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

Paolo Bonzini
2015-06-04T08:06:23Z

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.

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.
--
1.8.3.1