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authorThomas Gleixner <tglx@linutronix.de>2021-10-15 03:16:12 +0200
committerBorislav Petkov <bp@suse.de>2021-10-20 15:27:27 +0200
commita0ff0611c2fbde94f6c9db8351939b08f2cb6797 (patch)
tree19c4128a92592a76fd7378ee3ef4994af866a25f /arch/x86/kernel
parentx86/fpu/xstate: Mark all init only functions __init (diff)
downloadlinux-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.c30
-rw-r--r--arch/x86/kernel/fpu/init.c1
-rw-r--r--arch/x86/kernel/fpu/xstate.c1
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, &current->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};