Commit ee1a15e3 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

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

arch/s390/kvm/interrupt.c

+19 −6
Original line number Diff line number Diff line
@@ -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);

arch/s390/kvm/kvm-s390.c

+45 −34
Original line number Diff line number Diff line
@@ -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)) {
@@ -3021,7 +3046,7 @@ retry: 
	return 0;

}



void kvm_s390_set_tod_clock_ext(struct kvm *kvm,

void kvm_s390_set_tod_clock(struct kvm *kvm,

			    const struct kvm_s390_vm_tod_clock *gtod)

{

	struct kvm_vcpu *vcpu;
@@ -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 = 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

arch/s390/kvm/kvm-s390.h

+2 −3
Original line number Diff line number Diff line
@@ -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,

void kvm_s390_set_tod_clock(struct kvm *kvm,

			    const struct kvm_s390_vm_tod_clock *gtod);

void kvm_s390_set_tod_clock(struct kvm *kvm, u64 tod);

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);

arch/s390/kvm/priv.c

+5 −4
Original line number Diff line number Diff line
@@ -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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