On Mon, Mar 28, 2022 at 1:18 PM David Matlack <dmatlack@xxxxxxxxxx> wrote:
>
> On Mon, Mar 21, 2022 at 04:48:40PM -0700, Ben Gardon wrote:
> > Factor out the code to update the NX hugepages state for an individual
> > VM. This will be expanded in future commits to allow per-VM control of
> > Nx hugepages.
> >
> > No functional change intended.
> >
> > Signed-off-by: Ben Gardon <bgardon@xxxxxxxxxx>
> > ---
> > arch/x86/kvm/mmu/mmu.c | 18 +++++++++++-------
> > 1 file changed, 11 insertions(+), 7 deletions(-)
> >
> > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> > index 3b8da8b0745e..1b59b56642f1 100644
> > --- a/arch/x86/kvm/mmu/mmu.c
> > +++ b/arch/x86/kvm/mmu/mmu.c
> > @@ -6195,6 +6195,15 @@ static void __set_nx_huge_pages(bool val)
> > nx_huge_pages = itlb_multihit_kvm_mitigation = val;
> > }
> >
> > +static int kvm_update_nx_huge_pages(struct kvm *kvm)
> > +{
> > + mutex_lock(&kvm->slots_lock);
> > + kvm_mmu_zap_all_fast(kvm);
> > + mutex_unlock(&kvm->slots_lock);
> > +
> > + wake_up_process(kvm->arch.nx_lpage_recovery_thread);
> > +}
> > +
> > static int set_nx_huge_pages(const char *val, const struct kernel_param *kp)
> > {
> > bool old_val = nx_huge_pages;
> > @@ -6217,13 +6226,8 @@ static int set_nx_huge_pages(const char *val, const struct kernel_param *kp)
> >
> > mutex_lock(&kvm_lock);
> >
>
> nit: This blank line is asymmetrical with mutex_unlock().
>
> > - list_for_each_entry(kvm, &vm_list, vm_list) {
> > - mutex_lock(&kvm->slots_lock);
> > - kvm_mmu_zap_all_fast(kvm);
> > - mutex_unlock(&kvm->slots_lock);
> > -
> > - wake_up_process(kvm->arch.nx_lpage_recovery_thread);
> > - }
> > + list_for_each_entry(kvm, &vm_list, vm_list)
> > + kvm_set_nx_huge_pages(kvm);
>
> This should be kvm_update_nx_huge_pages() right?
Oh woops, duh. Apparently I did not compile-test this patch individually.
>
> > mutex_unlock(&kvm_lock);
> > }
> >
> > --
> > 2.35.1.894.gb6a874cedc-goog
> >
