[GIT PULL 0/9] KVM: s390: Fixes and features for kvm/next (4.6) part 2

[GIT PULL 0/9] KVM: s390: Fixes and features for kvm/next (4.6) part 2

[Christian Borntraeger]

Paolo,

the remaining patches for 4.6 on the s390 side.

The following changes since commit 1763f8d09d522b3ac998229dcf038476e88b78fc:

  KVM: s390: bail out early on fatal signal in dirty logging (2016-02-10 13:12:57 +0100)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux.git  tags/kvm-s390-next-4.6-2

for you to fetch changes up to c54f0d6ae057444453f5167e66ed999e8cf26936:

  KVM: s390: allocate only one DMA page per VM (2016-03-08 13:57:54 +0100)

----------------------------------------------------------------
KVM: s390: Fixes and features for kvm/next (4.6) part 2

- add watchdog diagnose to trace event decoder
- better handle the cpu timer when not inside the guest
- only provide STFLE if the CPU model has STFLE
- reduce DMA page usage

----------------------------------------------------------------
Alexander Yarygin (1):
      KVM: s390: Add diag "watchdog functions" to trace event decoding

David Hildenbrand (8):
      KVM: s390: store cpu id in vcpu->cpu when scheduled in
      KVM: s390: abstract access to the VCPU cpu timer
      KVM: s390: step VCPU cpu timer during kvm_run ioctl
      KVM: s390: protect VCPU cpu timer with a seqcount
      KVM: s390: step the VCPU timer while in enabled wait
      KVM: s390: wake up when the VCPU cpu timer expires
      KVM: s390: enable STFLE interpretation only if enabled for the guest
      KVM: s390: allocate only one DMA page per VM

 arch/s390/include/asm/kvm_host.h |  33 +++++--
 arch/s390/include/uapi/asm/sie.h |   1 +
 arch/s390/kvm/interrupt.c        |  53 ++++++++----
 arch/s390/kvm/kvm-s390.c         | 180 +++++++++++++++++++++++++++++----------
 arch/s390/kvm/kvm-s390.h         |  11 ++-
 arch/s390/kvm/priv.c             |   2 +-
 6 files changed, 209 insertions(+), 71 deletions(-)

[GIT PULL 1/9] KVM: s390: Add diag "watchdog functions" to trace event decoding

[Christian Borntraeger]

From: Alexander Yarygin <yarygin@linux.vnet.ibm.com>

DIAG 0x288 may occur now. Let's add its code to the diag table in
sie.h.

Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 arch/s390/include/uapi/asm/sie.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/s390/include/uapi/asm/sie.h b/arch/s390/include/uapi/asm/sie.h
index ee69c08..5dbaa72 100644
--- a/arch/s390/include/uapi/asm/sie.h
+++ b/arch/s390/include/uapi/asm/sie.h
@@ -7,6 +7,7 @@
 	{ 0x9c, "DIAG (0x9c) time slice end directed" },	\
 	{ 0x204, "DIAG (0x204) logical-cpu utilization" },	\
 	{ 0x258, "DIAG (0x258) page-reference services" },	\
+	{ 0x288, "DIAG (0x288) watchdog functions" },		\
 	{ 0x308, "DIAG (0x308) ipl functions" },		\
 	{ 0x500, "DIAG (0x500) KVM virtio functions" },		\
 	{ 0x501, "DIAG (0x501) KVM breakpoint" }
-- 
2.5.0

[GIT PULL 2/9] KVM: s390: store cpu id in vcpu->cpu when scheduled in

[Christian Borntraeger]

From: David Hildenbrand <dahi@linux.vnet.ibm.com>

By storing the cpu id, we have a way to verify if the current cpu is
owning a VCPU.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 arch/s390/kvm/kvm-s390.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 28bd5ea..bd5edb1 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1449,10 +1449,12 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 	restore_access_regs(vcpu->run->s.regs.acrs);
 	gmap_enable(vcpu->arch.gmap);
 	atomic_or(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
+	vcpu->cpu = cpu;
 }
 
 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 {
+	vcpu->cpu = -1;
 	atomic_andnot(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
 	gmap_disable(vcpu->arch.gmap);
 
-- 
2.5.0

[GIT PULL 3/9] KVM: s390: abstract access to the VCPU cpu timer

[Christian Borntraeger]

From: David Hildenbrand <dahi@linux.vnet.ibm.com>

We want to manually step the cpu timer in certain scenarios in the future.
Let's abstract any access to the cpu timer, so we can hide the complexity
internally.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 arch/s390/kvm/interrupt.c |  5 +++--
 arch/s390/kvm/kvm-s390.c  | 31 +++++++++++++++++++++++--------
 arch/s390/kvm/kvm-s390.h  |  2 ++
 3 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 87e2d1a..4604e9a 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -182,8 +182,9 @@ static int cpu_timer_interrupts_enabled(struct kvm_vcpu *vcpu)
 
 static int cpu_timer_irq_pending(struct kvm_vcpu *vcpu)
 {
-	return (vcpu->arch.sie_block->cputm >> 63) &&
-	       cpu_timer_interrupts_enabled(vcpu);
+	if (!cpu_timer_interrupts_enabled(vcpu))
+		return 0;
+	return kvm_s390_get_cpu_timer(vcpu) >> 63;
 }
 
 static inline int is_ioirq(unsigned long irq_type)
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index bd5edb1..2118a22 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1429,6 +1429,18 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
+/* set the cpu timer - may only be called from the VCPU thread itself */
+void kvm_s390_set_cpu_timer(struct kvm_vcpu *vcpu, __u64 cputm)
+{
+	vcpu->arch.sie_block->cputm = cputm;
+}
+
+/* get the cpu timer - can also be called from other VCPU threads */
+__u64 kvm_s390_get_cpu_timer(struct kvm_vcpu *vcpu)
+{
+	return vcpu->arch.sie_block->cputm;
+}
+
 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
 	/* Save host register state */
@@ -1476,7 +1488,7 @@ static void kvm_s390_vcpu_initial_reset(struct kvm_vcpu *vcpu)
 	vcpu->arch.sie_block->gpsw.mask = 0UL;
 	vcpu->arch.sie_block->gpsw.addr = 0UL;
 	kvm_s390_set_prefix(vcpu, 0);
-	vcpu->arch.sie_block->cputm     = 0UL;
+	kvm_s390_set_cpu_timer(vcpu, 0);
 	vcpu->arch.sie_block->ckc       = 0UL;
 	vcpu->arch.sie_block->todpr     = 0;
 	memset(vcpu->arch.sie_block->gcr, 0, 16 * sizeof(__u64));
@@ -1723,7 +1735,7 @@ static int kvm_arch_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu,
 			     (u64 __user *)reg->addr);
 		break;
 	case KVM_REG_S390_CPU_TIMER:
-		r = put_user(vcpu->arch.sie_block->cputm,
+		r = put_user(kvm_s390_get_cpu_timer(vcpu),
 			     (u64 __user *)reg->addr);
 		break;
 	case KVM_REG_S390_CLOCK_COMP:
@@ -1761,6 +1773,7 @@ static int kvm_arch_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu,
 					   struct kvm_one_reg *reg)
 {
 	int r = -EINVAL;
+	__u64 val;
 
 	switch (reg->id) {
 	case KVM_REG_S390_TODPR:
@@ -1772,8 +1785,9 @@ static int kvm_arch_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu,
 			     (u64 __user *)reg->addr);
 		break;
 	case KVM_REG_S390_CPU_TIMER:
-		r = get_user(vcpu->arch.sie_block->cputm,
-			     (u64 __user *)reg->addr);
+		r = get_user(val, (u64 __user *)reg->addr);
+		if (!r)
+			kvm_s390_set_cpu_timer(vcpu, val);
 		break;
 	case KVM_REG_S390_CLOCK_COMP:
 		r = get_user(vcpu->arch.sie_block->ckc,
@@ -2290,7 +2304,7 @@ static void sync_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 		kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
 	}
 	if (kvm_run->kvm_dirty_regs & KVM_SYNC_ARCH0) {
-		vcpu->arch.sie_block->cputm = kvm_run->s.regs.cputm;
+		kvm_s390_set_cpu_timer(vcpu, kvm_run->s.regs.cputm);
 		vcpu->arch.sie_block->ckc = kvm_run->s.regs.ckc;
 		vcpu->arch.sie_block->todpr = kvm_run->s.regs.todpr;
 		vcpu->arch.sie_block->pp = kvm_run->s.regs.pp;
@@ -2312,7 +2326,7 @@ static void store_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 	kvm_run->psw_addr = vcpu->arch.sie_block->gpsw.addr;
 	kvm_run->s.regs.prefix = kvm_s390_get_prefix(vcpu);
 	memcpy(&kvm_run->s.regs.crs, &vcpu->arch.sie_block->gcr, 128);
-	kvm_run->s.regs.cputm = vcpu->arch.sie_block->cputm;
+	kvm_run->s.regs.cputm = kvm_s390_get_cpu_timer(vcpu);
 	kvm_run->s.regs.ckc = vcpu->arch.sie_block->ckc;
 	kvm_run->s.regs.todpr = vcpu->arch.sie_block->todpr;
 	kvm_run->s.regs.pp = vcpu->arch.sie_block->pp;
@@ -2383,7 +2397,7 @@ int kvm_s390_store_status_unloaded(struct kvm_vcpu *vcpu, unsigned long gpa)
 	unsigned char archmode = 1;
 	freg_t fprs[NUM_FPRS];
 	unsigned int px;
-	u64 clkcomp;
+	u64 clkcomp, cputm;
 	int rc;
 
 	px = kvm_s390_get_prefix(vcpu);
@@ -2417,8 +2431,9 @@ int kvm_s390_store_status_unloaded(struct kvm_vcpu *vcpu, unsigned long gpa)
 			      &vcpu->run->s.regs.fpc, 4);
 	rc |= write_guest_abs(vcpu, gpa + __LC_TOD_PROGREG_SAVE_AREA,
 			      &vcpu->arch.sie_block->todpr, 4);
+	cputm = kvm_s390_get_cpu_timer(vcpu);
 	rc |= write_guest_abs(vcpu, gpa + __LC_CPU_TIMER_SAVE_AREA,
-			      &vcpu->arch.sie_block->cputm, 8);
+			      &cputm, 8);
 	clkcomp = vcpu->arch.sie_block->ckc >> 8;
 	rc |= write_guest_abs(vcpu, gpa + __LC_CLOCK_COMP_SAVE_AREA,
 			      &clkcomp, 8);
diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index 1c756c7..9787299 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -263,6 +263,8 @@ int kvm_s390_vcpu_setup_cmma(struct kvm_vcpu *vcpu);
 void kvm_s390_vcpu_unsetup_cmma(struct kvm_vcpu *vcpu);
 unsigned long kvm_s390_fac_list_mask_size(void);
 extern unsigned long kvm_s390_fac_list_mask[];
+void kvm_s390_set_cpu_timer(struct kvm_vcpu *vcpu, __u64 cputm);
+__u64 kvm_s390_get_cpu_timer(struct kvm_vcpu *vcpu);
 
 /* implemented in diag.c */
 int kvm_s390_handle_diag(struct kvm_vcpu *vcpu);
-- 
2.5.0

[GIT PULL 4/9] KVM: s390: step VCPU cpu timer during kvm_run ioctl

[Christian Borntraeger]

From: David Hildenbrand <dahi@linux.vnet.ibm.com>

Architecturally we should only provide steal time if we are scheduled
away, and not if the host interprets a guest exit. We have to step
the guest CPU timer in these cases.

In the first shot, we will step the VCPU timer only during the kvm_run
ioctl. Therefore all time spent e.g. in interception handlers or on irq
delivery will be accounted for that VCPU.

We have to take care of a few special cases:
- Other VCPUs can test for pending irqs. We can only report a consistent
  value for the VCPU thread itself when adding the delta.
- We have to take care of STP sync, therefore we have to extend
  kvm_clock_sync() and disable preemption accordingly
- During any call to disable/enable/start/stop we could get premeempted
  and therefore get start/stop calls. Therefore we have to make sure we
  don't get into an inconsistent state.

Whenever a VCPU is scheduled out, sleeping, in user space or just about
to enter the SIE, the guest cpu timer isn't stepped.

Please note that all primitives are prepared to be called from both
environments (cpu timer accounting enabled or not), although not completely
used in this patch yet (e.g. kvm_s390_set_cpu_timer() will never be called
while cpu timer accounting is enabled).

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 arch/s390/include/asm/kvm_host.h |  2 ++
 arch/s390/kvm/kvm-s390.c         | 76 ++++++++++++++++++++++++++++++++++++++--
 2 files changed, 76 insertions(+), 2 deletions(-)

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 727e7f7..91796dd 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -552,6 +552,8 @@ struct kvm_vcpu_arch {
 	unsigned long pfault_token;
 	unsigned long pfault_select;
 	unsigned long pfault_compare;
+	bool cputm_enabled;
+	__u64 cputm_start;
 };
 
 struct kvm_vm_stat {
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 2118a22..76b9914 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -158,6 +158,8 @@ static int kvm_clock_sync(struct notifier_block *notifier, unsigned long val,
 		kvm->arch.epoch -= *delta;
 		kvm_for_each_vcpu(i, vcpu, kvm) {
 			vcpu->arch.sie_block->epoch -= *delta;
+			if (vcpu->arch.cputm_enabled)
+				vcpu->arch.cputm_start += *delta;
 		}
 	}
 	return NOTIFY_OK;
@@ -1429,16 +1431,78 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
+/* needs disabled preemption to protect from TOD sync and vcpu_load/put */
+static void __start_cpu_timer_accounting(struct kvm_vcpu *vcpu)
+{
+	WARN_ON_ONCE(vcpu->arch.cputm_start != 0);
+	vcpu->arch.cputm_start = get_tod_clock_fast();
+}
+
+/* needs disabled preemption to protect from TOD sync and vcpu_load/put */
+static void __stop_cpu_timer_accounting(struct kvm_vcpu *vcpu)
+{
+	WARN_ON_ONCE(vcpu->arch.cputm_start == 0);
+	vcpu->arch.sie_block->cputm -= get_tod_clock_fast() - vcpu->arch.cputm_start;
+	vcpu->arch.cputm_start = 0;
+}
+
+/* needs disabled preemption to protect from TOD sync and vcpu_load/put */
+static void __enable_cpu_timer_accounting(struct kvm_vcpu *vcpu)
+{
+	WARN_ON_ONCE(vcpu->arch.cputm_enabled);
+	vcpu->arch.cputm_enabled = true;
+	__start_cpu_timer_accounting(vcpu);
+}
+
+/* needs disabled preemption to protect from TOD sync and vcpu_load/put */
+static void __disable_cpu_timer_accounting(struct kvm_vcpu *vcpu)
+{
+	WARN_ON_ONCE(!vcpu->arch.cputm_enabled);
+	__stop_cpu_timer_accounting(vcpu);
+	vcpu->arch.cputm_enabled = false;
+}
+
+static void enable_cpu_timer_accounting(struct kvm_vcpu *vcpu)
+{
+	preempt_disable(); /* protect from TOD sync and vcpu_load/put */
+	__enable_cpu_timer_accounting(vcpu);
+	preempt_enable();
+}
+
+static void disable_cpu_timer_accounting(struct kvm_vcpu *vcpu)
+{
+	preempt_disable(); /* protect from TOD sync and vcpu_load/put */
+	__disable_cpu_timer_accounting(vcpu);
+	preempt_enable();
+}
+
 /* set the cpu timer - may only be called from the VCPU thread itself */
 void kvm_s390_set_cpu_timer(struct kvm_vcpu *vcpu, __u64 cputm)
 {
+	preempt_disable(); /* protect from TOD sync and vcpu_load/put */
+	if (vcpu->arch.cputm_enabled)
+		vcpu->arch.cputm_start = get_tod_clock_fast();
 	vcpu->arch.sie_block->cputm = cputm;
+	preempt_enable();
 }
 
-/* get the cpu timer - can also be called from other VCPU threads */
+/* update and get the cpu timer - can also be called from other VCPU threads */
 __u64 kvm_s390_get_cpu_timer(struct kvm_vcpu *vcpu)
 {
-	return vcpu->arch.sie_block->cputm;
+	__u64 value;
+	int me;
+
+	if (unlikely(!vcpu->arch.cputm_enabled))
+		return vcpu->arch.sie_block->cputm;
+
+	me = get_cpu(); /* also protects from TOD sync and vcpu_load/put */
+	value = vcpu->arch.sie_block->cputm;
+	if (likely(me == vcpu->cpu)) {
+		/* the VCPU itself will always read consistent values */
+		value -= get_tod_clock_fast() - vcpu->arch.cputm_start;
+	}
+	put_cpu();
+	return value;
 }
 
 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
@@ -1461,12 +1525,16 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 	restore_access_regs(vcpu->run->s.regs.acrs);
 	gmap_enable(vcpu->arch.gmap);
 	atomic_or(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
+	if (vcpu->arch.cputm_enabled)
+		__start_cpu_timer_accounting(vcpu);
 	vcpu->cpu = cpu;
 }
 
 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 {
 	vcpu->cpu = -1;
+	if (vcpu->arch.cputm_enabled)
+		__stop_cpu_timer_accounting(vcpu);
 	atomic_andnot(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
 	gmap_disable(vcpu->arch.gmap);
 
@@ -2277,10 +2345,12 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
 		 */
 		local_irq_disable();
 		__kvm_guest_enter();
+		__disable_cpu_timer_accounting(vcpu);
 		local_irq_enable();
 		exit_reason = sie64a(vcpu->arch.sie_block,
 				     vcpu->run->s.regs.gprs);
 		local_irq_disable();
+		__enable_cpu_timer_accounting(vcpu);
 		__kvm_guest_exit();
 		local_irq_enable();
 		vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
@@ -2358,6 +2428,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 	}
 
 	sync_regs(vcpu, kvm_run);
+	enable_cpu_timer_accounting(vcpu);
 
 	might_fault();
 	rc = __vcpu_run(vcpu);
@@ -2377,6 +2448,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 		rc = 0;
 	}
 
+	disable_cpu_timer_accounting(vcpu);
 	store_regs(vcpu, kvm_run);
 
 	if (vcpu->sigset_active)
-- 
2.5.0

[GIT PULL 5/9] KVM: s390: protect VCPU cpu timer with a seqcount

[Christian Borntraeger]

From: David Hildenbrand <dahi@linux.vnet.ibm.com>

For now, only the owning VCPU thread (that has loaded the VCPU) can get a
consistent cpu timer value when calculating the delta. However, other
threads might also be interested in a more recent, consistent value. Of
special interest will be the timer callback of a VCPU that executes without
having the VCPU loaded and could run in parallel with the VCPU thread.

The cpu timer has a nice property: it is only updated by the owning VCPU
thread. And speaking about accounting, a consistent value can only be
calculated by looking at cputm_start and the cpu timer itself in
one shot, otherwise the result might be wrong.

As we only have one writing thread at a time (owning VCPU thread), we can
use a seqcount instead of a seqlock and retry if the VCPU refreshed its
cpu timer. This avoids any heavy locking and only introduces a counter
update/check plus a handful of smp_wmb().

The owning VCPU thread should never have to retry on reads, and also for
other threads this might be a very rare scenario.

Please note that we have to use the raw_* variants for locking the seqcount
as lockdep will produce false warnings otherwise. The rq->lock held during
vcpu_load/put is also acquired from hardirq context. Lockdep cannot know
that we avoid potential deadlocks by disabling preemption and thereby
disable concurrent write locking attempts (via vcpu_put/load).

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 arch/s390/include/asm/kvm_host.h |  8 ++++++++
 arch/s390/kvm/kvm-s390.c         | 30 ++++++++++++++++++++++--------
 2 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 91796dd..d61e645 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -20,6 +20,7 @@
 #include <linux/kvm_types.h>
 #include <linux/kvm_host.h>
 #include <linux/kvm.h>
+#include <linux/seqlock.h>
 #include <asm/debug.h>
 #include <asm/cpu.h>
 #include <asm/fpu/api.h>
@@ -553,6 +554,13 @@ struct kvm_vcpu_arch {
 	unsigned long pfault_select;
 	unsigned long pfault_compare;
 	bool cputm_enabled;
+	/*
+	 * The seqcount protects updates to cputm_start and sie_block.cputm,
+	 * this way we can have non-blocking reads with consistent values.
+	 * Only the owning VCPU thread (vcpu->cpu) is allowed to change these
+	 * values and to start/stop/enable/disable cpu timer accounting.
+	 */
+	seqcount_t cputm_seqcount;
 	__u64 cputm_start;
 };
 
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 76b9914..38223c4 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1435,15 +1435,19 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 static void __start_cpu_timer_accounting(struct kvm_vcpu *vcpu)
 {
 	WARN_ON_ONCE(vcpu->arch.cputm_start != 0);
+	raw_write_seqcount_begin(&vcpu->arch.cputm_seqcount);
 	vcpu->arch.cputm_start = get_tod_clock_fast();
+	raw_write_seqcount_end(&vcpu->arch.cputm_seqcount);
 }
 
 /* needs disabled preemption to protect from TOD sync and vcpu_load/put */
 static void __stop_cpu_timer_accounting(struct kvm_vcpu *vcpu)
 {
 	WARN_ON_ONCE(vcpu->arch.cputm_start == 0);
+	raw_write_seqcount_begin(&vcpu->arch.cputm_seqcount);
 	vcpu->arch.sie_block->cputm -= get_tod_clock_fast() - vcpu->arch.cputm_start;
 	vcpu->arch.cputm_start = 0;
+	raw_write_seqcount_end(&vcpu->arch.cputm_seqcount);
 }
 
 /* needs disabled preemption to protect from TOD sync and vcpu_load/put */
@@ -1480,28 +1484,37 @@ static void disable_cpu_timer_accounting(struct kvm_vcpu *vcpu)
 void kvm_s390_set_cpu_timer(struct kvm_vcpu *vcpu, __u64 cputm)
 {
 	preempt_disable(); /* protect from TOD sync and vcpu_load/put */
+	raw_write_seqcount_begin(&vcpu->arch.cputm_seqcount);
 	if (vcpu->arch.cputm_enabled)
 		vcpu->arch.cputm_start = get_tod_clock_fast();
 	vcpu->arch.sie_block->cputm = cputm;
+	raw_write_seqcount_end(&vcpu->arch.cputm_seqcount);
 	preempt_enable();
 }
 
 /* update and get the cpu timer - can also be called from other VCPU threads */
 __u64 kvm_s390_get_cpu_timer(struct kvm_vcpu *vcpu)
 {
+	unsigned int seq;
 	__u64 value;
-	int me;
 
 	if (unlikely(!vcpu->arch.cputm_enabled))
 		return vcpu->arch.sie_block->cputm;
 
-	me = get_cpu(); /* also protects from TOD sync and vcpu_load/put */
-	value = vcpu->arch.sie_block->cputm;
-	if (likely(me == vcpu->cpu)) {
-		/* the VCPU itself will always read consistent values */
-		value -= get_tod_clock_fast() - vcpu->arch.cputm_start;
-	}
-	put_cpu();
+	preempt_disable(); /* protect from TOD sync and vcpu_load/put */
+	do {
+		seq = raw_read_seqcount(&vcpu->arch.cputm_seqcount);
+		/*
+		 * If the writer would ever execute a read in the critical
+		 * section, e.g. in irq context, we have a deadlock.
+		 */
+		WARN_ON_ONCE((seq & 1) && smp_processor_id() == vcpu->cpu);
+		value = vcpu->arch.sie_block->cputm;
+		/* if cputm_start is 0, accounting is being started/stopped */
+		if (likely(vcpu->arch.cputm_start))
+			value -= get_tod_clock_fast() - vcpu->arch.cputm_start;
+	} while (read_seqcount_retry(&vcpu->arch.cputm_seqcount, seq & ~1));
+	preempt_enable();
 	return value;
 }
 
@@ -1704,6 +1717,7 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
 	vcpu->arch.local_int.float_int = &kvm->arch.float_int;
 	vcpu->arch.local_int.wq = &vcpu->wq;
 	vcpu->arch.local_int.cpuflags = &vcpu->arch.sie_block->cpuflags;
+	seqcount_init(&vcpu->arch.cputm_seqcount);
 
 	rc = kvm_vcpu_init(vcpu, kvm, id);
 	if (rc)
-- 
2.5.0

[GIT PULL 6/9] KVM: s390: step the VCPU timer while in enabled wait

[Christian Borntraeger]

From: David Hildenbrand <dahi@linux.vnet.ibm.com>

The cpu timer is a mean to measure task execution time. We want
to account everything for a VCPU for which it is responsible. Therefore,
if the VCPU wants to sleep, it shall be accounted for it.

We can easily get this done by not disabling cpu timer accounting when
scheduled out while sleeping because of enabled wait.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 arch/s390/kvm/kvm-s390.c | 4 ++--
 arch/s390/kvm/kvm-s390.h | 5 +++++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 38223c4..b54daed 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1538,7 +1538,7 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 	restore_access_regs(vcpu->run->s.regs.acrs);
 	gmap_enable(vcpu->arch.gmap);
 	atomic_or(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
-	if (vcpu->arch.cputm_enabled)
+	if (vcpu->arch.cputm_enabled && !is_vcpu_idle(vcpu))
 		__start_cpu_timer_accounting(vcpu);
 	vcpu->cpu = cpu;
 }
@@ -1546,7 +1546,7 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 {
 	vcpu->cpu = -1;
-	if (vcpu->arch.cputm_enabled)
+	if (vcpu->arch.cputm_enabled && !is_vcpu_idle(vcpu))
 		__stop_cpu_timer_accounting(vcpu);
 	atomic_andnot(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
 	gmap_disable(vcpu->arch.gmap);
diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index 9787299..b1f7ee3 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -54,6 +54,11 @@ static inline int is_vcpu_stopped(struct kvm_vcpu *vcpu)
 	return atomic_read(&vcpu->arch.sie_block->cpuflags) & CPUSTAT_STOPPED;
 }
 
+static inline int is_vcpu_idle(struct kvm_vcpu *vcpu)
+{
+	return atomic_read(&vcpu->arch.sie_block->cpuflags) & CPUSTAT_WAIT;
+}
+
 static inline int kvm_is_ucontrol(struct kvm *kvm)
 {
 #ifdef CONFIG_KVM_S390_UCONTROL
-- 
2.5.0

[GIT PULL 7/9] KVM: s390: wake up when the VCPU cpu timer expires

[Christian Borntraeger]

From: David Hildenbrand <dahi@linux.vnet.ibm.com>

When the VCPU cpu timer expires, we have to wake up just like when the ckc
triggers. For now, setting up a cpu timer in the guest and going into
enabled wait will never lead to a wakeup. This patch fixes this problem.
Just as for the ckc, we have to take care of waking up too early. We
have to recalculate the sleep time and go back to sleep.

Please note that the timer callback calls kvm_s390_get_cpu_timer() from
interrupt context. As the timer is canceled when leaving handle_wait(),
and we don't do any VCPU cpu timer writes/updates in that function, we can
be sure that we will never try to read the VCPU cpu timer from the same cpu
that is currentyl updating the timer (deadlock).

Reported-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Tested-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 arch/s390/kvm/interrupt.c | 48 ++++++++++++++++++++++++++++++++++-------------
 1 file changed, 35 insertions(+), 13 deletions(-)

diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 4604e9a..ef84a80 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -909,9 +909,35 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
 	return ckc_irq_pending(vcpu) || cpu_timer_irq_pending(vcpu);
 }
 
+static u64 __calculate_sltime(struct kvm_vcpu *vcpu)
+{
+	u64 now, 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)
+			return 0;
+		if (cpu_timer_interrupts_enabled(vcpu)) {
+			cputm = kvm_s390_get_cpu_timer(vcpu);
+			/* already expired? */
+			if (cputm >> 63)
+				return 0;
+			return min(sltime, tod_to_ns(cputm));
+		}
+	} else if (cpu_timer_interrupts_enabled(vcpu)) {
+		sltime = kvm_s390_get_cpu_timer(vcpu);
+		/* already expired? */
+		if (sltime >> 63)
+			return 0;
+	}
+	return sltime;
+}
+
 int kvm_s390_handle_wait(struct kvm_vcpu *vcpu)
 {
-	u64 now, sltime;
+	u64 sltime;
 
 	vcpu->stat.exit_wait_state++;
 
@@ -924,22 +950,20 @@ int kvm_s390_handle_wait(struct kvm_vcpu *vcpu)
 		return -EOPNOTSUPP; /* disabled wait */
 	}
 
-	if (!ckc_interrupts_enabled(vcpu)) {
+	if (!ckc_interrupts_enabled(vcpu) &&
+	    !cpu_timer_interrupts_enabled(vcpu)) {
 		VCPU_EVENT(vcpu, 3, "%s", "enabled wait w/o timer");
 		__set_cpu_idle(vcpu);
 		goto no_timer;
 	}
 
-	now = kvm_s390_get_tod_clock_fast(vcpu->kvm);
-	sltime = tod_to_ns(vcpu->arch.sie_block->ckc - now);
-
-	/* underflow */
-	if (vcpu->arch.sie_block->ckc < now)
+	sltime = __calculate_sltime(vcpu);
+	if (!sltime)
 		return 0;
 
 	__set_cpu_idle(vcpu);
 	hrtimer_start(&vcpu->arch.ckc_timer, ktime_set (0, sltime) , HRTIMER_MODE_REL);
-	VCPU_EVENT(vcpu, 4, "enabled wait via clock comparator: %llu ns", sltime);
+	VCPU_EVENT(vcpu, 4, "enabled wait: %llu ns", sltime);
 no_timer:
 	srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
 	kvm_vcpu_block(vcpu);
@@ -966,18 +990,16 @@ void kvm_s390_vcpu_wakeup(struct kvm_vcpu *vcpu)
 enum hrtimer_restart kvm_s390_idle_wakeup(struct hrtimer *timer)
 {
 	struct kvm_vcpu *vcpu;
-	u64 now, sltime;
+	u64 sltime;
 
 	vcpu = container_of(timer, struct kvm_vcpu, arch.ckc_timer);
-	now = kvm_s390_get_tod_clock_fast(vcpu->kvm);
-	sltime = tod_to_ns(vcpu->arch.sie_block->ckc - now);
+	sltime = __calculate_sltime(vcpu);
 
 	/*
 	 * If the monotonic clock runs faster than the tod clock we might be
 	 * woken up too early and have to go back to sleep to avoid deadlocks.
 	 */
-	if (vcpu->arch.sie_block->ckc > now &&
-	    hrtimer_forward_now(timer, ns_to_ktime(sltime)))
+	if (sltime && hrtimer_forward_now(timer, ns_to_ktime(sltime)))
 		return HRTIMER_RESTART;
 	kvm_s390_vcpu_wakeup(vcpu);
 	return HRTIMER_NORESTART;
-- 
2.5.0

[GIT PULL 8/9] KVM: s390: enable STFLE interpretation only if enabled for the guest

[Christian Borntraeger]

From: David Hildenbrand <dahi@linux.vnet.ibm.com>

Not setting the facility list designation disables STFLE interpretation,
this is what we want if the guest was told to not have it.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 arch/s390/kvm/kvm-s390.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index b54daed..b6a0654 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1639,7 +1639,8 @@ static void kvm_s390_vcpu_setup_model(struct kvm_vcpu *vcpu)
 
 	vcpu->arch.cpu_id = model->cpu_id;
 	vcpu->arch.sie_block->ibc = model->ibc;
-	vcpu->arch.sie_block->fac = (int) (long) model->fac->list;
+	if (test_kvm_facility(vcpu->kvm, 7))
+		vcpu->arch.sie_block->fac = (int) (long) model->fac->list;
 }
 
 int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
-- 
2.5.0

[GIT PULL 9/9] KVM: s390: allocate only one DMA page per VM

[Christian Borntraeger]

From: David Hildenbrand <dahi@linux.vnet.ibm.com>

We can fit the 2k for the STFLE interpretation and the crypto
control block into one DMA page. As we now only have to allocate
one DMA page, we can clean up the code a bit.

As a nice side effect, this also fixes a problem with crycbd alignment in
case special allocation debug options are enabled, debugged by Sascha
Silbe.

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 arch/s390/include/asm/kvm_host.h | 23 +++++++++------
 arch/s390/kvm/kvm-s390.c         | 60 +++++++++++++++-------------------------
 arch/s390/kvm/kvm-s390.h         |  4 +--
 arch/s390/kvm/priv.c             |  2 +-
 4 files changed, 41 insertions(+), 48 deletions(-)

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index d61e645..3c25495 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -600,15 +600,11 @@ struct s390_io_adapter {
 #define S390_ARCH_FAC_MASK_SIZE_U64 \
 	(S390_ARCH_FAC_MASK_SIZE_BYTE / sizeof(u64))
 
-struct kvm_s390_fac {
-	/* facility list requested by guest */
-	__u64 list[S390_ARCH_FAC_LIST_SIZE_U64];
-	/* facility mask supported by kvm & hosting machine */
-	__u64 mask[S390_ARCH_FAC_LIST_SIZE_U64];
-};
-
 struct kvm_s390_cpu_model {
-	struct kvm_s390_fac *fac;
+	/* facility mask supported by kvm & hosting machine */
+	__u64 fac_mask[S390_ARCH_FAC_LIST_SIZE_U64];
+	/* facility list requested by guest (in dma page) */
+	__u64 *fac_list;
 	struct cpuid cpu_id;
 	unsigned short ibc;
 };
@@ -627,6 +623,16 @@ struct kvm_s390_crypto_cb {
 	__u8    reserved80[128];                /* 0x0080 */
 };
 
+/*
+ * sie_page2 has to be allocated as DMA because fac_list and crycb need
+ * 31bit addresses in the sie control block.
+ */
+struct sie_page2 {
+	__u64 fac_list[S390_ARCH_FAC_LIST_SIZE_U64];	/* 0x0000 */
+	struct kvm_s390_crypto_cb crycb;		/* 0x0800 */
+	u8 reserved900[0x1000 - 0x900];			/* 0x0900 */
+} __packed;
+
 struct kvm_arch{
 	void *sca;
 	int use_esca;
@@ -647,6 +653,7 @@ struct kvm_arch{
 	int ipte_lock_count;
 	struct mutex ipte_mutex;
 	spinlock_t start_stop_lock;
+	struct sie_page2 *sie_page2;
 	struct kvm_s390_cpu_model model;
 	struct kvm_s390_crypto crypto;
 	u64 epoch;
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index b6a0654..c186d55 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -355,8 +355,8 @@ static int kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap)
 		if (atomic_read(&kvm->online_vcpus)) {
 			r = -EBUSY;
 		} else if (MACHINE_HAS_VX) {
-			set_kvm_facility(kvm->arch.model.fac->mask, 129);
-			set_kvm_facility(kvm->arch.model.fac->list, 129);
+			set_kvm_facility(kvm->arch.model.fac_mask, 129);
+			set_kvm_facility(kvm->arch.model.fac_list, 129);
 			r = 0;
 		} else
 			r = -EINVAL;
@@ -370,8 +370,8 @@ static int kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap)
 		if (atomic_read(&kvm->online_vcpus)) {
 			r = -EBUSY;
 		} else if (test_facility(64)) {
-			set_kvm_facility(kvm->arch.model.fac->mask, 64);
-			set_kvm_facility(kvm->arch.model.fac->list, 64);
+			set_kvm_facility(kvm->arch.model.fac_mask, 64);
+			set_kvm_facility(kvm->arch.model.fac_list, 64);
 			r = 0;
 		}
 		mutex_unlock(&kvm->lock);
@@ -654,7 +654,7 @@ static int kvm_s390_set_processor(struct kvm *kvm, struct kvm_device_attr *attr)
 		memcpy(&kvm->arch.model.cpu_id, &proc->cpuid,
 		       sizeof(struct cpuid));
 		kvm->arch.model.ibc = proc->ibc;
-		memcpy(kvm->arch.model.fac->list, proc->fac_list,
+		memcpy(kvm->arch.model.fac_list, proc->fac_list,
 		       S390_ARCH_FAC_LIST_SIZE_BYTE);
 	} else
 		ret = -EFAULT;
@@ -688,7 +688,8 @@ static int kvm_s390_get_processor(struct kvm *kvm, struct kvm_device_attr *attr)
 	}
 	memcpy(&proc->cpuid, &kvm->arch.model.cpu_id, sizeof(struct cpuid));
 	proc->ibc = kvm->arch.model.ibc;
-	memcpy(&proc->fac_list, kvm->arch.model.fac->list, S390_ARCH_FAC_LIST_SIZE_BYTE);
+	memcpy(&proc->fac_list, kvm->arch.model.fac_list,
+	       S390_ARCH_FAC_LIST_SIZE_BYTE);
 	if (copy_to_user((void __user *)attr->addr, proc, sizeof(*proc)))
 		ret = -EFAULT;
 	kfree(proc);
@@ -708,7 +709,7 @@ static int kvm_s390_get_machine(struct kvm *kvm, struct kvm_device_attr *attr)
 	}
 	get_cpu_id((struct cpuid *) &mach->cpuid);
 	mach->ibc = sclp.ibc;
-	memcpy(&mach->fac_mask, kvm->arch.model.fac->mask,
+	memcpy(&mach->fac_mask, kvm->arch.model.fac_mask,
 	       S390_ARCH_FAC_LIST_SIZE_BYTE);
 	memcpy((unsigned long *)&mach->fac_list, S390_lowcore.stfle_fac_list,
 	       S390_ARCH_FAC_LIST_SIZE_BYTE);
@@ -1085,16 +1086,12 @@ static void kvm_s390_get_cpu_id(struct cpuid *cpu_id)
 	cpu_id->version = 0xff;
 }
 
-static int kvm_s390_crypto_init(struct kvm *kvm)
+static void kvm_s390_crypto_init(struct kvm *kvm)
 {
 	if (!test_kvm_facility(kvm, 76))
-		return 0;
-
-	kvm->arch.crypto.crycb = kzalloc(sizeof(*kvm->arch.crypto.crycb),
-					 GFP_KERNEL | GFP_DMA);
-	if (!kvm->arch.crypto.crycb)
-		return -ENOMEM;
+		return;
 
+	kvm->arch.crypto.crycb = &kvm->arch.sie_page2->crycb;
 	kvm_s390_set_crycb_format(kvm);
 
 	/* Enable AES/DEA protected key functions by default */
@@ -1104,8 +1101,6 @@ static int kvm_s390_crypto_init(struct kvm *kvm)
 			 sizeof(kvm->arch.crypto.crycb->aes_wrapping_key_mask));
 	get_random_bytes(kvm->arch.crypto.crycb->dea_wrapping_key_mask,
 			 sizeof(kvm->arch.crypto.crycb->dea_wrapping_key_mask));
-
-	return 0;
 }
 
 static void sca_dispose(struct kvm *kvm)
@@ -1159,37 +1154,30 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 	if (!kvm->arch.dbf)
 		goto out_err;
 
-	/*
-	 * The architectural maximum amount of facilities is 16 kbit. To store
-	 * this amount, 2 kbyte of memory is required. Thus we need a full
-	 * page to hold the guest facility list (arch.model.fac->list) and the
-	 * facility mask (arch.model.fac->mask). Its address size has to be
-	 * 31 bits and word aligned.
-	 */
-	kvm->arch.model.fac =
-		(struct kvm_s390_fac *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
-	if (!kvm->arch.model.fac)
+	kvm->arch.sie_page2 =
+	     (struct sie_page2 *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
+	if (!kvm->arch.sie_page2)
 		goto out_err;
 
 	/* Populate the facility mask initially. */
-	memcpy(kvm->arch.model.fac->mask, S390_lowcore.stfle_fac_list,
+	memcpy(kvm->arch.model.fac_mask, S390_lowcore.stfle_fac_list,
 	       S390_ARCH_FAC_LIST_SIZE_BYTE);
 	for (i = 0; i < S390_ARCH_FAC_LIST_SIZE_U64; i++) {
 		if (i < kvm_s390_fac_list_mask_size())
-			kvm->arch.model.fac->mask[i] &= kvm_s390_fac_list_mask[i];
+			kvm->arch.model.fac_mask[i] &= kvm_s390_fac_list_mask[i];
 		else
-			kvm->arch.model.fac->mask[i] = 0UL;
+			kvm->arch.model.fac_mask[i] = 0UL;
 	}
 
 	/* Populate the facility list initially. */
-	memcpy(kvm->arch.model.fac->list, kvm->arch.model.fac->mask,
+	kvm->arch.model.fac_list = kvm->arch.sie_page2->fac_list;
+	memcpy(kvm->arch.model.fac_list, kvm->arch.model.fac_mask,
 	       S390_ARCH_FAC_LIST_SIZE_BYTE);
 
 	kvm_s390_get_cpu_id(&kvm->arch.model.cpu_id);
 	kvm->arch.model.ibc = sclp.ibc & 0x0fff;
 
-	if (kvm_s390_crypto_init(kvm) < 0)
-		goto out_err;
+	kvm_s390_crypto_init(kvm);
 
 	spin_lock_init(&kvm->arch.float_int.lock);
 	for (i = 0; i < FIRQ_LIST_COUNT; i++)
@@ -1225,8 +1213,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 
 	return 0;
 out_err:
-	kfree(kvm->arch.crypto.crycb);
-	free_page((unsigned long)kvm->arch.model.fac);
+	free_page((unsigned long)kvm->arch.sie_page2);
 	debug_unregister(kvm->arch.dbf);
 	sca_dispose(kvm);
 	KVM_EVENT(3, "creation of vm failed: %d", rc);
@@ -1272,10 +1259,9 @@ static void kvm_free_vcpus(struct kvm *kvm)
 void kvm_arch_destroy_vm(struct kvm *kvm)
 {
 	kvm_free_vcpus(kvm);
-	free_page((unsigned long)kvm->arch.model.fac);
 	sca_dispose(kvm);
 	debug_unregister(kvm->arch.dbf);
-	kfree(kvm->arch.crypto.crycb);
+	free_page((unsigned long)kvm->arch.sie_page2);
 	if (!kvm_is_ucontrol(kvm))
 		gmap_free(kvm->arch.gmap);
 	kvm_s390_destroy_adapters(kvm);
@@ -1640,7 +1626,7 @@ static void kvm_s390_vcpu_setup_model(struct kvm_vcpu *vcpu)
 	vcpu->arch.cpu_id = model->cpu_id;
 	vcpu->arch.sie_block->ibc = model->ibc;
 	if (test_kvm_facility(vcpu->kvm, 7))
-		vcpu->arch.sie_block->fac = (int) (long) model->fac->list;
+		vcpu->arch.sie_block->fac = (u32)(u64) model->fac_list;
 }
 
 int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index b1f7ee3..8621ab0 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -160,8 +160,8 @@ static inline void kvm_s390_set_psw_cc(struct kvm_vcpu *vcpu, unsigned long cc)
 /* test availability of facility in a kvm instance */
 static inline int test_kvm_facility(struct kvm *kvm, unsigned long nr)
 {
-	return __test_facility(nr, kvm->arch.model.fac->mask) &&
-		__test_facility(nr, kvm->arch.model.fac->list);
+	return __test_facility(nr, kvm->arch.model.fac_mask) &&
+		__test_facility(nr, kvm->arch.model.fac_list);
 }
 
 static inline int set_kvm_facility(u64 *fac_list, unsigned long nr)
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index add9909..f218ccf 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -354,7 +354,7 @@ static int handle_stfl(struct kvm_vcpu *vcpu)
 	 * We need to shift the lower 32 facility bits (bit 0-31) from a u64
 	 * into a u32 memory representation. They will remain bits 0-31.
 	 */
-	fac = *vcpu->kvm->arch.model.fac->list >> 32;
+	fac = *vcpu->kvm->arch.model.fac_list >> 32;
 	rc = write_guest_lc(vcpu, offsetof(struct lowcore, stfl_fac_list),
 			    &fac, sizeof(fac));
 	if (rc)
-- 
2.5.0

Re: [GIT PULL 0/9] KVM: s390: Fixes and features for kvm/next (4.6) part 2

[Paolo Bonzini]

On 10/03/2016 16:36, Christian Borntraeger wrote:
> Paolo,
> 
> the remaining patches for 4.6 on the s390 side.
> 
> The following changes since commit 1763f8d09d522b3ac998229dcf038476e88b78fc:
> 
>   KVM: s390: bail out early on fatal signal in dirty logging (2016-02-10 13:12:57 +0100)
> 
> are available in the git repository at:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux.git  tags/kvm-s390-next-4.6-2
> 
> for you to fetch changes up to c54f0d6ae057444453f5167e66ed999e8cf26936:
> 
>   KVM: s390: allocate only one DMA page per VM (2016-03-08 13:57:54 +0100)
> 
> ----------------------------------------------------------------
> KVM: s390: Fixes and features for kvm/next (4.6) part 2
> 
> - add watchdog diagnose to trace event decoder
> - better handle the cpu timer when not inside the guest
> - only provide STFLE if the CPU model has STFLE
> - reduce DMA page usage
> 
> ----------------------------------------------------------------
> Alexander Yarygin (1):
>       KVM: s390: Add diag "watchdog functions" to trace event decoding
> 
> David Hildenbrand (8):
>       KVM: s390: store cpu id in vcpu->cpu when scheduled in
>       KVM: s390: abstract access to the VCPU cpu timer
>       KVM: s390: step VCPU cpu timer during kvm_run ioctl
>       KVM: s390: protect VCPU cpu timer with a seqcount
>       KVM: s390: step the VCPU timer while in enabled wait
>       KVM: s390: wake up when the VCPU cpu timer expires
>       KVM: s390: enable STFLE interpretation only if enabled for the guest
>       KVM: s390: allocate only one DMA page per VM
> 
>  arch/s390/include/asm/kvm_host.h |  33 +++++--
>  arch/s390/include/uapi/asm/sie.h |   1 +
>  arch/s390/kvm/interrupt.c        |  53 ++++++++----
>  arch/s390/kvm/kvm-s390.c         | 180 +++++++++++++++++++++++++++++----------
>  arch/s390/kvm/kvm-s390.h         |  11 ++-
>  arch/s390/kvm/priv.c             |   2 +-
>  6 files changed, 209 insertions(+), 71 deletions(-)
> 
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

Pulled, thanks!

Paolo