>-----Original Message----- >From: Philippe Mathieu-Daudé [mailto:phi...@redhat.com] >Sent: Tuesday, July 23, 2019 5:18 PM >To: Zhangbo (Oscar) <oscar.zhan...@huawei.com>; qemu-devel@nongnu.org >Cc: fangying <fangyi...@huawei.com>; dengkai (A) <dengk...@huawei.com>; >limingwang (A) <limingw...@huawei.com>; m...@redhat.com >Subject: Re: [Qemu-devel] [PATCH] pcie: fix device hotplug failure at the >meantime of VM boot > >Hi Oscar, > >On 7/23/19 9:47 AM, 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: limingw...@huawei.com >> Signed-off-by: fangyi...@huawei.com > >QEMU contribution guideline says: > > Please use your real name to sign a patch (not an alias or acronym). > Thanks for reminding, I've sent a patch V2 just now, plz check there.
>See: >https://wiki.qemu.org/Contribute/SubmitAPatch#Patch_emails_must_include_a >_Signed-off-by:_line > >We can infer limingwang@ real name is Liming Wang, oscar.zhangbo@ is >Oscar Zhangbo, but for fangying1@ it is too hard. >Can you provide his real name? > >Thanks, > >Phil. > >> Signed-off-by: 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)); >> } >> >>
