From: Krish Sadhukhan Date: Wed, 3 Jul 2019 23:54:35 +0000 (-0400) Subject: KVM nVMX: Check Host Segment Registers and Descriptor Tables on vmentry of nested... X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=1ef23e1f16088f5a91b25bb17585c2d532a097f7;p=linux.git KVM nVMX: Check Host Segment Registers and Descriptor Tables on vmentry of nested guests According to section "Checks on Host Segment and Descriptor-Table Registers" in Intel SDM vol 3C, the following checks are performed on vmentry of nested guests: - In the selector field for each of CS, SS, DS, ES, FS, GS and TR, the RPL (bits 1:0) and the TI flag (bit 2) must be 0. - The selector fields for CS and TR cannot be 0000H. - The selector field for SS cannot be 0000H if the "host address-space size" VM-exit control is 0. - On processors that support Intel 64 architecture, the base-address fields for FS, GS and TR must contain canonical addresses. Signed-off-by: Krish Sadhukhan Reviewed-by: Karl Heubaum Signed-off-by: Paolo Bonzini --- diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index d125304ae2c99..6dd20e0ad2fad 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2627,6 +2627,30 @@ static int nested_vmx_check_host_state(struct kvm_vcpu *vcpu, !kvm_pat_valid(vmcs12->host_ia32_pat)) return -EINVAL; + ia32e = (vmcs12->vm_exit_controls & + VM_EXIT_HOST_ADDR_SPACE_SIZE) != 0; + + if (vmcs12->host_cs_selector & (SEGMENT_RPL_MASK | SEGMENT_TI_MASK) || + vmcs12->host_ss_selector & (SEGMENT_RPL_MASK | SEGMENT_TI_MASK) || + vmcs12->host_ds_selector & (SEGMENT_RPL_MASK | SEGMENT_TI_MASK) || + vmcs12->host_es_selector & (SEGMENT_RPL_MASK | SEGMENT_TI_MASK) || + vmcs12->host_fs_selector & (SEGMENT_RPL_MASK | SEGMENT_TI_MASK) || + vmcs12->host_gs_selector & (SEGMENT_RPL_MASK | SEGMENT_TI_MASK) || + vmcs12->host_tr_selector & (SEGMENT_RPL_MASK | SEGMENT_TI_MASK) || + vmcs12->host_cs_selector == 0 || + vmcs12->host_tr_selector == 0 || + (vmcs12->host_ss_selector == 0 && !ia32e)) + return -EINVAL; + +#ifdef CONFIG_X86_64 + if (is_noncanonical_address(vmcs12->host_fs_base, vcpu) || + is_noncanonical_address(vmcs12->host_gs_base, vcpu) || + is_noncanonical_address(vmcs12->host_gdtr_base, vcpu) || + is_noncanonical_address(vmcs12->host_idtr_base, vcpu) || + is_noncanonical_address(vmcs12->host_tr_base, vcpu)) + return -EINVAL; +#endif + /* * If the load IA32_EFER VM-exit control is 1, bits reserved in the * IA32_EFER MSR must be 0 in the field for that register. In addition, @@ -2634,8 +2658,6 @@ static int nested_vmx_check_host_state(struct kvm_vcpu *vcpu, * the host address-space size VM-exit control. */ if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_EFER) { - ia32e = (vmcs12->vm_exit_controls & - VM_EXIT_HOST_ADDR_SPACE_SIZE) != 0; if (!kvm_valid_efer(vcpu, vmcs12->host_ia32_efer) || ia32e != !!(vmcs12->host_ia32_efer & EFER_LMA) || ia32e != !!(vmcs12->host_ia32_efer & EFER_LME))