[PATCH] genirq/msi: Add the address and data that show MSI/MSIX

From: Hans Zhang
Date: Thu Feb 27 2025 - 11:33:27 EST


Add to view the addresses and data stored in the MSI capability or the
addresses and data stored in the MSIX vector table.

e.g.
root@root:/sys/bus/pci/devices/<dev>/msi_irqs# ls
86 87 88 89
root@root:/sys/bus/pci/devices/<dev>/msi_irqs# cat *
msix
address_hi: 0x00000000
address_lo: 0x0e060040
msg_data: 0x00000000
msix
address_hi: 0x00000000
address_lo: 0x0e060040
msg_data: 0x00000001
msix
address_hi: 0x00000000
address_lo: 0x0e060040
msg_data: 0x00000002
msix
address_hi: 0x00000000
address_lo: 0x0e060040
msg_data: 0x00000003

Signed-off-by: Hans Zhang <18255117159@xxxxxxx>
---
kernel/irq/msi.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index 396a067a8a56..a37a3e535fb8 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -503,8 +503,18 @@ static ssize_t msi_mode_show(struct device *dev, struct device_attribute *attr,
{
/* MSI vs. MSIX is per device not per interrupt */
bool is_msix = dev_is_pci(dev) ? to_pci_dev(dev)->msix_enabled : false;
+ struct msi_desc *desc;
+ u32 irq;
+
+ if (kstrtoint(attr->attr.name, 10, &irq) < 0)
+ return 0;

- return sysfs_emit(buf, "%s\n", is_msix ? "msix" : "msi");
+ desc = irq_get_msi_desc(irq);
+ return sysfs_emit(
+ buf,
+ "%s\n address_hi: 0x%08x\n address_lo: 0x%08x\n msg_data: 0x%08x\n",
+ is_msix ? "msix" : "msi", desc->msg.address_hi,
+ desc->msg.address_lo, desc->msg.data);
}

static void msi_sysfs_remove_desc(struct device *dev, struct msi_desc *desc)

base-commit: dd83757f6e686a2188997cb58b5975f744bb7786
--
2.25.1