public inbox for linux-arm-kernel@lists.infradead.org 
 help / color / mirror / Atom feed
* [Query] Does Linux & Qemu support KVM for ARM32 guest on ARM64 host
       [not found] <BE.E9.04928.D4C61275@epcpsbgx1.samsung.com>
@ 2016-04-28  2:33 ` Shannon Zhao
  0 siblings, 0 replies; 2+ messages in thread
From: Shannon Zhao @ 2016-04-28  2:33 UTC (permalink / raw)
  To: linux-arm-kernel



On 2016/4/28 9:50, RAVINDRA KUMAR SANDE wrote:
> 
> What I did  :
> 1) Just for investigation, I took a ARMv8 ( OdroidC2 ) board
> 2)  I compiled Linux 3.14 with KVM support for this ARMv8 ( OdroidC2 )
> board, with modification replacing meson_timer by arm timer in its dts
> file.
> Why Linux 3.14 : I took Linux 3.14 because display drivers for this
> board are officially for this version; and I am interested in seeing
> some Linux guest booting with display on.
> 3)  I see from boot log of  that KVM is initialized successfully, and I
> can see /dev/kvm node.
> 4) I built latest Qemu with --enable-kvm on this board natively.
> 
> What I find :
> 1) running "qemu-system-arm  -enable-kvm   -machine vexpress-a9 ...."
> gives error :  no accelerator found
> 2) running "qemu-system-aarch64 -enable-kvm  -machine vexpress-a9 ...."
> gives error : kmv_init_vcpu (IOCtl on /dev/kvm) failed, guest not supported
> ( I experimented some modifications as well to overcome above error,
> such as replacing value assigned to cpu->kvm_target etc, but IOCtl call
> is failing)
> 
> Query:
> 1) Does Arm64 Linux not enable KVM support for Arm32 guest ?
> 2) Can qemu-system-arm not use the KVM feature on Arm64 host ?
> 3) Can qemu-system-aarch64 not use KVM feature for Arm32 guest ?
> 
You can use below command to boot a ARM32 guest on ARM64?

qemu-system-aarch64 -enable-kvm -machine virt,kernel_irqchip=on -cpu
host,aarch64=off ....

-- 
Shannon

^ permalink raw reply	[flat|nested] 2+ messages in thread

* [Query] Does Linux & Qemu support KVM for ARM32 guest on ARM64 host
       [not found] <708585848.188261461823397987.JavaMail.weblogic@ep2mlwas06d>
@ 2016-04-28  6:46 ` Peter Maydell
  0 siblings, 0 replies; 2+ messages in thread
From: Peter Maydell @ 2016-04-28  6:46 UTC (permalink / raw)
  To: linux-arm-kernel

On 28 April 2016 at 07:03, RAVINDRA KUMAR SANDE <r.sande@samsung•com> wrote:
> I have another query, for Arm32 host with KVM enabled.
> I see that "qemu-system-arm  -enable-kvm   -machine vexpress-a9  ..." gives error
> kmv_init_vcpu (IOCtl on /dev/kvm) failed, guest not supported.
>
> Is there any way to emulate vexpress-a9  with  -enable-kvm   on qemu ?

No. You can only emulate a CPU of the same type as the host
you're using, and the vexpress-a9 must use a Cortex-A9 CPU,
so it can't be used under virtualization.

thanks
-- PMM

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2016-04-28  6:46 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
     [not found] <BE.E9.04928.D4C61275@epcpsbgx1.samsung.com>
2016-04-28  2:33 ` [Query] Does Linux & Qemu support KVM for ARM32 guest on ARM64 host Shannon Zhao
     [not found] <708585848.188261461823397987.JavaMail.weblogic@ep2mlwas06d>
2016-04-28  6:46 ` Peter Maydell

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox