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Subject[PATCH v13 06/16] x86/process/64: Make save_fsgs() public available
Date
From: Thomas Gleixner <tglx@linutronix.de>

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/include/asm/processor.h | 4 +---
arch/x86/kernel/process_64.c | 15 +++++++++------
arch/x86/kvm/vmx/vmx.c | 2 +-
3 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 3bcf27caf6c9..809bc013db70 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -456,10 +456,8 @@ static inline unsigned long cpu_kernelmode_gs_base(int cpu)
DECLARE_PER_CPU(unsigned int, irq_count);
extern asmlinkage void ignore_sysret(void);

-#if IS_ENABLED(CONFIG_KVM)
/* Save actual FS/GS selectors and bases to current->thread */
-void save_fsgs_for_kvm(void);
-#endif
+void current_save_fsgs(void);
#else /* X86_64 */
#ifdef CONFIG_STACKPROTECTOR
/*
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 85c7f9cabde2..aefb30bc56bc 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -247,18 +247,21 @@ static __always_inline void save_fsgs(struct task_struct *task)
}
}

-#if IS_ENABLED(CONFIG_KVM)
/*
* While a process is running,current->thread.fsbase and current->thread.gsbase
- * may not match the corresponding CPU registers (see save_base_legacy()). KVM
- * wants an efficient way to save and restore FSBASE and GSBASE.
- * When FSGSBASE extensions are enabled, this will have to use RD{FS,GS}BASE.
+ * may not match the corresponding CPU registers (see save_base_legacy()).
*/
-void save_fsgs_for_kvm(void)
+void current_save_fsgs(void)
{
+ unsigned long flags;
+
+ /* Interrupts need to be off for FSGSBASE */
+ local_irq_save(flags);
save_fsgs(current);
+ local_irq_restore(flags);
}
-EXPORT_SYMBOL_GPL(save_fsgs_for_kvm);
+#if IS_ENABLED(CONFIG_KVM)
+EXPORT_SYMBOL_GPL(current_save_fsgs);
#endif

static __always_inline void loadseg(enum which_selector which,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 89c766fad889..309e6dc975d5 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1167,7 +1167,7 @@ void vmx_prepare_switch_to_guest(struct kvm_vcpu *vcpu)

gs_base = cpu_kernelmode_gs_base(cpu);
if (likely(is_64bit_mm(current->mm))) {
- save_fsgs_for_kvm();
+ current_save_fsgs();
fs_sel = current->thread.fsindex;
gs_sel = current->thread.gsindex;
fs_base = current->thread.fsbase;
--
2.25.1
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