KVM: s390: abstract access to the VCPU cpu timer
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>
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_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 @@
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 @@
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 @@
(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 @@
struct kvm_one_reg *reg)
{
int r = -EINVAL;
+ __u64 val;
switch (reg->id) {
case KVM_REG_S390_TODPR:
@@ -1772,8 +1785,9 @@
(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 @@
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 @@
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 @@
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 @@
&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 @@
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);
