Commit c4c083d9 authored by Binbin Wu's avatar Binbin Wu Committed by Paolo Bonzini
Browse files

KVM: x86: Add a helper to check for user interception of KVM hypercalls 



Add and use user_exit_on_hypercall() to check if userspace wants to handle
a KVM hypercall instead of open-coding the logic everywhere.

No functional change intended.

Signed-off-by: default avatarBinbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: default avatarIsaku Yamahata <isaku.yamahata@intel.com>
Reviewed-by: default avatarKai Huang <kai.huang@intel.com>
Reviewed-by: default avatarXiaoyao Li <xiaoyao.li@intel.com>
[sean: squash into one patch, keep explicit KVM_HC_MAP_GPA_RANGE check]
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Reviewed-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
Message-ID: <20241128004344.4072099-3-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 9a1dfeff

arch/x86/kvm/svm/sev.c

+2 −2
Original line number Diff line number Diff line
@@ -3627,7 +3627,7 @@ static int snp_begin_psc_msr(struct vcpu_svm *svm, u64 ghcb_msr) 
		return 1; /* resume guest */

	}



	if (!(vcpu->kvm->arch.hypercall_exit_enabled & (1 << KVM_HC_MAP_GPA_RANGE))) {

	if (!user_exit_on_hypercall(vcpu->kvm, KVM_HC_MAP_GPA_RANGE)) {

		set_ghcb_msr(svm, GHCB_MSR_PSC_RESP_ERROR);

		return 1; /* resume guest */

	}
@@ -3717,7 +3717,7 @@ static int snp_begin_psc(struct vcpu_svm *svm, struct psc_buffer *psc) 
	bool huge;

	u64 gfn;



	if (!(vcpu->kvm->arch.hypercall_exit_enabled & (1 << KVM_HC_MAP_GPA_RANGE))) {

	if (!user_exit_on_hypercall(vcpu->kvm, KVM_HC_MAP_GPA_RANGE)) {

		snp_complete_psc(svm, VMGEXIT_PSC_ERROR_GENERIC);

		return 1;

	}

arch/x86/kvm/x86.c

+1 −1
Original line number Diff line number Diff line
@@ -10041,7 +10041,7 @@ unsigned long __kvm_emulate_hypercall(struct kvm_vcpu *vcpu, unsigned long nr, 
		u64 gpa = a0, npages = a1, attrs = a2;



		ret = -KVM_ENOSYS;

		if (!(vcpu->kvm->arch.hypercall_exit_enabled & (1 << KVM_HC_MAP_GPA_RANGE)))

		if (!user_exit_on_hypercall(vcpu->kvm, KVM_HC_MAP_GPA_RANGE))

			break;



		if (!PAGE_ALIGNED(gpa) || !npages ||

arch/x86/kvm/x86.h

+5 −0
Original line number Diff line number Diff line
@@ -612,4 +612,9 @@ int kvm_sev_es_string_io(struct kvm_vcpu *vcpu, unsigned int size, 
			 unsigned int port, void *data,  unsigned int count,

			 int in);



static inline bool user_exit_on_hypercall(struct kvm *kvm, unsigned long hc_nr)

{

	return kvm->arch.hypercall_exit_enabled & BIT(hc_nr);

}



#endif