[Qemu-devel] [PATCH v9 5/6] ppc: spapr: Enable FWNMI capability

Aravinda Prasad posted 6 patches 6 years, 5 months ago
Maintainers: David Gibson <david@gibson.dropbear.id.au>, Richard Henderson <rth@twiddle.net>, Paolo Bonzini <pbonzini@redhat.com>
There is a newer version of this series
[Qemu-devel] [PATCH v9 5/6] ppc: spapr: Enable FWNMI capability
Posted by Aravinda Prasad 6 years, 5 months ago
Enable the KVM capability KVM_CAP_PPC_FWNMI so that
the KVM causes guest exit with NMI as exit reason
when it encounters a machine check exception on the
address belonging to a guest. Without this capability
enabled, KVM redirects machine check exceptions to
guest's 0x200 vector.

This patch also deals with the case when a guest with
the KVM_CAP_PPC_FWNMI capability enabled is attempted
to migrate to a host that does not support this
capability.

Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
---
 hw/ppc/spapr.c         |    1 +
 hw/ppc/spapr_caps.c    |   24 ++++++++++++++++++++++++
 hw/ppc/spapr_rtas.c    |   18 ++++++++++++++++++
 include/hw/ppc/spapr.h |    4 +++-
 target/ppc/kvm.c       |   19 +++++++++++++++++++
 target/ppc/kvm_ppc.h   |   12 ++++++++++++
 6 files changed, 77 insertions(+), 1 deletion(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index c97f6a6..e8a77636 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -4364,6 +4364,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
     smc->default_caps.caps[SPAPR_CAP_NESTED_KVM_HV] = SPAPR_CAP_OFF;
     smc->default_caps.caps[SPAPR_CAP_LARGE_DECREMENTER] = SPAPR_CAP_ON;
     smc->default_caps.caps[SPAPR_CAP_CCF_ASSIST] = SPAPR_CAP_OFF;
+    smc->default_caps.caps[SPAPR_CAP_FWNMI_MCE] = SPAPR_CAP_ON;
     spapr_caps_add_properties(smc, &error_abort);
     smc->irq = &spapr_irq_dual;
     smc->dr_phb_enabled = true;
diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
index 31b4661..ef9e612 100644
--- a/hw/ppc/spapr_caps.c
+++ b/hw/ppc/spapr_caps.c
@@ -479,6 +479,20 @@ static void cap_ccf_assist_apply(SpaprMachineState *spapr, uint8_t val,
     }
 }
 
+static void cap_fwnmi_mce_apply(SpaprMachineState *spapr, uint8_t val,
+                                Error **errp)
+{
+    if (!val) {
+        return; /* Disabled by default */
+    }
+
+    if (tcg_enabled()) {
+            error_setg(errp, "No fwnmi support in TCG, try cap-fwnmi-mce=off");
+    } else if (kvm_enabled() && !kvmppc_has_cap_ppc_fwnmi()) {
+            error_setg(errp, "Requested fwnmi capability not support by KVM");
+    }
+}
+
 SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
     [SPAPR_CAP_HTM] = {
         .name = "htm",
@@ -578,6 +592,15 @@ SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
         .type = "bool",
         .apply = cap_ccf_assist_apply,
     },
+    [SPAPR_CAP_FWNMI_MCE] = {
+        .name = "fwnmi-mce",
+        .description = "Handle fwnmi machine check exceptions",
+        .index = SPAPR_CAP_FWNMI_MCE,
+        .get = spapr_cap_get_bool,
+        .set = spapr_cap_set_bool,
+        .type = "bool",
+        .apply = cap_fwnmi_mce_apply,
+    },
 };
 
 static SpaprCapabilities default_caps_with_cpu(SpaprMachineState *spapr,
@@ -717,6 +740,7 @@ SPAPR_CAP_MIG_STATE(hpt_maxpagesize, SPAPR_CAP_HPT_MAXPAGESIZE);
 SPAPR_CAP_MIG_STATE(nested_kvm_hv, SPAPR_CAP_NESTED_KVM_HV);
 SPAPR_CAP_MIG_STATE(large_decr, SPAPR_CAP_LARGE_DECREMENTER);
 SPAPR_CAP_MIG_STATE(ccf_assist, SPAPR_CAP_CCF_ASSIST);
+SPAPR_CAP_MIG_STATE(fwnmi, SPAPR_CAP_FWNMI_MCE);
 
 void spapr_caps_init(SpaprMachineState *spapr)
 {
diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
index e0bdfc8..91a7ab9 100644
--- a/hw/ppc/spapr_rtas.c
+++ b/hw/ppc/spapr_rtas.c
@@ -49,6 +49,7 @@
 #include "hw/ppc/fdt.h"
 #include "target/ppc/mmu-hash64.h"
 #include "target/ppc/mmu-book3s-v3.h"
+#include "kvm_ppc.h"
 
 static void rtas_display_character(PowerPCCPU *cpu, SpaprMachineState *spapr,
                                    uint32_t token, uint32_t nargs,
@@ -358,6 +359,7 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
                                   target_ulong args,
                                   uint32_t nret, target_ulong rets)
 {
+    int ret;
     hwaddr rtas_addr = spapr_get_rtas_addr();
 
     if (!rtas_addr) {
@@ -365,6 +367,22 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
         return;
     }
 
+    if (spapr_get_cap(spapr, SPAPR_CAP_FWNMI_MCE) == 0) {
+        rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
+        return;
+    }
+
+    ret = kvmppc_fwnmi_enable(cpu);
+    if (ret == 1) {
+        rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
+        return;
+    }
+
+    if (ret < 0) {
+        rtas_st(rets, 0, RTAS_OUT_HW_ERROR);
+        return;
+    }
+
     spapr->guest_machine_check_addr = rtas_ld(args, 1);
     rtas_st(rets, 0, RTAS_OUT_SUCCESS);
 }
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index c717ab2..bd75d4b 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -78,8 +78,10 @@ typedef enum {
 #define SPAPR_CAP_LARGE_DECREMENTER     0x08
 /* Count Cache Flush Assist HW Instruction */
 #define SPAPR_CAP_CCF_ASSIST            0x09
+/* FWNMI machine check handling */
+#define SPAPR_CAP_FWNMI_MCE             0x0A
 /* Num Caps */
-#define SPAPR_CAP_NUM                   (SPAPR_CAP_CCF_ASSIST + 1)
+#define SPAPR_CAP_NUM                   (SPAPR_CAP_FWNMI_MCE + 1)
 
 /*
  * Capability Values
diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index 39f1a73..368ec6e 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -84,6 +84,7 @@ static int cap_ppc_safe_indirect_branch;
 static int cap_ppc_count_cache_flush_assist;
 static int cap_ppc_nested_kvm_hv;
 static int cap_large_decr;
+static int cap_ppc_fwnmi;
 
 static uint32_t debug_inst_opcode;
 
@@ -152,6 +153,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
     kvmppc_get_cpu_characteristics(s);
     cap_ppc_nested_kvm_hv = kvm_vm_check_extension(s, KVM_CAP_PPC_NESTED_HV);
     cap_large_decr = kvmppc_get_dec_bits();
+    cap_ppc_fwnmi = kvm_check_extension(s, KVM_CAP_PPC_FWNMI);
     /*
      * Note: setting it to false because there is not such capability
      * in KVM at this moment.
@@ -2119,6 +2121,18 @@ void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
     }
 }
 
+int kvmppc_fwnmi_enable(PowerPCCPU *cpu)
+{
+    CPUState *cs = CPU(cpu);
+
+    if (!cap_ppc_fwnmi) {
+        return 1;
+    }
+
+    return kvm_vcpu_enable_cap(cs, KVM_CAP_PPC_FWNMI, 0);
+}
+
+
 int kvmppc_smt_threads(void)
 {
     return cap_ppc_smt ? cap_ppc_smt : 1;
@@ -2419,6 +2433,11 @@ bool kvmppc_has_cap_mmu_hash_v3(void)
     return cap_mmu_hash_v3;
 }
 
+bool kvmppc_has_cap_ppc_fwnmi(void)
+{
+    return cap_ppc_fwnmi;
+}
+
 static bool kvmppc_power8_host(void)
 {
     bool ret = false;
diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h
index 18693f1..3d9f0b4 100644
--- a/target/ppc/kvm_ppc.h
+++ b/target/ppc/kvm_ppc.h
@@ -27,6 +27,8 @@ void kvmppc_enable_h_page_init(void);
 void kvmppc_set_papr(PowerPCCPU *cpu);
 int kvmppc_set_compat(PowerPCCPU *cpu, uint32_t compat_pvr);
 void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy);
+int kvmppc_fwnmi_enable(PowerPCCPU *cpu);
+bool kvmppc_has_cap_ppc_fwnmi(void);
 int kvmppc_smt_threads(void);
 void kvmppc_hint_smt_possible(Error **errp);
 int kvmppc_set_smt_threads(int smt);
@@ -160,6 +162,16 @@ static inline void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
 {
 }
 
+static inline int kvmppc_fwnmi_enable(PowerPCCPU *cpu)
+{
+    return 1;
+}
+
+static inline bool kvmppc_has_cap_ppc_fwnmi(void)
+{
+    return false;
+}
+
 static inline int kvmppc_smt_threads(void)
 {
     return 1;


Re: [Qemu-devel] [Qemu-ppc] [PATCH v9 5/6] ppc: spapr: Enable FWNMI capability
Posted by Greg Kurz 6 years, 5 months ago
On Wed, 29 May 2019 11:10:49 +0530
Aravinda Prasad <aravinda@linux.vnet.ibm.com> wrote:

> Enable the KVM capability KVM_CAP_PPC_FWNMI so that
> the KVM causes guest exit with NMI as exit reason
> when it encounters a machine check exception on the
> address belonging to a guest. Without this capability
> enabled, KVM redirects machine check exceptions to
> guest's 0x200 vector.
> 
> This patch also deals with the case when a guest with
> the KVM_CAP_PPC_FWNMI capability enabled is attempted
> to migrate to a host that does not support this
> capability.
> 
> Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
> ---

As suggested in another mail, it may be worth introducing the sPAPR cap
in its own patch, earlier in the series.

Anyway, I have some comments below.

>  hw/ppc/spapr.c         |    1 +
>  hw/ppc/spapr_caps.c    |   24 ++++++++++++++++++++++++
>  hw/ppc/spapr_rtas.c    |   18 ++++++++++++++++++
>  include/hw/ppc/spapr.h |    4 +++-
>  target/ppc/kvm.c       |   19 +++++++++++++++++++
>  target/ppc/kvm_ppc.h   |   12 ++++++++++++
>  6 files changed, 77 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index c97f6a6..e8a77636 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -4364,6 +4364,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
>      smc->default_caps.caps[SPAPR_CAP_NESTED_KVM_HV] = SPAPR_CAP_OFF;
>      smc->default_caps.caps[SPAPR_CAP_LARGE_DECREMENTER] = SPAPR_CAP_ON;
>      smc->default_caps.caps[SPAPR_CAP_CCF_ASSIST] = SPAPR_CAP_OFF;
> +    smc->default_caps.caps[SPAPR_CAP_FWNMI_MCE] = SPAPR_CAP_ON;
>      spapr_caps_add_properties(smc, &error_abort);
>      smc->irq = &spapr_irq_dual;
>      smc->dr_phb_enabled = true;
> diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
> index 31b4661..ef9e612 100644
> --- a/hw/ppc/spapr_caps.c
> +++ b/hw/ppc/spapr_caps.c
> @@ -479,6 +479,20 @@ static void cap_ccf_assist_apply(SpaprMachineState *spapr, uint8_t val,
>      }
>  }
>  
> +static void cap_fwnmi_mce_apply(SpaprMachineState *spapr, uint8_t val,
> +                                Error **errp)
> +{
> +    if (!val) {
> +        return; /* Disabled by default */
> +    }
> +
> +    if (tcg_enabled()) {
> +            error_setg(errp, "No fwnmi support in TCG, try cap-fwnmi-mce=off");

Maybe expand "fwnmi" to "Firmware Assisted Non-Maskable Interrupts" ?

> +    } else if (kvm_enabled() && !kvmppc_has_cap_ppc_fwnmi()) {
> +            error_setg(errp, "Requested fwnmi capability not support by KVM");

Maybe reword and add a hint:

"KVM implementation does not support Firmware Assisted Non-Maskable Interrupts, try cap-fwnmi-mce=off"


> +    }
> +}
> +
>  SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
>      [SPAPR_CAP_HTM] = {
>          .name = "htm",
> @@ -578,6 +592,15 @@ SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
>          .type = "bool",
>          .apply = cap_ccf_assist_apply,
>      },
> +    [SPAPR_CAP_FWNMI_MCE] = {
> +        .name = "fwnmi-mce",
> +        .description = "Handle fwnmi machine check exceptions",
> +        .index = SPAPR_CAP_FWNMI_MCE,
> +        .get = spapr_cap_get_bool,
> +        .set = spapr_cap_set_bool,
> +        .type = "bool",
> +        .apply = cap_fwnmi_mce_apply,
> +    },
>  };
>  
>  static SpaprCapabilities default_caps_with_cpu(SpaprMachineState *spapr,
> @@ -717,6 +740,7 @@ SPAPR_CAP_MIG_STATE(hpt_maxpagesize, SPAPR_CAP_HPT_MAXPAGESIZE);
>  SPAPR_CAP_MIG_STATE(nested_kvm_hv, SPAPR_CAP_NESTED_KVM_HV);
>  SPAPR_CAP_MIG_STATE(large_decr, SPAPR_CAP_LARGE_DECREMENTER);
>  SPAPR_CAP_MIG_STATE(ccf_assist, SPAPR_CAP_CCF_ASSIST);
> +SPAPR_CAP_MIG_STATE(fwnmi, SPAPR_CAP_FWNMI_MCE);
>  
>  void spapr_caps_init(SpaprMachineState *spapr)
>  {
> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
> index e0bdfc8..91a7ab9 100644
> --- a/hw/ppc/spapr_rtas.c
> +++ b/hw/ppc/spapr_rtas.c
> @@ -49,6 +49,7 @@
>  #include "hw/ppc/fdt.h"
>  #include "target/ppc/mmu-hash64.h"
>  #include "target/ppc/mmu-book3s-v3.h"
> +#include "kvm_ppc.h"
>  
>  static void rtas_display_character(PowerPCCPU *cpu, SpaprMachineState *spapr,
>                                     uint32_t token, uint32_t nargs,
> @@ -358,6 +359,7 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
>                                    target_ulong args,
>                                    uint32_t nret, target_ulong rets)
>  {
> +    int ret;
>      hwaddr rtas_addr = spapr_get_rtas_addr();
>  
>      if (!rtas_addr) {
> @@ -365,6 +367,22 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
>          return;
>      }
>  
> +    if (spapr_get_cap(spapr, SPAPR_CAP_FWNMI_MCE) == 0) {
> +        rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
> +        return;
> +    }
> +
> +    ret = kvmppc_fwnmi_enable(cpu);
> +    if (ret == 1) {

I have the impression that this should really not happen,
otherwise something has gone terribly wrong in QEMU or
in KVM... this maybe deserves an error message as well ?
No big deal.

> +        rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
> +        return;
> +    }
> +
> +    if (ret < 0) {
> +        rtas_st(rets, 0, RTAS_OUT_HW_ERROR);
> +        return;
> +    }
> +
>      spapr->guest_machine_check_addr = rtas_ld(args, 1);
>      rtas_st(rets, 0, RTAS_OUT_SUCCESS);
>  }
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index c717ab2..bd75d4b 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -78,8 +78,10 @@ typedef enum {
>  #define SPAPR_CAP_LARGE_DECREMENTER     0x08
>  /* Count Cache Flush Assist HW Instruction */
>  #define SPAPR_CAP_CCF_ASSIST            0x09
> +/* FWNMI machine check handling */
> +#define SPAPR_CAP_FWNMI_MCE             0x0A
>  /* Num Caps */
> -#define SPAPR_CAP_NUM                   (SPAPR_CAP_CCF_ASSIST + 1)
> +#define SPAPR_CAP_NUM                   (SPAPR_CAP_FWNMI_MCE + 1)
>  
>  /*
>   * Capability Values
> diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
> index 39f1a73..368ec6e 100644
> --- a/target/ppc/kvm.c
> +++ b/target/ppc/kvm.c
> @@ -84,6 +84,7 @@ static int cap_ppc_safe_indirect_branch;
>  static int cap_ppc_count_cache_flush_assist;
>  static int cap_ppc_nested_kvm_hv;
>  static int cap_large_decr;
> +static int cap_ppc_fwnmi;
>  
>  static uint32_t debug_inst_opcode;
>  
> @@ -152,6 +153,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
>      kvmppc_get_cpu_characteristics(s);
>      cap_ppc_nested_kvm_hv = kvm_vm_check_extension(s, KVM_CAP_PPC_NESTED_HV);
>      cap_large_decr = kvmppc_get_dec_bits();
> +    cap_ppc_fwnmi = kvm_check_extension(s, KVM_CAP_PPC_FWNMI);
>      /*
>       * Note: setting it to false because there is not such capability
>       * in KVM at this moment.
> @@ -2119,6 +2121,18 @@ void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
>      }
>  }
>  
> +int kvmppc_fwnmi_enable(PowerPCCPU *cpu)
> +{
> +    CPUState *cs = CPU(cpu);
> +
> +    if (!cap_ppc_fwnmi) {
> +        return 1;
> +    }
> +
> +    return kvm_vcpu_enable_cap(cs, KVM_CAP_PPC_FWNMI, 0);
> +}
> +
> +
>  int kvmppc_smt_threads(void)
>  {
>      return cap_ppc_smt ? cap_ppc_smt : 1;
> @@ -2419,6 +2433,11 @@ bool kvmppc_has_cap_mmu_hash_v3(void)
>      return cap_mmu_hash_v3;
>  }
>  
> +bool kvmppc_has_cap_ppc_fwnmi(void)
> +{
> +    return cap_ppc_fwnmi;
> +}
> +
>  static bool kvmppc_power8_host(void)
>  {
>      bool ret = false;
> diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h
> index 18693f1..3d9f0b4 100644
> --- a/target/ppc/kvm_ppc.h
> +++ b/target/ppc/kvm_ppc.h
> @@ -27,6 +27,8 @@ void kvmppc_enable_h_page_init(void);
>  void kvmppc_set_papr(PowerPCCPU *cpu);
>  int kvmppc_set_compat(PowerPCCPU *cpu, uint32_t compat_pvr);
>  void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy);
> +int kvmppc_fwnmi_enable(PowerPCCPU *cpu);
> +bool kvmppc_has_cap_ppc_fwnmi(void);
>  int kvmppc_smt_threads(void);
>  void kvmppc_hint_smt_possible(Error **errp);
>  int kvmppc_set_smt_threads(int smt);
> @@ -160,6 +162,16 @@ static inline void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
>  {
>  }
>  
> +static inline int kvmppc_fwnmi_enable(PowerPCCPU *cpu)
> +{
> +    return 1;
> +}
> +
> +static inline bool kvmppc_has_cap_ppc_fwnmi(void)
> +{
> +    return false;
> +}
> +
>  static inline int kvmppc_smt_threads(void)
>  {
>      return 1;
> 
> 


Re: [Qemu-devel] [Qemu-ppc] [PATCH v9 5/6] ppc: spapr: Enable FWNMI capability
Posted by Aravinda Prasad 6 years, 5 months ago

On Monday 03 June 2019 08:55 PM, Greg Kurz wrote:
> On Wed, 29 May 2019 11:10:49 +0530
> Aravinda Prasad <aravinda@linux.vnet.ibm.com> wrote:
> 
>> Enable the KVM capability KVM_CAP_PPC_FWNMI so that
>> the KVM causes guest exit with NMI as exit reason
>> when it encounters a machine check exception on the
>> address belonging to a guest. Without this capability
>> enabled, KVM redirects machine check exceptions to
>> guest's 0x200 vector.
>>
>> This patch also deals with the case when a guest with
>> the KVM_CAP_PPC_FWNMI capability enabled is attempted
>> to migrate to a host that does not support this
>> capability.
>>
>> Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
>> ---
> 
> As suggested in another mail, it may be worth introducing the sPAPR cap
> in its own patch, earlier in the series.

Sure, also as a workaround mentioned in the reply to that mail, I am
thinking of returning RTAS_OUT_NOT_SUPPORTED to rtas nmi register call
until the entire functionality is implemented. This will help solve
spapr cap issue as well.

> 
> Anyway, I have some comments below.
> 
>>  hw/ppc/spapr.c         |    1 +
>>  hw/ppc/spapr_caps.c    |   24 ++++++++++++++++++++++++
>>  hw/ppc/spapr_rtas.c    |   18 ++++++++++++++++++
>>  include/hw/ppc/spapr.h |    4 +++-
>>  target/ppc/kvm.c       |   19 +++++++++++++++++++
>>  target/ppc/kvm_ppc.h   |   12 ++++++++++++
>>  6 files changed, 77 insertions(+), 1 deletion(-)
>>
>> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
>> index c97f6a6..e8a77636 100644
>> --- a/hw/ppc/spapr.c
>> +++ b/hw/ppc/spapr.c
>> @@ -4364,6 +4364,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
>>      smc->default_caps.caps[SPAPR_CAP_NESTED_KVM_HV] = SPAPR_CAP_OFF;
>>      smc->default_caps.caps[SPAPR_CAP_LARGE_DECREMENTER] = SPAPR_CAP_ON;
>>      smc->default_caps.caps[SPAPR_CAP_CCF_ASSIST] = SPAPR_CAP_OFF;
>> +    smc->default_caps.caps[SPAPR_CAP_FWNMI_MCE] = SPAPR_CAP_ON;
>>      spapr_caps_add_properties(smc, &error_abort);
>>      smc->irq = &spapr_irq_dual;
>>      smc->dr_phb_enabled = true;
>> diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
>> index 31b4661..ef9e612 100644
>> --- a/hw/ppc/spapr_caps.c
>> +++ b/hw/ppc/spapr_caps.c
>> @@ -479,6 +479,20 @@ static void cap_ccf_assist_apply(SpaprMachineState *spapr, uint8_t val,
>>      }
>>  }
>>  
>> +static void cap_fwnmi_mce_apply(SpaprMachineState *spapr, uint8_t val,
>> +                                Error **errp)
>> +{
>> +    if (!val) {
>> +        return; /* Disabled by default */
>> +    }
>> +
>> +    if (tcg_enabled()) {
>> +            error_setg(errp, "No fwnmi support in TCG, try cap-fwnmi-mce=off");
> 
> Maybe expand "fwnmi" to "Firmware Assisted Non-Maskable Interrupts" ?

sure..

> 
>> +    } else if (kvm_enabled() && !kvmppc_has_cap_ppc_fwnmi()) {
>> +            error_setg(errp, "Requested fwnmi capability not support by KVM");
> 
> Maybe reword and add a hint:
> 
> "KVM implementation does not support Firmware Assisted Non-Maskable Interrupts, try cap-fwnmi-mce=off"

sure..

> 
> 
>> +    }
>> +}
>> +
>>  SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
>>      [SPAPR_CAP_HTM] = {
>>          .name = "htm",
>> @@ -578,6 +592,15 @@ SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
>>          .type = "bool",
>>          .apply = cap_ccf_assist_apply,
>>      },
>> +    [SPAPR_CAP_FWNMI_MCE] = {
>> +        .name = "fwnmi-mce",
>> +        .description = "Handle fwnmi machine check exceptions",
>> +        .index = SPAPR_CAP_FWNMI_MCE,
>> +        .get = spapr_cap_get_bool,
>> +        .set = spapr_cap_set_bool,
>> +        .type = "bool",
>> +        .apply = cap_fwnmi_mce_apply,
>> +    },
>>  };
>>  
>>  static SpaprCapabilities default_caps_with_cpu(SpaprMachineState *spapr,
>> @@ -717,6 +740,7 @@ SPAPR_CAP_MIG_STATE(hpt_maxpagesize, SPAPR_CAP_HPT_MAXPAGESIZE);
>>  SPAPR_CAP_MIG_STATE(nested_kvm_hv, SPAPR_CAP_NESTED_KVM_HV);
>>  SPAPR_CAP_MIG_STATE(large_decr, SPAPR_CAP_LARGE_DECREMENTER);
>>  SPAPR_CAP_MIG_STATE(ccf_assist, SPAPR_CAP_CCF_ASSIST);
>> +SPAPR_CAP_MIG_STATE(fwnmi, SPAPR_CAP_FWNMI_MCE);
>>  
>>  void spapr_caps_init(SpaprMachineState *spapr)
>>  {
>> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
>> index e0bdfc8..91a7ab9 100644
>> --- a/hw/ppc/spapr_rtas.c
>> +++ b/hw/ppc/spapr_rtas.c
>> @@ -49,6 +49,7 @@
>>  #include "hw/ppc/fdt.h"
>>  #include "target/ppc/mmu-hash64.h"
>>  #include "target/ppc/mmu-book3s-v3.h"
>> +#include "kvm_ppc.h"
>>  
>>  static void rtas_display_character(PowerPCCPU *cpu, SpaprMachineState *spapr,
>>                                     uint32_t token, uint32_t nargs,
>> @@ -358,6 +359,7 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
>>                                    target_ulong args,
>>                                    uint32_t nret, target_ulong rets)
>>  {
>> +    int ret;
>>      hwaddr rtas_addr = spapr_get_rtas_addr();
>>  
>>      if (!rtas_addr) {
>> @@ -365,6 +367,22 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
>>          return;
>>      }
>>  
>> +    if (spapr_get_cap(spapr, SPAPR_CAP_FWNMI_MCE) == 0) {
>> +        rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
>> +        return;
>> +    }
>> +
>> +    ret = kvmppc_fwnmi_enable(cpu);
>> +    if (ret == 1) {
> 
> I have the impression that this should really not happen,
> otherwise something has gone terribly wrong in QEMU or
> in KVM... this maybe deserves an error message as well ?
> No big deal.

I think so..  will add an error message.

Also I should check for non zero return value, not just ret == 1, as
kvmppc_fwnmi_enable() returns the error value from ioctl().


> 
>> +        rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
>> +        return;
>> +    }
>> +
>> +    if (ret < 0) {
>> +        rtas_st(rets, 0, RTAS_OUT_HW_ERROR);
>> +        return;
>> +    }
>> +
>>      spapr->guest_machine_check_addr = rtas_ld(args, 1);
>>      rtas_st(rets, 0, RTAS_OUT_SUCCESS);
>>  }
>> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
>> index c717ab2..bd75d4b 100644
>> --- a/include/hw/ppc/spapr.h
>> +++ b/include/hw/ppc/spapr.h
>> @@ -78,8 +78,10 @@ typedef enum {
>>  #define SPAPR_CAP_LARGE_DECREMENTER     0x08
>>  /* Count Cache Flush Assist HW Instruction */
>>  #define SPAPR_CAP_CCF_ASSIST            0x09
>> +/* FWNMI machine check handling */
>> +#define SPAPR_CAP_FWNMI_MCE             0x0A
>>  /* Num Caps */
>> -#define SPAPR_CAP_NUM                   (SPAPR_CAP_CCF_ASSIST + 1)
>> +#define SPAPR_CAP_NUM                   (SPAPR_CAP_FWNMI_MCE + 1)
>>  
>>  /*
>>   * Capability Values
>> diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
>> index 39f1a73..368ec6e 100644
>> --- a/target/ppc/kvm.c
>> +++ b/target/ppc/kvm.c
>> @@ -84,6 +84,7 @@ static int cap_ppc_safe_indirect_branch;
>>  static int cap_ppc_count_cache_flush_assist;
>>  static int cap_ppc_nested_kvm_hv;
>>  static int cap_large_decr;
>> +static int cap_ppc_fwnmi;
>>  
>>  static uint32_t debug_inst_opcode;
>>  
>> @@ -152,6 +153,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
>>      kvmppc_get_cpu_characteristics(s);
>>      cap_ppc_nested_kvm_hv = kvm_vm_check_extension(s, KVM_CAP_PPC_NESTED_HV);
>>      cap_large_decr = kvmppc_get_dec_bits();
>> +    cap_ppc_fwnmi = kvm_check_extension(s, KVM_CAP_PPC_FWNMI);
>>      /*
>>       * Note: setting it to false because there is not such capability
>>       * in KVM at this moment.
>> @@ -2119,6 +2121,18 @@ void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
>>      }
>>  }
>>  
>> +int kvmppc_fwnmi_enable(PowerPCCPU *cpu)
>> +{
>> +    CPUState *cs = CPU(cpu);
>> +
>> +    if (!cap_ppc_fwnmi) {
>> +        return 1;
>> +    }
>> +
>> +    return kvm_vcpu_enable_cap(cs, KVM_CAP_PPC_FWNMI, 0);
>> +}
>> +
>> +
>>  int kvmppc_smt_threads(void)
>>  {
>>      return cap_ppc_smt ? cap_ppc_smt : 1;
>> @@ -2419,6 +2433,11 @@ bool kvmppc_has_cap_mmu_hash_v3(void)
>>      return cap_mmu_hash_v3;
>>  }
>>  
>> +bool kvmppc_has_cap_ppc_fwnmi(void)
>> +{
>> +    return cap_ppc_fwnmi;
>> +}
>> +
>>  static bool kvmppc_power8_host(void)
>>  {
>>      bool ret = false;
>> diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h
>> index 18693f1..3d9f0b4 100644
>> --- a/target/ppc/kvm_ppc.h
>> +++ b/target/ppc/kvm_ppc.h
>> @@ -27,6 +27,8 @@ void kvmppc_enable_h_page_init(void);
>>  void kvmppc_set_papr(PowerPCCPU *cpu);
>>  int kvmppc_set_compat(PowerPCCPU *cpu, uint32_t compat_pvr);
>>  void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy);
>> +int kvmppc_fwnmi_enable(PowerPCCPU *cpu);
>> +bool kvmppc_has_cap_ppc_fwnmi(void);
>>  int kvmppc_smt_threads(void);
>>  void kvmppc_hint_smt_possible(Error **errp);
>>  int kvmppc_set_smt_threads(int smt);
>> @@ -160,6 +162,16 @@ static inline void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
>>  {
>>  }
>>  
>> +static inline int kvmppc_fwnmi_enable(PowerPCCPU *cpu)
>> +{
>> +    return 1;
>> +}
>> +
>> +static inline bool kvmppc_has_cap_ppc_fwnmi(void)
>> +{
>> +    return false;
>> +}
>> +
>>  static inline int kvmppc_smt_threads(void)
>>  {
>>      return 1;
>>
>>
> 
> 

-- 
Regards,
Aravinda


Re: [Qemu-devel] [Qemu-ppc] [PATCH v9 5/6] ppc: spapr: Enable FWNMI capability
Posted by David Gibson 6 years, 5 months ago
On Tue, Jun 04, 2019 at 12:15:26PM +0530, Aravinda Prasad wrote:
> 
> 
> On Monday 03 June 2019 08:55 PM, Greg Kurz wrote:
> > On Wed, 29 May 2019 11:10:49 +0530
> > Aravinda Prasad <aravinda@linux.vnet.ibm.com> wrote:
> > 
> >> Enable the KVM capability KVM_CAP_PPC_FWNMI so that
> >> the KVM causes guest exit with NMI as exit reason
> >> when it encounters a machine check exception on the
> >> address belonging to a guest. Without this capability
> >> enabled, KVM redirects machine check exceptions to
> >> guest's 0x200 vector.
> >>
> >> This patch also deals with the case when a guest with
> >> the KVM_CAP_PPC_FWNMI capability enabled is attempted
> >> to migrate to a host that does not support this
> >> capability.
> >>
> >> Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
> >> ---
> > 
> > As suggested in another mail, it may be worth introducing the sPAPR cap
> > in its own patch, earlier in the series.
> 
> Sure, also as a workaround mentioned in the reply to that mail, I am
> thinking of returning RTAS_OUT_NOT_SUPPORTED to rtas nmi register call
> until the entire functionality is implemented. This will help solve
> spapr cap issue as well.

Not registering the RTAS call at all is the correct way to handle that
case.

> 
> > 
> > Anyway, I have some comments below.
> > 
> >>  hw/ppc/spapr.c         |    1 +
> >>  hw/ppc/spapr_caps.c    |   24 ++++++++++++++++++++++++
> >>  hw/ppc/spapr_rtas.c    |   18 ++++++++++++++++++
> >>  include/hw/ppc/spapr.h |    4 +++-
> >>  target/ppc/kvm.c       |   19 +++++++++++++++++++
> >>  target/ppc/kvm_ppc.h   |   12 ++++++++++++
> >>  6 files changed, 77 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> >> index c97f6a6..e8a77636 100644
> >> --- a/hw/ppc/spapr.c
> >> +++ b/hw/ppc/spapr.c
> >> @@ -4364,6 +4364,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
> >>      smc->default_caps.caps[SPAPR_CAP_NESTED_KVM_HV] = SPAPR_CAP_OFF;
> >>      smc->default_caps.caps[SPAPR_CAP_LARGE_DECREMENTER] = SPAPR_CAP_ON;
> >>      smc->default_caps.caps[SPAPR_CAP_CCF_ASSIST] = SPAPR_CAP_OFF;
> >> +    smc->default_caps.caps[SPAPR_CAP_FWNMI_MCE] = SPAPR_CAP_ON;
> >>      spapr_caps_add_properties(smc, &error_abort);
> >>      smc->irq = &spapr_irq_dual;
> >>      smc->dr_phb_enabled = true;
> >> diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
> >> index 31b4661..ef9e612 100644
> >> --- a/hw/ppc/spapr_caps.c
> >> +++ b/hw/ppc/spapr_caps.c
> >> @@ -479,6 +479,20 @@ static void cap_ccf_assist_apply(SpaprMachineState *spapr, uint8_t val,
> >>      }
> >>  }
> >>  
> >> +static void cap_fwnmi_mce_apply(SpaprMachineState *spapr, uint8_t val,
> >> +                                Error **errp)
> >> +{
> >> +    if (!val) {
> >> +        return; /* Disabled by default */
> >> +    }
> >> +
> >> +    if (tcg_enabled()) {
> >> +            error_setg(errp, "No fwnmi support in TCG, try cap-fwnmi-mce=off");
> > 
> > Maybe expand "fwnmi" to "Firmware Assisted Non-Maskable Interrupts" ?
> 
> sure..
> 
> > 
> >> +    } else if (kvm_enabled() && !kvmppc_has_cap_ppc_fwnmi()) {
> >> +            error_setg(errp, "Requested fwnmi capability not support by KVM");
> > 
> > Maybe reword and add a hint:
> > 
> > "KVM implementation does not support Firmware Assisted Non-Maskable Interrupts, try cap-fwnmi-mce=off"
> 
> sure..
> 
> > 
> > 
> >> +    }
> >> +}
> >> +
> >>  SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
> >>      [SPAPR_CAP_HTM] = {
> >>          .name = "htm",
> >> @@ -578,6 +592,15 @@ SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
> >>          .type = "bool",
> >>          .apply = cap_ccf_assist_apply,
> >>      },
> >> +    [SPAPR_CAP_FWNMI_MCE] = {
> >> +        .name = "fwnmi-mce",
> >> +        .description = "Handle fwnmi machine check exceptions",
> >> +        .index = SPAPR_CAP_FWNMI_MCE,
> >> +        .get = spapr_cap_get_bool,
> >> +        .set = spapr_cap_set_bool,
> >> +        .type = "bool",
> >> +        .apply = cap_fwnmi_mce_apply,
> >> +    },
> >>  };
> >>  
> >>  static SpaprCapabilities default_caps_with_cpu(SpaprMachineState *spapr,
> >> @@ -717,6 +740,7 @@ SPAPR_CAP_MIG_STATE(hpt_maxpagesize, SPAPR_CAP_HPT_MAXPAGESIZE);
> >>  SPAPR_CAP_MIG_STATE(nested_kvm_hv, SPAPR_CAP_NESTED_KVM_HV);
> >>  SPAPR_CAP_MIG_STATE(large_decr, SPAPR_CAP_LARGE_DECREMENTER);
> >>  SPAPR_CAP_MIG_STATE(ccf_assist, SPAPR_CAP_CCF_ASSIST);
> >> +SPAPR_CAP_MIG_STATE(fwnmi, SPAPR_CAP_FWNMI_MCE);
> >>  
> >>  void spapr_caps_init(SpaprMachineState *spapr)
> >>  {
> >> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
> >> index e0bdfc8..91a7ab9 100644
> >> --- a/hw/ppc/spapr_rtas.c
> >> +++ b/hw/ppc/spapr_rtas.c
> >> @@ -49,6 +49,7 @@
> >>  #include "hw/ppc/fdt.h"
> >>  #include "target/ppc/mmu-hash64.h"
> >>  #include "target/ppc/mmu-book3s-v3.h"
> >> +#include "kvm_ppc.h"
> >>  
> >>  static void rtas_display_character(PowerPCCPU *cpu, SpaprMachineState *spapr,
> >>                                     uint32_t token, uint32_t nargs,
> >> @@ -358,6 +359,7 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
> >>                                    target_ulong args,
> >>                                    uint32_t nret, target_ulong rets)
> >>  {
> >> +    int ret;
> >>      hwaddr rtas_addr = spapr_get_rtas_addr();
> >>  
> >>      if (!rtas_addr) {
> >> @@ -365,6 +367,22 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
> >>          return;
> >>      }
> >>  
> >> +    if (spapr_get_cap(spapr, SPAPR_CAP_FWNMI_MCE) == 0) {
> >> +        rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
> >> +        return;
> >> +    }
> >> +
> >> +    ret = kvmppc_fwnmi_enable(cpu);
> >> +    if (ret == 1) {
> > 
> > I have the impression that this should really not happen,
> > otherwise something has gone terribly wrong in QEMU or
> > in KVM... this maybe deserves an error message as well ?
> > No big deal.
> 
> I think so..  will add an error message.

Right, and because this is essentially a host side error,
RTAS_OUT_HW_ERROR would be more appropriate.

> 
> Also I should check for non zero return value, not just ret == 1, as
> kvmppc_fwnmi_enable() returns the error value from ioctl().
> 
> 
> > 
> >> +        rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
> >> +        return;
> >> +    }
> >> +
> >> +    if (ret < 0) {
> >> +        rtas_st(rets, 0, RTAS_OUT_HW_ERROR);
> >> +        return;
> >> +    }
> >> +
> >>      spapr->guest_machine_check_addr = rtas_ld(args, 1);
> >>      rtas_st(rets, 0, RTAS_OUT_SUCCESS);
> >>  }
> >> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> >> index c717ab2..bd75d4b 100644
> >> --- a/include/hw/ppc/spapr.h
> >> +++ b/include/hw/ppc/spapr.h
> >> @@ -78,8 +78,10 @@ typedef enum {
> >>  #define SPAPR_CAP_LARGE_DECREMENTER     0x08
> >>  /* Count Cache Flush Assist HW Instruction */
> >>  #define SPAPR_CAP_CCF_ASSIST            0x09
> >> +/* FWNMI machine check handling */
> >> +#define SPAPR_CAP_FWNMI_MCE             0x0A
> >>  /* Num Caps */
> >> -#define SPAPR_CAP_NUM                   (SPAPR_CAP_CCF_ASSIST + 1)
> >> +#define SPAPR_CAP_NUM                   (SPAPR_CAP_FWNMI_MCE + 1)
> >>  
> >>  /*
> >>   * Capability Values
> >> diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
> >> index 39f1a73..368ec6e 100644
> >> --- a/target/ppc/kvm.c
> >> +++ b/target/ppc/kvm.c
> >> @@ -84,6 +84,7 @@ static int cap_ppc_safe_indirect_branch;
> >>  static int cap_ppc_count_cache_flush_assist;
> >>  static int cap_ppc_nested_kvm_hv;
> >>  static int cap_large_decr;
> >> +static int cap_ppc_fwnmi;
> >>  
> >>  static uint32_t debug_inst_opcode;
> >>  
> >> @@ -152,6 +153,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
> >>      kvmppc_get_cpu_characteristics(s);
> >>      cap_ppc_nested_kvm_hv = kvm_vm_check_extension(s, KVM_CAP_PPC_NESTED_HV);
> >>      cap_large_decr = kvmppc_get_dec_bits();
> >> +    cap_ppc_fwnmi = kvm_check_extension(s, KVM_CAP_PPC_FWNMI);
> >>      /*
> >>       * Note: setting it to false because there is not such capability
> >>       * in KVM at this moment.
> >> @@ -2119,6 +2121,18 @@ void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
> >>      }
> >>  }
> >>  
> >> +int kvmppc_fwnmi_enable(PowerPCCPU *cpu)
> >> +{
> >> +    CPUState *cs = CPU(cpu);
> >> +
> >> +    if (!cap_ppc_fwnmi) {
> >> +        return 1;
> >> +    }
> >> +
> >> +    return kvm_vcpu_enable_cap(cs, KVM_CAP_PPC_FWNMI, 0);
> >> +}
> >> +
> >> +
> >>  int kvmppc_smt_threads(void)
> >>  {
> >>      return cap_ppc_smt ? cap_ppc_smt : 1;
> >> @@ -2419,6 +2433,11 @@ bool kvmppc_has_cap_mmu_hash_v3(void)
> >>      return cap_mmu_hash_v3;
> >>  }
> >>  
> >> +bool kvmppc_has_cap_ppc_fwnmi(void)
> >> +{
> >> +    return cap_ppc_fwnmi;
> >> +}
> >> +
> >>  static bool kvmppc_power8_host(void)
> >>  {
> >>      bool ret = false;
> >> diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h
> >> index 18693f1..3d9f0b4 100644
> >> --- a/target/ppc/kvm_ppc.h
> >> +++ b/target/ppc/kvm_ppc.h
> >> @@ -27,6 +27,8 @@ void kvmppc_enable_h_page_init(void);
> >>  void kvmppc_set_papr(PowerPCCPU *cpu);
> >>  int kvmppc_set_compat(PowerPCCPU *cpu, uint32_t compat_pvr);
> >>  void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy);
> >> +int kvmppc_fwnmi_enable(PowerPCCPU *cpu);
> >> +bool kvmppc_has_cap_ppc_fwnmi(void);
> >>  int kvmppc_smt_threads(void);
> >>  void kvmppc_hint_smt_possible(Error **errp);
> >>  int kvmppc_set_smt_threads(int smt);
> >> @@ -160,6 +162,16 @@ static inline void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
> >>  {
> >>  }
> >>  
> >> +static inline int kvmppc_fwnmi_enable(PowerPCCPU *cpu)
> >> +{
> >> +    return 1;
> >> +}
> >> +
> >> +static inline bool kvmppc_has_cap_ppc_fwnmi(void)
> >> +{
> >> +    return false;
> >> +}
> >> +
> >>  static inline int kvmppc_smt_threads(void)
> >>  {
> >>      return 1;
> >>
> >>
> > 
> > 
> 

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson
Re: [Qemu-devel] [Qemu-ppc] [PATCH v9 5/6] ppc: spapr: Enable FWNMI capability
Posted by Aravinda Prasad 6 years, 5 months ago

On Thursday 06 June 2019 08:32 AM, David Gibson wrote:
> On Tue, Jun 04, 2019 at 12:15:26PM +0530, Aravinda Prasad wrote:
>>
>>
>> On Monday 03 June 2019 08:55 PM, Greg Kurz wrote:
>>> On Wed, 29 May 2019 11:10:49 +0530
>>> Aravinda Prasad <aravinda@linux.vnet.ibm.com> wrote:
>>>
>>>> Enable the KVM capability KVM_CAP_PPC_FWNMI so that
>>>> the KVM causes guest exit with NMI as exit reason
>>>> when it encounters a machine check exception on the
>>>> address belonging to a guest. Without this capability
>>>> enabled, KVM redirects machine check exceptions to
>>>> guest's 0x200 vector.
>>>>
>>>> This patch also deals with the case when a guest with
>>>> the KVM_CAP_PPC_FWNMI capability enabled is attempted
>>>> to migrate to a host that does not support this
>>>> capability.
>>>>
>>>> Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
>>>> ---
>>>
>>> As suggested in another mail, it may be worth introducing the sPAPR cap
>>> in its own patch, earlier in the series.
>>
>> Sure, also as a workaround mentioned in the reply to that mail, I am
>> thinking of returning RTAS_OUT_NOT_SUPPORTED to rtas nmi register call
>> until the entire functionality is implemented. This will help solve
>> spapr cap issue as well.
> 
> Not registering the RTAS call at all is the correct way to handle that
> case.

ok.

> 
>>
>>>
>>> Anyway, I have some comments below.
>>>
>>>>  hw/ppc/spapr.c         |    1 +
>>>>  hw/ppc/spapr_caps.c    |   24 ++++++++++++++++++++++++
>>>>  hw/ppc/spapr_rtas.c    |   18 ++++++++++++++++++
>>>>  include/hw/ppc/spapr.h |    4 +++-
>>>>  target/ppc/kvm.c       |   19 +++++++++++++++++++
>>>>  target/ppc/kvm_ppc.h   |   12 ++++++++++++
>>>>  6 files changed, 77 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
>>>> index c97f6a6..e8a77636 100644
>>>> --- a/hw/ppc/spapr.c
>>>> +++ b/hw/ppc/spapr.c
>>>> @@ -4364,6 +4364,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
>>>>      smc->default_caps.caps[SPAPR_CAP_NESTED_KVM_HV] = SPAPR_CAP_OFF;
>>>>      smc->default_caps.caps[SPAPR_CAP_LARGE_DECREMENTER] = SPAPR_CAP_ON;
>>>>      smc->default_caps.caps[SPAPR_CAP_CCF_ASSIST] = SPAPR_CAP_OFF;
>>>> +    smc->default_caps.caps[SPAPR_CAP_FWNMI_MCE] = SPAPR_CAP_ON;
>>>>      spapr_caps_add_properties(smc, &error_abort);
>>>>      smc->irq = &spapr_irq_dual;
>>>>      smc->dr_phb_enabled = true;
>>>> diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
>>>> index 31b4661..ef9e612 100644
>>>> --- a/hw/ppc/spapr_caps.c
>>>> +++ b/hw/ppc/spapr_caps.c
>>>> @@ -479,6 +479,20 @@ static void cap_ccf_assist_apply(SpaprMachineState *spapr, uint8_t val,
>>>>      }
>>>>  }
>>>>  
>>>> +static void cap_fwnmi_mce_apply(SpaprMachineState *spapr, uint8_t val,
>>>> +                                Error **errp)
>>>> +{
>>>> +    if (!val) {
>>>> +        return; /* Disabled by default */
>>>> +    }
>>>> +
>>>> +    if (tcg_enabled()) {
>>>> +            error_setg(errp, "No fwnmi support in TCG, try cap-fwnmi-mce=off");
>>>
>>> Maybe expand "fwnmi" to "Firmware Assisted Non-Maskable Interrupts" ?
>>
>> sure..
>>
>>>
>>>> +    } else if (kvm_enabled() && !kvmppc_has_cap_ppc_fwnmi()) {
>>>> +            error_setg(errp, "Requested fwnmi capability not support by KVM");
>>>
>>> Maybe reword and add a hint:
>>>
>>> "KVM implementation does not support Firmware Assisted Non-Maskable Interrupts, try cap-fwnmi-mce=off"
>>
>> sure..
>>
>>>
>>>
>>>> +    }
>>>> +}
>>>> +
>>>>  SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
>>>>      [SPAPR_CAP_HTM] = {
>>>>          .name = "htm",
>>>> @@ -578,6 +592,15 @@ SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
>>>>          .type = "bool",
>>>>          .apply = cap_ccf_assist_apply,
>>>>      },
>>>> +    [SPAPR_CAP_FWNMI_MCE] = {
>>>> +        .name = "fwnmi-mce",
>>>> +        .description = "Handle fwnmi machine check exceptions",
>>>> +        .index = SPAPR_CAP_FWNMI_MCE,
>>>> +        .get = spapr_cap_get_bool,
>>>> +        .set = spapr_cap_set_bool,
>>>> +        .type = "bool",
>>>> +        .apply = cap_fwnmi_mce_apply,
>>>> +    },
>>>>  };
>>>>  
>>>>  static SpaprCapabilities default_caps_with_cpu(SpaprMachineState *spapr,
>>>> @@ -717,6 +740,7 @@ SPAPR_CAP_MIG_STATE(hpt_maxpagesize, SPAPR_CAP_HPT_MAXPAGESIZE);
>>>>  SPAPR_CAP_MIG_STATE(nested_kvm_hv, SPAPR_CAP_NESTED_KVM_HV);
>>>>  SPAPR_CAP_MIG_STATE(large_decr, SPAPR_CAP_LARGE_DECREMENTER);
>>>>  SPAPR_CAP_MIG_STATE(ccf_assist, SPAPR_CAP_CCF_ASSIST);
>>>> +SPAPR_CAP_MIG_STATE(fwnmi, SPAPR_CAP_FWNMI_MCE);
>>>>  
>>>>  void spapr_caps_init(SpaprMachineState *spapr)
>>>>  {
>>>> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
>>>> index e0bdfc8..91a7ab9 100644
>>>> --- a/hw/ppc/spapr_rtas.c
>>>> +++ b/hw/ppc/spapr_rtas.c
>>>> @@ -49,6 +49,7 @@
>>>>  #include "hw/ppc/fdt.h"
>>>>  #include "target/ppc/mmu-hash64.h"
>>>>  #include "target/ppc/mmu-book3s-v3.h"
>>>> +#include "kvm_ppc.h"
>>>>  
>>>>  static void rtas_display_character(PowerPCCPU *cpu, SpaprMachineState *spapr,
>>>>                                     uint32_t token, uint32_t nargs,
>>>> @@ -358,6 +359,7 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
>>>>                                    target_ulong args,
>>>>                                    uint32_t nret, target_ulong rets)
>>>>  {
>>>> +    int ret;
>>>>      hwaddr rtas_addr = spapr_get_rtas_addr();
>>>>  
>>>>      if (!rtas_addr) {
>>>> @@ -365,6 +367,22 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
>>>>          return;
>>>>      }
>>>>  
>>>> +    if (spapr_get_cap(spapr, SPAPR_CAP_FWNMI_MCE) == 0) {
>>>> +        rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
>>>> +        return;
>>>> +    }
>>>> +
>>>> +    ret = kvmppc_fwnmi_enable(cpu);
>>>> +    if (ret == 1) {
>>>
>>> I have the impression that this should really not happen,
>>> otherwise something has gone terribly wrong in QEMU or
>>> in KVM... this maybe deserves an error message as well ?
>>> No big deal.
>>
>> I think so..  will add an error message.
> 
> Right, and because this is essentially a host side error,
> RTAS_OUT_HW_ERROR would be more appropriate.

sure

> 
>>
>> Also I should check for non zero return value, not just ret == 1, as
>> kvmppc_fwnmi_enable() returns the error value from ioctl().
>>
>>
>>>
>>>> +        rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
>>>> +        return;
>>>> +    }
>>>> +
>>>> +    if (ret < 0) {
>>>> +        rtas_st(rets, 0, RTAS_OUT_HW_ERROR);
>>>> +        return;
>>>> +    }
>>>> +
>>>>      spapr->guest_machine_check_addr = rtas_ld(args, 1);
>>>>      rtas_st(rets, 0, RTAS_OUT_SUCCESS);
>>>>  }
>>>> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
>>>> index c717ab2..bd75d4b 100644
>>>> --- a/include/hw/ppc/spapr.h
>>>> +++ b/include/hw/ppc/spapr.h
>>>> @@ -78,8 +78,10 @@ typedef enum {
>>>>  #define SPAPR_CAP_LARGE_DECREMENTER     0x08
>>>>  /* Count Cache Flush Assist HW Instruction */
>>>>  #define SPAPR_CAP_CCF_ASSIST            0x09
>>>> +/* FWNMI machine check handling */
>>>> +#define SPAPR_CAP_FWNMI_MCE             0x0A
>>>>  /* Num Caps */
>>>> -#define SPAPR_CAP_NUM                   (SPAPR_CAP_CCF_ASSIST + 1)
>>>> +#define SPAPR_CAP_NUM                   (SPAPR_CAP_FWNMI_MCE + 1)
>>>>  
>>>>  /*
>>>>   * Capability Values
>>>> diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
>>>> index 39f1a73..368ec6e 100644
>>>> --- a/target/ppc/kvm.c
>>>> +++ b/target/ppc/kvm.c
>>>> @@ -84,6 +84,7 @@ static int cap_ppc_safe_indirect_branch;
>>>>  static int cap_ppc_count_cache_flush_assist;
>>>>  static int cap_ppc_nested_kvm_hv;
>>>>  static int cap_large_decr;
>>>> +static int cap_ppc_fwnmi;
>>>>  
>>>>  static uint32_t debug_inst_opcode;
>>>>  
>>>> @@ -152,6 +153,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
>>>>      kvmppc_get_cpu_characteristics(s);
>>>>      cap_ppc_nested_kvm_hv = kvm_vm_check_extension(s, KVM_CAP_PPC_NESTED_HV);
>>>>      cap_large_decr = kvmppc_get_dec_bits();
>>>> +    cap_ppc_fwnmi = kvm_check_extension(s, KVM_CAP_PPC_FWNMI);
>>>>      /*
>>>>       * Note: setting it to false because there is not such capability
>>>>       * in KVM at this moment.
>>>> @@ -2119,6 +2121,18 @@ void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
>>>>      }
>>>>  }
>>>>  
>>>> +int kvmppc_fwnmi_enable(PowerPCCPU *cpu)
>>>> +{
>>>> +    CPUState *cs = CPU(cpu);
>>>> +
>>>> +    if (!cap_ppc_fwnmi) {
>>>> +        return 1;
>>>> +    }
>>>> +
>>>> +    return kvm_vcpu_enable_cap(cs, KVM_CAP_PPC_FWNMI, 0);
>>>> +}
>>>> +
>>>> +
>>>>  int kvmppc_smt_threads(void)
>>>>  {
>>>>      return cap_ppc_smt ? cap_ppc_smt : 1;
>>>> @@ -2419,6 +2433,11 @@ bool kvmppc_has_cap_mmu_hash_v3(void)
>>>>      return cap_mmu_hash_v3;
>>>>  }
>>>>  
>>>> +bool kvmppc_has_cap_ppc_fwnmi(void)
>>>> +{
>>>> +    return cap_ppc_fwnmi;
>>>> +}
>>>> +
>>>>  static bool kvmppc_power8_host(void)
>>>>  {
>>>>      bool ret = false;
>>>> diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h
>>>> index 18693f1..3d9f0b4 100644
>>>> --- a/target/ppc/kvm_ppc.h
>>>> +++ b/target/ppc/kvm_ppc.h
>>>> @@ -27,6 +27,8 @@ void kvmppc_enable_h_page_init(void);
>>>>  void kvmppc_set_papr(PowerPCCPU *cpu);
>>>>  int kvmppc_set_compat(PowerPCCPU *cpu, uint32_t compat_pvr);
>>>>  void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy);
>>>> +int kvmppc_fwnmi_enable(PowerPCCPU *cpu);
>>>> +bool kvmppc_has_cap_ppc_fwnmi(void);
>>>>  int kvmppc_smt_threads(void);
>>>>  void kvmppc_hint_smt_possible(Error **errp);
>>>>  int kvmppc_set_smt_threads(int smt);
>>>> @@ -160,6 +162,16 @@ static inline void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
>>>>  {
>>>>  }
>>>>  
>>>> +static inline int kvmppc_fwnmi_enable(PowerPCCPU *cpu)
>>>> +{
>>>> +    return 1;
>>>> +}
>>>> +
>>>> +static inline bool kvmppc_has_cap_ppc_fwnmi(void)
>>>> +{
>>>> +    return false;
>>>> +}
>>>> +
>>>>  static inline int kvmppc_smt_threads(void)
>>>>  {
>>>>      return 1;
>>>>
>>>>
>>>
>>>
>>
> 

-- 
Regards,
Aravinda

Re: [Qemu-devel] [Qemu-ppc] [PATCH v9 5/6] ppc: spapr: Enable FWNMI capability
Posted by Aravinda Prasad 6 years, 5 months ago

On Thursday 06 June 2019 08:32 AM, David Gibson wrote:
> On Tue, Jun 04, 2019 at 12:15:26PM +0530, Aravinda Prasad wrote:
>>
>>
>> On Monday 03 June 2019 08:55 PM, Greg Kurz wrote:
>>> On Wed, 29 May 2019 11:10:49 +0530
>>> Aravinda Prasad <aravinda@linux.vnet.ibm.com> wrote:
>>>
>>>> Enable the KVM capability KVM_CAP_PPC_FWNMI so that
>>>> the KVM causes guest exit with NMI as exit reason
>>>> when it encounters a machine check exception on the
>>>> address belonging to a guest. Without this capability
>>>> enabled, KVM redirects machine check exceptions to
>>>> guest's 0x200 vector.
>>>>
>>>> This patch also deals with the case when a guest with
>>>> the KVM_CAP_PPC_FWNMI capability enabled is attempted
>>>> to migrate to a host that does not support this
>>>> capability.
>>>>
>>>> Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
>>>> ---
>>>
>>> As suggested in another mail, it may be worth introducing the sPAPR cap
>>> in its own patch, earlier in the series.
>>
>> Sure, also as a workaround mentioned in the reply to that mail, I am
>> thinking of returning RTAS_OUT_NOT_SUPPORTED to rtas nmi register call
>> until the entire functionality is implemented. This will help solve
>> spapr cap issue as well.
> 
> Not registering the RTAS call at all is the correct way to handle that
> case.
> 
>>
>>>
>>> Anyway, I have some comments below.
>>>
>>>>  hw/ppc/spapr.c         |    1 +
>>>>  hw/ppc/spapr_caps.c    |   24 ++++++++++++++++++++++++
>>>>  hw/ppc/spapr_rtas.c    |   18 ++++++++++++++++++
>>>>  include/hw/ppc/spapr.h |    4 +++-
>>>>  target/ppc/kvm.c       |   19 +++++++++++++++++++
>>>>  target/ppc/kvm_ppc.h   |   12 ++++++++++++
>>>>  6 files changed, 77 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
>>>> index c97f6a6..e8a77636 100644
>>>> --- a/hw/ppc/spapr.c
>>>> +++ b/hw/ppc/spapr.c
>>>> @@ -4364,6 +4364,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
>>>>      smc->default_caps.caps[SPAPR_CAP_NESTED_KVM_HV] = SPAPR_CAP_OFF;
>>>>      smc->default_caps.caps[SPAPR_CAP_LARGE_DECREMENTER] = SPAPR_CAP_ON;
>>>>      smc->default_caps.caps[SPAPR_CAP_CCF_ASSIST] = SPAPR_CAP_OFF;
>>>> +    smc->default_caps.caps[SPAPR_CAP_FWNMI_MCE] = SPAPR_CAP_ON;
>>>>      spapr_caps_add_properties(smc, &error_abort);
>>>>      smc->irq = &spapr_irq_dual;
>>>>      smc->dr_phb_enabled = true;
>>>> diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
>>>> index 31b4661..ef9e612 100644
>>>> --- a/hw/ppc/spapr_caps.c
>>>> +++ b/hw/ppc/spapr_caps.c
>>>> @@ -479,6 +479,20 @@ static void cap_ccf_assist_apply(SpaprMachineState *spapr, uint8_t val,
>>>>      }
>>>>  }
>>>>  
>>>> +static void cap_fwnmi_mce_apply(SpaprMachineState *spapr, uint8_t val,
>>>> +                                Error **errp)
>>>> +{
>>>> +    if (!val) {
>>>> +        return; /* Disabled by default */
>>>> +    }
>>>> +
>>>> +    if (tcg_enabled()) {
>>>> +            error_setg(errp, "No fwnmi support in TCG, try cap-fwnmi-mce=off");
>>>
>>> Maybe expand "fwnmi" to "Firmware Assisted Non-Maskable Interrupts" ?
>>
>> sure..
>>
>>>
>>>> +    } else if (kvm_enabled() && !kvmppc_has_cap_ppc_fwnmi()) {
>>>> +            error_setg(errp, "Requested fwnmi capability not support by KVM");
>>>
>>> Maybe reword and add a hint:
>>>
>>> "KVM implementation does not support Firmware Assisted Non-Maskable Interrupts, try cap-fwnmi-mce=off"
>>
>> sure..
>>
>>>
>>>
>>>> +    }
>>>> +}
>>>> +
>>>>  SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
>>>>      [SPAPR_CAP_HTM] = {
>>>>          .name = "htm",
>>>> @@ -578,6 +592,15 @@ SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
>>>>          .type = "bool",
>>>>          .apply = cap_ccf_assist_apply,
>>>>      },
>>>> +    [SPAPR_CAP_FWNMI_MCE] = {
>>>> +        .name = "fwnmi-mce",
>>>> +        .description = "Handle fwnmi machine check exceptions",
>>>> +        .index = SPAPR_CAP_FWNMI_MCE,
>>>> +        .get = spapr_cap_get_bool,
>>>> +        .set = spapr_cap_set_bool,
>>>> +        .type = "bool",
>>>> +        .apply = cap_fwnmi_mce_apply,
>>>> +    },
>>>>  };
>>>>  
>>>>  static SpaprCapabilities default_caps_with_cpu(SpaprMachineState *spapr,
>>>> @@ -717,6 +740,7 @@ SPAPR_CAP_MIG_STATE(hpt_maxpagesize, SPAPR_CAP_HPT_MAXPAGESIZE);
>>>>  SPAPR_CAP_MIG_STATE(nested_kvm_hv, SPAPR_CAP_NESTED_KVM_HV);
>>>>  SPAPR_CAP_MIG_STATE(large_decr, SPAPR_CAP_LARGE_DECREMENTER);
>>>>  SPAPR_CAP_MIG_STATE(ccf_assist, SPAPR_CAP_CCF_ASSIST);
>>>> +SPAPR_CAP_MIG_STATE(fwnmi, SPAPR_CAP_FWNMI_MCE);
>>>>  
>>>>  void spapr_caps_init(SpaprMachineState *spapr)
>>>>  {
>>>> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
>>>> index e0bdfc8..91a7ab9 100644
>>>> --- a/hw/ppc/spapr_rtas.c
>>>> +++ b/hw/ppc/spapr_rtas.c
>>>> @@ -49,6 +49,7 @@
>>>>  #include "hw/ppc/fdt.h"
>>>>  #include "target/ppc/mmu-hash64.h"
>>>>  #include "target/ppc/mmu-book3s-v3.h"
>>>> +#include "kvm_ppc.h"
>>>>  
>>>>  static void rtas_display_character(PowerPCCPU *cpu, SpaprMachineState *spapr,
>>>>                                     uint32_t token, uint32_t nargs,
>>>> @@ -358,6 +359,7 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
>>>>                                    target_ulong args,
>>>>                                    uint32_t nret, target_ulong rets)
>>>>  {
>>>> +    int ret;
>>>>      hwaddr rtas_addr = spapr_get_rtas_addr();
>>>>  
>>>>      if (!rtas_addr) {
>>>> @@ -365,6 +367,22 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
>>>>          return;
>>>>      }
>>>>  
>>>> +    if (spapr_get_cap(spapr, SPAPR_CAP_FWNMI_MCE) == 0) {
>>>> +        rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
>>>> +        return;
>>>> +    }
>>>> +
>>>> +    ret = kvmppc_fwnmi_enable(cpu);
>>>> +    if (ret == 1) {
>>>
>>> I have the impression that this should really not happen,
>>> otherwise something has gone terribly wrong in QEMU or
>>> in KVM... this maybe deserves an error message as well ?
>>> No big deal.
>>
>> I think so..  will add an error message.
> 
> Right, and because this is essentially a host side error,
> RTAS_OUT_HW_ERROR would be more appropriate.

In fact I am already doing that. If ret == 1 I set it to
RTAS_OUT_NOT_SUPPORTE else if ret < 0 than I set the error to
RTAS_OUT_HW_ERROR.

> 
>>
>> Also I should check for non zero return value, not just ret == 1, as
>> kvmppc_fwnmi_enable() returns the error value from ioctl().
>>
>>
>>>
>>>> +        rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
>>>> +        return;
>>>> +    }
>>>> +
>>>> +    if (ret < 0) {
>>>> +        rtas_st(rets, 0, RTAS_OUT_HW_ERROR);
>>>> +        return;
>>>> +    }
>>>> +
>>>>      spapr->guest_machine_check_addr = rtas_ld(args, 1);
>>>>      rtas_st(rets, 0, RTAS_OUT_SUCCESS);
>>>>  }
>>>> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
>>>> index c717ab2..bd75d4b 100644
>>>> --- a/include/hw/ppc/spapr.h
>>>> +++ b/include/hw/ppc/spapr.h
>>>> @@ -78,8 +78,10 @@ typedef enum {
>>>>  #define SPAPR_CAP_LARGE_DECREMENTER     0x08
>>>>  /* Count Cache Flush Assist HW Instruction */
>>>>  #define SPAPR_CAP_CCF_ASSIST            0x09
>>>> +/* FWNMI machine check handling */
>>>> +#define SPAPR_CAP_FWNMI_MCE             0x0A
>>>>  /* Num Caps */
>>>> -#define SPAPR_CAP_NUM                   (SPAPR_CAP_CCF_ASSIST + 1)
>>>> +#define SPAPR_CAP_NUM                   (SPAPR_CAP_FWNMI_MCE + 1)
>>>>  
>>>>  /*
>>>>   * Capability Values
>>>> diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
>>>> index 39f1a73..368ec6e 100644
>>>> --- a/target/ppc/kvm.c
>>>> +++ b/target/ppc/kvm.c
>>>> @@ -84,6 +84,7 @@ static int cap_ppc_safe_indirect_branch;
>>>>  static int cap_ppc_count_cache_flush_assist;
>>>>  static int cap_ppc_nested_kvm_hv;
>>>>  static int cap_large_decr;
>>>> +static int cap_ppc_fwnmi;
>>>>  
>>>>  static uint32_t debug_inst_opcode;
>>>>  
>>>> @@ -152,6 +153,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
>>>>      kvmppc_get_cpu_characteristics(s);
>>>>      cap_ppc_nested_kvm_hv = kvm_vm_check_extension(s, KVM_CAP_PPC_NESTED_HV);
>>>>      cap_large_decr = kvmppc_get_dec_bits();
>>>> +    cap_ppc_fwnmi = kvm_check_extension(s, KVM_CAP_PPC_FWNMI);
>>>>      /*
>>>>       * Note: setting it to false because there is not such capability
>>>>       * in KVM at this moment.
>>>> @@ -2119,6 +2121,18 @@ void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
>>>>      }
>>>>  }
>>>>  
>>>> +int kvmppc_fwnmi_enable(PowerPCCPU *cpu)
>>>> +{
>>>> +    CPUState *cs = CPU(cpu);
>>>> +
>>>> +    if (!cap_ppc_fwnmi) {
>>>> +        return 1;
>>>> +    }
>>>> +
>>>> +    return kvm_vcpu_enable_cap(cs, KVM_CAP_PPC_FWNMI, 0);
>>>> +}
>>>> +
>>>> +
>>>>  int kvmppc_smt_threads(void)
>>>>  {
>>>>      return cap_ppc_smt ? cap_ppc_smt : 1;
>>>> @@ -2419,6 +2433,11 @@ bool kvmppc_has_cap_mmu_hash_v3(void)
>>>>      return cap_mmu_hash_v3;
>>>>  }
>>>>  
>>>> +bool kvmppc_has_cap_ppc_fwnmi(void)
>>>> +{
>>>> +    return cap_ppc_fwnmi;
>>>> +}
>>>> +
>>>>  static bool kvmppc_power8_host(void)
>>>>  {
>>>>      bool ret = false;
>>>> diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h
>>>> index 18693f1..3d9f0b4 100644
>>>> --- a/target/ppc/kvm_ppc.h
>>>> +++ b/target/ppc/kvm_ppc.h
>>>> @@ -27,6 +27,8 @@ void kvmppc_enable_h_page_init(void);
>>>>  void kvmppc_set_papr(PowerPCCPU *cpu);
>>>>  int kvmppc_set_compat(PowerPCCPU *cpu, uint32_t compat_pvr);
>>>>  void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy);
>>>> +int kvmppc_fwnmi_enable(PowerPCCPU *cpu);
>>>> +bool kvmppc_has_cap_ppc_fwnmi(void);
>>>>  int kvmppc_smt_threads(void);
>>>>  void kvmppc_hint_smt_possible(Error **errp);
>>>>  int kvmppc_set_smt_threads(int smt);
>>>> @@ -160,6 +162,16 @@ static inline void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
>>>>  {
>>>>  }
>>>>  
>>>> +static inline int kvmppc_fwnmi_enable(PowerPCCPU *cpu)
>>>> +{
>>>> +    return 1;
>>>> +}
>>>> +
>>>> +static inline bool kvmppc_has_cap_ppc_fwnmi(void)
>>>> +{
>>>> +    return false;
>>>> +}
>>>> +
>>>>  static inline int kvmppc_smt_threads(void)
>>>>  {
>>>>      return 1;
>>>>
>>>>
>>>
>>>
>>
> 

-- 
Regards,
Aravinda


Re: [Qemu-devel] [PATCH v9 5/6] ppc: spapr: Enable FWNMI capability
Posted by David Gibson 6 years, 5 months ago
On Wed, May 29, 2019 at 11:10:49AM +0530, Aravinda Prasad wrote:
> Enable the KVM capability KVM_CAP_PPC_FWNMI so that
> the KVM causes guest exit with NMI as exit reason
> when it encounters a machine check exception on the
> address belonging to a guest. Without this capability
> enabled, KVM redirects machine check exceptions to
> guest's 0x200 vector.
> 
> This patch also deals with the case when a guest with
> the KVM_CAP_PPC_FWNMI capability enabled is attempted
> to migrate to a host that does not support this
> capability.
> 
> Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
> ---
>  hw/ppc/spapr.c         |    1 +
>  hw/ppc/spapr_caps.c    |   24 ++++++++++++++++++++++++
>  hw/ppc/spapr_rtas.c    |   18 ++++++++++++++++++
>  include/hw/ppc/spapr.h |    4 +++-
>  target/ppc/kvm.c       |   19 +++++++++++++++++++
>  target/ppc/kvm_ppc.h   |   12 ++++++++++++
>  6 files changed, 77 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index c97f6a6..e8a77636 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -4364,6 +4364,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
>      smc->default_caps.caps[SPAPR_CAP_NESTED_KVM_HV] = SPAPR_CAP_OFF;
>      smc->default_caps.caps[SPAPR_CAP_LARGE_DECREMENTER] = SPAPR_CAP_ON;
>      smc->default_caps.caps[SPAPR_CAP_CCF_ASSIST] = SPAPR_CAP_OFF;
> +    smc->default_caps.caps[SPAPR_CAP_FWNMI_MCE] = SPAPR_CAP_ON;

You need to turn this back off by default for the older machine types.

>      spapr_caps_add_properties(smc, &error_abort);
>      smc->irq = &spapr_irq_dual;
>      smc->dr_phb_enabled = true;
> diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
> index 31b4661..ef9e612 100644
> --- a/hw/ppc/spapr_caps.c
> +++ b/hw/ppc/spapr_caps.c
> @@ -479,6 +479,20 @@ static void cap_ccf_assist_apply(SpaprMachineState *spapr, uint8_t val,
>      }
>  }
>  
> +static void cap_fwnmi_mce_apply(SpaprMachineState *spapr, uint8_t val,
> +                                Error **errp)
> +{
> +    if (!val) {
> +        return; /* Disabled by default */
> +    }
> +
> +    if (tcg_enabled()) {
> +            error_setg(errp, "No fwnmi support in TCG, try cap-fwnmi-mce=off");
> +    } else if (kvm_enabled() && !kvmppc_has_cap_ppc_fwnmi()) {
> +            error_setg(errp, "Requested fwnmi capability not support by KVM");
> +    }
> +}
> +
>  SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
>      [SPAPR_CAP_HTM] = {
>          .name = "htm",
> @@ -578,6 +592,15 @@ SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
>          .type = "bool",
>          .apply = cap_ccf_assist_apply,
>      },
> +    [SPAPR_CAP_FWNMI_MCE] = {
> +        .name = "fwnmi-mce",
> +        .description = "Handle fwnmi machine check exceptions",
> +        .index = SPAPR_CAP_FWNMI_MCE,
> +        .get = spapr_cap_get_bool,
> +        .set = spapr_cap_set_bool,
> +        .type = "bool",
> +        .apply = cap_fwnmi_mce_apply,
> +    },
>  };
>  
>  static SpaprCapabilities default_caps_with_cpu(SpaprMachineState *spapr,
> @@ -717,6 +740,7 @@ SPAPR_CAP_MIG_STATE(hpt_maxpagesize, SPAPR_CAP_HPT_MAXPAGESIZE);
>  SPAPR_CAP_MIG_STATE(nested_kvm_hv, SPAPR_CAP_NESTED_KVM_HV);
>  SPAPR_CAP_MIG_STATE(large_decr, SPAPR_CAP_LARGE_DECREMENTER);
>  SPAPR_CAP_MIG_STATE(ccf_assist, SPAPR_CAP_CCF_ASSIST);
> +SPAPR_CAP_MIG_STATE(fwnmi, SPAPR_CAP_FWNMI_MCE);
>  
>  void spapr_caps_init(SpaprMachineState *spapr)
>  {
> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
> index e0bdfc8..91a7ab9 100644
> --- a/hw/ppc/spapr_rtas.c
> +++ b/hw/ppc/spapr_rtas.c
> @@ -49,6 +49,7 @@
>  #include "hw/ppc/fdt.h"
>  #include "target/ppc/mmu-hash64.h"
>  #include "target/ppc/mmu-book3s-v3.h"
> +#include "kvm_ppc.h"
>  
>  static void rtas_display_character(PowerPCCPU *cpu, SpaprMachineState *spapr,
>                                     uint32_t token, uint32_t nargs,
> @@ -358,6 +359,7 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
>                                    target_ulong args,
>                                    uint32_t nret, target_ulong rets)
>  {
> +    int ret;
>      hwaddr rtas_addr = spapr_get_rtas_addr();
>  
>      if (!rtas_addr) {
> @@ -365,6 +367,22 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
>          return;
>      }
>  
> +    if (spapr_get_cap(spapr, SPAPR_CAP_FWNMI_MCE) == 0) {
> +        rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
> +        return;
> +    }
> +
> +    ret = kvmppc_fwnmi_enable(cpu);
> +    if (ret == 1) {
> +        rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
> +        return;
> +    }
> +
> +    if (ret < 0) {
> +        rtas_st(rets, 0, RTAS_OUT_HW_ERROR);
> +        return;
> +    }
> +
>      spapr->guest_machine_check_addr = rtas_ld(args, 1);
>      rtas_st(rets, 0, RTAS_OUT_SUCCESS);
>  }
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index c717ab2..bd75d4b 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -78,8 +78,10 @@ typedef enum {
>  #define SPAPR_CAP_LARGE_DECREMENTER     0x08
>  /* Count Cache Flush Assist HW Instruction */
>  #define SPAPR_CAP_CCF_ASSIST            0x09
> +/* FWNMI machine check handling */
> +#define SPAPR_CAP_FWNMI_MCE             0x0A
>  /* Num Caps */
> -#define SPAPR_CAP_NUM                   (SPAPR_CAP_CCF_ASSIST + 1)
> +#define SPAPR_CAP_NUM                   (SPAPR_CAP_FWNMI_MCE + 1)
>  
>  /*
>   * Capability Values
> diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
> index 39f1a73..368ec6e 100644
> --- a/target/ppc/kvm.c
> +++ b/target/ppc/kvm.c
> @@ -84,6 +84,7 @@ static int cap_ppc_safe_indirect_branch;
>  static int cap_ppc_count_cache_flush_assist;
>  static int cap_ppc_nested_kvm_hv;
>  static int cap_large_decr;
> +static int cap_ppc_fwnmi;
>  
>  static uint32_t debug_inst_opcode;
>  
> @@ -152,6 +153,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
>      kvmppc_get_cpu_characteristics(s);
>      cap_ppc_nested_kvm_hv = kvm_vm_check_extension(s, KVM_CAP_PPC_NESTED_HV);
>      cap_large_decr = kvmppc_get_dec_bits();
> +    cap_ppc_fwnmi = kvm_check_extension(s, KVM_CAP_PPC_FWNMI);
>      /*
>       * Note: setting it to false because there is not such capability
>       * in KVM at this moment.
> @@ -2119,6 +2121,18 @@ void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
>      }
>  }
>  
> +int kvmppc_fwnmi_enable(PowerPCCPU *cpu)
> +{
> +    CPUState *cs = CPU(cpu);
> +
> +    if (!cap_ppc_fwnmi) {
> +        return 1;
> +    }
> +
> +    return kvm_vcpu_enable_cap(cs, KVM_CAP_PPC_FWNMI, 0);
> +}
> +
> +
>  int kvmppc_smt_threads(void)
>  {
>      return cap_ppc_smt ? cap_ppc_smt : 1;
> @@ -2419,6 +2433,11 @@ bool kvmppc_has_cap_mmu_hash_v3(void)
>      return cap_mmu_hash_v3;
>  }
>  
> +bool kvmppc_has_cap_ppc_fwnmi(void)
> +{
> +    return cap_ppc_fwnmi;
> +}
> +
>  static bool kvmppc_power8_host(void)
>  {
>      bool ret = false;
> diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h
> index 18693f1..3d9f0b4 100644
> --- a/target/ppc/kvm_ppc.h
> +++ b/target/ppc/kvm_ppc.h
> @@ -27,6 +27,8 @@ void kvmppc_enable_h_page_init(void);
>  void kvmppc_set_papr(PowerPCCPU *cpu);
>  int kvmppc_set_compat(PowerPCCPU *cpu, uint32_t compat_pvr);
>  void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy);
> +int kvmppc_fwnmi_enable(PowerPCCPU *cpu);
> +bool kvmppc_has_cap_ppc_fwnmi(void);
>  int kvmppc_smt_threads(void);
>  void kvmppc_hint_smt_possible(Error **errp);
>  int kvmppc_set_smt_threads(int smt);
> @@ -160,6 +162,16 @@ static inline void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
>  {
>  }
>  
> +static inline int kvmppc_fwnmi_enable(PowerPCCPU *cpu)
> +{
> +    return 1;
> +}
> +
> +static inline bool kvmppc_has_cap_ppc_fwnmi(void)
> +{
> +    return false;
> +}
> +
>  static inline int kvmppc_smt_threads(void)
>  {
>      return 1;
> 

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson