KVM: x86: Add module parameter for supporting VMware backdoor (c4ae60e4) · Commits · 戴 / test

Support access to VMware backdoor requires KVM to intercept #GP exceptions from guest which introduce slight performance hit. Therefore, control this support by module parameter. Note that module parameter is exported as it should be consumed by kvm_intel & kvm_amd to determine if they should intercept #GP or not. This commit doesn't change semantics. It is done as a preparation for future commits. Signed-off-by:

Liran Alon <liran.alon@oracle.com> Reviewed-by:

Nikita Leshenko <nikita.leshchenko@oracle.com> Reviewed-by:

Radim Krčmář <rkrcmar@redhat.com> Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

Documentation/admin-guide/kernel-parameters.txt

+3 −0

Original line number	Diff line number	Diff line
		@@ -1887,6 +1887,9 @@
		kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs.
		Default is 0 (don't ignore, but inject #GP)

		kvm.enable_vmware_backdoor=[KVM] Support VMware backdoor PV interface.
		Default is false (don't support).

		kvm.mmu_audit= [KVM] This is a R/W parameter which allows audit
		KVM MMU at runtime.
		Default is 0 (off)

arch/x86/kvm/x86.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -142,6 +142,10 @@ module_param(lapic_timer_advance_ns, uint, S_IRUGO \| S_IWUSR);
		static bool __read_mostly vector_hashing = true;
		module_param(vector_hashing, bool, S_IRUGO);

		bool __read_mostly enable_vmware_backdoor = false;
		module_param(enable_vmware_backdoor, bool, S_IRUGO);
		EXPORT_SYMBOL_GPL(enable_vmware_backdoor);

		#define KVM_NR_SHARED_MSRS 16

		struct kvm_shared_msrs_global {

arch/x86/kvm/x86.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -242,6 +242,8 @@ extern unsigned int min_timer_period_us;

		extern unsigned int lapic_timer_advance_ns;

		extern bool enable_vmware_backdoor;

		extern struct static_key kvm_no_apic_vcpu;

		static inline u64 nsec_to_cycles(struct kvm_vcpu *vcpu, u64 nsec)

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