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Commit 9e6dabef authored by Cornelia Huck's avatar Cornelia Huck Committed by Avi Kivity
Browse files

KVM: s390: Fix RUNNING flag misinterpretation 



CPUSTAT_RUNNING was implemented signifying that a vcpu is not stopped.
This is not, however, what the architecture says: RUNNING should be
set when the host is acting on the behalf of the guest operating
system.

CPUSTAT_RUNNING has been changed to be set in kvm_arch_vcpu_load()
and to be unset in kvm_arch_vcpu_put().

For signifying stopped state of a vcpu, a host-controlled bit has
been used and is set/unset basically on the reverse as the old
CPUSTAT_RUNNING bit (including pushing it down into stop handling
proper in handle_stop()).

Cc: stable@kernel.org
Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarCarsten Otte <cotte@de.ibm.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 3439a8da

arch/s390/include/asm/kvm_host.h

+1 −1
Original line number Diff line number Diff line
@@ -47,7 +47,7 @@ struct sca_block { 
#define KVM_HPAGE_MASK(x)	(~(KVM_HPAGE_SIZE(x) - 1))

#define KVM_PAGES_PER_HPAGE(x)	(KVM_HPAGE_SIZE(x) / PAGE_SIZE)



#define CPUSTAT_HOST       0x80000000

#define CPUSTAT_STOPPED    0x80000000

#define CPUSTAT_WAIT       0x10000000

#define CPUSTAT_ECALL_PEND 0x08000000

#define CPUSTAT_STOP_INT   0x04000000

arch/s390/kvm/diag.c

+1 −1
Original line number Diff line number Diff line
@@ -70,7 +70,7 @@ static int __diag_ipl_functions(struct kvm_vcpu *vcpu) 
		return -EOPNOTSUPP;

	}



	atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);

	atomic_set_mask(CPUSTAT_STOPPED, &vcpu->arch.sie_block->cpuflags);

	vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM;

	vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL;

	vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT;

arch/s390/kvm/intercept.c

+2 −1
Original line number Diff line number Diff line
@@ -132,7 +132,6 @@ static int handle_stop(struct kvm_vcpu *vcpu) 
	int rc = 0;



	vcpu->stat.exit_stop_request++;

	atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);

	spin_lock_bh(&vcpu->arch.local_int.lock);

	if (vcpu->arch.local_int.action_bits & ACTION_STORE_ON_STOP) {

		vcpu->arch.local_int.action_bits &= ~ACTION_STORE_ON_STOP;
@@ -149,6 +148,8 @@ static int handle_stop(struct kvm_vcpu *vcpu) 
	}



	if (vcpu->arch.local_int.action_bits & ACTION_STOP_ON_STOP) {

		atomic_set_mask(CPUSTAT_STOPPED,

				&vcpu->arch.sie_block->cpuflags);

		vcpu->arch.local_int.action_bits &= ~ACTION_STOP_ON_STOP;

		VCPU_EVENT(vcpu, 3, "%s", "cpu stopped");

		rc = -EOPNOTSUPP;

arch/s390/kvm/interrupt.c

+1 −0
Original line number Diff line number Diff line
@@ -252,6 +252,7 @@ static void __do_deliver_interrupt(struct kvm_vcpu *vcpu, 
			offsetof(struct _lowcore, restart_psw), sizeof(psw_t));

		if (rc == -EFAULT)

			exception = 1;

		atomic_clear_mask(CPUSTAT_STOPPED, &vcpu->arch.sie_block->cpuflags);

		break;



	case KVM_S390_PROGRAM_INT:

arch/s390/kvm/kvm-s390.c

+7 −3
Original line number Diff line number Diff line
@@ -270,10 +270,12 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) 
	restore_fp_regs(&vcpu->arch.guest_fpregs);

	restore_access_regs(vcpu->arch.guest_acrs);

	gmap_enable(vcpu->arch.gmap);

	atomic_set_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);

}



void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)

{

	atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);

	gmap_disable(vcpu->arch.gmap);

	save_fp_regs(&vcpu->arch.guest_fpregs);

	save_access_regs(vcpu->arch.guest_acrs);
@@ -301,7 +303,9 @@ static void kvm_s390_vcpu_initial_reset(struct kvm_vcpu *vcpu) 


int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)

{

	atomic_set(&vcpu->arch.sie_block->cpuflags, CPUSTAT_ZARCH | CPUSTAT_SM);

	atomic_set(&vcpu->arch.sie_block->cpuflags, CPUSTAT_ZARCH |

						    CPUSTAT_SM |

						    CPUSTAT_STOPPED);

	vcpu->arch.sie_block->ecb   = 6;

	vcpu->arch.sie_block->eca   = 0xC1002001U;

	vcpu->arch.sie_block->fac   = (int) (long) facilities;
@@ -428,7 +432,7 @@ static int kvm_arch_vcpu_ioctl_set_initial_psw(struct kvm_vcpu *vcpu, psw_t psw) 
{

	int rc = 0;



	if (atomic_read(&vcpu->arch.sie_block->cpuflags) & CPUSTAT_RUNNING)

	if (!(atomic_read(&vcpu->arch.sie_block->cpuflags) & CPUSTAT_STOPPED))

		rc = -EBUSY;

	else {

		vcpu->run->psw_mask = psw.mask;
@@ -501,7 +505,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	if (vcpu->sigset_active)

		sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);



	atomic_set_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);

	atomic_clear_mask(CPUSTAT_STOPPED, &vcpu->arch.sie_block->cpuflags);



	BUG_ON(vcpu->kvm->arch.float_int.local_int[vcpu->vcpu_id] == NULL);