Commit 0b020f5a authored by Peter Gonda's avatar Peter Gonda Committed by Paolo Bonzini
Browse files

KVM: SEV: Add support for SEV-ES intra host migration 



For SEV-ES to work with intra host migration the VMSAs, GHCB metadata,
and other SEV-ES info needs to be preserved along with the guest's
memory.

Signed-off-by: default avatarPeter Gonda <pgonda@google.com>
Reviewed-by: default avatarMarc Orr <marcorr@google.com>
Cc: Marc Orr <marcorr@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Message-Id: <20211021174303.385706-4-pgonda@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent b5663931

arch/x86/kvm/svm/sev.c

+47 −1
Original line number Diff line number Diff line
@@ -1612,6 +1612,46 @@ static void sev_migrate_from(struct kvm_sev_info *dst, 
	list_replace_init(&src->regions_list, &dst->regions_list);

}



static int sev_es_migrate_from(struct kvm *dst, struct kvm *src)

{

	int i;

	struct kvm_vcpu *dst_vcpu, *src_vcpu;

	struct vcpu_svm *dst_svm, *src_svm;



	if (atomic_read(&src->online_vcpus) != atomic_read(&dst->online_vcpus))

		return -EINVAL;



	kvm_for_each_vcpu(i, src_vcpu, src) {

		if (!src_vcpu->arch.guest_state_protected)

			return -EINVAL;

	}



	kvm_for_each_vcpu(i, src_vcpu, src) {

		src_svm = to_svm(src_vcpu);

		dst_vcpu = kvm_get_vcpu(dst, i);

		dst_svm = to_svm(dst_vcpu);



		/*

		 * Transfer VMSA and GHCB state to the destination.  Nullify and

		 * clear source fields as appropriate, the state now belongs to

		 * the destination.

		 */

		memcpy(&dst_svm->sev_es, &src_svm->sev_es, sizeof(src_svm->sev_es));

		dst_svm->vmcb->control.ghcb_gpa = src_svm->vmcb->control.ghcb_gpa;

		dst_svm->vmcb->control.vmsa_pa = src_svm->vmcb->control.vmsa_pa;

		dst_vcpu->arch.guest_state_protected = true;



		memset(&src_svm->sev_es, 0, sizeof(src_svm->sev_es));

		src_svm->vmcb->control.ghcb_gpa = INVALID_PAGE;

		src_svm->vmcb->control.vmsa_pa = INVALID_PAGE;

		src_vcpu->arch.guest_state_protected = false;

	}

	to_kvm_svm(src)->sev_info.es_active = false;

	to_kvm_svm(dst)->sev_info.es_active = true;



	return 0;

}



int svm_vm_migrate_from(struct kvm *kvm, unsigned int source_fd)

{

	struct kvm_sev_info *dst_sev = &to_kvm_svm(kvm)->sev_info;
@@ -1640,7 +1680,7 @@ int svm_vm_migrate_from(struct kvm *kvm, unsigned int source_fd) 
	if (ret)

		goto out_fput;



	if (!sev_guest(source_kvm) || sev_es_guest(source_kvm)) {

	if (!sev_guest(source_kvm)) {

		ret = -EINVAL;

		goto out_source;

	}
@@ -1660,10 +1700,16 @@ int svm_vm_migrate_from(struct kvm *kvm, unsigned int source_fd) 
	if (ret)

		goto out_dst_vcpu;



	if (sev_es_guest(source_kvm)) {

		ret = sev_es_migrate_from(kvm, source_kvm);

		if (ret)

			goto out_source_vcpu;

	}

	sev_migrate_from(dst_sev, src_sev);

	kvm_vm_dead(source_kvm);

	ret = 0;



out_source_vcpu:

	sev_unlock_vcpus_for_migration(source_kvm);

out_dst_vcpu:

	sev_unlock_vcpus_for_migration(kvm);