Message ID | 20221229123338.4142-1-wei.w.wang@intel.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | [v2] KVM: move KVM_CAP_DEVICE_CTRL to the generic check | expand |
On Thu, Dec 29, 2022, Wei Wang wrote: > KVM_CAP_DEVICE_CTRL allows userspace to check if the kvm_device > framework (e.g. KVM_CREATE_DEVICE) is supported by KVM. Move > KVM_CAP_DEVICE_CTRL to the generic check for the two reasons: > 1) it already supports arch agnostic usages (i.e. KVM_DEV_TYPE_VFIO). > For example, userspace VFIO implementation may needs to create > KVM_DEV_TYPE_VFIO on x86, riscv, or arm etc. It is simpler to have it > checked at the generic code than at each arch's code. > 2) KVM_CREATE_DEVICE has been added to the generic code. I think it's worth adding a link to the v1 patch, as that thread provides the context for how KVM ended up unconditionally advertising the feature, e.g. instead of trying to be more precise. Link: https://lore.kernel.org/all/20221215115207.14784-1-wei.w.wang@intel.com > Signed-off-by: Wei Wang <wei.w.wang@intel.com> > --- Reviewed-by: Sean Christopherson <seanjc@google.com>
On Thursday, February 2, 2023 7:30 AM, Sean Christopherson wrote: > On Thu, Dec 29, 2022, Wei Wang wrote: > > KVM_CAP_DEVICE_CTRL allows userspace to check if the kvm_device > > framework (e.g. KVM_CREATE_DEVICE) is supported by KVM. Move > > KVM_CAP_DEVICE_CTRL to the generic check for the two reasons: > > 1) it already supports arch agnostic usages (i.e. KVM_DEV_TYPE_VFIO). > > For example, userspace VFIO implementation may needs to create > > KVM_DEV_TYPE_VFIO on x86, riscv, or arm etc. It is simpler to have it > > checked at the generic code than at each arch's code. > > 2) KVM_CREATE_DEVICE has been added to the generic code. > > I think it's worth adding a link to the v1 patch, as that thread provides the > context for how KVM ended up unconditionally advertising the feature, e.g. > instead of trying to be more precise. > > Link: https://lore.kernel.org/all/20221215115207.14784-1- > wei.w.wang@intel.com > > > Signed-off-by: Wei Wang <wei.w.wang@intel.com> > > --- > > Reviewed-by: Sean Christopherson <seanjc@google.com> Thanks. Is this patch ready to be merged along with the link or need me to re-send to have the link added?
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 9c5573bc4614..190e9c3b10a7 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -212,7 +212,6 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = vgic_present; break; case KVM_CAP_IOEVENTFD: - case KVM_CAP_DEVICE_CTRL: case KVM_CAP_USER_MEMORY: case KVM_CAP_SYNC_MMU: case KVM_CAP_DESTROY_MEMORY_REGION_WORKS: diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 04494a4fb37a..21f9fbe96f6a 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -541,7 +541,6 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_ENABLE_CAP: case KVM_CAP_ONE_REG: case KVM_CAP_IOEVENTFD: - case KVM_CAP_DEVICE_CTRL: case KVM_CAP_IMMEDIATE_EXIT: case KVM_CAP_SET_GUEST_DEBUG: r = 1; diff --git a/arch/riscv/kvm/vm.c b/arch/riscv/kvm/vm.c index 65a964d7e70d..6efe93b282e1 100644 --- a/arch/riscv/kvm/vm.c +++ b/arch/riscv/kvm/vm.c @@ -57,7 +57,6 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) switch (ext) { case KVM_CAP_IOEVENTFD: - case KVM_CAP_DEVICE_CTRL: case KVM_CAP_USER_MEMORY: case KVM_CAP_SYNC_MMU: case KVM_CAP_DESTROY_MEMORY_REGION_WORKS: diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index e4890e04b210..191d220b6a30 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -567,7 +567,6 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_ENABLE_CAP: case KVM_CAP_S390_CSS_SUPPORT: case KVM_CAP_IOEVENTFD: - case KVM_CAP_DEVICE_CTRL: case KVM_CAP_S390_IRQCHIP: case KVM_CAP_VM_ATTRIBUTES: case KVM_CAP_MP_STATE: diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 582757ebdce6..84073464aea0 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4524,6 +4524,7 @@ static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg) #endif case KVM_CAP_BINARY_STATS_FD: case KVM_CAP_SYSTEM_EVENT_DATA: + case KVM_CAP_DEVICE_CTRL: return 1; default: break;
KVM_CAP_DEVICE_CTRL allows userspace to check if the kvm_device framework (e.g. KVM_CREATE_DEVICE) is supported by KVM. Move KVM_CAP_DEVICE_CTRL to the generic check for the two reasons: 1) it already supports arch agnostic usages (i.e. KVM_DEV_TYPE_VFIO). For example, userspace VFIO implementation may needs to create KVM_DEV_TYPE_VFIO on x86, riscv, or arm etc. It is simpler to have it checked at the generic code than at each arch's code. 2) KVM_CREATE_DEVICE has been added to the generic code. Signed-off-by: Wei Wang <wei.w.wang@intel.com> --- arch/arm64/kvm/arm.c | 1 - arch/powerpc/kvm/powerpc.c | 1 - arch/riscv/kvm/vm.c | 1 - arch/s390/kvm/kvm-s390.c | 1 - virt/kvm/kvm_main.c | 1 + 5 files changed, 1 insertion(+), 4 deletions(-)