Commit ee1a15e3 authored by Paolo Bonzini's avatar Paolo Bonzini

Merge tag 'kvm-s390-master-4.16-2' of...

Merge tag 'kvm-s390-master-4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

KVM: s390: fixes for multiple epoch facility

We have certain cases where the multiple epoch facility is broken:
- timer wakeup during epoch change
- cpu hotplug
- SCK instruction
- stp sync checks
Fix those.
parents 6c62cc43 0e7def5f
......@@ -169,8 +169,15 @@ static int ckc_interrupts_enabled(struct kvm_vcpu *vcpu)
static int ckc_irq_pending(struct kvm_vcpu *vcpu)
{
if (vcpu->arch.sie_block->ckc >= kvm_s390_get_tod_clock_fast(vcpu->kvm))
const u64 now = kvm_s390_get_tod_clock_fast(vcpu->kvm);
const u64 ckc = vcpu->arch.sie_block->ckc;
if (vcpu->arch.sie_block->gcr[0] & 0x0020000000000000ul) {
if ((s64)ckc >= (s64)now)
return 0;
} else if (ckc >= now) {
return 0;
}
return ckc_interrupts_enabled(vcpu);
}
......@@ -1047,13 +1054,19 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
static u64 __calculate_sltime(struct kvm_vcpu *vcpu)
{
u64 now, cputm, sltime = 0;
const u64 now = kvm_s390_get_tod_clock_fast(vcpu->kvm);
const u64 ckc = vcpu->arch.sie_block->ckc;
u64 cputm, sltime = 0;
if (ckc_interrupts_enabled(vcpu)) {
now = kvm_s390_get_tod_clock_fast(vcpu->kvm);
sltime = tod_to_ns(vcpu->arch.sie_block->ckc - now);
/* already expired or overflow? */
if (!sltime || vcpu->arch.sie_block->ckc <= now)
if (vcpu->arch.sie_block->gcr[0] & 0x0020000000000000ul) {
if ((s64)now < (s64)ckc)
sltime = tod_to_ns((s64)ckc - (s64)now);
} else if (now < ckc) {
sltime = tod_to_ns(ckc - now);
}
/* already expired */
if (!sltime)
return 0;
if (cpu_timer_interrupts_enabled(vcpu)) {
cputm = kvm_s390_get_cpu_timer(vcpu);
......
......@@ -179,6 +179,28 @@ int kvm_arch_hardware_enable(void)
static void kvm_gmap_notifier(struct gmap *gmap, unsigned long start,
unsigned long end);
static void kvm_clock_sync_scb(struct kvm_s390_sie_block *scb, u64 delta)
{
u8 delta_idx = 0;
/*
* The TOD jumps by delta, we have to compensate this by adding
* -delta to the epoch.
*/
delta = -delta;
/* sign-extension - we're adding to signed values below */
if ((s64)delta < 0)
delta_idx = -1;
scb->epoch += delta;
if (scb->ecd & ECD_MEF) {
scb->epdx += delta_idx;
if (scb->epoch < delta)
scb->epdx += 1;
}
}
/*
* This callback is executed during stop_machine(). All CPUs are therefore
* temporarily stopped. In order not to change guest behavior, we have to
......@@ -194,13 +216,17 @@ static int kvm_clock_sync(struct notifier_block *notifier, unsigned long val,
unsigned long long *delta = v;
list_for_each_entry(kvm, &vm_list, vm_list) {
kvm->arch.epoch -= *delta;
kvm_for_each_vcpu(i, vcpu, kvm) {
vcpu->arch.sie_block->epoch -= *delta;
kvm_clock_sync_scb(vcpu->arch.sie_block, *delta);
if (i == 0) {
kvm->arch.epoch = vcpu->arch.sie_block->epoch;
kvm->arch.epdx = vcpu->arch.sie_block->epdx;
}
if (vcpu->arch.cputm_enabled)
vcpu->arch.cputm_start += *delta;
if (vcpu->arch.vsie_block)
vcpu->arch.vsie_block->epoch -= *delta;
kvm_clock_sync_scb(vcpu->arch.vsie_block,
*delta);
}
}
return NOTIFY_OK;
......@@ -902,12 +928,9 @@ static int kvm_s390_set_tod_ext(struct kvm *kvm, struct kvm_device_attr *attr)
if (copy_from_user(&gtod, (void __user *)attr->addr, sizeof(gtod)))
return -EFAULT;
if (test_kvm_facility(kvm, 139))
kvm_s390_set_tod_clock_ext(kvm, &gtod);
else if (gtod.epoch_idx == 0)
kvm_s390_set_tod_clock(kvm, gtod.tod);
else
if (!test_kvm_facility(kvm, 139) && gtod.epoch_idx)
return -EINVAL;
kvm_s390_set_tod_clock(kvm, &gtod);
VM_EVENT(kvm, 3, "SET: TOD extension: 0x%x, TOD base: 0x%llx",
gtod.epoch_idx, gtod.tod);
......@@ -932,13 +955,14 @@ static int kvm_s390_set_tod_high(struct kvm *kvm, struct kvm_device_attr *attr)
static int kvm_s390_set_tod_low(struct kvm *kvm, struct kvm_device_attr *attr)
{
u64 gtod;
struct kvm_s390_vm_tod_clock gtod = { 0 };
if (copy_from_user(&gtod, (void __user *)attr->addr, sizeof(gtod)))
if (copy_from_user(&gtod.tod, (void __user *)attr->addr,
sizeof(gtod.tod)))
return -EFAULT;
kvm_s390_set_tod_clock(kvm, gtod);
VM_EVENT(kvm, 3, "SET: TOD base: 0x%llx", gtod);
kvm_s390_set_tod_clock(kvm, &gtod);
VM_EVENT(kvm, 3, "SET: TOD base: 0x%llx", gtod.tod);
return 0;
}
......@@ -2389,6 +2413,7 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
mutex_lock(&vcpu->kvm->lock);
preempt_disable();
vcpu->arch.sie_block->epoch = vcpu->kvm->arch.epoch;
vcpu->arch.sie_block->epdx = vcpu->kvm->arch.epdx;
preempt_enable();
mutex_unlock(&vcpu->kvm->lock);
if (!kvm_is_ucontrol(vcpu->kvm)) {
......@@ -3021,8 +3046,8 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu)
return 0;
}
void kvm_s390_set_tod_clock_ext(struct kvm *kvm,
const struct kvm_s390_vm_tod_clock *gtod)
void kvm_s390_set_tod_clock(struct kvm *kvm,
const struct kvm_s390_vm_tod_clock *gtod)
{
struct kvm_vcpu *vcpu;
struct kvm_s390_tod_clock_ext htod;
......@@ -3034,10 +3059,12 @@ void kvm_s390_set_tod_clock_ext(struct kvm *kvm,
get_tod_clock_ext((char *)&htod);
kvm->arch.epoch = gtod->tod - htod.tod;
kvm->arch.epdx = gtod->epoch_idx - htod.epoch_idx;
if (kvm->arch.epoch > gtod->tod)
kvm->arch.epdx -= 1;
kvm->arch.epdx = 0;
if (test_kvm_facility(kvm, 139)) {
kvm->arch.epdx = gtod->epoch_idx - htod.epoch_idx;
if (kvm->arch.epoch > gtod->tod)
kvm->arch.epdx -= 1;
}
kvm_s390_vcpu_block_all(kvm);
kvm_for_each_vcpu(i, vcpu, kvm) {
......@@ -3050,22 +3077,6 @@ void kvm_s390_set_tod_clock_ext(struct kvm *kvm,
mutex_unlock(&kvm->lock);
}
void kvm_s390_set_tod_clock(struct kvm *kvm, u64 tod)
{
struct kvm_vcpu *vcpu;
int i;
mutex_lock(&kvm->lock);
preempt_disable();
kvm->arch.epoch = tod - get_tod_clock();
kvm_s390_vcpu_block_all(kvm);
kvm_for_each_vcpu(i, vcpu, kvm)
vcpu->arch.sie_block->epoch = kvm->arch.epoch;
kvm_s390_vcpu_unblock_all(kvm);
preempt_enable();
mutex_unlock(&kvm->lock);
}
/**
* kvm_arch_fault_in_page - fault-in guest page if necessary
* @vcpu: The corresponding virtual cpu
......
......@@ -281,9 +281,8 @@ int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu);
int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu);
/* implemented in kvm-s390.c */
void kvm_s390_set_tod_clock_ext(struct kvm *kvm,
const struct kvm_s390_vm_tod_clock *gtod);
void kvm_s390_set_tod_clock(struct kvm *kvm, u64 tod);
void kvm_s390_set_tod_clock(struct kvm *kvm,
const struct kvm_s390_vm_tod_clock *gtod);
long kvm_arch_fault_in_page(struct kvm_vcpu *vcpu, gpa_t gpa, int writable);
int kvm_s390_store_status_unloaded(struct kvm_vcpu *vcpu, unsigned long addr);
int kvm_s390_vcpu_store_status(struct kvm_vcpu *vcpu, unsigned long addr);
......
......@@ -85,9 +85,10 @@ int kvm_s390_handle_e3(struct kvm_vcpu *vcpu)
/* Handle SCK (SET CLOCK) interception */
static int handle_set_clock(struct kvm_vcpu *vcpu)
{
struct kvm_s390_vm_tod_clock gtod = { 0 };
int rc;
u8 ar;
u64 op2, val;
u64 op2;
vcpu->stat.instruction_sck++;
......@@ -97,12 +98,12 @@ static int handle_set_clock(struct kvm_vcpu *vcpu)
op2 = kvm_s390_get_base_disp_s(vcpu, &ar);
if (op2 & 7) /* Operand must be on a doubleword boundary */
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
rc = read_guest(vcpu, op2, ar, &val, sizeof(val));
rc = read_guest(vcpu, op2, ar, &gtod.tod, sizeof(gtod.tod));
if (rc)
return kvm_s390_inject_prog_cond(vcpu, rc);
VCPU_EVENT(vcpu, 3, "SCK: setting guest TOD to 0x%llx", val);
kvm_s390_set_tod_clock(vcpu->kvm, val);
VCPU_EVENT(vcpu, 3, "SCK: setting guest TOD to 0x%llx", gtod.tod);
kvm_s390_set_tod_clock(vcpu->kvm, &gtod);
kvm_s390_set_psw_cc(vcpu, 0);
return 0;
......
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