From: Michael S. Tsirkin <mst@redhat.com>
Date: Mon, 1 Dec 2014 18:06:52 +0000 (+0200)
Subject: e1000: defer packets until BM enabled
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=20302e71a5b654d7b4d0d61c7384e9dd8d112971;p=qemu.git

e1000: defer packets until BM enabled

Some guests seem to set BM for e1000 after
enabling RX.
If packets arrive in the window, device is wedged.
Probably works by luck on real hardware, work around
this by making can_receive depend on BM.

Tested-by: Gabriel Somlo <somlo@cmu.edu>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---

diff --git a/hw/net/e1000.c b/hw/net/e1000.c
index e33a4da9fa..89c5788b1c 100644
--- a/hw/net/e1000.c
+++ b/hw/net/e1000.c
@@ -33,6 +33,7 @@
 #include "sysemu/sysemu.h"
 #include "sysemu/dma.h"
 #include "qemu/iov.h"
+#include "qemu/range.h"
 
 #include "e1000_regs.h"
 
@@ -923,7 +924,9 @@ e1000_can_receive(NetClientState *nc)
     E1000State *s = qemu_get_nic_opaque(nc);
 
     return (s->mac_reg[STATUS] & E1000_STATUS_LU) &&
-        (s->mac_reg[RCTL] & E1000_RCTL_EN) && e1000_has_rxbufs(s, 1);
+        (s->mac_reg[RCTL] & E1000_RCTL_EN) &&
+        (s->parent_obj.config[PCI_COMMAND] & PCI_COMMAND_MASTER) &&
+        e1000_has_rxbufs(s, 1);
 }
 
 static uint64_t rx_desc_base(E1000State *s)
@@ -1529,6 +1532,20 @@ static NetClientInfo net_e1000_info = {
     .link_status_changed = e1000_set_link_status,
 };
 
+static void e1000_write_config(PCIDevice *pci_dev, uint32_t address,
+                                uint32_t val, int len)
+{
+    E1000State *s = E1000(pci_dev);
+
+    pci_default_write_config(pci_dev, address, val, len);
+
+    if (range_covers_byte(address, len, PCI_COMMAND) &&
+        (pci_dev->config[PCI_COMMAND] & PCI_COMMAND_MASTER)) {
+        qemu_flush_queued_packets(qemu_get_queue(s->nic));
+    }
+}
+
+
 static int pci_e1000_init(PCIDevice *pci_dev)
 {
     DeviceState *dev = DEVICE(pci_dev);
@@ -1539,6 +1556,8 @@ static int pci_e1000_init(PCIDevice *pci_dev)
     int i;
     uint8_t *macaddr;
 
+    pci_dev->config_write = e1000_write_config;
+
     pci_conf = pci_dev->config;
 
     /* TODO: RST# value should be 0, PCI spec 6.2.4 */