diff options
| author | Yang, Wei Y <wei.y.yang@intel.com> | 2011-06-03 07:14:16 +0400 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2011-07-12 14:16:15 +0400 |
| commit | e57d4a356ad3ac46881399c424cc6cf6dd16359d (patch) | |
| tree | c1b903ecb1a70905510f635adfa74cf582334a03 | |
| parent | 611c120f7486a19e7df2225f875a52ef0b599ae8 (diff) | |
| download | linux-e57d4a356ad3ac46881399c424cc6cf6dd16359d.tar.xz | |
KVM: Add instruction fetch checking when walking guest page table
This patch adds instruction fetch checking when walking guest page table,
to implement SMEP when emulating instead of executing natively.
Signed-off-by: Yang, Wei <wei.y.yang@intel.com>
Signed-off-by: Shan, Haitao <haitao.shan@intel.com>
Signed-off-by: Li, Xin <xin.li@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
| -rw-r--r-- | arch/x86/kvm/paging_tmpl.h | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 9d03ad4dd5ec..1caeb4d22e01 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -246,6 +246,12 @@ walk: gfn_t gfn; u32 ac; + /* check if the kernel is fetching from user page */ + if (unlikely(pte_access & PT_USER_MASK) && + kvm_read_cr4_bits(vcpu, X86_CR4_SMEP)) + if (fetch_fault && !user_fault) + eperm = true; + gfn = gpte_to_gfn_lvl(pte, lvl); gfn += (addr & PT_LVL_OFFSET_MASK(lvl)) >> PAGE_SHIFT; @@ -305,7 +311,8 @@ error: walker->fault.error_code |= write_fault | user_fault; - if (fetch_fault && mmu->nx) + if (fetch_fault && (mmu->nx || + kvm_read_cr4_bits(vcpu, X86_CR4_SMEP))) walker->fault.error_code |= PFERR_FETCH_MASK; if (rsvd_fault) walker->fault.error_code |= PFERR_RSVD_MASK; |