EPT misconfig handler in kvm will check which reason lead to EPT 
misconfiguration after vmexit. One of the reasons is that an EPT 
paging-structure entry is configured with settings reserved for 
future functionality. However, the handler can't identify if 
paging-structure entry of reserved bits for 1-GByte page are 
configured, since PDPTE which point to 1-GByte page will reserve 
bits 29:12 instead of bits 7:3 which are reserved for PDPTE that 
references an EPT Page Directory. This patch fix it by reserve 
bits 29:12 for 1-GByte page. 

Signed-off-by: Wanpeng Li <wanpeng...@linux.intel.com>
---
v1 -> v2:
 * same "if" statement cover both 2MB and 1GB pages
 * return 0xf8 for level == 4
 * get the level by checking the return value of ept_rsvd_mask 

 arch/x86/kvm/vmx.c | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index cad37d5..2763f37 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5521,17 +5521,12 @@ static u64 ept_rsvd_mask(u64 spte, int level)
        for (i = 51; i > boot_cpu_data.x86_phys_bits; i--)
                mask |= (1ULL << i);
 
-       if (level > 2)
-               /* bits 7:3 reserved */
-               mask |= 0xf8;
-       else if (level == 2) {
-               if (spte & (1ULL << 7))
-                       /* 2MB ref, bits 20:12 reserved */
-                       mask |= 0x1ff000;
-               else
-                       /* bits 6:3 reserved */
-                       mask |= 0x78;
-       }
+       if (spte & (1ULL << 7))
+               /* 1GB/2MB page, bits 29:12 or 20:12 reserved respectively */
+               mask |= (PAGE_SIZE << ((level - 1) * 9)) - PAGE_SIZE;
+       else
+               /* bits 6:3 reserved */
+               mask |= 0x78;
 
        return mask;
 }
@@ -5561,7 +5556,7 @@ static void ept_misconfig_inspect_spte(struct kvm_vcpu 
*vcpu, u64 spte,
                        WARN_ON(1);
                }
 
-               if (level == 1 || (level == 2 && (spte & (1ULL << 7)))) {
+               if (level == 1 || (rsvd_bits & 0x38)) {
                        u64 ept_mem_type = (spte & 0x38) >> 3;
 
                        if (ept_mem_type == 2 || ept_mem_type == 3 ||
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to