From: "K. Y. Srinivasan" <kys@microsoft.com>
To: x86@kernel.org, gregkh@linuxfoundation.org,
linux-kernel@vger.kernel.org, devel@linuxdriverproject.org,
olaf@aepfle.de, apw@canonical.com, jasowang@redhat.com,
tglx@linutronix.de, hpa@zytor.com, JBeulich@suse.com,
bp@alien8.de
Cc: Olaf Hering <"[mailto:olaf@aepfle.de]"@linuxonhyperv.com>,
"K. Y. Srinivasan" <kys@microsoft.com>,
stable@kernel.org
Subject: [PATCH 1/3] x86: Hyper-V: register clocksource only if its advertised
Date: Sun, 3 Feb 2013 17:22:37 -0800 [thread overview]
Message-ID: <1359940959-32168-1-git-send-email-kys@microsoft.com> (raw)
In-Reply-To: <1359940910-32114-1-git-send-email-kys@microsoft.com>
From: Olaf Hering <[mailto:olaf@aepfle.de]>
Enable hyperv_clocksource only if its advertised as a feature.
XenServer 6 returns the signature which is checked in
ms_hyperv_platform(), but it does not offer all features. Currently the
clocksource is enabled unconditionally in ms_hyperv_init_platform(), and
the result is a hanging guest.
Hyper-V spec Bit 1 indicates the availability of Partition Reference
Counter. Register the clocksource only if this bit is set.
The guest in question prints this in dmesg:
[ 0.000000] Hypervisor detected: Microsoft HyperV
[ 0.000000] HyperV: features 0x70, hints 0x0
This bug can be reproduced easily be setting 'viridian=1' in a HVM domU
.cfg file. A workaround without this patch is to boot the HVM guest with
'clocksource=jiffies'.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: stable@kernel.org
Cc: Greg KH <gregkh@linuxfoundation.org>
---
arch/x86/kernel/cpu/mshyperv.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 0a630dd..646d192 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -68,7 +68,8 @@ static void __init ms_hyperv_init_platform(void)
printk(KERN_INFO "HyperV: features 0x%x, hints 0x%x\n",
ms_hyperv.features, ms_hyperv.hints);
- clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100);
+ if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE)
+ clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100);
}
const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
--
1.7.4.1
next prev parent reply other threads:[~2013-02-04 0:55 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-04 1:21 [PATCH 0/3] X86: Deliver Hyper-V interrupts on a seperate IDT vector K. Y. Srinivasan
2013-02-04 1:22 ` K. Y. Srinivasan [this message]
2013-02-04 1:22 ` [PATCH 2/3] X86: Add a check to catch Xen emulation of Hyper-V K. Y. Srinivasan
2013-02-13 0:57 ` [tip:x86/hyperv] " tip-bot for K. Y. Srinivasan
2013-04-17 7:06 ` [PATCH 2/3] " Michael S. Tsirkin
2013-04-17 9:10 ` KVM "Hyper-V emulation" -- this can be related "Linux on Hyper-V" ? Or "KVM emulates Hyper-V" as "Hyper-V emulates Hyper-V" ? " Victor Miasnikov
2013-04-17 10:16 ` Michael S. Tsirkin
2013-04-17 12:12 ` Jan Beulich
2013-04-17 12:15 ` Michael S. Tsirkin
[not found] ` <CAP2xkNqGgbYz1gdS85xjA8gwROGY89fAsiaRiGSE90xnzjJ4Xw@mail.gmail.com>
2013-04-17 12:43 ` Michael S. Tsirkin
2013-04-17 14:08 ` Victor Miasnikov
2013-04-17 13:20 ` KY Srinivasan
2013-04-17 12:48 ` Michael S. Tsirkin
2013-04-17 14:12 ` KY Srinivasan
2013-04-17 13:25 ` Michael S. Tsirkin
2013-04-17 14:34 ` KY Srinivasan
2013-04-17 13:48 ` Michael S. Tsirkin
2013-04-17 15:31 ` KY Srinivasan
2013-04-17 15:50 ` Jan Beulich
2013-04-17 16:28 ` KY Srinivasan
2013-04-18 7:48 ` Michael S. Tsirkin
2013-04-18 13:23 ` KY Srinivasan
2013-04-18 13:30 ` KY Srinivasan
2013-04-17 13:52 ` Jan Beulich
2013-04-17 13:01 ` Michael S. Tsirkin
2013-04-17 13:11 ` Michael S. Tsirkin
2013-04-17 14:09 ` Jan Beulich
2013-04-17 15:17 ` H. Peter Anvin
2013-02-04 1:22 ` [PATCH 3/3] X86: Handle Hyper-V vmbus interrupts as special hypervisor interrupts K. Y. Srinivasan
2013-02-13 0:58 ` [tip:x86/hyperv] " tip-bot for K. Y. Srinivasan
2013-02-13 1:58 ` [tip:x86/hyperv] x86, hyperv: HYPERV depends on X86_LOCAL_APIC tip-bot for H. Peter Anvin
2013-02-13 2:05 ` KY Srinivasan
2013-02-13 2:56 ` [tip:x86/hyperv] X86: Handle Hyper-V vmbus interrupts as special hypervisor interrupts Yinghai Lu
2013-02-13 3:32 ` KY Srinivasan
2013-02-13 3:46 ` H. Peter Anvin
2013-02-13 3:49 ` KY Srinivasan
2013-02-13 3:54 ` H. Peter Anvin
2013-02-13 3:58 ` KY Srinivasan
2013-02-13 4:42 ` Yinghai Lu
2013-02-13 12:47 ` KY Srinivasan
2013-02-13 0:56 ` [tip:x86/hyperv] x86: Hyper-V: register clocksource only if its advertised tip-bot for Olaf Hering
2013-02-05 11:16 ` [PATCH 0/3] X86: Deliver Hyper-V interrupts on a seperate IDT vector KY Srinivasan
-- strict thread matches above, loose matches on Subject: below --
2013-01-30 0:51 K. Y. Srinivasan
2013-01-30 0:51 ` [PATCH 1/3] x86: Hyper-V: register clocksource only if its advertised K. Y. Srinivasan
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