Now that all architectures (arm64 and x86) that utilize "generic" page
faults also support userfault exits, advertise support for
KVM_CAP_USERFAULT and let userspace set KVM_MEM_USERFAULT in memslots.
Signed-off-by: James Houghton <jthoughton@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
include/uapi/linux/kvm.h | 1 +
virt/kvm/kvm_main.c | 6 ++++++
2 files changed, 7 insertions(+)
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index af1fc86ddbe0..262e2bde9b3b 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -934,6 +934,7 @@ struct kvm_enable_cap {
#define KVM_CAP_X86_APIC_BUS_CYCLES_NS 237
#define KVM_CAP_X86_GUEST_MODE 238
#define KVM_CAP_ARM_WRITABLE_IMP_ID_REGS 239
+#define KVM_CAP_USERFAULT 240
struct kvm_irq_routing_irqchip {
__u32 irqchip;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index ca08075a9b7b..c3384847dd5b 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1545,6 +1545,9 @@ static int check_memory_region_flags(struct kvm *kvm,
!(mem->flags & KVM_MEM_GUEST_MEMFD))
valid_flags |= KVM_MEM_READONLY;
+ if (IS_ENABLED(CONFIG_KVM_GENERIC_PAGE_FAULT))
+ valid_flags |= KVM_MEM_USERFAULT;
+
if (mem->flags & ~valid_flags)
return -EINVAL;
@@ -4823,6 +4826,9 @@ static int kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
case KVM_CAP_CHECK_EXTENSION_VM:
case KVM_CAP_ENABLE_CAP_VM:
case KVM_CAP_HALT_POLL:
+#ifdef CONFIG_KVM_GENERIC_PAGE_FAULT
+ case KVM_CAP_USERFAULT:
+#endif
return 1;
#ifdef CONFIG_KVM_MMIO
case KVM_CAP_COALESCED_MMIO:
--
2.49.0.967.g6a0df3ecc3-goog
--Viq7rgPFWdewsyKO--
