On Tue, Mar 30, 2021 at 12:59:57PM -0400, Paolo Bonzini wrote: > There is no need to include changes to vcpu->requests into > the pvclock_gtod_sync_lock critical section. The changes to > the shared data structures (in pvclock_update_vm_gtod_copy) > already occur under the lock. > > Cc: David Woodhouse <dwmw@xxxxxxxxxxxx> > Cc: Marcelo Tosatti <mtosatti@xxxxxxxxxx> > Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> > --- > arch/x86/kvm/x86.c | 10 ++++------ > 1 file changed, 4 insertions(+), 6 deletions(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index fe806e894212..0a83eff40b43 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -2562,10 +2562,12 @@ static void kvm_gen_update_masterclock(struct kvm *kvm) > > kvm_hv_invalidate_tsc_page(kvm); > > - spin_lock(&ka->pvclock_gtod_sync_lock); > kvm_make_mclock_inprogress_request(kvm); > + Might be good to serialize against two kvm_gen_update_masterclock callers? Otherwise one caller could clear KVM_REQ_MCLOCK_INPROGRESS, while the other is still at pvclock_update_vm_gtod_copy(). Otherwise, looks good.
