Introduce a static branch that would be set during boot if the OS
happens to be a KVM guest. Subsequent checks to see if we are on KVM
will rely on this static branch. This static branch would be used in
vcpu_is_preempted() in a subsequent patch.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201202050456.164005-4-srikar@linux.vnet.ibm.com
#define _ASM_POWERPC_KVM_GUEST_H_
#if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_KVM_GUEST)
+#include <linux/jump_label.h>
+
+DECLARE_STATIC_KEY_FALSE(kvm_guest);
+
+static inline bool is_kvm_guest(void)
+{
+ return static_branch_unlikely(&kvm_guest);
+}
+
bool check_kvm_guest(void);
#else
+static inline bool is_kvm_guest(void) { return false; }
static inline bool check_kvm_guest(void) { return false; }
#endif
static inline int kvm_para_available(void)
{
- return IS_ENABLED(CONFIG_KVM_GUEST) && check_kvm_guest();
+ return IS_ENABLED(CONFIG_KVM_GUEST) && is_kvm_guest();
}
static inline unsigned int kvm_arch_para_features(void)
#endif
#if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_KVM_GUEST)
+DEFINE_STATIC_KEY_FALSE(kvm_guest);
bool check_kvm_guest(void)
{
struct device_node *hyper_node;
if (!of_device_is_compatible(hyper_node, "linux,kvm"))
return false;
+ static_branch_enable(&kvm_guest);
return true;
}
#endif