On Tue, 30 Jul 2019 at 01:50, Sean Christopherson <sean.j.christopherson@xxxxxxxxx> wrote: > > On Fri, Jul 26, 2019 at 02:15:27PM +0800, Wanpeng Li wrote: > > From: Wanpeng Li <wanpengli@xxxxxxxxxxx> > > > > IPI shorthand is supported now by linux apic/x2apic driver, switch to > > IPI shorthand for all excluding self and all including self destination > > shorthand in kvm guest, to avoid splitting the target mask into serveral > > PV IPI hypercalls. > > > > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > > Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> > > Cc: Radim Krčmář <rkrcmar@xxxxxxxxxx> > > Cc: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> > > Cc: Nadav Amit <namit@xxxxxxxxxx> > > Signed-off-by: Wanpeng Li <wanpengli@xxxxxxxxxxx> > > --- > > Note: rebase against tip tree's x86/apic branch > > > > arch/x86/kernel/kvm.c | 14 ++++++++++++-- > > 1 file changed, 12 insertions(+), 2 deletions(-) > > > > diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c > > index b7f34fe..87b73b8 100644 > > --- a/arch/x86/kernel/kvm.c > > +++ b/arch/x86/kernel/kvm.c > > @@ -34,7 +34,9 @@ > > #include <asm/hypervisor.h> > > #include <asm/tlb.h> > > > > +static struct apic orig_apic; > > Copying the entire struct apic to snapshot two functions is funky, > explicitly capturing the two functions would be more intuitive. > > Tangentially related, kvm_setup_pv_ipi() can be annotated __init, > which means the function snapshots can be __ro_after_init. > > That being said, can't we just remove kvm_send_ipi_all() and > kvm_send_ipi_allbutself()? AFAICT, the variations that lead to shorthand > are only used when apic_use_ipi_shorthand is true. If that isn't the > case, fixing the callers in the APIC code seems like the correct thing to > do. The callers in the APIC codes have already done this, so I just remove the two hooks in v2. Regards, Wanpeng Li
