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-rw-r--r--arch/x86/include/asm/fpu/api.h1
-rw-r--r--arch/x86/kernel/fpu/core.c22
2 files changed, 23 insertions, 0 deletions
diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h
index d8c222290e68..1ed2a247a84e 100644
--- a/arch/x86/include/asm/fpu/api.h
+++ b/arch/x86/include/asm/fpu/api.h
@@ -138,6 +138,7 @@ extern inline u64 xstate_get_guest_group_perm(void);
extern bool fpu_alloc_guest_fpstate(struct fpu_guest *gfpu);
extern void fpu_free_guest_fpstate(struct fpu_guest *gfpu);
extern int fpu_swap_kvm_fpstate(struct fpu_guest *gfpu, bool enter_guest);
+extern int fpu_enable_guest_xfd_features(struct fpu_guest *guest_fpu, u64 xfeatures);
extern void fpu_copy_guest_fpstate_to_uabi(struct fpu_guest *gfpu, void *buf, unsigned int size, u32 pkru);
extern int fpu_copy_uabi_to_guest_fpstate(struct fpu_guest *gfpu, const void *buf, u64 xcr0, u32 *vpkru);
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index a78bc547fc03..64b2ee39bece 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -261,6 +261,28 @@ void fpu_free_guest_fpstate(struct fpu_guest *gfpu)
}
EXPORT_SYMBOL_GPL(fpu_free_guest_fpstate);
+/*
+ * fpu_enable_guest_xfd_features - Check xfeatures against guest perm and enable
+ * @guest_fpu: Pointer to the guest FPU container
+ * @xfeatures: Features requested by guest CPUID
+ *
+ * Enable all dynamic xfeatures according to guest perm and requested CPUID.
+ *
+ * Return: 0 on success, error code otherwise
+ */
+int fpu_enable_guest_xfd_features(struct fpu_guest *guest_fpu, u64 xfeatures)
+{
+ lockdep_assert_preemption_enabled();
+
+ /* Nothing to do if all requested features are already enabled. */
+ xfeatures &= ~guest_fpu->xfeatures;
+ if (!xfeatures)
+ return 0;
+
+ return __xfd_enable_feature(xfeatures, guest_fpu);
+}
+EXPORT_SYMBOL_GPL(fpu_enable_guest_xfd_features);
+
int fpu_swap_kvm_fpstate(struct fpu_guest *guest_fpu, bool enter_guest)
{
struct fpstate *guest_fps = guest_fpu->fpstate;