[PATCH 1/1] x86/platform/hyperv: When on Hyper-v use NULL legacy PIC

From: K. Y. Srinivasan
Date: Thu Apr 03 2014 - 20:22:41 EST

Use the NULL legacy PIC when on Hyper-V. With this change we can support kexec
even when booting on EFI firmware. This patch has been tested on both EFI as
well as non-EFI firmware stacks on Hyper-V.

This patch is required to support kexec on EFI firmware on Hyper-V. Please

Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> [3.13+]
arch/x86/kernel/cpu/mshyperv.c | 10 ++--------
1 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 76f98fe..47359f7 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -133,14 +133,8 @@ static void __init ms_hyperv_init_platform(void)
printk(KERN_INFO "HyperV: LAPIC Timer Frequency: %#x\n",

- /*
- * On Hyper-V, when we are booting off an EFI firmware stack,
- * we do not have many legacy devices including PIC, PIT etc.
- */
- if (efi_enabled(EFI_BOOT)) {
- printk(KERN_INFO "HyperV: Using null_legacy_pic\n");
- legacy_pic = &null_legacy_pic;
- }
+ printk(KERN_INFO "HyperV: Using null_legacy_pic\n");
+ legacy_pic = &null_legacy_pic;


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