On Tue, Jan 15, 2019 at 09:48:45AM -0800, Sean Christopherson wrote: > On Tue, Jan 15, 2019 at 11:43:20AM -0500, Qian Cai wrote: > > > > > > On 1/15/19 2:13 AM, Paolo Bonzini wrote: > > > Hmm, maybe like this: > > > > > > diff --git a/arch/x86/kvm/vmx/vmenter.S b/arch/x86/kvm/vmx/vmenter.S > > > index bcef2c7e9bc4..33122fa9d4bd 100644 > > > --- a/arch/x86/kvm/vmx/vmenter.S > > > +++ b/arch/x86/kvm/vmx/vmenter.S > > > @@ -26,19 +26,17 @@ ENTRY(vmx_vmenter) > > > ret > > > > > > 2: vmlaunch > > > +3: > > > ret > > > > > > -3: cmpb $0, kvm_rebooting > > > - jne 4f > > > - call kvm_spurious_fault > > > -4: ret > > > - > > > .pushsection .fixup, "ax" > > > -5: jmp 3b > > > +4: cmpb $0, kvm_rebooting > > > + jne 3b > > > + jmp kvm_spurious_fault > > > .popsection > > > > > > - _ASM_EXTABLE(1b, 5b) > > > - _ASM_EXTABLE(2b, 5b) > > > + _ASM_EXTABLE(1b, 4b) > > > + _ASM_EXTABLE(2b, 4b) > > > > > > ENDPROC(vmx_vmenter) > > > > No, that will not work. The problem is in vmx.o where I just sent another patch > > for it. > > > > I can see there are five options to solve it. > > > > 1) always inline vmx_vcpu_run() > > 2) always noinline vmx_vcpu_run() > > 3) add -fdiable-ipa-fnsplit option to Makefile for vmx.o > > 4) let STACK_FRAME_NON_STANDARD support part.* syntax. > > What is ".part." and where does it come from? Searching for information > is futile, the term is too generic. And never mind, my eyes glazed over -fdiable-ipa-fnsplit. > > 5) trim-down vmx_vcpu_run() even more to not causing splitting by GCC. > > > > Option 1) and 2) seems give away the decision for user with > > CONFIG_CC_OPTIMIZE_FOR_(PERFORMANCE/SIZE). > > > > Option 3) prevents other functions there for splitting for optimization. > > > > Option 4) and 5) seems tricky to implement. > > > > I am not more leaning to 3) as only other fuction will miss splitting is > > vmx_segment_access_rights().
