This is a note to let you know that I've just added the patch titled x86/pci/xen: Fix PCIBIOS_* return code handling to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86-pci-xen-fix-pcibios_-return-code-handling.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit e5647a225f9a7cbde21deef103da8d91667911f1 Author: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> Date: Mon May 27 15:55:37 2024 +0300 x86/pci/xen: Fix PCIBIOS_* return code handling [ Upstream commit e9d7b435dfaec58432f4106aaa632bf39f52ce9f ] xen_pcifront_enable_irq() uses pci_read_config_byte() that returns PCIBIOS_* codes. The error handling, however, assumes the codes are normal errnos because it checks for < 0. xen_pcifront_enable_irq() also returns the PCIBIOS_* code back to the caller but the function is used as the (*pcibios_enable_irq) function which should return normal errnos. Convert the error check to plain non-zero check which works for PCIBIOS_* return codes and convert the PCIBIOS_* return code using pcibios_err_to_errno() into normal errno before returning it. Fixes: 3f2a230caf21 ("xen: handled remapped IRQs when enabling a pcifront PCI device.") Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx> Reviewed-by: Juergen Gross <jgross@xxxxxxxx> Link: https://lore.kernel.org/r/20240527125538.13620-3-ilpo.jarvinen@xxxxxxxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c index 9cf8f5417e7f4..f93e03b236457 100644 --- a/arch/x86/pci/xen.c +++ b/arch/x86/pci/xen.c @@ -37,10 +37,10 @@ static int xen_pcifront_enable_irq(struct pci_dev *dev) u8 gsi; rc = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi); - if (rc < 0) { + if (rc) { dev_warn(&dev->dev, "Xen PCI: failed to read interrupt line: %d\n", rc); - return rc; + return pcibios_err_to_errno(rc); } /* In PV DomU the Xen PCI backend puts the PIRQ in the interrupt line.*/ pirq = gsi;