On Tue, 28 Apr 2020 at 02:30, Sean Christopherson
<sean.j.christopherson@xxxxxxxxx> wrote:
>
> On Fri, Apr 24, 2020 at 02:22:41PM +0800, Wanpeng Li wrote:
> > From: Wanpeng Li <wanpengli@xxxxxxxxxxx>
> >
> > Introduce need_cancel_enter_guest() helper, we need to check some
> > conditions before doing CONT_RUN, in addition, it can also catch
> > the case vmexit occurred while another event was being delivered
> > to guest software since vmx_complete_interrupts() adds the request
> > bit.
> >
> > Tested-by: Haiwei Li <lihaiwei@xxxxxxxxxxx>
> > Cc: Haiwei Li <lihaiwei@xxxxxxxxxxx>
> > Signed-off-by: Wanpeng Li <wanpengli@xxxxxxxxxxx>
> > ---
> > arch/x86/kvm/vmx/vmx.c | 12 +++++++-----
> > arch/x86/kvm/x86.c | 10 ++++++++--
> > arch/x86/kvm/x86.h | 1 +
> > 3 files changed, 16 insertions(+), 7 deletions(-)
> >
> > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> > index f1f6638..5c21027 100644
> > --- a/arch/x86/kvm/vmx/vmx.c
> > +++ b/arch/x86/kvm/vmx/vmx.c
> > @@ -6577,7 +6577,7 @@ bool __vmx_vcpu_run(struct vcpu_vmx *vmx, unsigned long *regs, bool launched);
> >
> > static enum exit_fastpath_completion vmx_vcpu_run(struct kvm_vcpu *vcpu)
> > {
> > - enum exit_fastpath_completion exit_fastpath;
> > + enum exit_fastpath_completion exit_fastpath = EXIT_FASTPATH_NONE;
> > struct vcpu_vmx *vmx = to_vmx(vcpu);
> > unsigned long cr3, cr4;
> >
> > @@ -6754,10 +6754,12 @@ static enum exit_fastpath_completion vmx_vcpu_run(struct kvm_vcpu *vcpu)
> > vmx_recover_nmi_blocking(vmx);
> > vmx_complete_interrupts(vmx);
> >
> > - exit_fastpath = vmx_exit_handlers_fastpath(vcpu);
> > - /* static call is better with retpolines */
> > - if (exit_fastpath == EXIT_FASTPATH_CONT_RUN)
> > - goto cont_run;
> > + if (!kvm_need_cancel_enter_guest(vcpu)) {
> > + exit_fastpath = vmx_exit_handlers_fastpath(vcpu);
> > + /* static call is better with retpolines */
> > + if (exit_fastpath == EXIT_FASTPATH_CONT_RUN)
> > + goto cont_run;
> > + }
> >
> > return exit_fastpath;
> > }
> > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> > index 59958ce..4561104 100644
> > --- a/arch/x86/kvm/x86.c
> > +++ b/arch/x86/kvm/x86.c
> > @@ -1581,6 +1581,13 @@ int kvm_emulate_wrmsr(struct kvm_vcpu *vcpu)
> > }
> > EXPORT_SYMBOL_GPL(kvm_emulate_wrmsr);
> >
> > +bool kvm_need_cancel_enter_guest(struct kvm_vcpu *vcpu)
>
> What about kvm_vcpu_<???>_pending()? Not sure what a good ??? would be.
> The "cancel_enter_guest" wording is a bit confusing when this is called
> from the VM-Exit path.
>
> > +{
> > + return (vcpu->mode == EXITING_GUEST_MODE || kvm_request_pending(vcpu)
> > + || need_resched() || signal_pending(current));
>
> Parantheses around the whole statement are unnecessary. Personal preference
> is to put the || before the newline.
Handle the comments in v4.
Wanpeng
