From: Avi Kivity <avi@redhat.com>
To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
x86@kernel.org, yrl.pp-manager.tt@hitachi.com
Subject: Re: [RFC PATCH 00/18] KVM: x86: CPU isolation and direct interrupts handling by guests
Date: Thu, 28 Jun 2012 20:34:52 +0300 [thread overview]
Message-ID: <4FEC95BC.200@redhat.com> (raw)
In-Reply-To: <4FEC93BD.2070809@siemens.com>
On 06/28/2012 08:26 PM, Jan Kiszka wrote:
>>
>> This is both impressive and scary. What is the target scenario here?
>> Partitioning? I don't see this working for generic consolidation.
>>
>
> From my POV, partitioning - including hard realtime partitions - would
> provide some use cases. But, as far as I saw, there are still major
> restrictions in this approach, e.g. that you can't return to userspace
> on the slave core. Or even execute the in-kernel device models on that core.
>
> I think we need something based on the no-hz work on the long run, ie.
> the ability to run a single VCPU thread of the userland hypervisor on a
> single core with zero rescheduling and unrelated interruptions - as far
> as the guest load scenario allows this (we have some here).
What we can do perhaps is switch from direct mode to indirect mode on
exit. Instead of running with interrupts disabled, enable interrupts
and make sure they are forwarded to the guest on the next entry.
> Well, and we need proper hardware support for direct IRQ injection on x86...
Hardware support always helps, but it always seems to come after the
software support is in place and needs to be supported forever.
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2012-06-28 17:34 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-28 6:07 [RFC PATCH 00/18] KVM: x86: CPU isolation and direct interrupts handling by guests Tomoki Sekiyama
2012-06-28 6:07 ` [RFC PATCH 01/18] x86: Split memory hotplug function from cpu_up() as cpu_memory_up() Tomoki Sekiyama
2012-06-28 6:07 ` [RFC PATCH 02/18] x86: Add a facility to use offlined CPUs as slave CPUs Tomoki Sekiyama
2012-06-28 6:07 ` [RFC PATCH 03/18] x86: Support hrtimer on " Tomoki Sekiyama
2012-06-28 6:07 ` [RFC PATCH 04/18] KVM: Replace local_irq_disable/enable with local_irq_save/restore Tomoki Sekiyama
2012-06-28 6:07 ` [RFC PATCH 05/18] KVM: Enable/Disable virtualization on slave CPUs are activated/dying Tomoki Sekiyama
2012-06-28 6:07 ` [RFC PATCH 06/18] KVM: Add facility to run guests on slave CPUs Tomoki Sekiyama
2012-06-28 17:02 ` Avi Kivity
2012-06-29 9:26 ` Tomoki Sekiyama
2012-06-28 6:07 ` [RFC PATCH 07/18] KVM: handle page faults occured in slave CPUs on online CPUs Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 08/18] KVM: Add KVM_GET_SLAVE_CPU and KVM_SET_SLAVE_CPU to vCPU ioctl Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 09/18] KVM: Go back to online CPU on VM exit by external interrupt Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 10/18] KVM: proxy slab operations for slave CPUs on online CPUs Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 11/18] KVM: no exiting from guest when slave CPU halted Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 12/18] x86/apic: Enable external interrupt routing to slave CPUs Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 13/18] x86/apic: IRQ vector remapping on slave for " Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 14/18] KVM: Directly handle interrupts by guests without VM EXIT on " Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 15/18] KVM: vmx: Add definitions PIN_BASED_PREEMPTION_TIMER Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 16/18] KVM: add kvm_arch_vcpu_prevent_run to prevent VM ENTER when NMI is received Tomoki Sekiyama
2012-06-28 16:48 ` Avi Kivity
2012-06-29 9:26 ` Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 17/18] KVM: route assigned devices' MSI/MSI-X directly to guests on slave CPUs Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 18/18] x86: request TLB flush to slave CPU using NMI Tomoki Sekiyama
2012-06-28 16:38 ` Avi Kivity
2012-06-29 9:26 ` Tomoki Sekiyama
2012-06-28 16:58 ` [RFC PATCH 00/18] KVM: x86: CPU isolation and direct interrupts handling by guests Avi Kivity
2012-06-28 17:26 ` Jan Kiszka
2012-06-28 17:34 ` Avi Kivity [this message]
2012-06-29 9:25 ` Tomoki Sekiyama
2012-06-29 14:56 ` Avi Kivity
2012-07-06 10:33 ` Tomoki Sekiyama
2012-07-12 9:04 ` Avi Kivity
2012-07-04 9:33 ` Tomoki Sekiyama
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