[PATCH v5 04/28] x86/fpu/xstate: Modify the context restore helper to handle both static and dynamic buffers

Chang S. Bae
2021-05-23T19:38:47Z

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.bae@intel.com>
Reviewed-by: Len Brown <len.brown@intel.com>
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: kvm@vger.kernel.org
---
Changes from v3:
* Updated the changelog. (Borislav Petkov)
* Reverted the change of 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 52f886477b07..830b1bc75ed4 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);
}
}

@@ -258,7 +258,7 @@ 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 01c8642cb56c..b428ff496bca 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9649,7 +9649,7 @@ 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