> -----Original Message----- > From: H. Peter Anvin [mailto:hpa@xxxxxxxxxxxxxxx] > Sent: Friday, April 11, 2014 10:39 AM > To: Linus Torvalds > Cc: stable@xxxxxxxxxxxxxxx; H. Peter Anvin; H. Peter Anvin; Ingo Molnar; KY > Srinivasan; Linux Kernel Mailing List; Thomas Gleixner > Subject: [GIT PULL] x86/hyperv fix for v3.15-rc1 > > Hi Linus, > > A single fix for HyperV -- we never NEED the legacy PIC on HyperV, and in > kexec/kdump scenarios we don't always know that we originally booted EFI. > The right answer is probably to augment the legacy PIC initialization code to > detect a not-present PIC, but that is way too high risk for right now. > > The following changes since commit > ca3ba2a2f4a49a308e7d78c784d51b2332064f15: > > x86, hyperv: Bypass the timer_irq_works() check (2014-03-27 11:02:45 - > 0700) > > are available in the git repository at: > > git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-hyperv-for- > linus > > for you to fetch changes up to 8df28b82ff0649dd293f0469b97792cfb9ed10ab: > > x86, hyperv: When on Hyper-v use NULL legacy PIC (2014-04-03 22:00:13 - > 0700) Peter, It may be better not to include the patch titled: x86, hyperv: When on Hyper-v use NULL legacy PIC (2014-04-03 22:00:13 - 0700) Without this patch, kexec will not work on Hyper-V efi firmware and that is the way it has been. While I tested this patch on both legacy and EFI firmware on Hyper-V, Olaf is reporting that on the configurations he is building, this patch causes problems on Hyper-V legacy firmware. I am currently working on the idea you have had - using NULL legacy PIC only when PIC is not there. Regards, K. Y > > ---------------------------------------------------------------- > K. Y. Srinivasan (1): > x86, hyperv: When on Hyper-v use NULL legacy PIC > > arch/x86/kernel/cpu/mshyperv.c | 10 ++-------- > 1 file changed, 2 insertions(+), 8 deletions(-) > > diff --git a/arch/x86/kernel/cpu/mshyperv.c > b/arch/x86/kernel/cpu/mshyperv.c index 832d05a914ba..b7d82c7e1257 > 100644 > --- a/arch/x86/kernel/cpu/mshyperv.c > +++ b/arch/x86/kernel/cpu/mshyperv.c > @@ -93,14 +93,8 @@ static void __init ms_hyperv_init_platform(void) > printk(KERN_INFO "HyperV: LAPIC Timer Frequency: %#x\n", > lapic_timer_frequency); > > - /* > - * 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; > } > #endif > -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html