KVM: arm64: timers: Fix percpu address space issues in kvm_timer_hyp_init()

percpu_base is used in various percpu functions that expect variable in __percpu address space. Correct the declaration of percpu_base to

void __iomem * __percpu *percpu_base;

to declare the variable as __percpu pointer.

The patch fixes several sparse warnings:

irq-gic.c:1172:44: warning: incorrect type in assignment (different address spaces)
irq-gic.c:1172:44: expected void [noderef] __percpu *[noderef] __iomem *percpu_base
irq-gic.c:1172:44: got void [noderef] __iomem *[noderef] __percpu *
...
irq-gic.c:1184:26: warning: incorrect type in initializer (different address spaces)
irq-gic.c:1184:26: expected void const [noderef] __percpu *__vpp_verify
irq-gic.c:1184:26: got void [noderef] __percpu *[noderef] __iomem *
...
irq-gic.c:1184:71: warning: incorrect type in assignment (different address spaces)
irq-gic.c:1184:71: expected void [noderef] __percpu *
irq-gic.c:1184:71: got void [noderef] __iomem *
...
irq-gic.c:1231:43: warning: incorrect type in argument 1 (different address spaces)
irq-gic.c:1231:43: expected void [noderef] __percpu *__pdata
irq-gic.c:1231:43: got void [noderef] __percpu *[noderef] __iomem *percpu_base

There were no changes in the resulting object files.

Signed-off-by Uros Bizjak <[email protected]>

Cc Marc Zyngier <[email protected]>

Cc Thomas Gleixner <[email protected]>

---
 drivers/irqchip/irq-gic.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

drivers/irqchip/irq-gic.c +0 -0

index 8fae6dc01024..6503573557fd 100644

struct zynqmp_ipi_pdata __percpu *pdata is not a per-cpu variable, so it shoul not be annotated with __percpu annotation.

Remove invalid __percpu annotation to fix several

zynqmp-ipi-mailbox.c:920:15: warning: incorrect type in assignment (different address spaces)
zynqmp-ipi-mailbox.c:920:15: expected struct zynqmp_ipi_pdata [noderef] __percpu *pdata
zynqmp-ipi-mailbox.c:920:15: got void *
zynqmp-ipi-mailbox.c:927:56: warning: incorrect type in argument 3 (different address spaces)
zynqmp-ipi-mailbox.c:927:56: expected unsigned int [usertype] *out_value
zynqmp-ipi-mailbox.c:927:56: got unsigned int [noderef] __percpu *
...

and several

drivers/mailbox/zynqmp-ipi-mailbox.c:924:9: warning: dereference of noderef expression
...

sparse warnings.

There were no changes in the resulting object files.

Signed-off-by Uros Bizjak <[email protected]>

Cc Jassi Brar <[email protected]>

Cc Michal Simek <[email protected]>

---
  drivers/mailbox/zynqmp-ipi-mailbox.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

drivers/mailbox/zynqmp-ipi-mailbox.c +0 -0

index aa5249da59b2..0c143beaafda 100644

Cast return value from kvm_get_running_vcpus() in the __percpu address space to the generic address space via uintptr_t [1] to fix a couple of:

arch_timer.c:1395:66: warning: incorrect type in argument 2 (different address spaces)
arch_timer.c:1395:66: expected void *vcpu_info
arch_timer.c:1395:66: got struct kvm_vcpu *[noderef] __percpu *

sparse warnings.

There were no changes in the resulting object files.

[1] https://sparse.docs.kernel.org/en/latest/annotations.html#address-space-name

Signed-off-by Uros Bizjak <[email protected]>

Cc Marc Zyngier <[email protected]>

Cc Oliver Upton <[email protected]>

Cc Joey Gouly <[email protected]>

Cc Suzuki K Poulose <[email protected]>

Cc Zenghui Yu <[email protected]>

Cc Catalin Marinas <[email protected]>

Cc Will Deacon <[email protected]>

---
 arch/arm64/kvm/arch_timer.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

arch/arm64/kvm/arch_timer.c +1 -1

index 1215df590418..a13bb9e8dc19 100644
@@ -1392,7 +1392,7 @@ int __init kvm_timer_hyp_init(bool has_gic)
 
 	if (has_gic) {
 		err = irq_set_vcpu_affinity(host_vtimer_irq,
-					    kvm_get_running_vcpus());
+					    (void *)(uintptr_t)kvm_get_running_vcpus());
 		if (err) {
 			kvm_err("kvm_arch_timer: error setting vcpu affinity\n");
 			goto out_free_vtimer_irq;

Quoted 41 lines · Uros Bizjak

Cast return value from kvm_get_running_vcpus() in the __percpu address space to the generic address space via uintptr_t [1] to fix a couple of:

arch_timer.c:1395:66: warning: incorrect type in argument 2 (different address spaces)
arch_timer.c:1395:66: expected void *vcpu_info
arch_timer.c:1395:66: got struct kvm_vcpu *[noderef] __percpu *

sparse warnings.

There were no changes in the resulting object files.

[1] https://sparse.docs.kernel.org/en/latest/annotations.html#address-space-name

Signed-off-by Uros Bizjak <[email protected]>

Cc Marc Zyngier <[email protected]>

Cc Oliver Upton <[email protected]>

Cc Joey Gouly <[email protected]>

Cc Suzuki K Poulose <[email protected]>

Cc Zenghui Yu <[email protected]>

Cc Catalin Marinas <[email protected]>

Cc Will Deacon <[email protected]>

---
 arch/arm64/kvm/arch_timer.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

arch/arm64/kvm/arch_timer.c +1 -1

index 1215df590418..a13bb9e8dc19 100644
@@ -1392,7 +1392,7 @@ int __init kvm_timer_hyp_init(bool has_gic)
 
      if (has_gic) {
              err = irq_set_vcpu_affinity(host_vtimer_irq,
-                                         kvm_get_running_vcpus());
+                                         (void *)(uintptr_t)kvm_get_running_vcpus());
              if (err) {
                      kvm_err("kvm_arch_timer: error setting vcpu affinity\n");
                      goto out_free_vtimer_irq;

arch/arm64/kvm/arch_timer.c int __init kvm_timer_hyp_init(bool has_gic) · line 1422

Quoted 8 lines

arch/arm64/kvm/arch_timer.c +1 -1

@@ -1416,7 +1416,7 @@ int __init kvm_timer_hyp_init(bool has_gic)
 
              if (has_gic) {
                      err = irq_set_vcpu_affinity(host_ptimer_irq,
-                                                 kvm_get_running_vcpus());
+                                                 (void *)(uintptr_t)kvm_get_running_vcpus());
                      if (err) {
                              kvm_err("kvm_arch_timer: error setting vcpu affinity\n");
                              goto out_free_ptimer_irq;

I think the fix is worse than the current code, because there is no real semantics behind the pointer being passed to irq_set_vcpu_affinity(). All that is required is that it is a non-NULL pointer.

I expect the following hack to work just as well and not suffer from any sparse indigestion. Untested though.

Quoted 42 lines · Uros Bizjak

Cast return value from kvm_get_running_vcpus() in the __percpu address space to the generic address space via uintptr_t [1] to fix a couple of:

arch_timer.c:1395:66: warning: incorrect type in argument 2 (different address spaces)
arch_timer.c:1395:66: expected void *vcpu_info
arch_timer.c:1395:66: got struct kvm_vcpu *[noderef] __percpu *

sparse warnings.

There were no changes in the resulting object files.

[1] https://sparse.docs.kernel.org/en/latest/annotations.html#address-space-name

Signed-off-by Uros Bizjak <[email protected]>

Cc Marc Zyngier <[email protected]>

Cc Oliver Upton <[email protected]>

Cc Joey Gouly <[email protected]>

Cc Suzuki K Poulose <[email protected]>

Cc Zenghui Yu <[email protected]>

Cc Catalin Marinas <[email protected]>

Cc Will Deacon <[email protected]>

---
 arch/arm64/kvm/arch_timer.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

arch/arm64/kvm/arch_timer.c +1 -1

index 1215df590418..a13bb9e8dc19 100644
@@ -1392,7 +1392,7 @@ int __init kvm_timer_hyp_init(bool has_gic)
 
      if (has_gic) {
              err = irq_set_vcpu_affinity(host_vtimer_irq,
-                                         kvm_get_running_vcpus());
+                                         (void *)(uintptr_t)kvm_get_running_vcpus());
              if (err) {
                      kvm_err("kvm_arch_timer: error setting vcpu affinity\n");
                      goto out_free_vtimer_irq;

@@ -1416,7 +1416,7 @@ int __init kvm_timer_hyp_init(bool has_gic)
 

arch/arm64/kvm/arch_timer.c int __init kvm_timer_hyp_init(bool has_gic) · line 1422

Quoted 7 lines

arch/arm64/kvm/arch_timer.c +1 -1

              if (has_gic) {
                      err = irq_set_vcpu_affinity(host_ptimer_irq,
-                                                 kvm_get_running_vcpus());
+                                                 (void *)(uintptr_t)kvm_get_running_vcpus());
                      if (err) {
                              kvm_err("kvm_arch_timer: error setting vcpu affinity\n");
                              goto out_free_ptimer_irq;

I think the fix is worse than the current code, because there is no real semantics behind the pointer being passed to irq_set_vcpu_affinity(). All that is required is that it is a non-NULL pointer.

I expect the following hack to work just as well and not suffer from any sparse indigestion. Untested though.

        M.

arch/arm64/kvm/arch_timer.c +2 -5

index 1215df5904185..8058d92048fb4 100644
@@ -1391,8 +1391,7 @@ int __init kvm_timer_hyp_init(bool has_gic)
        }
 
        if (has_gic) {
-               err = irq_set_vcpu_affinity(host_vtimer_irq,
-                                           kvm_get_running_vcpus());
+               err = irq_set_vcpu_affinity(host_vtimer_irq, info);
                if (err) {
                        kvm_err("kvm_arch_timer: error setting vcpu affinity\n");
                        goto out_free_vtimer_irq;

@@ -1415,8 +1414,7 @@ int __init kvm_timer_hyp_init(bool has_gic)
                }
 
                if (has_gic) {
-                       err = irq_set_vcpu_affinity(host_ptimer_irq,
-                                                   kvm_get_running_vcpus());
+                       err = irq_set_vcpu_affinity(host_ptimer_irq, info);
                        if (err) {
                                kvm_err("kvm_arch_timer: error setting vcpu affinity\n");
                                goto out_free_ptimer_irq;
 
--

Without deviation from the norm, progress is not possible.

Quoted 45 lines · Marc Zyngier

Quoted 42 lines · Uros Bizjak

Cast return value from kvm_get_running_vcpus() in the __percpu address space to the generic address space via uintptr_t [1] to fix a couple of:

arch_timer.c:1395:66: warning: incorrect type in argument 2 (different address spaces)
arch_timer.c:1395:66: expected void *vcpu_info
arch_timer.c:1395:66: got struct kvm_vcpu *[noderef] __percpu *

sparse warnings.

There were no changes in the resulting object files.

[1] https://sparse.docs.kernel.org/en/latest/annotations.html#address-space-name

Signed-off-by Uros Bizjak <[email protected]>

Cc Marc Zyngier <[email protected]>

Cc Oliver Upton <[email protected]>

Cc Joey Gouly <[email protected]>

Cc Suzuki K Poulose <[email protected]>

Cc Zenghui Yu <[email protected]>

Cc Catalin Marinas <[email protected]>

Cc Will Deacon <[email protected]>

---
 arch/arm64/kvm/arch_timer.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

arch/arm64/kvm/arch_timer.c +1 -1

index 1215df590418..a13bb9e8dc19 100644
@@ -1392,7 +1392,7 @@ int __init kvm_timer_hyp_init(bool has_gic)
 
      if (has_gic) {
              err = irq_set_vcpu_affinity(host_vtimer_irq,
-                                         kvm_get_running_vcpus());
+                                         (void *)(uintptr_t)kvm_get_running_vcpus());
              if (err) {
                      kvm_err("kvm_arch_timer: error setting vcpu affinity\n");
                      goto out_free_vtimer_irq;

@@ -1416,7 +1416,7 @@ int __init kvm_timer_hyp_init(bool has_gic)
 

Quoted 12 lines

arch/arm64/kvm/arch_timer.c int __init kvm_timer_hyp_init(bool has_gic) · line 1418

Quoted 7 lines

arch/arm64/kvm/arch_timer.c +1 -1

              if (has_gic) {
                      err = irq_set_vcpu_affinity(host_ptimer_irq,
-                                                 kvm_get_running_vcpus());
+                                                 (void *)(uintptr_t)kvm_get_running_vcpus());
                      if (err) {
                              kvm_err("kvm_arch_timer: error setting vcpu affinity\n");
                              goto out_free_ptimer_irq;

I think the fix is worse than the current code, because there is no real semantics behind the pointer being passed to irq_set_vcpu_affinity(). All that is required is that it is a non-NULL pointer.

If this is the case, we can just remove dependence on the pointer in the called function.

Something like in the attached patch.

arch/arm64/kvm/arch_timer.c +4 -7

index 1215df590418..10c293c2d2f5 100644
@@ -1238,12 +1238,10 @@ void kvm_arm_timer_write_sysreg(struct kvm_vcpu *vcpu,
 	}
 }
 
-static int timer_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu)
+static int timer_irq_set_vcpu_affinity(struct irq_data *d,
+				       void __always_unused *vcpu)
 {
-	if (vcpu)
-		irqd_set_forwarded_to_vcpu(d);
-	else
-		irqd_clr_forwarded_to_vcpu(d);
+	irqd_set_forwarded_to_vcpu(d);
 
 	return 0;
 }

@@ -1391,8 +1389,7 @@ int __init kvm_timer_hyp_init(bool has_gic)
 	}
 
 	if (has_gic) {
-		err = irq_set_vcpu_affinity(host_vtimer_irq,
-					    kvm_get_running_vcpus());
+		err = irq_set_vcpu_affinity(host_vtimer_irq, NULL);
 		if (err) {
 			kvm_err("kvm_arch_timer: error setting vcpu affinity\n");
 			goto out_free_vtimer_irq;