lkml.org 
[lkml]   [2019]   [Jul]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 1/5] objtool: KVM: x86: Check kvm_rebooting in kvm_spurious_fault()
Date
Explicitly check kvm_reboot 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 <pbonzini@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
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 8282b8d41209..9739ed615faf 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1496,7 +1496,7 @@ 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 4a0b74ecd1de..6bc012afb86a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -356,7 +356,8 @@ 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 5f26620f13f5..688a9af8124d 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",
--
2.22.0
\
 
 \ /
  Last update: 2019-07-19 22:42    [W:0.115 / U:8.888 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site