> -----Original Message----- > From: Dexuan Cui > Sent: Tuesday, March 6, 2018 10:22 AM > To: bhelgaas@xxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; KY Srinivasan <kys@xxxxxxxxxxxxx>; > Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>; olaf@xxxxxxxxx; apw@xxxxxxxxxxxxx; > jasowang@xxxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx; driverdev-devel@xxxxxxxxxxxxxxxxxxxxxx; Haiyang Zhang > <haiyangz@xxxxxxxxxxxxx>; vkuznets@xxxxxxxxxx; marcelo.cerri@xxxxxxxxxxxxx; Michael > Kelley (EOSG) <Michael.H.Kelley@xxxxxxxxxxxxx>; Dexuan Cui <decui@xxxxxxxxxxxxx>; > stable@xxxxxxxxxxxxxxx; Jack Morgenstein <jackm@xxxxxxxxxxxx> > Subject: [PATCH v3 6/6] PCI: hv: fix 2 hang issues in hv_compose_msi_msg() > > 1. With the patch "x86/vector/msi: Switch to global reservation mode" > (4900be8360), the recent v4.15 and newer kernels always hang for 1-vCPU > Hyper-V VM with SR-IOV. This is because when we reach hv_compose_msi_msg() > by request_irq() -> request_threaded_irq() -> __setup_irq()->irq_startup() > -> __irq_startup() -> irq_domain_activate_irq() -> ... -> > msi_domain_activate() -> ... -> hv_compose_msi_msg(), local irq is > disabled in __setup_irq(). > > Fix this by polling the channel. > > 2. If the host is ejecting the VF device before we reach > hv_compose_msi_msg(), in a UP VM, we can hang in hv_compose_msi_msg() > forever, because at this time the host doesn't respond to the > CREATE_INTERRUPT request. This issue also happens to old kernels like > v4.14, v4.13, etc. > > Fix this by polling the channel for the PCI_EJECT message and > hpdev->state, and by checking the PCI vendor ID. > > Note: actually the above issues also happen to a SMP VM, if > "hbus->hdev->channel->target_cpu == smp_processor_id()" is true. > > Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx> > Tested-by: Adrian Suhov <v-adsuho@xxxxxxxxxxxxx> > Tested-by: Chris Valean <v-chvale@xxxxxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > Cc: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx> > Cc: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> > Cc: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> > Cc: Jack Morgenstein <jackm@xxxxxxxxxxxx> > --- > drivers/pci/host/pci-hyperv.c | 58 ++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 57 insertions(+), 1 deletion(-) > Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>