From: Marcelo Tosatti <mtosatti@redhat.com>
Date: Fri, 28 May 2010 12:44:59 +0000 (-0300)
Subject: KVM: MMU: invalidate and flush on spte small->large page size change
X-Git-Tag: firefly_0821_release~10186^2~1297
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=05ae56ca1cd57e3b6fb57173e8f9e23f289880e9;p=firefly-linux-kernel-4.4.55.git

KVM: MMU: invalidate and flush on spte small->large page size change

Always invalidate spte and flush TLBs when changing page size, to make
sure different sized translations for the same address are never cached
in a CPU's TLB.

Currently the only case where this occurs is when a non-leaf spte pointer is
overwritten by a leaf, large spte entry. This can happen after dirty
logging is disabled on a memslot, for example.

Noticed by Andrea.

KVM-Stable-Tag
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
(cherry picked from commit 3be2264be3c00865116f997dc53ebcc90fe7fc4b)
---

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index d5fc36cb4f05..fdf2e28f3bc6 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1901,6 +1901,8 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
 
 			child = page_header(pte & PT64_BASE_ADDR_MASK);
 			mmu_page_remove_parent_pte(child, sptep);
+			__set_spte(sptep, shadow_trap_nonpresent_pte);
+			kvm_flush_remote_tlbs(vcpu->kvm);
 		} else if (pfn != spte_to_pfn(*sptep)) {
 			pgprintk("hfn old %lx new %lx\n",
 				 spte_to_pfn(*sptep), pfn);