Commit 7746f735 authored by Claudio Imbrenda's avatar Claudio Imbrenda Committed by Janosch Frank
Browse files

KVM: s390: pv: destroy the configuration before its memory 



Move the Destroy Secure Configuration UVC before the loop to destroy
the memory. If the protected VM has memory, it will be cleaned up and
made accessible by the Destroy Secure Configuration UVC. The struct
page for the relevant pages will still have the protected bit set, so
the loop is still needed to clean that up.

Switching the order of those two operations does not change the
outcome, but it is significantly faster.

Signed-off-by: default avatarClaudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: default avatarNico Boehr <nrb@linux.ibm.com>
Reviewed-by: default avatarJanosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20220628135619.32410-13-imbrenda@linux.ibm.com


Message-Id: <20220628135619.32410-13-imbrenda@linux.ibm.com>
Signed-off-by: default avatarJanosch Frank <frankja@linux.ibm.com>
parent da15fbc6

arch/s390/kvm/pv.c

+3 −3
Original line number Diff line number Diff line
@@ -164,6 +164,9 @@ int kvm_s390_pv_deinit_vm(struct kvm *kvm, u16 *rc, u16 *rrc) 
{

	int cc;



	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);

	/*

	 * if the mm still has a mapping, make all its pages accessible

	 * before destroying the guest
@@ -173,9 +176,6 @@ int kvm_s390_pv_deinit_vm(struct kvm *kvm, u16 *rc, u16 *rrc) 
		mmput(kvm->mm);

	}



	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);

	if (!cc) {

		atomic_dec(&kvm->mm->context.protected_count);

		kvm_s390_pv_dealloc_vm(kvm);