Commit a0c13434 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

KVM: VMX: introduce vmx_need_pf_intercept 



Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200710154811.418214-7-mgamal@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 32de2b5e

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 */