From: ebiederm@xmission.com (Eric W. Biederman)
To: Gleb Natapov <gleb@redhat.com>
Cc: "linux-kernel\@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Suresh Siddha <suresh.b.siddha@intel.com>,
Sheng Yang <sheng@linux.intel.com>,
"kvm\@vger.kernel.org" <kvm@vger.kernel.org>,
"avi\@redhat.com" <avi@redhat.com>
Subject: Re: [PATCH v3] enable x2APIC without interrupt remapping under KVM
Date: Tue, 30 Jun 2009 12:43:47 -0700 [thread overview]
Message-ID: <m17hyt1p8s.fsf@fess.ebiederm.org> (raw)
In-Reply-To: <20090630190307.GE8122@redhat.com> (Gleb Natapov's message of "Tue\, 30 Jun 2009 22\:03\:07 +0300")
Gleb Natapov <gleb@redhat.com> writes:
> Considering that interrupt remapping is fairly new feature
> are you saying that hotplug (pci and cpu) on x86 is a horrible
> hack on Linux?
Just the current cpu hotplug path.
>> It is better than nothing but it certainly is not something
>> I would expect to work all of the time.
>>
> Because of horrible code or non-complaint ioapic implementation out
> there? If later this is not a big issue for KVM.
Both. And even in spec ioapics can't be made to work 100% reliably.
>> Interrupt remapping is the one case where we have hardware
>> that works according to spec and that works reasonably well.
>>
> I am sure when there was only one ioapic implementation in existence
> it worked according to a spec (and if not spec was changed :)) Give
> interrupt remapping some time and than we will see how above statement
> holds.
What we need for cpu hotplug/unplug is on the tested path now.
That is a significant difference.
Eric
prev parent reply other threads:[~2009-06-30 19:43 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-29 13:29 [PATCH v3] enable x2APIC without interrupt remapping under KVM Gleb Natapov
2009-06-29 14:58 ` Suresh Siddha
2009-06-29 15:10 ` Gleb Natapov
2009-06-29 15:15 ` Suresh Siddha
2009-06-29 15:45 ` Gleb Natapov
2009-06-30 9:24 ` Eric W. Biederman
2009-06-30 9:26 ` Gleb Natapov
2009-06-30 16:44 ` Eric W. Biederman
2009-06-30 17:12 ` Avi Kivity
2009-06-30 19:08 ` Eric W. Biederman
2009-06-30 19:16 ` Avi Kivity
2009-06-30 19:36 ` Eric W. Biederman
2009-07-01 8:30 ` Avi Kivity
2009-07-01 13:31 ` Eric W. Biederman
2009-07-01 22:53 ` Suresh Siddha
2009-07-02 0:17 ` Eric W. Biederman
2009-07-07 16:14 ` Suresh Siddha
2009-07-10 20:29 ` Eric W. Biederman
2009-06-30 19:03 ` Gleb Natapov
2009-06-30 19:43 ` Eric W. Biederman [this message]
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