From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Date: Fri, 12 Nov 2010 06:47:01 +0000 (+0800)
Subject: KVM: MMU: clear apfs if page state is changed
X-Git-Tag: v5.15~26911^2~95
X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=e5f3f027960128035a5fa176877b5e9160b35397;p=mirror_ubuntu-kernels.git

KVM: MMU: clear apfs if page state is changed

If CR0.PG is changed, the page fault cann't be avoid when the prefault address
is accessed later

And it also fix a bug: it can retry a page enabled #PF in page disabled context
if mmu is shadow page

This idear is from Gleb Natapov

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
---

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b7ee61d5bc81..9b875ff05410 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -520,6 +520,9 @@ int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
 
 	kvm_x86_ops->set_cr0(vcpu, cr0);
 
+	if ((cr0 ^ old_cr0) & X86_CR0_PG)
+		kvm_clear_async_pf_completion_queue(vcpu);
+
 	if ((cr0 ^ old_cr0) & update_bits)
 		kvm_mmu_reset_context(vcpu);
 	return 0;