-----Original Message----- From: Dexuan Cui Sent: Tuesday, March 6, 2018 1:22 PM To: bhelgaas@google.com; linux-pci@vger.kernel.org; KY Srinivasan kys@microsoft.com; Stephen Hemminger sthemmin@microsoft.com; olaf@aepfle.de; apw@canonical.com; jasowang@redhat.com Cc: linux-kernel@vger.kernel.org; driverdev-devel@linuxdriverproject.org; Haiyang Zhang haiyangz@microsoft.com; vkuznets@redhat.com; marcelo.cerri@canonical.com; Michael Kelley (EOSG) Michael.H.Kelley@microsoft.com; Dexuan Cui decui@microsoft.com; stable@vger.kernel.org; Jack Morgenstein jackm@mellanox.com Subject: [PATCH v3 6/6] PCI: hv: fix 2 hang issues in hv_compose_msi_msg()
- 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.
- 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@microsoft.com Tested-by: Adrian Suhov v-adsuho@microsoft.com Tested-by: Chris Valean v-chvale@microsoft.com Cc: stable@vger.kernel.org Cc: Stephen Hemminger sthemmin@microsoft.com Cc: K. Y. Srinivasan kys@microsoft.com Cc: Vitaly Kuznetsov vkuznets@redhat.com Cc: Jack Morgenstein jackm@mellanox.com
Acked-by: Haiyang Zhang haiyangz@microsoft.com