* [Qemu-devel] [patch] Poor user-net performance.
@ 2005-12-18 23:28 Paul Brook
2005-12-20 20:56 ` Juergen Lock
0 siblings, 1 reply; 5+ messages in thread
From: Paul Brook @ 2005-12-18 23:28 UTC (permalink / raw)
To: qemu-devel
[-- Attachment #1: Type: text/plain, Size: 854 bytes --]
Dan mentioned he was seeing very poor network performance when using user-net.
It turns out this is because packets were getting dropped (the NIC buffers
were full), and the slirp code doesn't throttle properly when this occurs.
You end up with a bunch of packets getting sent to the guest, half of which
get dropped, then a delay until slirp retransmits.
This is much more noticeable on Arm because the NIC only has a small memory
buffer.
Teaching the slirp code how to do tcp backoff/window scaling is probably a
fair amount of work. The easy alternative is to throttle the slirp output
when we know the card's buffers are full. slirp has a convenient hook for
this, so it's a matter of adding the hooks to the hardware emulation.
This increases arm user-net performance from painfully slow (~200kbit) to
guest CPU bound (~20Mbit).
Paul
[-- Attachment #2: patch.qemu_slirp_throttle --]
[-- Type: text/x-diff, Size: 8442 bytes --]
Index: vl.c
===================================================================
RCS file: /sources/qemu/qemu/vl.c,v
retrieving revision 1.157
diff -u -p -r1.157 vl.c
--- vl.c 18 Dec 2005 20:34:32 -0000 1.157
+++ vl.c 18 Dec 2005 23:12:02 -0000
@@ -1768,13 +1768,16 @@ VLANState *qemu_find_vlan(int id)
}
VLANClientState *qemu_new_vlan_client(VLANState *vlan,
- IOReadHandler *fd_read, void *opaque)
+ IOReadHandler *fd_read,
+ IOCanRWHandler *fd_can_read,
+ void *opaque)
{
VLANClientState *vc, **pvc;
vc = qemu_mallocz(sizeof(VLANClientState));
if (!vc)
return NULL;
vc->fd_read = fd_read;
+ vc->fd_can_read = fd_can_read;
vc->opaque = opaque;
vc->vlan = vlan;
@@ -1786,6 +1789,20 @@ VLANClientState *qemu_new_vlan_client(VL
return vc;
}
+int qemu_can_send_packet(VLANClientState *vc1)
+{
+ VLANState *vlan = vc1->vlan;
+ VLANClientState *vc;
+
+ for(vc = vlan->first_client; vc != NULL; vc = vc->next) {
+ if (vc != vc1) {
+ if (vc->fd_can_read && !vc->fd_can_read(vc->opaque))
+ return 0;
+ }
+ }
+ return 1;
+}
+
void qemu_send_packet(VLANClientState *vc1, const uint8_t *buf, int size)
{
VLANState *vlan = vc1->vlan;
@@ -1811,7 +1828,7 @@ static VLANClientState *slirp_vc;
int slirp_can_output(void)
{
- return 1;
+ qemu_can_send_packet(slirp_vc);
}
void slirp_output(const uint8_t *pkt, int pkt_len)
@@ -1839,7 +1856,7 @@ static int net_slirp_init(VLANState *vla
slirp_init();
}
slirp_vc = qemu_new_vlan_client(vlan,
- slirp_receive, NULL);
+ slirp_receive, NULL, NULL);
snprintf(slirp_vc->info_str, sizeof(slirp_vc->info_str), "user redirector");
return 0;
}
@@ -2024,7 +2041,7 @@ static TAPState *net_tap_fd_init(VLANSta
if (!s)
return NULL;
s->fd = fd;
- s->vc = qemu_new_vlan_client(vlan, tap_receive, s);
+ s->vc = qemu_new_vlan_client(vlan, tap_receive, NULL, s);
qemu_set_fd_handler(s->fd, tap_send, NULL, s);
snprintf(s->vc->info_str, sizeof(s->vc->info_str), "tap: fd=%d", fd);
return s;
@@ -2327,7 +2344,7 @@ static NetSocketState *net_socket_fd_ini
return NULL;
s->fd = fd;
- s->vc = qemu_new_vlan_client(vlan, net_socket_receive_dgram, s);
+ s->vc = qemu_new_vlan_client(vlan, net_socket_receive_dgram, NULL, s);
qemu_set_fd_handler(s->fd, net_socket_send_dgram, NULL, s);
/* mcast: save bound address as dst */
@@ -2355,7 +2372,7 @@ static NetSocketState *net_socket_fd_ini
return NULL;
s->fd = fd;
s->vc = qemu_new_vlan_client(vlan,
- net_socket_receive, s);
+ net_socket_receive, NULL, s);
snprintf(s->vc->info_str, sizeof(s->vc->info_str),
"socket: fd=%d", fd);
if (is_connected) {
Index: vl.h
===================================================================
RCS file: /sources/qemu/qemu/vl.h,v
retrieving revision 1.99
diff -u -p -r1.99 vl.h
--- vl.h 18 Dec 2005 20:34:32 -0000 1.99
+++ vl.h 18 Dec 2005 23:12:03 -0000
@@ -279,6 +279,9 @@ typedef struct VLANClientState VLANClien
struct VLANClientState {
IOReadHandler *fd_read;
+ /* Packets may still be sent if this returns zero. It's used to
+ rate-limit the slirp code. */
+ IOCanRWHandler *fd_can_read;
void *opaque;
struct VLANClientState *next;
struct VLANState *vlan;
@@ -293,8 +296,12 @@ typedef struct VLANState {
VLANState *qemu_find_vlan(int id);
VLANClientState *qemu_new_vlan_client(VLANState *vlan,
- IOReadHandler *fd_read, void *opaque);
+ IOReadHandler *fd_read,
+ IOCanRWHandler *fd_can_read,
+ void *opaque);
+int qemu_can_send_packet(VLANClientState *vc);
void qemu_send_packet(VLANClientState *vc, const uint8_t *buf, int size);
+void qemu_handler_true(void *opaque);
void do_info_network(void);
Index: hw/lance.c
===================================================================
RCS file: /sources/qemu/qemu/hw/lance.c,v
retrieving revision 1.5
diff -u -p -r1.5 lance.c
--- hw/lance.c 15 Nov 2005 22:16:05 -0000 1.5
+++ hw/lance.c 18 Dec 2005 23:12:03 -0000
@@ -283,6 +283,11 @@ static CPUWriteMemoryFunc *lance_mem_wri
#define MIN_BUF_SIZE 60
+static void lance_can_receive(void *opaque)
+{
+ return 1;
+}
+
static void lance_receive(void *opaque, const uint8_t *buf, int size)
{
LANCEState *s = opaque;
@@ -440,7 +445,7 @@ void lance_init(NICInfo *nd, int irq, ui
lance_reset(s);
- s->vc = qemu_new_vlan_client(nd->vlan, lance_receive, s);
+ s->vc = qemu_new_vlan_client(nd->vlan, lance_receive, lance_can_receive, s);
snprintf(s->vc->info_str, sizeof(s->vc->info_str),
"lance macaddr=%02x:%02x:%02x:%02x:%02x:%02x",
Index: hw/ne2000.c
===================================================================
RCS file: /sources/qemu/qemu/hw/ne2000.c,v
retrieving revision 1.17
diff -u -p -r1.17 ne2000.c
--- hw/ne2000.c 22 Nov 2005 20:16:13 -0000 1.17
+++ hw/ne2000.c 18 Dec 2005 23:12:03 -0000
@@ -200,14 +200,10 @@ static int compute_mcast_idx(const uint8
return (crc >> 26);
}
-/* return the max buffer size if the NE2000 can receive more data */
-static int ne2000_can_receive(void *opaque)
+static int ne2000_buffer_full(NE2000State *s)
{
- NE2000State *s = opaque;
int avail, index, boundary;
-
- if (s->cmd & E8390_STOP)
- return 0;
+
index = s->curpag << 8;
boundary = s->boundary << 8;
if (index < boundary)
@@ -219,6 +215,15 @@ static int ne2000_can_receive(void *opaq
return MAX_ETH_FRAME_SIZE;
}
+static int ne2000_can_receive(void *opaque)
+{
+ NE2000State *s = opaque;
+
+ if (s->cmd & E8390_STOP)
+ return 1;
+ return !ne2000_buffer_full(s);
+}
+
#define MIN_BUF_SIZE 60
static void ne2000_receive(void *opaque, const uint8_t *buf, int size)
@@ -234,7 +239,7 @@ static void ne2000_receive(void *opaque,
printf("NE2000: received len=%d\n", size);
#endif
- if (!ne2000_can_receive(s))
+ if (s->cmd & E8390_STOP || ne2000_buffer_full(s))
return;
/* XXX: check this */
@@ -715,7 +720,8 @@ void isa_ne2000_init(int base, int irq,
ne2000_reset(s);
- s->vc = qemu_new_vlan_client(nd->vlan, ne2000_receive, s);
+ s->vc = qemu_new_vlan_client(nd->vlan, ne2000_receive,
+ ne2000_can_receive, s);
snprintf(s->vc->info_str, sizeof(s->vc->info_str),
"ne2000 macaddr=%02x:%02x:%02x:%02x:%02x:%02x",
@@ -784,7 +790,8 @@ void pci_ne2000_init(PCIBus *bus, NICInf
s->pci_dev = (PCIDevice *)d;
memcpy(s->macaddr, nd->macaddr, 6);
ne2000_reset(s);
- s->vc = qemu_new_vlan_client(nd->vlan, ne2000_receive, s);
+ s->vc = qemu_new_vlan_client(nd->vlan, ne2000_receive,
+ ne2000_can_receive, s);
snprintf(s->vc->info_str, sizeof(s->vc->info_str),
"ne2000 pci macaddr=%02x:%02x:%02x:%02x:%02x:%02x",
Index: hw/smc91c111.c
===================================================================
RCS file: /sources/qemu/qemu/hw/smc91c111.c,v
retrieving revision 1.2
diff -u -p -r1.2 smc91c111.c
--- hw/smc91c111.c 18 Dec 2005 17:39:52 -0000 1.2
+++ hw/smc91c111.c 18 Dec 2005 23:12:03 -0000
@@ -593,6 +593,17 @@ static uint32_t smc91c111_readl(void *op
return val;
}
+static int smc91c111_can_receive(void *opaque)
+{
+ smc91c111_state *s = (smc91c111_state *)opaque;
+
+ if ((s->rcr & RCR_RXEN) == 0 || (s->rcr & RCR_SOFT_RST))
+ return 1;
+ if (s->allocated == (1 << NUM_PACKETS) - 1)
+ return 0;
+ return 1;
+}
+
static void smc91c111_receive(void *opaque, const uint8_t *buf, int size)
{
smc91c111_state *s = (smc91c111_state *)opaque;
@@ -697,6 +708,7 @@ void smc91c111_init(NICInfo *nd, uint32_
smc91c111_reset(s);
- s->vc = qemu_new_vlan_client(nd->vlan, smc91c111_receive, s);
+ s->vc = qemu_new_vlan_client(nd->vlan, smc91c111_receive,
+ smc91c111_can_receive, s);
/* ??? Save/restore. */
}
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [Qemu-devel] [patch] Poor user-net performance.
2005-12-18 23:28 [Qemu-devel] [patch] Poor user-net performance Paul Brook
@ 2005-12-20 20:56 ` Juergen Lock
2005-12-20 21:14 ` Paul Brook
0 siblings, 1 reply; 5+ messages in thread
From: Juergen Lock @ 2005-12-20 20:56 UTC (permalink / raw)
To: Paul Brook; +Cc: qemu-devel
On Sun, Dec 18, 2005 at 11:28:27PM +0000, Paul Brook wrote:
> Dan mentioned he was seeing very poor network performance when using user-net.
> It turns out this is because packets were getting dropped (the NIC buffers
> were full), and the slirp code doesn't throttle properly when this occurs.
> You end up with a bunch of packets getting sent to the guest, half of which
> get dropped, then a delay until slirp retransmits.
>
> This is much more noticeable on Arm because the NIC only has a small memory
> buffer.
>
> Teaching the slirp code how to do tcp backoff/window scaling is probably a
> fair amount of work. The easy alternative is to throttle the slirp output
> when we know the card's buffers are full. slirp has a convenient hook for
> this, so it's a matter of adding the hooks to the hardware emulation.
>
> This increases arm user-net performance from painfully slow (~200kbit) to
> guest CPU bound (~20Mbit).
>
Hmm is the patch supposed to work for i386 guests too? I get no dhcp
response and network unreachable when i try to ssh to the host from the
guest after manually ifconfig'ing, seem like the ne2k doesn't receive
any packets. (FreeBSD/i386 host, linux i386 guest - kanotix livecd iso).
The same works normally without the patch.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [patch] Poor user-net performance.
2005-12-20 20:56 ` Juergen Lock
@ 2005-12-20 21:14 ` Paul Brook
2005-12-21 21:11 ` Juergen Lock
2005-12-21 21:41 ` Filip Navara
0 siblings, 2 replies; 5+ messages in thread
From: Paul Brook @ 2005-12-20 21:14 UTC (permalink / raw)
To: Juergen Lock; +Cc: qemu-devel
[-- Attachment #1: Type: text/plain, Size: 855 bytes --]
On Tuesday 20 December 2005 20:56, Juergen Lock wrote:
> On Sun, Dec 18, 2005 at 11:28:27PM +0000, Paul Brook wrote:
> > Teaching the slirp code how to do tcp backoff/window scaling is probably
> > a fair amount of work. The easy alternative is to throttle the slirp
> > output when we know the card's buffers are full. slirp has a convenient
> > hook for this, so it's a matter of adding the hooks to the hardware
> > emulation.
>
> Hmm is the patch supposed to work for i386 guests too? I get no dhcp
> response and network unreachable when i try to ssh to the host from the
> guest after manually ifconfig'ing, seem like the ne2k doesn't receive
> any packets. (FreeBSD/i386 host, linux i386 guest - kanotix livecd iso).
> The same works normally without the patch.
Oops. Updated patch should fix this. It was a dumb error in the ne2k code.
Paul
[-- Attachment #2: patch.qemu_slirp_throttle --]
[-- Type: text/x-diff, Size: 8534 bytes --]
Index: vl.c
===================================================================
RCS file: /sources/qemu/qemu/vl.c,v
retrieving revision 1.157
diff -u -p -r1.157 vl.c
--- vl.c 18 Dec 2005 20:34:32 -0000 1.157
+++ vl.c 20 Dec 2005 21:11:37 -0000
@@ -1768,13 +1768,16 @@ VLANState *qemu_find_vlan(int id)
}
VLANClientState *qemu_new_vlan_client(VLANState *vlan,
- IOReadHandler *fd_read, void *opaque)
+ IOReadHandler *fd_read,
+ IOCanRWHandler *fd_can_read,
+ void *opaque)
{
VLANClientState *vc, **pvc;
vc = qemu_mallocz(sizeof(VLANClientState));
if (!vc)
return NULL;
vc->fd_read = fd_read;
+ vc->fd_can_read = fd_can_read;
vc->opaque = opaque;
vc->vlan = vlan;
@@ -1786,6 +1789,20 @@ VLANClientState *qemu_new_vlan_client(VL
return vc;
}
+int qemu_can_send_packet(VLANClientState *vc1)
+{
+ VLANState *vlan = vc1->vlan;
+ VLANClientState *vc;
+
+ for(vc = vlan->first_client; vc != NULL; vc = vc->next) {
+ if (vc != vc1) {
+ if (vc->fd_can_read && !vc->fd_can_read(vc->opaque))
+ return 0;
+ }
+ }
+ return 1;
+}
+
void qemu_send_packet(VLANClientState *vc1, const uint8_t *buf, int size)
{
VLANState *vlan = vc1->vlan;
@@ -1811,7 +1828,7 @@ static VLANClientState *slirp_vc;
int slirp_can_output(void)
{
- return 1;
+ qemu_can_send_packet(slirp_vc);
}
void slirp_output(const uint8_t *pkt, int pkt_len)
@@ -1839,7 +1856,7 @@ static int net_slirp_init(VLANState *vla
slirp_init();
}
slirp_vc = qemu_new_vlan_client(vlan,
- slirp_receive, NULL);
+ slirp_receive, NULL, NULL);
snprintf(slirp_vc->info_str, sizeof(slirp_vc->info_str), "user redirector");
return 0;
}
@@ -2024,7 +2041,7 @@ static TAPState *net_tap_fd_init(VLANSta
if (!s)
return NULL;
s->fd = fd;
- s->vc = qemu_new_vlan_client(vlan, tap_receive, s);
+ s->vc = qemu_new_vlan_client(vlan, tap_receive, NULL, s);
qemu_set_fd_handler(s->fd, tap_send, NULL, s);
snprintf(s->vc->info_str, sizeof(s->vc->info_str), "tap: fd=%d", fd);
return s;
@@ -2327,7 +2344,7 @@ static NetSocketState *net_socket_fd_ini
return NULL;
s->fd = fd;
- s->vc = qemu_new_vlan_client(vlan, net_socket_receive_dgram, s);
+ s->vc = qemu_new_vlan_client(vlan, net_socket_receive_dgram, NULL, s);
qemu_set_fd_handler(s->fd, net_socket_send_dgram, NULL, s);
/* mcast: save bound address as dst */
@@ -2355,7 +2372,7 @@ static NetSocketState *net_socket_fd_ini
return NULL;
s->fd = fd;
s->vc = qemu_new_vlan_client(vlan,
- net_socket_receive, s);
+ net_socket_receive, NULL, s);
snprintf(s->vc->info_str, sizeof(s->vc->info_str),
"socket: fd=%d", fd);
if (is_connected) {
Index: vl.h
===================================================================
RCS file: /sources/qemu/qemu/vl.h,v
retrieving revision 1.99
diff -u -p -r1.99 vl.h
--- vl.h 18 Dec 2005 20:34:32 -0000 1.99
+++ vl.h 20 Dec 2005 21:11:38 -0000
@@ -279,6 +279,9 @@ typedef struct VLANClientState VLANClien
struct VLANClientState {
IOReadHandler *fd_read;
+ /* Packets may still be sent if this returns zero. It's used to
+ rate-limit the slirp code. */
+ IOCanRWHandler *fd_can_read;
void *opaque;
struct VLANClientState *next;
struct VLANState *vlan;
@@ -293,8 +296,12 @@ typedef struct VLANState {
VLANState *qemu_find_vlan(int id);
VLANClientState *qemu_new_vlan_client(VLANState *vlan,
- IOReadHandler *fd_read, void *opaque);
+ IOReadHandler *fd_read,
+ IOCanRWHandler *fd_can_read,
+ void *opaque);
+int qemu_can_send_packet(VLANClientState *vc);
void qemu_send_packet(VLANClientState *vc, const uint8_t *buf, int size);
+void qemu_handler_true(void *opaque);
void do_info_network(void);
Index: hw/lance.c
===================================================================
RCS file: /sources/qemu/qemu/hw/lance.c,v
retrieving revision 1.5
diff -u -p -r1.5 lance.c
--- hw/lance.c 15 Nov 2005 22:16:05 -0000 1.5
+++ hw/lance.c 20 Dec 2005 21:11:38 -0000
@@ -283,6 +283,11 @@ static CPUWriteMemoryFunc *lance_mem_wri
#define MIN_BUF_SIZE 60
+static void lance_can_receive(void *opaque)
+{
+ return 1;
+}
+
static void lance_receive(void *opaque, const uint8_t *buf, int size)
{
LANCEState *s = opaque;
@@ -440,7 +445,7 @@ void lance_init(NICInfo *nd, int irq, ui
lance_reset(s);
- s->vc = qemu_new_vlan_client(nd->vlan, lance_receive, s);
+ s->vc = qemu_new_vlan_client(nd->vlan, lance_receive, lance_can_receive, s);
snprintf(s->vc->info_str, sizeof(s->vc->info_str),
"lance macaddr=%02x:%02x:%02x:%02x:%02x:%02x",
Index: hw/ne2000.c
===================================================================
RCS file: /sources/qemu/qemu/hw/ne2000.c,v
retrieving revision 1.17
diff -u -p -r1.17 ne2000.c
--- hw/ne2000.c 22 Nov 2005 20:16:13 -0000 1.17
+++ hw/ne2000.c 20 Dec 2005 21:11:38 -0000
@@ -200,14 +200,10 @@ static int compute_mcast_idx(const uint8
return (crc >> 26);
}
-/* return the max buffer size if the NE2000 can receive more data */
-static int ne2000_can_receive(void *opaque)
+static int ne2000_buffer_full(NE2000State *s)
{
- NE2000State *s = opaque;
int avail, index, boundary;
-
- if (s->cmd & E8390_STOP)
- return 0;
+
index = s->curpag << 8;
boundary = s->boundary << 8;
if (index < boundary)
@@ -215,8 +211,17 @@ static int ne2000_can_receive(void *opaq
else
avail = (s->stop - s->start) - (index - boundary);
if (avail < (MAX_ETH_FRAME_SIZE + 4))
- return 0;
- return MAX_ETH_FRAME_SIZE;
+ return 1;
+ return 0;
+}
+
+static int ne2000_can_receive(void *opaque)
+{
+ NE2000State *s = opaque;
+
+ if (s->cmd & E8390_STOP)
+ return 1;
+ return !ne2000_buffer_full(s);
}
#define MIN_BUF_SIZE 60
@@ -234,7 +239,7 @@ static void ne2000_receive(void *opaque,
printf("NE2000: received len=%d\n", size);
#endif
- if (!ne2000_can_receive(s))
+ if (s->cmd & E8390_STOP || ne2000_buffer_full(s))
return;
/* XXX: check this */
@@ -715,7 +720,8 @@ void isa_ne2000_init(int base, int irq,
ne2000_reset(s);
- s->vc = qemu_new_vlan_client(nd->vlan, ne2000_receive, s);
+ s->vc = qemu_new_vlan_client(nd->vlan, ne2000_receive,
+ ne2000_can_receive, s);
snprintf(s->vc->info_str, sizeof(s->vc->info_str),
"ne2000 macaddr=%02x:%02x:%02x:%02x:%02x:%02x",
@@ -784,7 +790,8 @@ void pci_ne2000_init(PCIBus *bus, NICInf
s->pci_dev = (PCIDevice *)d;
memcpy(s->macaddr, nd->macaddr, 6);
ne2000_reset(s);
- s->vc = qemu_new_vlan_client(nd->vlan, ne2000_receive, s);
+ s->vc = qemu_new_vlan_client(nd->vlan, ne2000_receive,
+ ne2000_can_receive, s);
snprintf(s->vc->info_str, sizeof(s->vc->info_str),
"ne2000 pci macaddr=%02x:%02x:%02x:%02x:%02x:%02x",
Index: hw/smc91c111.c
===================================================================
RCS file: /sources/qemu/qemu/hw/smc91c111.c,v
retrieving revision 1.2
diff -u -p -r1.2 smc91c111.c
--- hw/smc91c111.c 18 Dec 2005 17:39:52 -0000 1.2
+++ hw/smc91c111.c 20 Dec 2005 21:11:38 -0000
@@ -593,6 +593,17 @@ static uint32_t smc91c111_readl(void *op
return val;
}
+static int smc91c111_can_receive(void *opaque)
+{
+ smc91c111_state *s = (smc91c111_state *)opaque;
+
+ if ((s->rcr & RCR_RXEN) == 0 || (s->rcr & RCR_SOFT_RST))
+ return 1;
+ if (s->allocated == (1 << NUM_PACKETS) - 1)
+ return 0;
+ return 1;
+}
+
static void smc91c111_receive(void *opaque, const uint8_t *buf, int size)
{
smc91c111_state *s = (smc91c111_state *)opaque;
@@ -697,6 +708,7 @@ void smc91c111_init(NICInfo *nd, uint32_
smc91c111_reset(s);
- s->vc = qemu_new_vlan_client(nd->vlan, smc91c111_receive, s);
+ s->vc = qemu_new_vlan_client(nd->vlan, smc91c111_receive,
+ smc91c111_can_receive, s);
/* ??? Save/restore. */
}
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [Qemu-devel] [patch] Poor user-net performance.
2005-12-20 21:14 ` Paul Brook
@ 2005-12-21 21:11 ` Juergen Lock
2005-12-21 21:41 ` Filip Navara
1 sibling, 0 replies; 5+ messages in thread
From: Juergen Lock @ 2005-12-21 21:11 UTC (permalink / raw)
To: Paul Brook; +Cc: qemu-devel
On Tue, Dec 20, 2005 at 09:14:09PM +0000, Paul Brook wrote:
> On Tuesday 20 December 2005 20:56, Juergen Lock wrote:
> > On Sun, Dec 18, 2005 at 11:28:27PM +0000, Paul Brook wrote:
> > > Teaching the slirp code how to do tcp backoff/window scaling is probably
> > > a fair amount of work. The easy alternative is to throttle the slirp
> > > output when we know the card's buffers are full. slirp has a convenient
> > > hook for this, so it's a matter of adding the hooks to the hardware
> > > emulation.
> >
> > Hmm is the patch supposed to work for i386 guests too? I get no dhcp
> > response and network unreachable when i try to ssh to the host from the
> > guest after manually ifconfig'ing, seem like the ne2k doesn't receive
> > any packets. (FreeBSD/i386 host, linux i386 guest - kanotix livecd iso).
> > The same works normally without the patch.
>
> Oops. Updated patch should fix this. It was a dumb error in the ne2k code.
:)
Updated patch works, thanx, I get nearly 2 MB/sec host to guest over smb
now. (And I'm adding the patch to the FreeBSD port.)
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [patch] Poor user-net performance.
2005-12-20 21:14 ` Paul Brook
2005-12-21 21:11 ` Juergen Lock
@ 2005-12-21 21:41 ` Filip Navara
1 sibling, 0 replies; 5+ messages in thread
From: Filip Navara @ 2005-12-21 21:41 UTC (permalink / raw)
To: qemu-devel
Paul Brook wrote:
[snip]
> int slirp_can_output(void)
> {
>- return 1;
>+ qemu_can_send_packet(slirp_vc);
> }
>
It would be wise to return the value here.
- Filip
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2005-12-21 21:43 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2005-12-18 23:28 [Qemu-devel] [patch] Poor user-net performance Paul Brook
2005-12-20 20:56 ` Juergen Lock
2005-12-20 21:14 ` Paul Brook
2005-12-21 21:11 ` Juergen Lock
2005-12-21 21:41 ` Filip Navara
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