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authorAvi Kivity <avi@redhat.com>2010-05-27 13:35:58 +0200
committerAvi Kivity <avi@redhat.com>2010-06-09 17:48:37 +0200
commit69325a122580d3a7b26589e8efdd6663001c3297 (patch)
tree714358f2e6229e699740bc249b2327b10ba67854
parentKVM: MMU: invalidate and flush on spte small->large page size change (diff)
downloadlinux-69325a122580d3a7b26589e8efdd6663001c3297.tar.xz
linux-69325a122580d3a7b26589e8efdd6663001c3297.zip
KVM: MMU: Remove user access when allowing kernel access to gpte.w=0 page
If cr0.wp=0, we have to allow the guest kernel access to a page with pte.w=0. We do that by setting spte.w=1, since the host cr0.wp must remain set so the host can write protect pages. Once we allow write access, we must remove user access otherwise we mistakenly allow the user to write the page. Reviewed-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
-rw-r--r--arch/x86/kvm/mmu.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 6fbcb48d5a9b..a6f695d76928 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1815,6 +1815,9 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
spte |= PT_WRITABLE_MASK;
+ if (!tdp_enabled && !(pte_access & ACC_WRITE_MASK))
+ spte &= ~PT_USER_MASK;
+
/*
* Optimization: for pte sync, if spte was writable the hash
* lookup is unnecessary (and expensive). Write protection