From a32e84594ddf018cc618a8781298804c3e6131ce Mon Sep 17 00:00:00 2001 From: Wanpeng Li Date: Wed, 20 Aug 2014 15:31:53 +0800 Subject: [PATCH] KVM: vmx: fix ept reserved bits for 1-GByte page 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 Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index cad37d57cc47..286c2835e25c 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -5521,17 +5521,18 @@ 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) + if (level == 4) /* 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; - } + else if (spte & (1ULL << 7)) + /* + * 1GB/2MB page, bits 29:12 or 20:12 reserved respectively, + * level == 1 if the hypervisor is using the ignored bit 7. + */ + mask |= (PAGE_SIZE << ((level - 1) * 9)) - PAGE_SIZE; + else if (level > 1) + /* bits 6:3 reserved */ + mask |= 0x78; return mask; } @@ -5561,7 +5562,8 @@ static void ept_misconfig_inspect_spte(struct kvm_vcpu *vcpu, u64 spte, WARN_ON(1); } - if (level == 1 || (level == 2 && (spte & (1ULL << 7)))) { + /* bits 5:3 are _not_ reserved for large page or leaf page */ + if ((rsvd_bits & 0x38) == 0) { u64 ept_mem_type = (spte & 0x38) >> 3; if (ept_mem_type == 2 || ept_mem_type == 3 || -- 2.39.2