From: Alexander Graf <agraf@suse.de>
To: Paul Mackerras <paulus@samba.org>
Cc: Linuxppc-dev <linuxppc-dev@ozlabs.org>,
KVM list <kvm@vger.kernel.org>,
kvm-ppc@vger.kernel.org
Subject: Re: [PATCH 10/13] kvm/powerpc: Add support for Book3S processors in hypervisor mode
Date: Fri, 27 May 2011 12:43:10 +0200 [thread overview]
Message-ID: <196413A8-500A-4A72-99D2-7ED7E3BBD056@suse.de> (raw)
In-Reply-To: <20110527103334.GA4236@brick.ozlabs.ibm.com>
On 27.05.2011, at 12:33, Paul Mackerras wrote:
> On Tue, May 17, 2011 at 12:17:50PM +0200, Alexander Graf wrote:
>>
>> On 16.05.2011, at 07:58, Paul Mackerras wrote:
>>
>>> I do the check there because I was having problems where, if the HDEC
>>> goes negative before we do the partition switch, we would occasionally
>>> not get the HDEC interrupt at all until the next time HDEC went
>>> negative, ~ 8.4 seconds later.
>>
>> Yikes - so HDEC is edge and doesn't even keep the interrupt line up?
>> That sounds like a serious hardware limitation. What if you only use
>> HDEC and it triggers while interrupts are off in a critical section?
>> Is the hardware really that broken?
>
> If HDEC expires when interrupts are off, the HDEC interrupt stays
> pending until interrupts get re-enabled. I'm not sure exactly what
> the conditions are that cause an HDEC interrupt to get lost, but they
> seem to involve at least a partition switch.
Please try to contact some of your hardware designers and figure out what exactly the conditions are. Maybe we don't need this hack.
Alex
WARNING: multiple messages have this Message-ID (diff)
From: Alexander Graf <agraf@suse.de>
To: Paul Mackerras <paulus@samba.org>
Cc: Linuxppc-dev <linuxppc-dev@ozlabs.org>,
kvm-ppc@vger.kernel.org, KVM list <kvm@vger.kernel.org>
Subject: Re: [PATCH 10/13] kvm/powerpc: Add support for Book3S processors in hypervisor mode
Date: Fri, 27 May 2011 12:43:10 +0200 [thread overview]
Message-ID: <196413A8-500A-4A72-99D2-7ED7E3BBD056@suse.de> (raw)
In-Reply-To: <20110527103334.GA4236@brick.ozlabs.ibm.com>
On 27.05.2011, at 12:33, Paul Mackerras wrote:
> On Tue, May 17, 2011 at 12:17:50PM +0200, Alexander Graf wrote:
>>=20
>> On 16.05.2011, at 07:58, Paul Mackerras wrote:
>>=20
>>> I do the check there because I was having problems where, if the =
HDEC
>>> goes negative before we do the partition switch, we would =
occasionally
>>> not get the HDEC interrupt at all until the next time HDEC went
>>> negative, ~ 8.4 seconds later.
>>=20
>> Yikes - so HDEC is edge and doesn't even keep the interrupt line up?
>> That sounds like a serious hardware limitation. What if you only use
>> HDEC and it triggers while interrupts are off in a critical section?
>> Is the hardware really that broken?
>=20
> If HDEC expires when interrupts are off, the HDEC interrupt stays
> pending until interrupts get re-enabled. I'm not sure exactly what
> the conditions are that cause an HDEC interrupt to get lost, but they
> seem to involve at least a partition switch.
Please try to contact some of your hardware designers and figure out =
what exactly the conditions are. Maybe we don't need this hack.
Alex
WARNING: multiple messages have this Message-ID (diff)
From: Alexander Graf <agraf@suse.de>
To: Paul Mackerras <paulus@samba.org>
Cc: Linuxppc-dev <linuxppc-dev@ozlabs.org>,
KVM list <kvm@vger.kernel.org>,
kvm-ppc@vger.kernel.org
Subject: Re: [PATCH 10/13] kvm/powerpc: Add support for Book3S processors in hypervisor mode
Date: Fri, 27 May 2011 10:43:10 +0000 [thread overview]
Message-ID: <196413A8-500A-4A72-99D2-7ED7E3BBD056@suse.de> (raw)
In-Reply-To: <20110527103334.GA4236@brick.ozlabs.ibm.com>
On 27.05.2011, at 12:33, Paul Mackerras wrote:
> On Tue, May 17, 2011 at 12:17:50PM +0200, Alexander Graf wrote:
>>
>> On 16.05.2011, at 07:58, Paul Mackerras wrote:
>>
>>> I do the check there because I was having problems where, if the HDEC
>>> goes negative before we do the partition switch, we would occasionally
>>> not get the HDEC interrupt at all until the next time HDEC went
>>> negative, ~ 8.4 seconds later.
>>
>> Yikes - so HDEC is edge and doesn't even keep the interrupt line up?
>> That sounds like a serious hardware limitation. What if you only use
>> HDEC and it triggers while interrupts are off in a critical section?
>> Is the hardware really that broken?
>
> If HDEC expires when interrupts are off, the HDEC interrupt stays
> pending until interrupts get re-enabled. I'm not sure exactly what
> the conditions are that cause an HDEC interrupt to get lost, but they
> seem to involve at least a partition switch.
Please try to contact some of your hardware designers and figure out what exactly the conditions are. Maybe we don't need this hack.
Alex
next prev parent reply other threads:[~2011-05-27 10:43 UTC|newest]
Thread overview: 103+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-11 10:34 [PATCH 0/13] Hypervisor-mode KVM on POWER7 Paul Mackerras
2011-05-11 10:36 ` [PATCH 01/13] kvm/powerpc: Move fields between struct kvm_vcpu_arch and kvmppc_vcpu_book3s Paul Mackerras
2011-05-11 10:38 ` [PATCH 02/13] kvm/powerpc: Fix kvmppc_core_pending_dec Paul Mackerras
2011-05-11 10:39 ` [PATCH 03/13] kvm/powerpc: Fix the build for 32-bit Book 3S (classic) processors Paul Mackerras
2011-05-12 9:33 ` Alexander Graf
2011-05-12 9:33 ` Alexander Graf
2011-05-12 11:15 ` Paul Mackerras
2011-05-12 11:15 ` Paul Mackerras
2011-05-12 11:16 ` Benjamin Herrenschmidt
2011-05-12 11:16 ` Benjamin Herrenschmidt
2011-05-12 11:57 ` Alexander Graf
2011-05-12 11:57 ` Alexander Graf
2011-05-11 10:40 ` [PATCH 04/13] kvm/powerpc: Split out code from book3s.c into book3s_pr.c Paul Mackerras
2011-05-11 10:41 ` [PATCH 05/13] powerpc, kvm: Rework KVM checks in first-level interrupt handlers Paul Mackerras
2011-05-11 10:42 ` [PATCH 06/13] kvm/powerpc: Deliver program interrupts right away instead of queueing them Paul Mackerras
2011-05-11 10:42 ` [PATCH 07/13] kvm/powerpc: Pass init/destroy vm and prepare/commit memory region ops down Paul Mackerras
2011-05-11 10:43 ` [PATCH 08/13] kvm/powerpc: Move guest enter/exit down into subarch-specific code Paul Mackerras
2011-05-17 18:05 ` Marcelo Tosatti
2011-05-17 18:05 ` Marcelo Tosatti
2011-05-17 18:10 ` Marcelo Tosatti
2011-05-17 18:10 ` Marcelo Tosatti
2011-05-11 10:44 ` [PATCH 09/13] powerpc: Set up LPCR for running guest partitions Paul Mackerras
2011-05-11 10:44 ` [PATCH 10/13] kvm/powerpc: Add support for Book3S processors in hypervisor mode Paul Mackerras
2011-05-12 9:07 ` Avi Kivity
2011-05-12 9:07 ` Avi Kivity
2011-05-16 1:07 ` Paul Mackerras
2011-05-16 1:07 ` Paul Mackerras
2011-05-15 21:58 ` Alexander Graf
2011-05-15 21:58 ` Alexander Graf
2011-05-15 21:58 ` Alexander Graf
2011-05-16 5:58 ` Paul Mackerras
2011-05-16 5:58 ` [PATCH 10/13] kvm/powerpc: Add support for Book3S processors in Paul Mackerras
2011-05-16 5:58 ` [PATCH 10/13] kvm/powerpc: Add support for Book3S processors in hypervisor mode Paul Mackerras
2011-05-17 10:17 ` Alexander Graf
2011-05-17 10:17 ` Alexander Graf
2011-05-17 10:17 ` Alexander Graf
2011-05-27 10:33 ` Paul Mackerras
2011-05-27 10:33 ` [PATCH 10/13] kvm/powerpc: Add support for Book3S processors in Paul Mackerras
2011-05-27 10:33 ` [PATCH 10/13] kvm/powerpc: Add support for Book3S processors in hypervisor mode Paul Mackerras
2011-05-27 10:43 ` Alexander Graf [this message]
2011-05-27 10:43 ` Alexander Graf
2011-05-27 10:43 ` Alexander Graf
2011-05-27 20:59 ` Segher Boessenkool
2011-05-27 20:59 ` Segher Boessenkool
2011-05-27 20:59 ` Segher Boessenkool
2011-05-27 23:19 ` Alexander Graf
2011-05-27 23:19 ` Alexander Graf
2011-05-27 23:19 ` Alexander Graf
2011-05-28 1:07 ` Segher Boessenkool
2011-05-28 1:07 ` Segher Boessenkool
2011-05-28 1:07 ` Segher Boessenkool
2011-05-31 20:26 ` Jimi Xenidis
2011-05-31 20:26 ` Jimi Xenidis
2011-05-31 20:26 ` Jimi Xenidis
2011-05-31 22:34 ` Segher Boessenkool
2011-05-31 22:34 ` Segher Boessenkool
2011-05-31 22:34 ` Segher Boessenkool
2011-06-01 5:11 ` Paul Mackerras
2011-06-01 5:11 ` [PATCH 10/13] kvm/powerpc: Add support for Book3S processors in Paul Mackerras
2011-06-01 5:11 ` [PATCH 10/13] kvm/powerpc: Add support for Book3S processors in hypervisor mode Paul Mackerras
2011-05-11 10:45 ` [PATCH 11/13] kvm/powerpc: Handle some PAPR hcalls in the kernel Paul Mackerras
2011-05-17 7:54 ` Alexander Graf
2011-05-17 7:54 ` Alexander Graf
2011-05-17 10:28 ` Paul Mackerras
2011-05-11 10:46 ` [PATCH 12/13] kvm/powerpc: Accelerate H_PUT_TCE by implementing it in real mode Paul Mackerras
2011-05-17 8:01 ` Alexander Graf
2011-05-17 8:01 ` Alexander Graf
2011-05-17 9:11 ` Benjamin Herrenschmidt
2011-05-17 9:11 ` Benjamin Herrenschmidt
2011-05-17 9:31 ` Alexander Graf
2011-05-17 9:31 ` Alexander Graf
2011-05-17 9:35 ` Benjamin Herrenschmidt
2011-05-17 9:35 ` Benjamin Herrenschmidt
2011-05-17 9:39 ` Alexander Graf
2011-05-17 9:39 ` Alexander Graf
2011-05-11 10:46 ` [PATCH 13/13] kvm/powerpc: Allow book3s_hv guests to use SMT processor modes Paul Mackerras
2011-05-11 13:44 ` Christoph Hellwig
2011-05-11 21:17 ` Paul Mackerras
2011-05-11 21:17 ` Paul Mackerras
2011-05-17 8:21 ` Alexander Graf
2011-05-17 8:21 ` Alexander Graf
2011-05-17 10:44 ` Paul Mackerras
2011-05-17 11:36 ` Alexander Graf
2011-05-17 11:36 ` Alexander Graf
2011-05-19 6:06 ` Paul Mackerras
2011-05-17 9:46 ` [PATCH 0/13] Hypervisor-mode KVM on POWER7 Alexander Graf
2011-05-17 9:46 ` Alexander Graf
2011-05-17 11:15 ` Paul Mackerras
2011-05-17 11:38 ` Alexander Graf
2011-05-17 11:38 ` Alexander Graf
2011-05-17 11:42 ` Avi Kivity
2011-05-17 11:42 ` Avi Kivity
2011-05-19 5:22 ` Paul Mackerras
2011-05-19 5:22 ` Paul Mackerras
2011-05-19 6:01 ` Alexander Graf
2011-05-19 6:01 ` Alexander Graf
2011-05-19 6:01 ` Alexander Graf
2011-05-21 16:41 ` Alexander Graf
2011-05-21 16:41 ` Alexander Graf
2011-05-21 17:00 ` Alexander Graf
2011-05-21 17:00 ` Alexander Graf
2011-05-21 18:15 ` Alexander Graf
2011-05-21 18:15 ` Alexander Graf
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