Messages in this thread Patch in this message | | | Date | Mon, 18 Sep 2023 12:29:46 -0300 | From | Jason Gunthorpe <> | Subject | Re: [PATCH 06/26] KVM: Drop CONFIG_KVM_VFIO and just look at KVM+VFIO |
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On Fri, Sep 15, 2023 at 05:30:58PM -0700, Sean Christopherson wrote: > Drop KVM's KVM_VFIO Kconfig, and instead compile in VFIO support if > and only if VFIO itself is enabled. Similar to the recent change to have > VFIO stop looking at HAVE_KVM, compiling in support for talking to VFIO > just because the architecture supports VFIO is nonsensical. > > This fixes a bug where RISC-V doesn't select KVM_VFIO, i.e. would silently > fail to do connect KVM and VFIO, even though RISC-V supports VFIO. The > bug is benign as the only driver in all of Linux that actually uses the > KVM reference provided by VFIO is KVM-GT, which is x86/Intel specific.
Hmm, I recall that all the S390 drivers need it as well.
static int vfio_ap_mdev_open_device(struct vfio_device *vdev) { struct ap_matrix_mdev *matrix_mdev = container_of(vdev, struct ap_matrix_mdev, vdev);
if (!vdev->kvm) return -EINVAL;
return vfio_ap_mdev_set_kvm(matrix_mdev, vdev->kvm);
I wonder if we should be making the VFIO drivers that need the kvm to ask for it? 'select CONFIG_NEED_VFIO_KVM' or something?
Regardless, I fully agree with getting rid of the arch flag.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
> --- a/virt/kvm/Makefile.kvm > +++ b/virt/kvm/Makefile.kvm > @@ -6,7 +6,9 @@ > KVM ?= ../../../virt/kvm > > kvm-y := $(KVM)/kvm_main.o $(KVM)/eventfd.o $(KVM)/binary_stats.o > -kvm-$(CONFIG_KVM_VFIO) += $(KVM)/vfio.o > +ifdef CONFIG_VFIO > +kvm-y += $(KVM)/vfio.o > +endif
I wonder if kvm-m magically works in kbuild so you don't need the ifdef?
Jason
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