[libvirt] [PATCH v7 3/4] kvm: add kvm_device_supported() helper function
This can be used when probing whether KVM support specific device. Here,
a raw vmfd is used.
Signed-off-by: Peter Xu <peterx(a)redhat.com>
---
include/sysemu/kvm.h | 9 +++++++++
kvm-all.c | 15 +++++++++++++++
2 files changed, 24 insertions(+)
diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index 6695fa7..0e18f15 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -306,6 +306,15 @@ void kvm_device_access(int fd, int group, uint64_t attr,
*/
int kvm_create_device(KVMState *s, uint64_t type, bool test);
+/**
+ * kvm_device_supported - probe whether KVM supports specific device
+ *
+ * @vmfd: The fd handler for VM
+ * @type: type of device
+ *
+ * @return: true if supported, otherwise false.
+ */
+bool kvm_device_supported(int vmfd, uint64_t type);
/* Arch specific hooks */
diff --git a/kvm-all.c b/kvm-all.c
index 44c0464..e7b66df 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -2339,6 +2339,21 @@ int kvm_create_device(KVMState *s, uint64_t type, bool test)
return test ? 0 : create_dev.fd;
}
+bool kvm_device_supported(int vmfd, uint64_t type)
+{
+ struct kvm_create_device create_dev = {
+ .type = type,
+ .fd = -1,
+ .flags = KVM_CREATE_DEVICE_TEST,
+ };
+
+ if (ioctl(vmfd, KVM_CHECK_EXTENSION, KVM_CAP_DEVICE_CTRL) <= 0) {
+ return false;
+ }
+
+ return (ioctl(vmfd, KVM_CREATE_DEVICE, &create_dev) >= 0);
+}
+
int kvm_set_one_reg(CPUState *cs, uint64_t id, void *source)
{
struct kvm_one_reg reg;
--
2.4.3