linux-kernel - Re: [RFC 9/9] KVM: KVM_VFIO: ARM: implement irq forwarding control

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 27 Aug 2014 17:24:26 +0200
From:	Eric Auger <eric.auger@...aro.org>
To:	Alex Williamson <alex.williamson@...hat.com>
CC:	eric.auger@...com, christoffer.dall@...aro.org,
	marc.zyngier@....com, linux-arm-kernel@...ts.infradead.org,
	kvmarm@...ts.cs.columbia.edu, kvm@...r.kernel.org,
	joel.schopp@....com, kim.phillips@...escale.com,
	linux-kernel@...r.kernel.org, patches@...aro.org,
	will.deacon@....com, a.motakis@...tualopensystems.com,
	a.rigo@...tualopensystems.com, john.liuli@...wei.com
Subject: Re: [RFC 9/9] KVM: KVM_VFIO: ARM: implement irq forwarding control

On 08/26/2014 09:02 PM, Alex Williamson wrote:
> On Mon, 2014-08-25 at 15:27 +0200, Eric Auger wrote:
>> Implements ARM specific KVM-VFIO device group commands:
>> - KVM_DEV_VFIO_DEVICE_ASSIGN_IRQ
>> - KVM_DEV_VFIO_DEVICE_DEASSIGN_IRQ
>> capability can be queried using KVM_HAS_DEVICE_ATTR.
>>
>> The new commands enable to set IRQ forwarding on/off for a given
>> IRQ index of a VFIO platform device.
>>
>> as soon as a forwarded irq is set, a reference to the VFIO device
>> is taken by the kvm-vfio device.
>>
>> The kvm-vfio device stores in the kvm_vfio_arch_data the list
>> of "assigned" devices (kvm_vfio_device). Each kvm_vfio_device
>> stores the list of assigned IRQs (potentially allowed a subset of
>> IRQ to be forwarded)
>>
>> The kvm-vfio device programs both the GIC and vGIC. Also it
>> clears the active bit on destruction, in case the guest did not
>> do it itself.
>>
>> Changing the forwarded state is not allowed in the critical
>> section starting from VFIO IRQ handler to LR programming. It is
>> up to the client to take care of this.
>>
>> Signed-off-by: Eric Auger <eric.auger@...aro.org>
>> ---
>>  arch/arm/include/asm/kvm_host.h |   2 +
>>  arch/arm/kvm/Makefile           |   2 +-
>>  arch/arm/kvm/kvm_vfio_arm.c     | 599 ++++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 602 insertions(+), 1 deletion(-)
>>  create mode 100644 arch/arm/kvm/kvm_vfio_arm.c
> 
> I'm really happy that it seems like the kvm-vfio device is going to work
> for you, but I think too much stuff is being pushed out to arch code
> here.  Exporting the interfaces in patches 7 & 8 are setting the stage
> for duplicate code for anyone wanting to implement device attributes.
> Instead, I think the core code should support the list of
> kvm_vfio_devices with proper cleanup, and we should attempt to access
> the kvm_vfio_ callbacks as little as possible from arch code.  Thanks,

OK. my next iteration will feature much more generic code.

Thanks for the review

Best Regards

Eric

> 
> Alex
> 

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/