From 4b526de50e39b38cd828396267379183c7c21354 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Fri, 19 Jul 2019 13:41:06 -0700 Subject: [PATCH] KVM: x86: Check kvm_rebooting in kvm_spurious_fault() Explicitly check kvm_rebooting in kvm_spurious_fault() prior to invoking BUG(), as opposed to assuming the caller has already done so. Letting kvm_spurious_fault() be called "directly" will allow VMX to better optimize its low level assembly flows. As a happy side effect, kvm_spurious_fault() no longer needs to be marked as a dead end since it doesn't unconditionally BUG(). Acked-by: Paolo Bonzini Cc: Josh Poimboeuf Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/kvm_host.h | 2 +- arch/x86/kvm/x86.c | 3 ++- tools/objtool/check.c | 1 - 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index c5ed92482e2c..de0c9d8097c2 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1534,7 +1534,7 @@ enum { #define kvm_arch_vcpu_memslots_id(vcpu) ((vcpu)->arch.hflags & HF_SMM_MASK ? 1 : 0) #define kvm_memslots_for_spte_role(kvm, role) __kvm_memslots(kvm, (role).smm) -asmlinkage void __noreturn kvm_spurious_fault(void); +asmlinkage void kvm_spurious_fault(void); /* * Hardware virtualization extension instructions may fault if a diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c9a3d8efe1c2..0ed07d8d2caa 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -360,7 +360,8 @@ EXPORT_SYMBOL_GPL(kvm_set_apic_base); asmlinkage __visible void kvm_spurious_fault(void) { /* Fault while not rebooting. We want the trace. */ - BUG(); + if (!kvm_rebooting) + BUG(); } EXPORT_SYMBOL_GPL(kvm_spurious_fault); diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 176f2f084060..044c9a3cb247 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -138,7 +138,6 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func, "do_task_dead", "__module_put_and_exit", "complete_and_exit", - "kvm_spurious_fault", "__reiserfs_panic", "lbug_with_loc", "fortify_panic",