLO, txbufHI));
 
-    /* TODO: the following discard cast should clean clang analyzer output */
-    (void)txdw1;
-
 /* w0 ownership flag */
 #define CP_TX_OWN (1<<31)
 /* w0 end of ring flag */
@@ -1951,8 +1953,8 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s)
 /* w0 bits 0...15 : buffer size */
 #define CP_TX_BUFFER_SIZE (1<<16)
 #define CP_TX_BUFFER_SIZE_MASK (CP_TX_BUFFER_SIZE - 1)
-/* w1 tag available flag */
-#define CP_RX_TAGC (1<<17)
+/* w1 add tag flag */
+#define CP_TX_TAGC (1<<17)
 /* w1 bits 0...15 : VLAN tag */
 #define CP_TX_VLAN_TAG_MASK ((1<<16) - 1)
 /* w2 low  32bit of Rx buffer ptr */
@@ -1978,12 +1980,22 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s)
 
     DEBUG_PRINT(("RTL8139: +++ C+ Tx mode : transmitting from descriptor %d\n", descriptor));
 
+    int vlan_extra_size = 0;
     if (txdw0 & CP_TX_FS)
     {
         DEBUG_PRINT(("RTL8139: +++ C+ Tx mode : descriptor %d is first segment descriptor\n", descriptor));
 
+        DEBUG_PRINT(("RTL8139: +++ C+ Tx mode : add vlan tag: %u tci: %u\n",
+                !!(txdw1 & CP_TX_TAGC), bswap16(txdw1 &
+                    CP_TX_VLAN_TAG_MASK)));
+
         /* reset internal buffer offset */
         s->cplus_txbuffer_offset = 0;
+
+        if (txdw1 & CP_TX_TAGC)
+        {
+            vlan_extra_size = VLAN_HDR_LEN;
+        }
     }
 
     int txsize = txdw0 & CP_TX_BUFFER_SIZE_MASK;
@@ -1992,14 +2004,15 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s)
     /* make sure we have enough space to assemble the packet */
     if (!s->cplus_txbuffer)
     {
-        s->cplus_txbuffer_len = CP_TX_BUFFER_SIZE;
+        s->cplus_txbuffer_len = CP_TX_BUFFER_SIZE + VLAN_HDR_LEN;
         s->cplus_txbuffer = qemu_malloc(s->cplus_txbuffer_len);
         s->cplus_txbuffer_offset = 0;
 
         DEBUG_PRINT(("RTL8139: +++ C+ mode transmission buffer allocated space %d\n", s->cplus_txbuffer_len));
     }
 
-    while (s->cplus_txbuffer && s->cplus_txbuffer_offset + txsize >= s->cplus_txbuffer_len)
+    while (s->cplus_txbuffer && s->cplus_txbuffer_offset + txsize +
+        vlan_extra_size >= s->cplus_txbuffer_len)
     {
         s->cplus_txbuffer_len += CP_TX_BUFFER_SIZE;
         s->cplus_txbuffer = qemu_realloc(s->cplus_txbuffer, s->cplus_txbuffer_len);
@@ -2025,6 +2038,20 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s)
     DEBUG_PRINT(("RTL8139: +++ C+ mode transmit reading %d bytes from host memory at %016" PRIx64 " to offset %d\n",
                  txsize, (uint64_t)tx_addr, s->cplus_txbuffer_offset));
 
+    if (vlan_extra_size && txsize >= 2 * ETHER_ADDR_LEN)
+    {
+        /* copy addresses */
+        cpu_physical_memory_read(tx_addr, s->cplus_txbuffer, 2 *
+            ETHER_ADDR_LEN);
+        tx_addr += 2 * ETHER_ADDR_LEN;
+        txsize -= 2 * ETHER_ADDR_LEN;
+        /* insert vlan tag */
+        *(uint16_t *)(s->cplus_txbuffer + 2 * ETHER_ADDR_LEN) =
+            cpu_to_be16(ETHERTYPE_VLAN);
+        *(uint16_t *)(s->cplus_txbuffer + 2 * ETHER_ADDR_LEN + ETHER_TYPE_LEN)
+            = cpu_to_le16(txdw1 & CP_TX_VLAN_TAG_MASK);
+        s->cplus_txbuffer_offset += 2 * ETHER_ADDR_LEN + VLAN_HDR_LEN;
+    }
     cpu_physical_memory_read(tx_addr, s->cplus_txbuffer + s->cplus_txbuffer_offset, txsize);
     s->cplus_txbuffer_offset += txsize;
 
@@ -2053,9 +2080,6 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s)
     /* update ring data */
     val = cpu_to_le32(txdw0);
     cpu_physical_memory_write(cplus_tx_ring_desc,    (uint8_t *)&val, 4);
-    /* TODO: implement VLAN tagging support, VLAN tag data is read to txdw1 */
-//    val = cpu_to_le32(txdw1);
-//    cpu_physical_memory_write(cplus_tx_ring_desc+4,  &val, 4);
 
     /* Now decide if descriptor being processed is holding the last segment of packet */
     if (txdw0 & CP_TX_LS)
-- 
1.7.2.3

[Qemu-devel] [PATCH 2/2] rtl8139: add vlan tag extraction

[Benjamin Poirier]

Add support to the emulated hardware to remove vlan tags in packets
going from the network to the guest.

Signed-off-by: Benjamin Poirier <benjamin.poirier@polymtl.ca>
Cc: Igor V. Kovalenko <igor.v.kovalenko@gmail.com>

--

AFAIK, extraction is optional to get vlans working. The driver
requests rx detagging but should not assume that it was done. Under
Linux, the mac layer will catch the vlan ethertype. I only added this
part for completeness (to emulate the hardware more truthfully..?).
---
 hw/rtl8139.c |   41 ++++++++++++++++++++++++++++++++++++++---
 1 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/hw/rtl8139.c b/hw/rtl8139.c
index ac294da..557a460 100644
--- a/hw/rtl8139.c
+++ b/hw/rtl8139.c
@@ -1024,6 +1024,44 @@ static ssize_t rtl8139_do_receive(VLANClientState *nc, const uint8_t *buf, size_
 
         target_phys_addr_t rx_addr = rtl8139_addr64(rxbufLO, rxbufHI);
 
+        if (s->CpCmd & CPlusRxVLAN && size >= ETHER_ADDR_LEN * 2 +
+            VLAN_HDR_LEN && be16_to_cpup((uint16_t *) &buf[ETHER_ADDR_LEN *
+                2]) == ETHERTYPE_VLAN)
+        {
+            size_t new_size = size - VLAN_HDR_LEN;
+
+            rxdw1 &= ~CP_RX_VLAN_TAG_MASK;
+            rxdw1 |= CP_RX_TAVA |
+                le16_to_cpup((uint16_t *)&buf[ETHER_HDR_LEN]);
+
+            if (buf == buf1 || new_size < MIN_BUF_SIZE)
+            {
+                /* move the end and pad */
+                memmove((uint8_t *)buf + ETHER_ADDR_LEN * 2, buf +
+                    ETHER_ADDR_LEN * 2 + VLAN_HDR_LEN, new_size -
+                    ETHER_ADDR_LEN * 2);
+                memset((uint8_t *)buf + new_size, 0, MIN_BUF_SIZE - new_size);
+                size = MIN_BUF_SIZE;
+            }
+            else
+            {
+                /* move the beginning */
+                memmove((uint8_t *)buf + VLAN_HDR_LEN, buf, ETHER_ADDR_LEN *
+                    2);
+                buf += VLAN_HDR_LEN;
+                size = new_size;
+            }
+        }
+        else
+        {
+            /* reset VLAN tag flag */
+            rxdw1 &= ~CP_RX_TAVA;
+        }
+
+        DEBUG_PRINT(("RTL8139: C+ Rx mode : removed vlan tag: %u tci: %u\n",
+                !!(rxdw1 & CP_RX_TAVA), bswap16(rxdw1 &
+                    CP_RX_VLAN_TAG_MASK)));
+
         /* receive/copy to target memory */
         cpu_physical_memory_write( rx_addr, buf, size );
 
@@ -1082,9 +1120,6 @@ static ssize_t rtl8139_do_receive(VLANClientState *nc, const uint8_t *buf, size_
         rxdw0 &= ~CP_RX_BUFFER_SIZE_MASK;
         rxdw0 |= (size+4);
 
-        /* reset VLAN tag flag */
-        rxdw1 &= ~CP_RX_TAVA;
-
         /* update ring data */
         val = cpu_to_le32(rxdw0);
         cpu_physical_memory_write(cplus_rx_ring_desc,    (uint8_t *)&val, 4);
-- 
1.7.2.3

Re: [Qemu-devel] [PATCH 1/2] rtl8139: add vlan tag insertion

[Stefan Hajnoczi]

On Sun, Nov 7, 2010 at 9:25 PM, Benjamin Poirier
<benjamin.poirier@polymtl.ca> wrote:
> Add support to the emulated hardware to add vlan tags in packets going
> from the guest to the network.
>
> Signed-off-by: Benjamin Poirier <benjamin.poirier@polymtl.ca>
> Cc: Igor V. Kovalenko <igor.v.kovalenko@gmail.com>
> ---
>  hw/rtl8139.c |   46 +++++++++++++++++++++++++++++++++++-----------
>  1 files changed, 35 insertions(+), 11 deletions(-)
>
> diff --git a/hw/rtl8139.c b/hw/rtl8139.c
> index d92981d..ac294da 100644
> --- a/hw/rtl8139.c
> +++ b/hw/rtl8139.c
> @@ -47,6 +47,8 @@
>  *                                  Darwin)
>  */
>
> +#include <net/ethernet.h>
> +
>  #include "hw.h"
>  #include "pci.h"
>  #include "qemu-timer.h"
> @@ -58,6 +60,10 @@
>
>  #define PCI_FREQUENCY 33000000L
>
> +/* bytes in VLAN tag */
> +#define VLAN_TCI_LEN 2
> +#define VLAN_HDR_LEN (ETHER_TYPE_LEN + VLAN_TCI_LEN)
> +
>  /* debug RTL8139 card C+ mode only */
>  //#define DEBUG_RTL8139CP 1
>
> @@ -1913,7 +1919,6 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s)
>
>     cpu_physical_memory_read(cplus_tx_ring_desc,    (uint8_t *)&val, 4);
>     txdw0 = le32_to_cpu(val);
> -    /* TODO: implement VLAN tagging support, VLAN tag data is read to txdw1 */
>     cpu_physical_memory_read(cplus_tx_ring_desc+4,  (uint8_t *)&val, 4);
>     txdw1 = le32_to_cpu(val);
>     cpu_physical_memory_read(cplus_tx_ring_desc+8,  (uint8_t *)&val, 4);
> @@ -1925,9 +1930,6 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s)
>            descriptor,
>            txdw0, txdw1, txbufLO, txbufHI));
>
> -    /* TODO: the following discard cast should clean clang analyzer output */
> -    (void)txdw1;
> -
>  /* w0 ownership flag */
>  #define CP_TX_OWN (1<<31)
>  /* w0 end of ring flag */
> @@ -1951,8 +1953,8 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s)
>  /* w0 bits 0...15 : buffer size */
>  #define CP_TX_BUFFER_SIZE (1<<16)
>  #define CP_TX_BUFFER_SIZE_MASK (CP_TX_BUFFER_SIZE - 1)
> -/* w1 tag available flag */
> -#define CP_RX_TAGC (1<<17)
> +/* w1 add tag flag */
> +#define CP_TX_TAGC (1<<17)
>  /* w1 bits 0...15 : VLAN tag */
>  #define CP_TX_VLAN_TAG_MASK ((1<<16) - 1)
>  /* w2 low  32bit of Rx buffer ptr */
> @@ -1978,12 +1980,22 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s)
>
>     DEBUG_PRINT(("RTL8139: +++ C+ Tx mode : transmitting from descriptor %d\n", descriptor));
>
> +    int vlan_extra_size = 0;
>     if (txdw0 & CP_TX_FS)
>     {
>         DEBUG_PRINT(("RTL8139: +++ C+ Tx mode : descriptor %d is first segment descriptor\n", descriptor));
>
> +        DEBUG_PRINT(("RTL8139: +++ C+ Tx mode : add vlan tag: %u tci: %u\n",
> +                !!(txdw1 & CP_TX_TAGC), bswap16(txdw1 &
> +                    CP_TX_VLAN_TAG_MASK)));

Please use leXX_to_cpu() and cpu_to_leXX() instead of bswapXX() for
little-endian conversion.  This is more explicit than unconditional
byteswapping and work on both big- and little-endian QEMU host
architectures.

Stefan

Re: [Qemu-devel] [PATCH 1/2] rtl8139: add vlan tag insertion

[Benjamin Poirier]

On 08/11/10 11:34 AM, Stefan Hajnoczi wrote:
> On Sun, Nov 7, 2010 at 9:25 PM, Benjamin Poirier
> <benjamin.poirier@polymtl.ca> wrote:
>> Add support to the emulated hardware to add vlan tags in packets going
>> from the guest to the network.
>>
>> Signed-off-by: Benjamin Poirier <benjamin.poirier@polymtl.ca>
>> Cc: Igor V. Kovalenko <igor.v.kovalenko@gmail.com>
>> ---
>>  hw/rtl8139.c |   46 +++++++++++++++++++++++++++++++++++-----------
>>  1 files changed, 35 insertions(+), 11 deletions(-)
>>
>> diff --git a/hw/rtl8139.c b/hw/rtl8139.c
>> index d92981d..ac294da 100644
>> --- a/hw/rtl8139.c
>> +++ b/hw/rtl8139.c
>> @@ -47,6 +47,8 @@
>>  *                                  Darwin)
>>  */
>>
>> +#include <net/ethernet.h>
>> +
>>  #include "hw.h"
>>  #include "pci.h"
>>  #include "qemu-timer.h"
>> @@ -58,6 +60,10 @@
>>
>>  #define PCI_FREQUENCY 33000000L
>>
>> +/* bytes in VLAN tag */
>> +#define VLAN_TCI_LEN 2
>> +#define VLAN_HDR_LEN (ETHER_TYPE_LEN + VLAN_TCI_LEN)
>> +
>>  /* debug RTL8139 card C+ mode only */
>>  //#define DEBUG_RTL8139CP 1
>>
>> @@ -1913,7 +1919,6 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s)
>>
>>     cpu_physical_memory_read(cplus_tx_ring_desc,    (uint8_t *)&val, 4);
>>     txdw0 = le32_to_cpu(val);
>> -    /* TODO: implement VLAN tagging support, VLAN tag data is read to txdw1 */
>>     cpu_physical_memory_read(cplus_tx_ring_desc+4,  (uint8_t *)&val, 4);
>>     txdw1 = le32_to_cpu(val);
>>     cpu_physical_memory_read(cplus_tx_ring_desc+8,  (uint8_t *)&val, 4);
>> @@ -1925,9 +1930,6 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s)
>>            descriptor,
>>            txdw0, txdw1, txbufLO, txbufHI));
>>
>> -    /* TODO: the following discard cast should clean clang analyzer output */
>> -    (void)txdw1;
>> -
>>  /* w0 ownership flag */
>>  #define CP_TX_OWN (1<<31)
>>  /* w0 end of ring flag */
>> @@ -1951,8 +1953,8 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s)
>>  /* w0 bits 0...15 : buffer size */
>>  #define CP_TX_BUFFER_SIZE (1<<16)
>>  #define CP_TX_BUFFER_SIZE_MASK (CP_TX_BUFFER_SIZE - 1)
>> -/* w1 tag available flag */
>> -#define CP_RX_TAGC (1<<17)
>> +/* w1 add tag flag */
>> +#define CP_TX_TAGC (1<<17)
>>  /* w1 bits 0...15 : VLAN tag */
>>  #define CP_TX_VLAN_TAG_MASK ((1<<16) - 1)
>>  /* w2 low  32bit of Rx buffer ptr */
>> @@ -1978,12 +1980,22 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s)
>>
>>     DEBUG_PRINT(("RTL8139: +++ C+ Tx mode : transmitting from descriptor %d\n", descriptor));
>>
>> +    int vlan_extra_size = 0;
>>     if (txdw0 & CP_TX_FS)
>>     {
>>         DEBUG_PRINT(("RTL8139: +++ C+ Tx mode : descriptor %d is first segment descriptor\n", descriptor));
>>
>> +        DEBUG_PRINT(("RTL8139: +++ C+ Tx mode : add vlan tag: %u tci: %u\n",
>> +                !!(txdw1 & CP_TX_TAGC), bswap16(txdw1 &
>> +                    CP_TX_VLAN_TAG_MASK)));
> 
> Please use leXX_to_cpu() and cpu_to_leXX() instead of bswapXX() for
> little-endian conversion.  This is more explicit than unconditional
> byteswapping and work on both big- and little-endian QEMU host
> architectures.

I believe the use of flat out swapping is warranted here. The data has
been adjusted for host-endianness when the register was read:
	txdw1 = le32_to_cpu(val);
We have to mask and swap to accomodate the format used by the card's
registers, which is always the same regardless of machine endianness.

txdw1 is extracted from a 32 bit register like such (when the descriptor
specifies tx tagging), in increasing address order:
tci8-15 tci0-7 0x01 0x00

-Ben

> 
> Stefan
>