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: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration")
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/svm/sev.c | 25 +++++++++++--------------
1 file changed, 11 insertions(+), 14 deletions(-)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 531613f758ba..902c52a8dd0c 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -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:
--
2.27.0
