Re: [PATCH v5] enable x2APIC without interrupt remapping under KVM

2009-07-04 Thread Avi Kivity
On 07/05/2009 03:22 AM, Eric W. Biederman wrote: Gleb Natapov writes: Therefore I don't see the point of supporting one without the other. x2apic provide us with other benefits as commit message explains, and doesn't add any problems that we don't have now already. If this

Re: [PATCH v5] enable x2APIC without interrupt remapping under KVM

2009-07-04 Thread Eric W. Biederman
Gleb Natapov writes: >> Therefore I don't see the point of supporting one without the other. > x2apic provide us with other benefits as commit message explains, and > doesn't add any problems that we don't have now already. If this code has a legitimate place on real hardware I am all for it. I

Re: [PATCH v5] enable x2APIC without interrupt remapping under KVM

2009-07-04 Thread Gleb Natapov
On Sat, Jul 04, 2009 at 07:33:39AM -0700, Eric W. Biederman wrote: > Gleb Natapov writes: > > > On Sat, Jul 04, 2009 at 02:35:30AM -0700, Eric W. Biederman wrote: > >> Ingo Molnar writes: > >> > >> > * Suresh Siddha wrote: > >> > > >> >> On Wed, 2009-07-01 at 06:30 -0700, Gleb Natapov wrote: >

Re: [PATCH v5] enable x2APIC without interrupt remapping under KVM

2009-07-04 Thread Avi Kivity
On 07/03/2009 11:29 AM, Ingo Molnar wrote: Now, since this affects core x86 APIC code non-trivially so should submitted to and go via the x86 tree. (Can prepare a special branch with just this change if KVM tree wants/needs to pull it before v2.6.32.) The kvm tree won't depend on this chang

Re: [PATCH v5] enable x2APIC without interrupt remapping under KVM

2009-07-04 Thread Eric W. Biederman
Gleb Natapov writes: > On Sat, Jul 04, 2009 at 02:35:30AM -0700, Eric W. Biederman wrote: >> Ingo Molnar writes: >> >> > * Suresh Siddha wrote: >> > >> >> On Wed, 2009-07-01 at 06:30 -0700, Gleb Natapov wrote: >> >> > KVM would like to provide x2APIC interface to a guest without emulating >> >

Re: [PATCH v5] enable x2APIC without interrupt remapping under KVM

2009-07-04 Thread Gleb Natapov
On Sat, Jul 04, 2009 at 02:35:30AM -0700, Eric W. Biederman wrote: > Ingo Molnar writes: > > > * Suresh Siddha wrote: > > > >> On Wed, 2009-07-01 at 06:30 -0700, Gleb Natapov wrote: > >> > KVM would like to provide x2APIC interface to a guest without emulating > >> > interrupt remapping device.

Re: [PATCH v5] enable x2APIC without interrupt remapping under KVM

2009-07-04 Thread Eric W. Biederman
Ingo Molnar writes: > * Suresh Siddha wrote: > >> On Wed, 2009-07-01 at 06:30 -0700, Gleb Natapov wrote: >> > KVM would like to provide x2APIC interface to a guest without emulating >> > interrupt remapping device. The reason KVM prefers guest to use x2APIC >> > is that x2APIC interface is bette

Re: [PATCH v5] enable x2APIC without interrupt remapping under KVM

2009-07-03 Thread Ingo Molnar
* Suresh Siddha wrote: > On Wed, 2009-07-01 at 06:30 -0700, Gleb Natapov wrote: > > KVM would like to provide x2APIC interface to a guest without emulating > > interrupt remapping device. The reason KVM prefers guest to use x2APIC > > is that x2APIC interface is better virtualizable and provides

Re: [PATCH v5] enable x2APIC without interrupt remapping under KVM

2009-07-01 Thread Suresh Siddha
On Wed, 2009-07-01 at 06:30 -0700, Gleb Natapov wrote: > KVM would like to provide x2APIC interface to a guest without emulating > interrupt remapping device. The reason KVM prefers guest to use x2APIC > is that x2APIC interface is better virtualizable and provides better > performance than mmio xA

[PATCH v5] enable x2APIC without interrupt remapping under KVM

2009-07-01 Thread Gleb Natapov
KVM would like to provide x2APIC interface to a guest without emulating interrupt remapping device. The reason KVM prefers guest to use x2APIC is that x2APIC interface is better virtualizable and provides better performance than mmio xAPIC interface: - msr exits are faster than mmio (no page t