4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: David Gibson david@gibson.dropbear.id.au
commit ecba8297aafd50db6ae867e90844eead1611ef1c upstream.
The KVM_PPC_ALLOCATE_HTAB ioctl(), implemented by kvmppc_alloc_reset_hpt() is supposed to completely clear and reset a guest's Hashed Page Table (HPT) allocating or re-allocating it if necessary.
In the case where an HPT of the right size already exists and it just zeroes it, it forces a TLB flush on all guest CPUs, to remove any stale TLB entries loaded from the old HPT.
However, that situation can arise when the HPT is resizing as well - or even when switching from an RPT to HPT - so those cases need a TLB flush as well.
So, move the TLB flush to trigger in all cases except for errors.
Fixes: f98a8bf9ee20 ("KVM: PPC: Book3S HV: Allow KVM_PPC_ALLOCATE_HTAB ioctl() to change HPT size") Signed-off-by: David Gibson david@gibson.dropbear.id.au Signed-off-by: Paul Mackerras paulus@ozlabs.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/powerpc/kvm/book3s_64_mmu_hv.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -165,8 +165,6 @@ long kvmppc_alloc_reset_hpt(struct kvm * * Reset all the reverse-mapping chains for all memslots */ kvmppc_rmap_reset(kvm); - /* Ensure that each vcpu will flush its TLB on next entry. */ - cpumask_setall(&kvm->arch.need_tlb_flush); err = 0; goto out; } @@ -182,6 +180,10 @@ long kvmppc_alloc_reset_hpt(struct kvm * kvmppc_set_hpt(kvm, &info);
out: + if (err == 0) + /* Ensure that each vcpu will flush its TLB on next entry. */ + cpumask_setall(&kvm->arch.need_tlb_flush); + mutex_unlock(&kvm->lock); return err; }