I'd prefer a shortlog that states what change is being made, but otherwise:
Reviewed-by: Sean Christopherson <seanjc@google.com>
On Wed, Dec 24, 2025, Paolo Bonzini wrote:
> The only difference is the usage of switch_fpu_return() vs.
> fpregs_restore_userregs(). In turn, these are only different
> if there is no FPU at all, but KVM requires one. Therefore use the
> pre-made export---the code is simpler and there is no functional change.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> arch/x86/kernel/fpu/core.c | 2 +--
> arch/x86/kvm/fpu.h | 6 +-----
> 2 files changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
> index ff17c96d290a..6571952c6ef1 100644
> --- a/arch/x86/kernel/fpu/core.c
> +++ b/arch/x86/kernel/fpu/core.c
> @@ -846,7 +846,6 @@ void switch_fpu_return(void)
>
> fpregs_restore_userregs();
> }
> -EXPORT_SYMBOL_FOR_KVM(switch_fpu_return);
>
> void fpregs_lock_and_load(void)
> {
> @@ -865,6 +864,7 @@ void fpregs_lock_and_load(void)
>
> fpregs_assert_state_consistent();
> }
> +EXPORT_SYMBOL_FOR_KVM(fpregs_lock_and_load);
>
> void fpu_load_guest_fpstate(struct fpu_guest *gfpu)
> {
> @@ -899,7 +899,6 @@ void fpregs_assert_state_consistent(void)
>
> WARN_ON_FPU(!fpregs_state_valid(fpu, smp_processor_id()));
> }
> -EXPORT_SYMBOL_FOR_KVM(fpregs_assert_state_consistent);
> #endif
>
> void fpregs_mark_activate(void)
> diff --git a/arch/x86/kvm/fpu.h b/arch/x86/kvm/fpu.h
> index f898781b6a06..b6a03d8fa8af 100644
> --- a/arch/x86/kvm/fpu.h
> +++ b/arch/x86/kvm/fpu.h
> @@ -149,11 +149,7 @@ static inline void _kvm_write_mmx_reg(int reg, const u64 *data)
>
> static inline void kvm_fpu_get(void)
> {
> - fpregs_lock();
> -
> - fpregs_assert_state_consistent();
> - if (test_thread_flag(TIF_NEED_FPU_LOAD))
> - switch_fpu_return();
> + fpregs_lock_and_load();
> }
>
> static inline void kvm_fpu_put(void)
> --
> 2.52.0
>