diff mbox series

[3/3] s390x: protvirt: Add new VCPU reset functions

Message ID 20191129142025.21453-4-frankja@linux.ibm.com
State New
Headers show
Series s390x: Increase architectural compliance | expand

Commit Message

Janosch Frank Nov. 29, 2019, 2:20 p.m. UTC 
CPU resets for protected guests need to be done via Ultravisor
calls. Hence we need a way to issue these calls for each reset.

As we formerly had only one reset function and it was called for
initial, as well as for the clear reset, we now need a new interface.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
---
 target/s390x/cpu.c       | 14 ++++++++++++--
 target/s390x/kvm-stub.c  | 10 +++++++++-
 target/s390x/kvm.c       | 38 ++++++++++++++++++++++++++++++++------
 target/s390x/kvm_s390x.h |  4 +++-
 4 files changed, 56 insertions(+), 10 deletions(-)

Comments

David Hildenbrand Nov. 29, 2019, 2:24 p.m. UTC | #1 
On 29.11.19 15:20, Janosch Frank wrote:
> CPU resets for protected guests need to be done via Ultravisor
> calls. Hence we need a way to issue these calls for each reset.
> 
> As we formerly had only one reset function and it was called for
> initial, as well as for the clear reset, we now need a new interface.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
>  target/s390x/cpu.c       | 14 ++++++++++++--
>  target/s390x/kvm-stub.c  | 10 +++++++++-
>  target/s390x/kvm.c       | 38 ++++++++++++++++++++++++++++++++------
>  target/s390x/kvm_s390x.h |  4 +++-
>  4 files changed, 56 insertions(+), 10 deletions(-)
> 
> diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
> index 829ce6ad54..906285888e 100644
> --- a/target/s390x/cpu.c
> +++ b/target/s390x/cpu.c
> @@ -139,8 +139,18 @@ static void s390_cpu_reset(CPUState *s, cpu_reset_type type)
>      }
>  
>      /* Reset state inside the kernel that we cannot access yet from QEMU. */
> -    if (kvm_enabled() && type != S390_CPU_RESET_NORMAL) {
> -        kvm_s390_reset_vcpu(cpu);
> +    if (kvm_enabled()) {
> +        switch (type) {
> +        case S390_CPU_RESET_CLEAR:
> +            kvm_s390_reset_vcpu_clear(cpu);
> +            break;
> +        case S390_CPU_RESET_INITIAL:
> +            kvm_s390_reset_vcpu_initial(cpu);
> +            break;
> +        case S390_CPU_RESET_NORMAL:
> +            kvm_s390_reset_vcpu_normal(cpu);
> +            break;
> +        }
>      }
>  }
>  
> diff --git a/target/s390x/kvm-stub.c b/target/s390x/kvm-stub.c
> index 5152e2bdf1..c4cd497f85 100644
> --- a/target/s390x/kvm-stub.c
> +++ b/target/s390x/kvm-stub.c
> @@ -83,7 +83,15 @@ void kvm_s390_cmma_reset(void)
>  {
>  }
>  
> -void kvm_s390_reset_vcpu(S390CPU *cpu)
> +void kvm_s390_reset_vcpu_initial(S390CPU *cpu)
> +{
> +}
> +
> +void kvm_s390_reset_vcpu_clear(S390CPU *cpu)
> +{
> +}
> +
> +void kvm_s390_reset_vcpu_normal(S390CPU *cpu)
>  {
>  }
>  
> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
> index ad6e38c876..502fc71664 100644
> --- a/target/s390x/kvm.c
> +++ b/target/s390x/kvm.c
> @@ -151,6 +151,7 @@ static int cap_s390_irq;
>  static int cap_ri;
>  static int cap_gs;
>  static int cap_hpage_1m;
> +static int cap_vcpu_resets;
>  
>  static int active_cmma;
>  
> @@ -342,6 +343,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
>      cap_async_pf = kvm_check_extension(s, KVM_CAP_ASYNC_PF);
>      cap_mem_op = kvm_check_extension(s, KVM_CAP_S390_MEM_OP);
>      cap_s390_irq = kvm_check_extension(s, KVM_CAP_S390_INJECT_IRQ);
> +    cap_vcpu_resets = kvm_check_extension(s, KVM_CAP_S390_VCPU_RESETS);
>  
>      if (!kvm_check_extension(s, KVM_CAP_S390_GMAP)
>          || !kvm_check_extension(s, KVM_CAP_S390_COW)) {
> @@ -403,20 +405,44 @@ int kvm_arch_destroy_vcpu(CPUState *cs)
>      return 0;
>  }
>  
> -void kvm_s390_reset_vcpu(S390CPU *cpu)
> +static void kvm_s390_reset_vcpu(S390CPU *cpu, unsigned long type)
>  {
>      CPUState *cs = CPU(cpu);
>  
> -    /* The initial reset call is needed here to reset in-kernel
> -     * vcpu data that we can't access directly from QEMU
> -     * (i.e. with older kernels which don't support sync_regs/ONE_REG).
> -     * Before this ioctl cpu_synchronize_state() is called in common kvm
> -     * code (kvm-all) */
> +    /*
> +     * The reset call is needed here to reset in-kernel vcpu data that
> +     * we can't access directly from QEMU (i.e. with older kernels
> +     * which don't support sync_regs/ONE_REG).  Before this ioctl
> +     * cpu_synchronize_state() is called in common kvm code
> +     * (kvm-all).
> +     */
> +    if (cap_vcpu_resets) {
> +        if (kvm_vcpu_ioctl(cs, KVM_S390_VCPU_RESET, type)) {
> +            error_report("CPU reset type %ld failed on CPU %i",
> +                         type, cs->cpu_index);
> +        }
> +        return;
> +    }
>      if (kvm_vcpu_ioctl(cs, KVM_S390_INITIAL_RESET, NULL)) {
>          error_report("Initial CPU reset failed on CPU %i", cs->cpu_index);
>      }
>  }

I think I commented this already: The issue is that without
cap_vcpu_requests, you would no do a KVM_S390_INITIAL_RESET for type ==
S390_CPU_RESET_NORMAL. You have to fence that.


if (type != S390_CPU_RESET_NORMAL &&
    kvm_vcpu_ioctl(cs, KVM_S390_INITIAL_RESET, NULL)) {
	...
}
Janosch Frank Nov. 29, 2019, 2:34 p.m. UTC | #2 
On 11/29/19 3:24 PM, David Hildenbrand wrote:
> On 29.11.19 15:20, Janosch Frank wrote:
>> CPU resets for protected guests need to be done via Ultravisor
>> calls. Hence we need a way to issue these calls for each reset.
>>
>> As we formerly had only one reset function and it was called for
>> initial, as well as for the clear reset, we now need a new interface.
>>
>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>> ---
>>  target/s390x/cpu.c       | 14 ++++++++++++--
>>  target/s390x/kvm-stub.c  | 10 +++++++++-
>>  target/s390x/kvm.c       | 38 ++++++++++++++++++++++++++++++++------
>>  target/s390x/kvm_s390x.h |  4 +++-
>>  4 files changed, 56 insertions(+), 10 deletions(-)
>>
>> diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
>> index 829ce6ad54..906285888e 100644
>> --- a/target/s390x/cpu.c
>> +++ b/target/s390x/cpu.c
>> @@ -139,8 +139,18 @@ static void s390_cpu_reset(CPUState *s, cpu_reset_type type)
>>      }
>>  
>>      /* Reset state inside the kernel that we cannot access yet from QEMU. */
>> -    if (kvm_enabled() && type != S390_CPU_RESET_NORMAL) {
>> -        kvm_s390_reset_vcpu(cpu);
>> +    if (kvm_enabled()) {
>> +        switch (type) {
>> +        case S390_CPU_RESET_CLEAR:
>> +            kvm_s390_reset_vcpu_clear(cpu);
>> +            break;
>> +        case S390_CPU_RESET_INITIAL:
>> +            kvm_s390_reset_vcpu_initial(cpu);
>> +            break;
>> +        case S390_CPU_RESET_NORMAL:
>> +            kvm_s390_reset_vcpu_normal(cpu);
>> +            break;
>> +        }
>>      }
>>  }
>>  
>> diff --git a/target/s390x/kvm-stub.c b/target/s390x/kvm-stub.c
>> index 5152e2bdf1..c4cd497f85 100644
>> --- a/target/s390x/kvm-stub.c
>> +++ b/target/s390x/kvm-stub.c
>> @@ -83,7 +83,15 @@ void kvm_s390_cmma_reset(void)
>>  {
>>  }
>>  
>> -void kvm_s390_reset_vcpu(S390CPU *cpu)
>> +void kvm_s390_reset_vcpu_initial(S390CPU *cpu)
>> +{
>> +}
>> +
>> +void kvm_s390_reset_vcpu_clear(S390CPU *cpu)
>> +{
>> +}
>> +
>> +void kvm_s390_reset_vcpu_normal(S390CPU *cpu)
>>  {
>>  }
>>  
>> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
>> index ad6e38c876..502fc71664 100644
>> --- a/target/s390x/kvm.c
>> +++ b/target/s390x/kvm.c
>> @@ -151,6 +151,7 @@ static int cap_s390_irq;
>>  static int cap_ri;
>>  static int cap_gs;
>>  static int cap_hpage_1m;
>> +static int cap_vcpu_resets;
>>  
>>  static int active_cmma;
>>  
>> @@ -342,6 +343,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
>>      cap_async_pf = kvm_check_extension(s, KVM_CAP_ASYNC_PF);
>>      cap_mem_op = kvm_check_extension(s, KVM_CAP_S390_MEM_OP);
>>      cap_s390_irq = kvm_check_extension(s, KVM_CAP_S390_INJECT_IRQ);
>> +    cap_vcpu_resets = kvm_check_extension(s, KVM_CAP_S390_VCPU_RESETS);
>>  
>>      if (!kvm_check_extension(s, KVM_CAP_S390_GMAP)
>>          || !kvm_check_extension(s, KVM_CAP_S390_COW)) {
>> @@ -403,20 +405,44 @@ int kvm_arch_destroy_vcpu(CPUState *cs)
>>      return 0;
>>  }
>>  
>> -void kvm_s390_reset_vcpu(S390CPU *cpu)
>> +static void kvm_s390_reset_vcpu(S390CPU *cpu, unsigned long type)
>>  {
>>      CPUState *cs = CPU(cpu);
>>  
>> -    /* The initial reset call is needed here to reset in-kernel
>> -     * vcpu data that we can't access directly from QEMU
>> -     * (i.e. with older kernels which don't support sync_regs/ONE_REG).
>> -     * Before this ioctl cpu_synchronize_state() is called in common kvm
>> -     * code (kvm-all) */
>> +    /*
>> +     * The reset call is needed here to reset in-kernel vcpu data that
>> +     * we can't access directly from QEMU (i.e. with older kernels
>> +     * which don't support sync_regs/ONE_REG).  Before this ioctl
>> +     * cpu_synchronize_state() is called in common kvm code
>> +     * (kvm-all).
>> +     */
>> +    if (cap_vcpu_resets) {
>> +        if (kvm_vcpu_ioctl(cs, KVM_S390_VCPU_RESET, type)) {
>> +            error_report("CPU reset type %ld failed on CPU %i",
>> +                         type, cs->cpu_index);
>> +        }
>> +        return;
>> +    }
>>      if (kvm_vcpu_ioctl(cs, KVM_S390_INITIAL_RESET, NULL)) {
>>          error_report("Initial CPU reset failed on CPU %i", cs->cpu_index);
>>      }
>>  }
> 
> I think I commented this already: The issue is that without
> cap_vcpu_requests, you would no do a KVM_S390_INITIAL_RESET for type ==
> S390_CPU_RESET_NORMAL. You have to fence that.

I did fix that, but not on this branch -_-

> 
> 
> if (type != S390_CPU_RESET_NORMAL &&
>     kvm_vcpu_ioctl(cs, KVM_S390_INITIAL_RESET, NULL)) {
> 	...
> }
>
David Hildenbrand Nov. 29, 2019, 2:36 p.m. UTC | #3 
On 29.11.19 15:34, Janosch Frank wrote:
> On 11/29/19 3:24 PM, David Hildenbrand wrote:
>> On 29.11.19 15:20, Janosch Frank wrote:
>>> CPU resets for protected guests need to be done via Ultravisor
>>> calls. Hence we need a way to issue these calls for each reset.
>>>
>>> As we formerly had only one reset function and it was called for
>>> initial, as well as for the clear reset, we now need a new interface.
>>>
>>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>>> ---
>>>  target/s390x/cpu.c       | 14 ++++++++++++--
>>>  target/s390x/kvm-stub.c  | 10 +++++++++-
>>>  target/s390x/kvm.c       | 38 ++++++++++++++++++++++++++++++++------
>>>  target/s390x/kvm_s390x.h |  4 +++-
>>>  4 files changed, 56 insertions(+), 10 deletions(-)
>>>
>>> diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
>>> index 829ce6ad54..906285888e 100644
>>> --- a/target/s390x/cpu.c
>>> +++ b/target/s390x/cpu.c
>>> @@ -139,8 +139,18 @@ static void s390_cpu_reset(CPUState *s, cpu_reset_type type)
>>>      }
>>>  
>>>      /* Reset state inside the kernel that we cannot access yet from QEMU. */
>>> -    if (kvm_enabled() && type != S390_CPU_RESET_NORMAL) {
>>> -        kvm_s390_reset_vcpu(cpu);
>>> +    if (kvm_enabled()) {
>>> +        switch (type) {
>>> +        case S390_CPU_RESET_CLEAR:
>>> +            kvm_s390_reset_vcpu_clear(cpu);
>>> +            break;
>>> +        case S390_CPU_RESET_INITIAL:
>>> +            kvm_s390_reset_vcpu_initial(cpu);
>>> +            break;
>>> +        case S390_CPU_RESET_NORMAL:
>>> +            kvm_s390_reset_vcpu_normal(cpu);
>>> +            break;
>>> +        }
>>>      }
>>>  }
>>>  
>>> diff --git a/target/s390x/kvm-stub.c b/target/s390x/kvm-stub.c
>>> index 5152e2bdf1..c4cd497f85 100644
>>> --- a/target/s390x/kvm-stub.c
>>> +++ b/target/s390x/kvm-stub.c
>>> @@ -83,7 +83,15 @@ void kvm_s390_cmma_reset(void)
>>>  {
>>>  }
>>>  
>>> -void kvm_s390_reset_vcpu(S390CPU *cpu)
>>> +void kvm_s390_reset_vcpu_initial(S390CPU *cpu)
>>> +{
>>> +}
>>> +
>>> +void kvm_s390_reset_vcpu_clear(S390CPU *cpu)
>>> +{
>>> +}
>>> +
>>> +void kvm_s390_reset_vcpu_normal(S390CPU *cpu)
>>>  {
>>>  }
>>>  
>>> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
>>> index ad6e38c876..502fc71664 100644
>>> --- a/target/s390x/kvm.c
>>> +++ b/target/s390x/kvm.c
>>> @@ -151,6 +151,7 @@ static int cap_s390_irq;
>>>  static int cap_ri;
>>>  static int cap_gs;
>>>  static int cap_hpage_1m;
>>> +static int cap_vcpu_resets;
>>>  
>>>  static int active_cmma;
>>>  
>>> @@ -342,6 +343,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
>>>      cap_async_pf = kvm_check_extension(s, KVM_CAP_ASYNC_PF);
>>>      cap_mem_op = kvm_check_extension(s, KVM_CAP_S390_MEM_OP);
>>>      cap_s390_irq = kvm_check_extension(s, KVM_CAP_S390_INJECT_IRQ);
>>> +    cap_vcpu_resets = kvm_check_extension(s, KVM_CAP_S390_VCPU_RESETS);
>>>  
>>>      if (!kvm_check_extension(s, KVM_CAP_S390_GMAP)
>>>          || !kvm_check_extension(s, KVM_CAP_S390_COW)) {
>>> @@ -403,20 +405,44 @@ int kvm_arch_destroy_vcpu(CPUState *cs)
>>>      return 0;
>>>  }
>>>  
>>> -void kvm_s390_reset_vcpu(S390CPU *cpu)
>>> +static void kvm_s390_reset_vcpu(S390CPU *cpu, unsigned long type)
>>>  {
>>>      CPUState *cs = CPU(cpu);
>>>  
>>> -    /* The initial reset call is needed here to reset in-kernel
>>> -     * vcpu data that we can't access directly from QEMU
>>> -     * (i.e. with older kernels which don't support sync_regs/ONE_REG).
>>> -     * Before this ioctl cpu_synchronize_state() is called in common kvm
>>> -     * code (kvm-all) */
>>> +    /*
>>> +     * The reset call is needed here to reset in-kernel vcpu data that
>>> +     * we can't access directly from QEMU (i.e. with older kernels
>>> +     * which don't support sync_regs/ONE_REG).  Before this ioctl
>>> +     * cpu_synchronize_state() is called in common kvm code
>>> +     * (kvm-all).
>>> +     */
>>> +    if (cap_vcpu_resets) {
>>> +        if (kvm_vcpu_ioctl(cs, KVM_S390_VCPU_RESET, type)) {
>>> +            error_report("CPU reset type %ld failed on CPU %i",
>>> +                         type, cs->cpu_index);
>>> +        }
>>> +        return;
>>> +    }
>>>      if (kvm_vcpu_ioctl(cs, KVM_S390_INITIAL_RESET, NULL)) {
>>>          error_report("Initial CPU reset failed on CPU %i", cs->cpu_index);
>>>      }
>>>  }
>>
>> I think I commented this already: The issue is that without
>> cap_vcpu_requests, you would no do a KVM_S390_INITIAL_RESET for type ==
>> S390_CPU_RESET_NORMAL. You have to fence that.
> 
> I did fix that, but not on this branch -_-

You can avoid that completely once you switch to two new separate ioctls ;)
diff mbox series

Patch

diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
index 829ce6ad54..906285888e 100644
--- a/target/s390x/cpu.c
+++ b/target/s390x/cpu.c
@@ -139,8 +139,18 @@  static void s390_cpu_reset(CPUState *s, cpu_reset_type type)
     }
 
     /* Reset state inside the kernel that we cannot access yet from QEMU. */
-    if (kvm_enabled() && type != S390_CPU_RESET_NORMAL) {
-        kvm_s390_reset_vcpu(cpu);
+    if (kvm_enabled()) {
+        switch (type) {
+        case S390_CPU_RESET_CLEAR:
+            kvm_s390_reset_vcpu_clear(cpu);
+            break;
+        case S390_CPU_RESET_INITIAL:
+            kvm_s390_reset_vcpu_initial(cpu);
+            break;
+        case S390_CPU_RESET_NORMAL:
+            kvm_s390_reset_vcpu_normal(cpu);
+            break;
+        }
     }
 }
 
diff --git a/target/s390x/kvm-stub.c b/target/s390x/kvm-stub.c
index 5152e2bdf1..c4cd497f85 100644
--- a/target/s390x/kvm-stub.c
+++ b/target/s390x/kvm-stub.c
@@ -83,7 +83,15 @@  void kvm_s390_cmma_reset(void)
 {
 }
 
-void kvm_s390_reset_vcpu(S390CPU *cpu)
+void kvm_s390_reset_vcpu_initial(S390CPU *cpu)
+{
+}
+
+void kvm_s390_reset_vcpu_clear(S390CPU *cpu)
+{
+}
+
+void kvm_s390_reset_vcpu_normal(S390CPU *cpu)
 {
 }
 
diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
index ad6e38c876..502fc71664 100644
--- a/target/s390x/kvm.c
+++ b/target/s390x/kvm.c
@@ -151,6 +151,7 @@  static int cap_s390_irq;
 static int cap_ri;
 static int cap_gs;
 static int cap_hpage_1m;
+static int cap_vcpu_resets;
 
 static int active_cmma;
 
@@ -342,6 +343,7 @@  int kvm_arch_init(MachineState *ms, KVMState *s)
     cap_async_pf = kvm_check_extension(s, KVM_CAP_ASYNC_PF);
     cap_mem_op = kvm_check_extension(s, KVM_CAP_S390_MEM_OP);
     cap_s390_irq = kvm_check_extension(s, KVM_CAP_S390_INJECT_IRQ);
+    cap_vcpu_resets = kvm_check_extension(s, KVM_CAP_S390_VCPU_RESETS);
 
     if (!kvm_check_extension(s, KVM_CAP_S390_GMAP)
         || !kvm_check_extension(s, KVM_CAP_S390_COW)) {
@@ -403,20 +405,44 @@  int kvm_arch_destroy_vcpu(CPUState *cs)
     return 0;
 }
 
-void kvm_s390_reset_vcpu(S390CPU *cpu)
+static void kvm_s390_reset_vcpu(S390CPU *cpu, unsigned long type)
 {
     CPUState *cs = CPU(cpu);
 
-    /* The initial reset call is needed here to reset in-kernel
-     * vcpu data that we can't access directly from QEMU
-     * (i.e. with older kernels which don't support sync_regs/ONE_REG).
-     * Before this ioctl cpu_synchronize_state() is called in common kvm
-     * code (kvm-all) */
+    /*
+     * The reset call is needed here to reset in-kernel vcpu data that
+     * we can't access directly from QEMU (i.e. with older kernels
+     * which don't support sync_regs/ONE_REG).  Before this ioctl
+     * cpu_synchronize_state() is called in common kvm code
+     * (kvm-all).
+     */
+    if (cap_vcpu_resets) {
+        if (kvm_vcpu_ioctl(cs, KVM_S390_VCPU_RESET, type)) {
+            error_report("CPU reset type %ld failed on CPU %i",
+                         type, cs->cpu_index);
+        }
+        return;
+    }
     if (kvm_vcpu_ioctl(cs, KVM_S390_INITIAL_RESET, NULL)) {
         error_report("Initial CPU reset failed on CPU %i", cs->cpu_index);
     }
 }
 
+void kvm_s390_reset_vcpu_initial(S390CPU *cpu)
+{
+    kvm_s390_reset_vcpu(cpu, KVM_S390_VCPU_RESET_INITIAL);
+}
+
+void kvm_s390_reset_vcpu_clear(S390CPU *cpu)
+{
+    kvm_s390_reset_vcpu(cpu, KVM_S390_VCPU_RESET_CLEAR);
+}
+
+void kvm_s390_reset_vcpu_normal(S390CPU *cpu)
+{
+    kvm_s390_reset_vcpu(cpu, KVM_S390_VCPU_RESET_NORMAL);
+}
+
 static int can_sync_regs(CPUState *cs, int regs)
 {
     return cap_sync_regs && (cs->kvm_run->kvm_valid_regs & regs) == regs;
diff --git a/target/s390x/kvm_s390x.h b/target/s390x/kvm_s390x.h
index caf985955b..0b21789796 100644
--- a/target/s390x/kvm_s390x.h
+++ b/target/s390x/kvm_s390x.h
@@ -34,7 +34,9 @@  int kvm_s390_assign_subch_ioeventfd(EventNotifier *notifier, uint32_t sch,
                                     int vq, bool assign);
 int kvm_s390_cmma_active(void);
 void kvm_s390_cmma_reset(void);
-void kvm_s390_reset_vcpu(S390CPU *cpu);
+void kvm_s390_reset_vcpu_clear(S390CPU *cpu);
+void kvm_s390_reset_vcpu_normal(S390CPU *cpu);
+void kvm_s390_reset_vcpu_initial(S390CPU *cpu);
 int kvm_s390_set_mem_limit(uint64_t new_limit, uint64_t *hw_limit);
 void kvm_s390_set_max_pagesize(uint64_t pagesize, Error **errp);
 void kvm_s390_crypto_reset(void);