KVM capabilities can be per-VM, in this case the ioctl should be
issued on the VM file descriptor, not on the system fd.
Since this feature is guarded by a (system) capability itself, wrap
the call into a function of its own.
Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
include/kvm/kvm.h | 1 +
kvm.c | 28 ++++++++++++++++++++++++++++
2 files changed, 29 insertions(+)
diff --git a/include/kvm/kvm.h b/include/kvm/kvm.h
index 4a76ec2..a76a25d 100644
--- a/include/kvm/kvm.h
+++ b/include/kvm/kvm.h
@@ -129,6 +129,7 @@ static inline bool host_ptr_in_ram(struct kvm *kvm, void *p)
}
bool kvm__supports_extension(struct kvm *kvm, unsigned int extension);
+bool kvm__supports_vm_extension(struct kvm *kvm, unsigned int extension);
static inline void kvm__set_thread_name(const char *name)
{
diff --git a/kvm.c b/kvm.c
index 7fa76f7..665ed14 100644
--- a/kvm.c
+++ b/kvm.c
@@ -93,6 +93,34 @@ const char *kvm__get_dir(void)
return kvm_dir;
}
+bool kvm__supports_vm_extension(struct kvm *kvm, unsigned int extension)
+{
+ static int supports_vm_ext_check = 0;
+ int ret;
+
+ switch (supports_vm_ext_check) {
+ case 0:
+ ret = ioctl(kvm->sys_fd, KVM_CHECK_EXTENSION,
+ KVM_CAP_CHECK_EXTENSION_VM);
+ if (ret <= 0) {
+ supports_vm_ext_check = -1;
+ return false;
+ }
+ supports_vm_ext_check = 1;
+ /* fall through */
+ case 1:
+ break;
+ case -1:
+ return false;
+ }
+
+ ret = ioctl(kvm->vm_fd, KVM_CHECK_EXTENSION, extension);
+ if (ret < 0)
+ return false;
+
+ return ret;
+}
+
bool kvm__supports_extension(struct kvm *kvm, unsigned int extension)
{
int ret;
--
2.9.0
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