| Message ID | 0259E1C966E8C54AA93AA2B1240828E672DF3D38@dggeml509-mbx.china.huawei.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] pcie: fix device hotplug failure at the meantime of VM boot | expand |
On Tue, Jul 23, 2019 at 09:31:30AM +0000, Zhangbo (Oscar) wrote: > 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 <limingwang@huawei.com> > Signed-off-by: Fang Ying <fangying1@huawei.com> > Signed-off-by: Zhang Bo <oscar.zhangbo@huawei.com> I responded on v1 before seeing v2. As there's no change to patch or commit log, same comments apply. > --- > 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
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)); }