Skip to content

Commit

Permalink
KVM: s390: Fix RUNNING flag misinterpretation
Browse files Browse the repository at this point in the history 
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: [email protected]
Signed-off-by: Cornelia Huck <[email protected]>
Signed-off-by: Carsten Otte <[email protected]>
Signed-off-by: Avi Kivity <[email protected]>
  • Loading branch information
@cohuck @avikivity
cohuck authored and avikivity committed Nov 17, 2011
1 parent 3439a8d commit 9e6dabe
Show file tree
Hide file tree
Showing 6 changed files with 15 additions and 9 deletions.
2 changes: 1 addition & 1 deletion arch/s390/include/asm/kvm_host.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down
2 changes: 1 addition & 1 deletion arch/s390/kvm/diag.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down
3 changes: 2 additions & 1 deletion arch/s390/kvm/intercept.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand All @@ -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;
Expand Down
1 change: 1 addition & 0 deletions arch/s390/kvm/interrupt.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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:
Expand Down
10 changes: 7 additions & 3 deletions arch/s390/kvm/kvm-s390.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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);

Expand Down
6 changes: 3 additions & 3 deletions arch/s390/kvm/sigp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -57,8 +57,8 @@ static int __sigp_sense(struct kvm_vcpu *vcpu, u16 cpu_addr,
spin_lock(&fi->lock);
if (fi->local_int[cpu_addr] == NULL)
rc = 3; /* not operational */
else if (atomic_read(fi->local_int[cpu_addr]->cpuflags)
& CPUSTAT_RUNNING) {
else if (!(atomic_read(fi->local_int[cpu_addr]->cpuflags)
& CPUSTAT_STOPPED)) {
*reg &= 0xffffffff00000000UL;
rc = 1; /* status stored */
} else {
Expand Down Expand Up @@ -251,7 +251,7 @@ static int __sigp_set_prefix(struct kvm_vcpu *vcpu, u16 cpu_addr, u32 address,

spin_lock_bh(&li->lock);
/* cpu must be in stopped state */
if (atomic_read(li->cpuflags) & CPUSTAT_RUNNING) {
if (!(atomic_read(li->cpuflags) & CPUSTAT_STOPPED)) {
rc = 1; /* incorrect state */
*reg &= SIGP_STAT_INCORRECT_STATE;
kfree(inti);
Expand Down

0 comments on commit 9e6dabe

Please sign in to comment.