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* [PATCH AUTOSEL 4.14 085/109] x86/hyperv: Suppress "PCI: Fatal: No config space access function found"
       [not found] <20191110024541.31567-1-sashal@kernel.org>
@ 2019-11-10  2:45 ` Sasha Levin
  0 siblings, 0 replies; only message in thread
From: Sasha Levin @ 2019-11-10  2:45 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: Dexuan Cui, Thomas Gleixner, Michael Kelley, H. Peter Anvin,
	KY Srinivasan, Haiyang Zhang, Stephen Hemminger, devel,
	Olaf Aepfle, Andy Whitcroft, Jason Wang, Vitaly Kuznetsov,
	Marcelo Cerri, Josh Poulson, Sasha Levin, linux-hyperv

From: Dexuan Cui <decui@microsoft.com>

[ Upstream commit 2f285f46240d67060061d153786740d4df53cd78 ]

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
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/x86/hyperv/hv_init.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 2e9d58cc371e6..2653b7b25d176 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -17,6 +17,7 @@
  *
  */
 
+#include <linux/efi.h>
 #include <linux/types.h>
 #include <asm/hypervisor.h>
 #include <asm/hyperv.h>
@@ -101,6 +102,22 @@ static int hv_cpu_init(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.
@@ -154,6 +171,8 @@ void hyperv_init(void)
 
 	hyper_alloc_mmu();
 
+	x86_init.pci.arch_init = hv_pci_init;
+
 	/*
 	 * Register Hyper-V specific clocksource.
 	 */
-- 
2.20.1


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2019-11-10  2:45 ` [PATCH AUTOSEL 4.14 085/109] x86/hyperv: Suppress "PCI: Fatal: No config space access function found" Sasha Levin

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