Re: [PATCH] KVM: arm/arm64: Fix bug in advertising KVM_CAP_MSI_DEVID capability

[Auger Eric <eric.auger@redhat.com>]

Hi,

On 08/07/2017 15:48, Shanker Donthineni wrote:
> Commit 0e4e82f154e3 ("KVM: arm64: vgic-its: Enable ITS emulation as
> a virtual MSI controller") tried to advertise KVM_CAP_MSI_DEVID, but
> the code logic was not updating the dist->msis_require_devid field
> correctly. If hypervisor tool creates the ITS device after VGIC
> initialization then we don't advertise KVM_CAP_MSI_DEVID capability.
> 
> Update the field msis_require_devid to true inside vgic_its_create()
> to fix the issue.
> 
> Fixes: 0e4e82f154e3 ("vgic-its: Enable ITS emulation as a virtual MSI controller")
> Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>

In QEMU the capability is not checked as "kvm_msi_use_devid" is directly
set in the ITS device :-(

Thanks

Eric

> ---
>  virt/kvm/arm/vgic/vgic-init.c | 3 ---
>  virt/kvm/arm/vgic/vgic-its.c  | 1 +
>  2 files changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
> index 3a0b899..5801261 100644
> --- a/virt/kvm/arm/vgic/vgic-init.c
> +++ b/virt/kvm/arm/vgic/vgic-init.c
> @@ -285,9 +285,6 @@ int vgic_init(struct kvm *kvm)
>  	if (ret)
>  		goto out;
>  
> -	if (vgic_has_its(kvm))
> -		dist->msis_require_devid = true;
> -
>  	kvm_for_each_vcpu(i, vcpu, kvm)
>  		kvm_vgic_vcpu_enable(vcpu);
>  
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index 2dff288..aa6b68d 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -1598,6 +1598,7 @@ static int vgic_its_create(struct kvm_device *dev, u32 type)
>  	INIT_LIST_HEAD(&its->device_list);
>  	INIT_LIST_HEAD(&its->collection_list);
>  
> +	dev->kvm->arch.vgic.msis_require_devid = true;
>  	dev->kvm->arch.vgic.has_its = true;
>  	its->enabled = false;
>  	its->dev = dev;
>