Re: [PATCH] kvm: x86: default legacy PCI device assignment support to "n"

[Bandan Das <bsd@redhat.com>]

Paolo Bonzini <pbonzini@redhat.com> writes:

> VFIO has proved itself a much better option than KVM's built-in
> device assignment.  It is mature, provides better isolation because
> it enforces ACS, and even the userspace code is being tested on
> a wider variety of hardware these days than the legacy support.
>
> Disable legacy device assignment by default.

Shouldn't we mark it as Deprecated then ?

Bandan
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  arch/x86/kvm/Kconfig | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
> index 413a7bf9efbb..a0f06a5947c5 100644
> --- a/arch/x86/kvm/Kconfig
> +++ b/arch/x86/kvm/Kconfig
> @@ -88,13 +88,14 @@ config KVM_MMU_AUDIT
>  config KVM_DEVICE_ASSIGNMENT
>  	bool "KVM legacy PCI device assignment support"
>  	depends on KVM && PCI && IOMMU_API
> -	default y
> +	default n
>  	---help---
>  	  Provide support for legacy PCI device assignment through KVM.  The
>  	  kernel now also supports a full featured userspace device driver
> -	  framework through VFIO, which supersedes much of this support.
> +	  framework through VFIO, which supersedes this support and provides
> +	  better security.
>  
> -	  If unsure, say Y.
> +	  If unsure, say N.
>  
>  # OK, it's a little counter-intuitive to do this, but it puts it neatly under
>  # the virtualization menu.