KVM: VMX: introduce vmx_need_pf_intercept (a0c13434) · Commits · 戴 / test

arch/x86/kvm/vmx/nested.c

+17 −11

Original line number	Diff line number	Diff line
		@@ -2438,22 +2438,28 @@ static void prepare_vmcs02_rare(struct vcpu_vmx vmx, struct vmcs12 vmcs12)

		/*
		* Whether page-faults are trapped is determined by a combination of
		* 3 settings: PFEC_MASK, PFEC_MATCH and EXCEPTION_BITMAP.PF.
		* If enable_ept, L0 doesn't care about page faults and we should
		* set all of these to L1's desires. However, if !enable_ept, L0 does
		* care about (at least some) page faults, and because it is not easy
		* (if at all possible?) to merge L0 and L1's desires, we simply ask
		* to exit on each and every L2 page fault. This is done by setting
		* MASK=MATCH=0 and (see below) EB.PF=1.
		* 3 settings: PFEC_MASK, PFEC_MATCH and EXCEPTION_BITMAP.PF. If L0
		* doesn't care about page faults then we should set all of these to
		* L1's desires. However, if L0 does care about (some) page faults, it
		* is not easy (if at all possible?) to merge L0 and L1's desires, we
		* simply ask to exit on each and every L2 page fault. This is done by
		* setting MASK=MATCH=0 and (see below) EB.PF=1.
		* Note that below we don't need special code to set EB.PF beyond the
		* "or"ing of the EB of vmcs01 and vmcs12, because when enable_ept,
		* vmcs01's EB.PF is 0 so the "or" will take vmcs12's value, and when
		* !enable_ept, EB.PF is 1, so the "or" will always be 1.
		*/
		vmcs_write32(PAGE_FAULT_ERROR_CODE_MASK,
		enable_ept ? vmcs12->page_fault_error_code_mask : 0);
		vmcs_write32(PAGE_FAULT_ERROR_CODE_MATCH,
		enable_ept ? vmcs12->page_fault_error_code_match : 0);
		if (vmx_need_pf_intercept(&vmx->vcpu)) {
		/*
		* TODO: if both L0 and L1 need the same MASK and MATCH,
		* go ahead and use it?
		*/
		vmcs_write32(PAGE_FAULT_ERROR_CODE_MASK, 0);
		vmcs_write32(PAGE_FAULT_ERROR_CODE_MATCH, 0);
		} else {
		vmcs_write32(PAGE_FAULT_ERROR_CODE_MASK, vmcs12->page_fault_error_code_mask);
		vmcs_write32(PAGE_FAULT_ERROR_CODE_MATCH, vmcs12->page_fault_error_code_match);
		}

		if (cpu_has_vmx_apicv()) {
		vmcs_write64(EOI_EXIT_BITMAP0, vmcs12->eoi_exit_bitmap0);

arch/x86/kvm/vmx/vmx.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -780,7 +780,7 @@ void update_exception_bitmap(struct kvm_vcpu *vcpu)
		eb \|= 1u << BP_VECTOR;
		if (to_vmx(vcpu)->rmode.vm86_active)
		eb = ~0;
		if (enable_ept)
		if (!vmx_need_pf_intercept(vcpu))
		eb &= ~(1u << PF_VECTOR);

		/* When we are running a nested L2 guest and L1 specified for it a

arch/x86/kvm/vmx/vmx.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -550,6 +550,11 @@ static inline bool vmx_has_waitpkg(struct vcpu_vmx *vmx)
		SECONDARY_EXEC_ENABLE_USR_WAIT_PAUSE;
		}

		static inline bool vmx_need_pf_intercept(struct kvm_vcpu *vcpu)
		{
		return !enable_ept;
		}

		void dump_vmcs(void);

		#endif /* __KVM_X86_VMX_H */

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