Re: [PATCH 14/16] PCI: hv: Switch to msi_create_parent_irq_domain()

[Nam Cao <namcao@linutronix.de>]

On Fri, Jul 04, 2025 at 02:27:01AM +0000, Michael Kelley wrote:
> I haven't resolved the conflict. As a shortcut for testing I just
> removed the conflicting patch since it is for a Microsoft custom NIC
> ("MANA") that's not in the configuration I'm testing with. I'll have to
> look more closely to figure out the resolution.
> 
> Separately, this patch (the switch to misc_create_parent_irq_domain)
> isn't working for Linux VMs on Hyper-V on ARM64. The initial symptom
> is that interrupts from the NVMe controller aren't getting handled
> and everything hangs. Here's the dmesg output:
> 
> [   84.463419] hv_vmbus: registering driver hv_pci
> [   84.463875] hv_pci abee639e-0b9d-49b7-9a07-c54ba8cd5734: PCI VMBus probing: Using version 0x10004
> [   84.464518] hv_pci abee639e-0b9d-49b7-9a07-c54ba8cd5734: PCI host bridge to bus 0b9d:00
> [   84.464529] pci_bus 0b9d:00: root bus resource [mem 0xfc0000000-0xfc00fffff window]
> [   84.464531] pci_bus 0b9d:00: No busn resource found for root bus, will use [bus 00-ff]
> [   84.465211] pci 0b9d:00:00.0: [1414:b111] type 00 class 0x010802 PCIe Endpoint
> [   84.466657] pci 0b9d:00:00.0: BAR 0 [mem 0xfc0000000-0xfc00fffff 64bit]
> [   84.481923] pci_bus 0b9d:00: busn_res: [bus 00-ff] end is updated to 00
> [   84.481936] pci 0b9d:00:00.0: BAR 0 [mem 0xfc0000000-0xfc00fffff 64bit]: assigned
> [   84.482413] nvme nvme0: pci function 0b9d:00:00.0
> [   84.482513] nvme 0b9d:00:00.0: enabling device (0000 -> 0002)
> [   84.556871] irq 17, desc: 00000000e8529819, depth: 0, count: 0, unhandled: 0
> [   84.556883] ->handle_irq():  0000000062fa78bc, handle_bad_irq+0x0/0x270
> [   84.556892] ->irq_data.chip(): 00000000ba07832f, 0xffff00011469dc30
> [   84.556895] ->action(): 0000000069f160b3
> [   84.556896] ->action->handler(): 00000000e15d8191, nvme_irq+0x0/0x3e8
> [  172.307920] watchdog: BUG: soft lockup - CPU#6 stuck for 26s! [kworker/6:1H:195]

Thanks for the report.

On arm64, this driver relies on the parent irq domain to set handler. So
the driver must not overwrite it to NULL.

This should cures it:

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index 3a24fadddb83..f4a435b0456c 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -577,8 +577,6 @@ static void hv_pci_onchannelcallback(void *context);
 
 #ifdef CONFIG_X86
 #define DELIVERY_MODE	APIC_DELIVERY_MODE_FIXED
-#define FLOW_HANDLER	handle_edge_irq
-#define FLOW_NAME	"edge"
 
 static int hv_pci_irqchip_init(void)
 {
@@ -723,8 +721,6 @@ static void hv_arch_irq_unmask(struct irq_data *data)
 #define HV_PCI_MSI_SPI_START	64
 #define HV_PCI_MSI_SPI_NR	(1020 - HV_PCI_MSI_SPI_START)
 #define DELIVERY_MODE		0
-#define FLOW_HANDLER		NULL
-#define FLOW_NAME		NULL
 #define hv_msi_prepare		NULL
 
 struct hv_pci_chip_data {
@@ -2162,8 +2158,9 @@ static int hv_pcie_domain_alloc(struct irq_domain *d, unsigned int virq, unsigne
 		return ret;
 
 	for (int i = 0; i < nr_irqs; i++) {
-		irq_domain_set_info(d, virq + i, 0, &hv_msi_irq_chip, NULL, FLOW_HANDLER, NULL,
-				    FLOW_NAME);
+		irq_domain_set_hwirq_and_chip(d, virq + i, 0, &hv_msi_irq_chip, NULL);
+		if (IS_ENABLED(CONFIG_X86))
+			__irq_set_handler(virq + i, handle_edge_irq, 0, "edge");
 	}
 
 	return 0;