From ecba8297aafd50db6ae867e90844eead1611ef1c Mon Sep 17 00:00:00 2001
From: David Gibson <david@gibson.dropbear.id.au>
Date: Wed, 10 Jan 2018 17:04:39 +1100
Subject: [PATCH] KVM: PPC: Book3S HV: Always flush TLB in
kvmppc_alloc_reset_hpt()
References: bsc#1061840
Patch-mainline: v4.15-rc8
Git-commit: ecba8297aafd50db6ae867e90844eead1611ef1c
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.
Cc: stable@vger.kernel.org # v4.10+
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>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/kvm/book3s_64_mmu_hv.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index 8355398f0bb6..b73dbc9e797d 100644
--- 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 *kvm, int order)
* 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 *kvm, int order)
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;
}
--
2.13.6