diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2021-10-15 03:16:12 +0200 |
---|---|---|
committer | Borislav Petkov <bp@suse.de> | 2021-10-20 15:27:27 +0200 |
commit | a0ff0611c2fbde94f6c9db8351939b08f2cb6797 (patch) | |
tree | 19c4128a92592a76fd7378ee3ef4994af866a25f /arch/x86/kernel | |
parent | x86/fpu/xstate: Mark all init only functions __init (diff) | |
download | linux-a0ff0611c2fbde94f6c9db8351939b08f2cb6797.tar.xz linux-a0ff0611c2fbde94f6c9db8351939b08f2cb6797.zip |
x86/fpu: Move KVMs FPU swapping to FPU core
Swapping the host/guest FPU is directly fiddling with FPU internals which
requires 5 exports. The upcoming support of dynamically enabled states
would even need more.
Implement a swap function in the FPU core code and export that instead.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Link: https://lkml.kernel.org/r/20211015011539.076072399@linutronix.de
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r-- | arch/x86/kernel/fpu/core.c | 30 | ||||
-rw-r--r-- | arch/x86/kernel/fpu/init.c | 1 | ||||
-rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 1 |
3 files changed, 26 insertions, 6 deletions
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 0789f0c3dca9..023bfe857907 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -124,9 +124,8 @@ void save_fpregs_to_fpstate(struct fpu *fpu) asm volatile("fnsave %[fp]; fwait" : [fp] "=m" (fpu->state.fsave)); frstor(&fpu->state.fsave); } -EXPORT_SYMBOL(save_fpregs_to_fpstate); -void __restore_fpregs_from_fpstate(union fpregs_state *fpstate, u64 mask) +void restore_fpregs_from_fpstate(union fpregs_state *fpstate, u64 mask) { /* * AMD K7/K8 and later CPUs up to Zen don't save/restore @@ -151,7 +150,31 @@ void __restore_fpregs_from_fpstate(union fpregs_state *fpstate, u64 mask) frstor(&fpstate->fsave); } } -EXPORT_SYMBOL_GPL(__restore_fpregs_from_fpstate); + +#if IS_ENABLED(CONFIG_KVM) +void fpu_swap_kvm_fpu(struct fpu *save, struct fpu *rstor, u64 restore_mask) +{ + fpregs_lock(); + + if (save) { + if (test_thread_flag(TIF_NEED_FPU_LOAD)) { + memcpy(&save->state, ¤t->thread.fpu.state, + fpu_kernel_xstate_size); + } else { + save_fpregs_to_fpstate(save); + } + } + + if (rstor) { + restore_mask &= xfeatures_mask_fpstate(); + restore_fpregs_from_fpstate(&rstor->state, restore_mask); + } + + fpregs_mark_activate(); + fpregs_unlock(); +} +EXPORT_SYMBOL_GPL(fpu_swap_kvm_fpu); +#endif void kernel_fpu_begin_mask(unsigned int kfpu_mask) { @@ -457,7 +480,6 @@ void fpregs_mark_activate(void) fpu->last_cpu = smp_processor_id(); clear_thread_flag(TIF_NEED_FPU_LOAD); } -EXPORT_SYMBOL_GPL(fpregs_mark_activate); /* * x87 math exception handling: diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c index 37f872630a0e..545c91c723b8 100644 --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -136,7 +136,6 @@ static void __init fpu__init_system_generic(void) * components into a single, continuous memory block: */ unsigned int fpu_kernel_xstate_size __ro_after_init; -EXPORT_SYMBOL_GPL(fpu_kernel_xstate_size); /* Get alignment of the TYPE. */ #define TYPE_ALIGN(TYPE) offsetof(struct { char x; TYPE test; }, test) diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index b35ecfa8d450..68355605ca75 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -65,7 +65,6 @@ static short xsave_cpuid_features[] __initdata = { * XSAVE buffer, both supervisor and user xstates. */ u64 xfeatures_mask_all __ro_after_init; -EXPORT_SYMBOL_GPL(xfeatures_mask_all); static unsigned int xstate_offsets[XFEATURE_MAX] __ro_after_init = { [ 0 ... XFEATURE_MAX - 1] = -1}; |