[PATCH v3 08/14] KVM: s390: pv: usage counter instead of flag

Claudio Imbrenda
2021-08-04T15:41:09Z

Use the is_protected field as a counter instead of a flag. This will
be used in upcoming patches.

Increment the counter when a secure configuration is created, and
decrement it when it is destroyed. Previously the flag was set when the
set secure parameters UVC was performed.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
---
arch/s390/kvm/pv.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c
index 1e7f63c06a63..fd37e97a26b3 100644
--- a/arch/s390/kvm/pv.c
+++ b/arch/s390/kvm/pv.c
@@ -174,7 +174,8 @@ int kvm_s390_pv_deinit_vm(struct kvm *kvm, u16 *rc, u16 *rrc)
cc = uv_cmd_nodata(kvm_s390_pv_get_handle(kvm),
UVC_CMD_DESTROY_SEC_CONF, rc, rrc);
WRITE_ONCE(kvm->arch.gmap->guest_handle, 0);
- atomic_set(&kvm->mm->context.is_protected, 0);
+ if (!cc)
+ atomic_dec(&kvm->mm->context.is_protected);
KVM_UV_EVENT(kvm, 3, "PROTVIRT DESTROY VM: rc %x rrc %x", *rc, *rrc);
WARN_ONCE(cc, "protvirt destroy vm failed rc %x rrc %x", *rc, *rrc);
/* Intended memory leak on "impossible" error */
@@ -215,11 +216,14 @@ int kvm_s390_pv_init_vm(struct kvm *kvm, u16 *rc, u16 *rrc)
/* Outputs */
kvm->arch.pv.handle = uvcb.guest_handle;

+ atomic_inc(&kvm->mm->context.is_protected);
if (cc) {
- if (uvcb.header.rc & UVC_RC_NEED_DESTROY)
+ if (uvcb.header.rc & UVC_RC_NEED_DESTROY) {
kvm_s390_pv_deinit_vm(kvm, &dummy, &dummy);
- else
+ } else {
+ atomic_dec(&kvm->mm->context.is_protected);
kvm_s390_pv_dealloc_vm(kvm);
+ }
return -EIO;
}
kvm->arch.gmap->guest_handle = uvcb.guest_handle;
@@ -242,8 +246,6 @@ int kvm_s390_pv_set_sec_parms(struct kvm *kvm, void *hdr, u64 length, u16 *rc,
*rrc = uvcb.header.rrc;
KVM_UV_EVENT(kvm, 3, "PROTVIRT VM SET PARMS: rc %x rrc %x",
*rc, *rrc);
- if (!cc)
- atomic_set(&kvm->mm->context.is_protected, 1);
return cc ? -EINVAL : 0;
}

--
2.31.1