Commit 2f285f46 authored Sep 18, 2018 by Dexuan Cui Committed by Thomas Gleixner Sep 27, 2018

x86/hyperv: Suppress "PCI: Fatal: No config space access function found"



A Generation-2 Linux VM on Hyper-V doesn't have the legacy PCI bus, and
users always see the scary warning, which is actually harmless.

Suppress it.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: KY Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: "devel@linuxdriverproject.org" <devel@linuxdriverproject.org>
Cc: Olaf Aepfle <olaf@aepfle.de>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Marcelo Cerri <marcelo.cerri@canonical.com>
Cc: Josh Poulson <jopoulso@microsoft.com>
Link: https://lkml.kernel.org/r/ <KU1P153MB0166D977DC930996C4BF538ABF1D0@KU1P153MB0166.APCP153.PROD.OUTLOOK.COM

parent c307aaf3

arch/x86/hyperv/hv_init.c

+19 −0

Original line number	Diff line number	Diff line
		@@ -17,6 +17,7 @@
		*
		*/

		#include <linux/efi.h>
		#include <linux/types.h>
		#include <asm/apic.h>
		#include <asm/desc.h>
		@@ -253,6 +254,22 @@ static int hv_cpu_die(unsigned int cpu)
		return 0;
		}

		static int __init hv_pci_init(void)
		{
		int gen2vm = efi_enabled(EFI_BOOT);

		/*
		* For Generation-2 VM, we exit from pci_arch_init() by returning 0.
		* The purpose is to suppress the harmless warning:
		* "PCI: Fatal: No config space access function found"
		*/
		if (gen2vm)
		return 0;

		/* For Generation-1 VM, we'll proceed in pci_arch_init(). */
		return 1;
		}

		/*
		* This function is to be invoked early in the boot sequence after the
		* hypervisor has been detected.
		@@ -329,6 +346,8 @@ void __init hyperv_init(void)

		hv_apic_init();

		x86_init.pci.arch_init = hv_pci_init;

		/*
		* Register Hyper-V specific clocksource.
		*/