Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
Pre-existing issues: - [High] The fix for dropped pending interrupts during CPU hot-unplug was missed in the sister Hyper-V root partition MSI domain. -- --- Patch [1]: [PATCH 1/3] PCI: hv: Set irq_retrigger callback for the Hyper-V PCI MSI irqchip --- commit b8b1c843c457dd145f0d360b44f4b1bf34bd8cf5 Author: Naman Jain <[email protected]> PCI: hv: Set irq_retrigger callback for the Hyper-V PCI MSI irqchip The Hyper-V vPCI MSI irqchip never installs an irq_retrigger() callback. On CPU hot-unplug fixup_irqs() migrates the interrupts which are affine to the outgoing CPU to a new target. As the Hyper-V PCI/MSI chip does not provide that callback, the pending interrupt is silently dropped, which can result in lost interrupts, stalls and "No irq handler for vector" messages. Fixes: 4daace0d8ce85 ("PCI: hv: Add paravirtual PCI front-end for Microsoft Hyper-V VMs") Cc: [email protected] Suggested-by: Long Li <[email protected]> Suggested-by: Thomas Gleixner <[email protected]> Signed-off-by: Naman Jain <[email protected]> > diff --git a/drivers/pci/controller/pci-hyperv.c > b/drivers/pci/controller/pci-hyperv.c > index cfc8fa403dad6..89816a2bd7cd3 100644 > --- a/drivers/pci/controller/pci-hyperv.c > +++ b/drivers/pci/controller/pci-hyperv.c > @@ -2119,6 +2119,7 @@ static bool hv_pcie_init_dev_msi_info(struct device > *dev, struct irq_domain *dom > info->ops->msi_prepare = hv_msi_prepare; > > chip->irq_set_affinity = irq_chip_set_affinity_parent; > + chip->irq_retrigger = irq_chip_retrigger_hierarchy; [Severity: High] This isn't a bug introduced by this patch, but does the sister Hyper-V root partition MSI domain in arch/x86/hyperv/irqdomain.c also need this fix? Looking at hv_init_dev_msi_info(), it appears to be missing the exact same callback initialization for the root partition's top-level irq_chip: arch/x86/hyperv/irqdomain.c:hv_init_dev_msi_info() { ... if (!msi_lib_init_dev_msi_info(dev, domain, real_parent, info)) return false; chip->flags |= IRQCHIP_SKIP_SET_WAKE | IRQCHIP_MOVE_DEFERRED; info->ops->msi_prepare = pci_msi_prepare; return true; } If a CPU is hot-unplugged while a device MSI interrupt is pending in its local APIC IRR, could fixup_irqs() fail to resend the pending interrupt to the new target CPU because this callback is NULL? This could potentially lead to the same lost interrupts and I/O stalls described in this commit message, just in the root partition MSI domain instead of the guest paravirtual MSI domain. > > if (IS_ENABLED(CONFIG_X86)) > chip->flags |= IRQCHIP_MOVE_DEFERRED; > -- Sashiko AI review ยท https://sashiko.dev/#/patchset/[email protected]?part=1
