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

Bandan Das
2015-06-04T14:31:24Z

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.