Commit 501cfe06 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

KVM: SEV: unify cgroup cleanup code for svm_vm_migrate_from 



Use the same cleanup code independent of whether the cgroup to be
uncharged and unref'd is the source or the destination cgroup.  Use a
bool to track whether the destination cgroup has been charged, which also
fixes a bug in the error case: the destination cgroup must be uncharged
only if it does not match the source.

Fixes: b5663931 ("KVM: SEV: Add support for SEV intra host migration")
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 3e067fd8

arch/x86/kvm/svm/sev.c

+11 −14
Original line number Diff line number Diff line
@@ -1614,12 +1614,6 @@ static void sev_migrate_from(struct kvm_sev_info *dst, 
	src->handle = 0;

	src->pages_locked = 0;



	if (dst->misc_cg != src->misc_cg)

		sev_misc_cg_uncharge(src);



	put_misc_cg(src->misc_cg);

	src->misc_cg = NULL;



	INIT_LIST_HEAD(&dst->regions_list);

	list_replace_init(&src->regions_list, &dst->regions_list);

}
@@ -1667,9 +1661,10 @@ static int sev_es_migrate_from(struct kvm *dst, struct kvm *src) 
int svm_vm_migrate_from(struct kvm *kvm, unsigned int source_fd)

{

	struct kvm_sev_info *dst_sev = &to_kvm_svm(kvm)->sev_info;

	struct kvm_sev_info *src_sev;

	struct kvm_sev_info *src_sev, *cg_cleanup_sev;

	struct file *source_kvm_file;

	struct kvm *source_kvm;

	bool charged = false;

	int ret;



	ret = sev_lock_for_migration(kvm);
@@ -1699,10 +1694,12 @@ int svm_vm_migrate_from(struct kvm *kvm, unsigned int source_fd) 


	src_sev = &to_kvm_svm(source_kvm)->sev_info;

	dst_sev->misc_cg = get_current_misc_cg();

	cg_cleanup_sev = dst_sev;

	if (dst_sev->misc_cg != src_sev->misc_cg) {

		ret = sev_misc_cg_try_charge(dst_sev);

		if (ret)

			goto out_dst_put_cgroup;

			goto out_dst_cgroup;

		charged = true;

	}



	ret = sev_lock_vcpus_for_migration(kvm);
@@ -1719,6 +1716,7 @@ int svm_vm_migrate_from(struct kvm *kvm, unsigned int source_fd) 
	}

	sev_migrate_from(dst_sev, src_sev);

	kvm_vm_dead(source_kvm);

	cg_cleanup_sev = src_sev;

	ret = 0;



out_source_vcpu:
@@ -1726,12 +1724,11 @@ int svm_vm_migrate_from(struct kvm *kvm, unsigned int source_fd) 
out_dst_vcpu:

	sev_unlock_vcpus_for_migration(kvm);

out_dst_cgroup:

	if (ret < 0) {

		sev_misc_cg_uncharge(dst_sev);

out_dst_put_cgroup:

		put_misc_cg(dst_sev->misc_cg);

		dst_sev->misc_cg = NULL;

	}

	/* Operates on the source on success, on the destination on failure.  */

	if (charged)

		sev_misc_cg_uncharge(cg_cleanup_sev);

	put_misc_cg(cg_cleanup_sev->misc_cg);

	cg_cleanup_sev->misc_cg = NULL;

out_source:

	sev_unlock_after_migration(source_kvm);

out_fput: