Message ID | 1359974470-17044-47-git-send-email-mjt@msgid.tls.msk.ru |
---|---|
State | New |
Headers | show |
On Mon, Feb 04, 2013 at 02:40:56PM +0400, Michael Tokarev wrote: > From: Michael Contreras <michael@inetric.com> > > Discard packets longer than 16384 when !SBP to match the hardware behavior. > > Signed-off-by: Michael Contreras <michael@inetric.com> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> > (cherry picked from commit 2c0331f4f7d241995452b99afaf0aab00493334a) > > Signed-off-by: Michael Tokarev <mjt@tls.msk.ru> > --- > hw/e1000.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/hw/e1000.c b/hw/e1000.c > index e22ba3d..87c798b 100644 > --- a/hw/e1000.c > +++ b/hw/e1000.c > @@ -61,6 +61,8 @@ static int debugflags = DBGBIT(TXERR) | DBGBIT(GENERAL); > > /* this is the size past which hardware will drop packets when setting LPE=0 */ > #define MAXIMUM_ETHERNET_VLAN_SIZE 1522 > +/* this is the size past which hardware will drop packets when setting LPE=1 */ > +#define MAXIMUM_ETHERNET_LPE_SIZE 16384 > > /* > * HW models: > @@ -799,8 +801,9 @@ e1000_receive(VLANClientState *nc, const uint8_t *buf, size_t size) > } > > /* Discard oversized packets if !LPE and !SBP. */ > - if (size > MAXIMUM_ETHERNET_VLAN_SIZE > - && !(s->mac_reg[RCTL] & E1000_RCTL_LPE) > + if ((size > MAXIMUM_ETHERNET_LPE_SIZE || > + (size > MAXIMUM_ETHERNET_VLAN_SIZE > + && !(s->mac_reg[RCTL] & E1000_RCTL_LPE))) > && !(s->mac_reg[RCTL] & E1000_RCTL_SBP)) { > return size; This change is correct. I have a related question to ask. I enabled E1000_DEBUG in qemu, and try to change nic MTU to >1500 in Windows 7/ Windows 8 guest. I found RCTL register isn't changed. It mean E1000_RCTL_LPE bit is 0, so I ping guest from host with > 1500 size packet, the request ICMP packets will be dropped. It seems a e1000 driver bug of Windows? Thanks, Amos > } > -- > 1.7.10.4
On Wed, Nov 27, 2013 at 07:14:30PM +0800, Amos Kong wrote: > On Mon, Feb 04, 2013 at 02:40:56PM +0400, Michael Tokarev wrote: > > From: Michael Contreras <michael@inetric.com> > > > > Discard packets longer than 16384 when !SBP to match the hardware behavior. > > > > Signed-off-by: Michael Contreras <michael@inetric.com> > > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> > > (cherry picked from commit 2c0331f4f7d241995452b99afaf0aab00493334a) > > > > Signed-off-by: Michael Tokarev <mjt@tls.msk.ru> > > --- > > hw/e1000.c | 7 +++++-- > > 1 file changed, 5 insertions(+), 2 deletions(-) > > > > diff --git a/hw/e1000.c b/hw/e1000.c > > index e22ba3d..87c798b 100644 > > --- a/hw/e1000.c > > +++ b/hw/e1000.c > > @@ -61,6 +61,8 @@ static int debugflags = DBGBIT(TXERR) | DBGBIT(GENERAL); > > > > /* this is the size past which hardware will drop packets when setting LPE=0 */ > > #define MAXIMUM_ETHERNET_VLAN_SIZE 1522 > > +/* this is the size past which hardware will drop packets when setting LPE=1 */ > > +#define MAXIMUM_ETHERNET_LPE_SIZE 16384 > > > > /* > > * HW models: > > @@ -799,8 +801,9 @@ e1000_receive(VLANClientState *nc, const uint8_t *buf, size_t size) > > } > > > > /* Discard oversized packets if !LPE and !SBP. */ > > - if (size > MAXIMUM_ETHERNET_VLAN_SIZE > > - && !(s->mac_reg[RCTL] & E1000_RCTL_LPE) > > + if ((size > MAXIMUM_ETHERNET_LPE_SIZE || > > + (size > MAXIMUM_ETHERNET_VLAN_SIZE > > + && !(s->mac_reg[RCTL] & E1000_RCTL_LPE))) > > && !(s->mac_reg[RCTL] & E1000_RCTL_SBP)) { > > return size; > > > This change is correct. I have a related question to ask. > > I enabled E1000_DEBUG in qemu, and try to change nic MTU to >1500 > in Windows 7/ Windows 8 guest. I found RCTL register isn't changed. > > It mean E1000_RCTL_LPE bit is 0, so I ping guest from host with > > 1500 size packet, the request ICMP packets will be dropped. > > It seems a e1000 driver bug of Windows? In e1000 driver of Windows, there is a "Jumbo Packet" option, it's used to enable LPE, after enabled Jumbo packet, I can ping guest with large packet (>1500)
diff --git a/hw/e1000.c b/hw/e1000.c index e22ba3d..87c798b 100644 --- a/hw/e1000.c +++ b/hw/e1000.c @@ -61,6 +61,8 @@ static int debugflags = DBGBIT(TXERR) | DBGBIT(GENERAL); /* this is the size past which hardware will drop packets when setting LPE=0 */ #define MAXIMUM_ETHERNET_VLAN_SIZE 1522 +/* this is the size past which hardware will drop packets when setting LPE=1 */ +#define MAXIMUM_ETHERNET_LPE_SIZE 16384 /* * HW models: @@ -799,8 +801,9 @@ e1000_receive(VLANClientState *nc, const uint8_t *buf, size_t size) } /* Discard oversized packets if !LPE and !SBP. */ - if (size > MAXIMUM_ETHERNET_VLAN_SIZE - && !(s->mac_reg[RCTL] & E1000_RCTL_LPE) + if ((size > MAXIMUM_ETHERNET_LPE_SIZE || + (size > MAXIMUM_ETHERNET_VLAN_SIZE + && !(s->mac_reg[RCTL] & E1000_RCTL_LPE))) && !(s->mac_reg[RCTL] & E1000_RCTL_SBP)) { return size; }