Subject: [PATCH v3 2/8] KVM: arm64: Enable the KVM-VFIO device

From: [email-masked] (Eric Auger)
Date: Mon, 01 Dec 2014 15:55:34 +0100

On 11/30/2014 01:14 PM, Christoffer Dall wrote:
> On Sun, Nov 23, 2014 at 07:35:54PM +0100, Eric Auger wrote:
>> Used by KVM-enabled VFIO-based device passthrough support in QEMU.
>>
>> Signed-off-by: Joel Schopp <[email-masked]>
>> Signed-off-by: Eric Auger <[email-masked]>
>>
>> ---
>>
>> Extracted from [RFC PATCH] arm64: KVM: add irqfd support
>> http://www.spinics.net/lists/kvm-arm/msg10798.html
>> ---
>>  arch/arm64/kvm/Kconfig  | 1 +
>>  arch/arm64/kvm/Makefile | 2 +-
>>  2 files changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
>> index 09c25c2..2edf926 100644
>> --- a/arch/arm64/kvm/Kconfig
>> +++ b/arch/arm64/kvm/Kconfig
>> @@ -26,6 +26,7 @@ config KVM
>>  	select KVM_ARM_HOST
>>  	select KVM_ARM_VGIC
>>  	select KVM_ARM_TIMER
>> +	select KVM_VFIO
>>  	select HAVE_KVM_EVENTFD
>>  	---help---
>>  	  Support hosting virtualized guest machines.
>> diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
>> index 2e6b827..81ed091 100644
>> --- a/arch/arm64/kvm/Makefile
>> +++ b/arch/arm64/kvm/Makefile
>> @@ -11,7 +11,7 @@ ARM=../../../arch/arm/kvm
>>  
>>  obj-$(CONFIG_KVM_ARM_HOST) += kvm.o
>>  
>> -kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o
>> +kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o $(KVM)/vfio.o
>>  kvm-$(CONFIG_KVM_ARM_HOST) += $(ARM)/arm.o $(ARM)/mmu.o $(ARM)/mmio.o
>>  kvm-$(CONFIG_KVM_ARM_HOST) += $(ARM)/psci.o $(ARM)/perf.o
>>  
>> -- 
>> 1.9.1
>>
> 
> Should these patches not be squashed into one?
Yes I can do.
> 
> Also, what do they enable at this point?  Should they be queued by the
> end of the series instead?
Well to me this patch should be moved even outside of this series. The
KVM-VFIO device is loaded when the QEMU VFIO device is instantiated.
This is used to record the VFIO groups in use. In VFIO platform case, if
the KVM-VFIO device does not exist, this is not fatal but we get a
warning in QEMU.

The KVM-VFIO device however is mandatory to enable forwarded irq feature.

Best Regards

Eric
> -Christoffer