[PATCH v2 05/50] KVM: s390: Unwind kvm_arch_init() piece-by-piece() if a step fails
From: Sean Christopherson <seanjc@google.com>
Date: 2022-11-30 23:10:14
Also in:
kvm, kvm-riscv, kvmarm, linux-arm-kernel, linux-mips, linux-riscv, linux-s390, lkml
Subsystem:
kernel virtual machine for s390 (kvm/s390), s390 architecture, the rest · Maintainers:
Christian Borntraeger, Janosch Frank, Claudio Imbrenda, Heiko Carstens, Vasily Gorbik, Alexander Gordeev, Linus Torvalds
In preparation for folding kvm_arch_hardware_setup() into kvm_arch_init(), unwind initialization one step at a time instead of simply calling kvm_arch_exit(). Using kvm_arch_exit() regardless of which initialization step failed relies on all affected state playing nice with being undone even if said state wasn't first setup. That holds true for state that is currently configured by kvm_arch_init(), but not for state that's handled by kvm_arch_hardware_setup(), e.g. calling gmap_unregister_pte_notifier() without first registering a notifier would result in list corruption due to attempting to delete an entry that was never added to the list. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Eric Farman <farman@linux.ibm.com> --- arch/s390/kvm/kvm-s390.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-)
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index e4890e04b210..221481a09742 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c@@ -498,11 +498,11 @@ int kvm_arch_init(void *opaque) kvm_s390_dbf_uv = debug_register("kvm-uv", 32, 1, 7 * sizeof(long)); if (!kvm_s390_dbf_uv) - goto out; + goto err_kvm_uv; if (debug_register_view(kvm_s390_dbf, &debug_sprintf_view) || debug_register_view(kvm_s390_dbf_uv, &debug_sprintf_view)) - goto out; + goto err_debug_view; kvm_s390_cpu_feat_init();
@@ -510,25 +510,32 @@ int kvm_arch_init(void *opaque) rc = kvm_register_device_ops(&kvm_flic_ops, KVM_DEV_TYPE_FLIC); if (rc) { pr_err("A FLIC registration call failed with rc=%d\n", rc); - goto out; + goto err_flic; } if (IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM)) { rc = kvm_s390_pci_init(); if (rc) { pr_err("Unable to allocate AIFT for PCI\n"); - goto out; + goto err_pci; } } rc = kvm_s390_gib_init(GAL_ISC); if (rc) - goto out; + goto err_gib; return 0; -out: - kvm_arch_exit(); +err_gib: + if (IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM)) + kvm_s390_pci_exit(); +err_pci: +err_flic: +err_debug_view: + debug_unregister(kvm_s390_dbf_uv); +err_kvm_uv: + debug_unregister(kvm_s390_dbf); return rc; }
--
2.38.1.584.g0f3c55d4c2-goog