diff options
| author | Marcelo Tosatti | 2009-06-11 17:07:43 +0200 |
|---|---|---|
| committer | Avi Kivity | 2009-09-10 07:32:56 +0200 |
| commit | 68f89400bc92421d6da22e1ec8e3ec599c3c8244 (patch) | |
| tree | be63fcdb8ddf3513b6011a3fc93aee4b2adcf447 /arch/x86/kvm/vmx.c | |
| parent | KVM: MMU: add kvm_mmu_get_spte_hierarchy helper (diff) | |
| download | kernel-qcow2-linux-68f89400bc92421d6da22e1ec8e3ec599c3c8244.tar.gz kernel-qcow2-linux-68f89400bc92421d6da22e1ec8e3ec599c3c8244.tar.xz kernel-qcow2-linux-68f89400bc92421d6da22e1ec8e3ec599c3c8244.zip | |
KVM: VMX: EPT misconfiguration handler
Handler for EPT misconfiguration which checks for valid state
in the shadow pagetables, printing the spte on each level.
The separate WARN_ONs are useful for kerneloops.org.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86/kvm/vmx.c')
| -rw-r--r-- | arch/x86/kvm/vmx.c | 86 |
1 files changed, 85 insertions, 1 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 6610181267b1..94c07ada103e 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3227,6 +3227,89 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) return kvm_mmu_page_fault(vcpu, gpa & PAGE_MASK, 0); } +static u64 ept_rsvd_mask(u64 spte, int level) +{ + int i; + u64 mask = 0; + + 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; + } + + return mask; +} + +static void ept_misconfig_inspect_spte(struct kvm_vcpu *vcpu, u64 spte, + int level) +{ + printk(KERN_ERR "%s: spte 0x%llx level %d\n", __func__, spte, level); + + /* 010b (write-only) */ + WARN_ON((spte & 0x7) == 0x2); + + /* 110b (write/execute) */ + WARN_ON((spte & 0x7) == 0x6); + + /* 100b (execute-only) and value not supported by logical processor */ + if (!cpu_has_vmx_ept_execute_only()) + WARN_ON((spte & 0x7) == 0x4); + + /* not 000b */ + if ((spte & 0x7)) { + u64 rsvd_bits = spte & ept_rsvd_mask(spte, level); + + if (rsvd_bits != 0) { + printk(KERN_ERR "%s: rsvd_bits = 0x%llx\n", + __func__, rsvd_bits); + WARN_ON(1); + } + + if (level == 1 || (level == 2 && (spte & (1ULL << 7)))) { + u64 ept_mem_type = (spte & 0x38) >> 3; + + if (ept_mem_type == 2 || ept_mem_type == 3 || + ept_mem_type == 7) { + printk(KERN_ERR "%s: ept_mem_type=0x%llx\n", + __func__, ept_mem_type); + WARN_ON(1); + } + } + } +} + +static int handle_ept_misconfig(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) +{ + u64 sptes[4]; + int nr_sptes, i; + gpa_t gpa; + + gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS); + + printk(KERN_ERR "EPT: Misconfiguration.\n"); + printk(KERN_ERR "EPT: GPA: 0x%llx\n", gpa); + + nr_sptes = kvm_mmu_get_spte_hierarchy(vcpu, gpa, sptes); + + for (i = PT64_ROOT_LEVEL; i > PT64_ROOT_LEVEL - nr_sptes; --i) + ept_misconfig_inspect_spte(vcpu, sptes[i-1], i); + + kvm_run->exit_reason = KVM_EXIT_UNKNOWN; + kvm_run->hw.hardware_exit_reason = EXIT_REASON_EPT_MISCONFIG; + + return 0; +} + static int handle_nmi_window(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) { u32 cpu_based_vm_exec_control; @@ -3306,8 +3389,9 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu, [EXIT_REASON_APIC_ACCESS] = handle_apic_access, [EXIT_REASON_WBINVD] = handle_wbinvd, [EXIT_REASON_TASK_SWITCH] = handle_task_switch, - [EXIT_REASON_EPT_VIOLATION] = handle_ept_violation, [EXIT_REASON_MCE_DURING_VMENTRY] = handle_machine_check, + [EXIT_REASON_EPT_VIOLATION] = handle_ept_violation, + [EXIT_REASON_EPT_MISCONFIG] = handle_ept_misconfig, }; static const int kvm_vmx_max_exit_handlers = |