[PATCH v4 04/22] x86/fpu/xstate: Modify the context restore helper to handle both static and dynamic buffers

[Chang S. Bae]

Have the function restoring xstate take a struct fpu * pointer in
preparation for dynamic state buffer support.

No functional change.

Signed-off-by: Chang S. Bae <chang.seok....@intel.com>
Reviewed-by: Len Brown <len.br...@intel.com>
Cc: x...@kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: k...@vger.kernel.org
---
Changes from v3:
* Updated the changelog. (Borislav Petkov)
* Reverted the change on the copy_kernel_to_xregs_err() function as not
  needed.

Changes from v2:
* Updated the changelog with task->fpu removed. (Borislav Petkov)
---
 arch/x86/include/asm/fpu/internal.h | 6 ++++--
 arch/x86/kernel/fpu/core.c          | 4 ++--
 arch/x86/kvm/x86.c                  | 2 +-
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/fpu/internal.h 
b/arch/x86/include/asm/fpu/internal.h
index 0153c4d4ca77..b34d0d29e4b8 100644
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -425,8 +425,10 @@ static inline void __copy_kernel_to_fpregs(union 
fpregs_state *fpstate, u64 mask
        }
 }
 
-static inline void copy_kernel_to_fpregs(union fpregs_state *fpstate)
+static inline void copy_kernel_to_fpregs(struct fpu *fpu)
 {
+       union fpregs_state *fpstate = &fpu->state;
+
        /*
         * AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception is
         * pending. Clear the x87 state here by setting it to fixed values.
@@ -511,7 +513,7 @@ static inline void __fpregs_load_activate(void)
                return;
 
        if (!fpregs_state_valid(fpu, cpu)) {
-               copy_kernel_to_fpregs(&fpu->state);
+               copy_kernel_to_fpregs(fpu);
                fpregs_activate(fpu);
                fpu->last_cpu = cpu;
        }
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index d43661d309ab..5775e64b0172 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -173,7 +173,7 @@ void fpu__save(struct fpu *fpu)
 
        if (!test_thread_flag(TIF_NEED_FPU_LOAD)) {
                if (!copy_fpregs_to_fpstate(fpu)) {
-                       copy_kernel_to_fpregs(&fpu->state);
+                       copy_kernel_to_fpregs(fpu);
                }
        }
 
@@ -251,7 +251,7 @@ int fpu__copy(struct task_struct *dst, struct task_struct 
*src)
                memcpy(&dst_fpu->state, &src_fpu->state, 
fpu_kernel_xstate_size);
 
        else if (!copy_fpregs_to_fpstate(dst_fpu))
-               copy_kernel_to_fpregs(&dst_fpu->state);
+               copy_kernel_to_fpregs(dst_fpu);
 
        fpregs_unlock();
 
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index cc3b604ddcd2..dd9565d12d81 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9313,7 +9313,7 @@ static void kvm_put_guest_fpu(struct kvm_vcpu *vcpu)
        if (vcpu->arch.guest_fpu)
                kvm_save_current_fpu(vcpu->arch.guest_fpu);
 
-       copy_kernel_to_fpregs(&vcpu->arch.user_fpu->state);
+       copy_kernel_to_fpregs(vcpu->arch.user_fpu);
 
        fpregs_mark_activate();
        fpregs_unlock();
-- 
2.17.1