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From: Gleb Natapov <gleb@redhat.com>
To: "Zhang, Yang Z" <yang.z.zhang@intel.com>
Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org>
Subject: Re: [PATCH v3 1/4] x86: PIT connects to pin 2 of IOAPIC
Date: Tue, 4 Dec 2012 14:55:22 +0200	[thread overview]
Message-ID: <20121204125522.GI19514@redhat.com> (raw)
In-Reply-To: <A9667DDFB95DB7438FA9D7D576C3D87E2D26ED@SHSMSX101.ccr.corp.intel.com>

On Tue, Dec 04, 2012 at 05:32:31AM +0000, Zhang, Yang Z wrote:
> Gleb Natapov wrote on 2012-12-03:
> > On Mon, Dec 03, 2012 at 03:01:01PM +0800, Yang Zhang wrote:
> >> When PIT connects to IOAPIC, it route to pin 2 not pin 0.
> >> 
> > This hack didn't work for a long time and nobody complained. It
> > should be safe to get rid of it.
> This hack is used to work around an issue about RHEL4. Not sure whether anyone still uses RHEL4.
> 
Yes, I traced it back to 8c35f237, but the hack is broken for a long time
(~3 years?) and nobody complained. It is broken in rhel6 too and rhel4
is tested as a guest there, may be the problem was solved in rhel4. I
think we can remove it now. If problem re-appear, at least we will know
which guest exactly actually needs it.


> >> Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
> >> ---
> >>  virt/kvm/ioapic.c |    2 +-
> >>  1 files changed, 1 insertions(+), 1 deletions(-)
> >> diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c index
> >> cfb7e4d..166c450 100644 --- a/virt/kvm/ioapic.c +++ b/virt/kvm/ioapic.c
> >> @@ -181,7 +181,7 @@ static int ioapic_deliver(struct kvm_ioapic
> >> *ioapic, int irq)
> >> 
> >>  #ifdef CONFIG_X86
> >>  	/* Always delivery PIT interrupt to vcpu 0 */
> >> -	if (irq == 0) {
> >> +	if (irq == 2) {
> >>  		irqe.dest_mode = 0; /* Physical mode. */
> >>  		/* need to read apic_id from apic regiest since
> >>  		 * it can be rewritten */
> >> --
> >> 1.7.1
> > 
> > --
> > 			Gleb.
> 
> 
> Best regards,
> Yang
> 

--
			Gleb.

  reply	other threads:[~2012-12-04 12:55 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-12-03  7:01 [PATCH v3 0/4] x86, apicv: Add APIC virtualization support Yang Zhang
2012-12-03  7:01 ` [PATCH v3 1/4] x86: PIT connects to pin 2 of IOAPIC Yang Zhang
2012-12-03  9:42   ` Gleb Natapov
2012-12-04  5:32     ` Zhang, Yang Z
2012-12-04 12:55       ` Gleb Natapov [this message]
2012-12-05  1:28         ` Zhang, Yang Z
2012-12-03  7:01 ` [PATCH v3 2/4] x86, apicv: add APICv register virtualization support Yang Zhang
2012-12-05  0:29   ` Marcelo Tosatti
2012-12-05  3:17     ` Zhang, Yang Z
2012-12-05 23:11       ` Marcelo Tosatti
2012-12-06  6:45         ` Gleb Natapov
2012-12-03  7:01 ` [PATCH v3 3/4] x86, apicv: add virtual interrupt delivery support Yang Zhang
2012-12-03 11:37   ` Gleb Natapov
2012-12-04  6:39     ` Zhang, Yang Z
2012-12-04 10:58       ` Gleb Natapov
2012-12-05  1:55         ` Zhang, Yang Z
2012-12-05  5:02           ` Gleb Natapov
2012-12-05  6:02             ` Zhang, Yang Z
2012-12-05 10:18               ` Gleb Natapov
2012-12-05 13:51                 ` Zhang, Yang Z
2012-12-05 14:00                   ` Gleb Natapov
2012-12-06  2:55                     ` Zhang, Yang Z
2012-12-06  7:07                       ` Gleb Natapov
2012-12-06  7:16                         ` Zhang, Yang Z
2012-12-06  7:19                           ` Gleb Natapov
2012-12-06  7:20                             ` Zhang, Yang Z
2012-12-04 16:46   ` Michael S. Tsirkin
2012-12-05  2:00   ` Marcelo Tosatti
2012-12-05  3:43     ` Zhang, Yang Z
2012-12-05 11:14       ` Gleb Natapov
2012-12-05 14:16         ` Zhang, Yang Z
2012-12-05 14:34           ` Gleb Natapov
2012-12-06  2:58             ` Zhang, Yang Z
2012-12-05 22:38         ` Marcelo Tosatti
2012-12-06  9:28           ` Gleb Natapov
2012-12-06 11:35             ` Zhang, Yang Z
2012-12-05 22:31   ` Marcelo Tosatti
2012-12-06  3:31     ` Zhang, Yang Z
2012-12-06  5:02     ` Zhang, Yang Z
2012-12-06  6:36       ` Gleb Natapov
2012-12-06  6:56         ` Zhang, Yang Z
2012-12-06 20:08         ` Marcelo Tosatti
2012-12-07  1:00           ` Zhang, Yang Z
2012-12-07  7:28             ` Gleb Natapov
2012-12-03  7:01 ` [PATCH v3 4/4] x86, apicv: add virtual x2apic support Yang Zhang

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