If the PCI_EXP_LNKSTA_DLLLA capability is set by default, linux kernel will
send
PDC event to detect whether there is a device in pcie slot. If a device is
pluged
in the pcie-root-port at the same time, hot-plug device will send ABP + PDC
events to the kernel. The VM kernel will wrongly unplug the device if two PDC
events get too close. Thus we'd better set the PCI_EXP_LNKSTA_DLLLA
capability only in hotplug callback.
By the way, we should clean up the PCI_EXP_LNKSTA_DLLLA capability during
unplug to avoid VM restart or migration failure which will enter the same
abnormal scenario as above.
Signed-off-by: Li Mingwang <limingw...@huawei.com>
Signed-off-by: Fang Ying <fangyi...@huawei.com>
Signed-off-by: Zhang Bo <oscar.zhan...@huawei.com>
---
hw/pci/pcie.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index a6beb56..174f392 100644
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -75,10 +75,6 @@ pcie_cap_v1_fill(PCIDevice *dev, uint8_t port, uint8_t type,
uint8_t version)
QEMU_PCI_EXP_LNKSTA_NLW(QEMU_PCI_EXP_LNK_X1) |
QEMU_PCI_EXP_LNKSTA_CLS(QEMU_PCI_EXP_LNK_2_5GT));
- if (dev->cap_present & QEMU_PCIE_LNKSTA_DLLLA) {
- pci_word_test_and_set_mask(exp_cap + PCI_EXP_LNKSTA,
- PCI_EXP_LNKSTA_DLLLA);
- }
/* We changed link status bits over time, and changing them across
* migrations is generally fine as hardware changes them too.
@@ -484,6 +480,11 @@ void pcie_cap_slot_unplug_request_cb(HotplugHandler
*hotplug_dev,
return;
}
+ if (pci_dev->cap_present & QEMU_PCIE_LNKSTA_DLLLA) {
+ pci_word_test_and_clear_mask(exp_cap + PCI_EXP_LNKSTA,
+ PCI_EXP_LNKSTA_DLLLA);
+ }
+
pcie_cap_slot_push_attention_button(PCI_DEVICE(hotplug_dev));
}
--
1.8.3.1
