KVM: VMX: Fix VPID capability detection (61f1dd90) · Commits · 戴 / test

In my setup, EPT is not exposed to L1, the VPID capability is exposed and can be observed by vmxcap tool in L1: INVVPID supported yes Individual-address INVVPID yes Single-context INVVPID yes All-context INVVPID yes Single-context-retaining-globals INVVPID yes However, the module parameter of VPID observed in L1 is always N, the cpu_has_vmx_invvpid() check in L1 KVM fails since vmx_capability.vpid is 0 and it is not read from MSR due to EPT is not exposed. The VPID can be used to tag linear mappings when EPT is not enabled. However, current logic just detects VPID capability if EPT is enabled, this patch fixes it. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Jim Mattson <jmattson@google.com> Signed-off-by:

Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by:

Radim Krčmář <rkrcmar@redhat.com>

arch/x86/kvm/vmx.c

+13 −2

Original line number	Diff line number	Diff line
		@@ -3681,14 +3681,25 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf)
		SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE \|
		SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY);

		rdmsr_safe(MSR_IA32_VMX_EPT_VPID_CAP,
		&vmx_capability.ept, &vmx_capability.vpid);

		if (_cpu_based_2nd_exec_control & SECONDARY_EXEC_ENABLE_EPT) {
		/* CR3 accesses and invlpg don't need to cause VM Exits when EPT
		enabled */
		_cpu_based_exec_control &= ~(CPU_BASED_CR3_LOAD_EXITING \|
		CPU_BASED_CR3_STORE_EXITING \|
		CPU_BASED_INVLPG_EXITING);
		rdmsr(MSR_IA32_VMX_EPT_VPID_CAP,
		vmx_capability.ept, vmx_capability.vpid);
		} else if (vmx_capability.ept) {
		vmx_capability.ept = 0;
		pr_warn_once("EPT CAP should not exist if not support "
		"1-setting enable EPT VM-execution control\n");
		}
		if (!(_cpu_based_2nd_exec_control & SECONDARY_EXEC_ENABLE_VPID) &&
		vmx_capability.vpid) {
		vmx_capability.vpid = 0;
		pr_warn_once("VPID CAP should not exist if not support "
		"1-setting enable VPID VM-execution control\n");
		}

		min = VM_EXIT_SAVE_DEBUG_CONTROLS \| VM_EXIT_ACK_INTR_ON_EXIT;

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