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author | Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> | 2010-06-30 16:02:45 +0800 |
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committer | Avi Kivity <avi@redhat.com> | 2010-07-23 09:07:04 +0300 |
commit | 6aa0b9dec5d6dde26ea17b0b5be8fccfe19df3c9 (patch) | |
tree | 622e57dd0373a86b98f4976096fa6f670540dab6 /arch/x86/kvm | |
parent | b37fa16e78d6f9790462b3181602a26b5af36260 (diff) | |
download | op-kernel-dev-6aa0b9dec5d6dde26ea17b0b5be8fccfe19df3c9.zip op-kernel-dev-6aa0b9dec5d6dde26ea17b0b5be8fccfe19df3c9.tar.gz |
KVM: MMU: fix conflict access permissions in direct sp
In no-direct mapping, we mark sp is 'direct' when we mapping the
guest's larger page, but its access is encoded form upper page-struct
entire not include the last mapping, it will cause access conflict.
For example, have this mapping:
[W]
/ PDE1 -> |---|
P[W] | | LPA
\ PDE2 -> |---|
[R]
P have two children, PDE1 and PDE2, both PDE1 and PDE2 mapping the
same lage page(LPA). The P's access is WR, PDE1's access is WR,
PDE2's access is RO(just consider read-write permissions here)
When guest access PDE1, we will create a direct sp for LPA, the sp's
access is from P, is W, then we will mark the ptes is W in this sp.
Then, guest access PDE2, we will find LPA's shadow page, is the same as
PDE's, and mark the ptes is RO.
So, if guest access PDE1, the incorrect #PF is occured.
Fixed by encode the last mapping access into direct shadow page
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
-rw-r--r-- | arch/x86/kvm/paging_tmpl.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 89d66ca..2331bdc 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -342,6 +342,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, /* advance table_gfn when emulating 1gb pages with 4k */ if (delta == 0) table_gfn += PT_INDEX(addr, level); + access &= gw->pte_access; } else { direct = 0; table_gfn = gw->table_gfn[level - 2]; |