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.
Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
---
hw/ppc/spapr_rtas.c | 15 +++++++++++++++
target/ppc/kvm.c | 14 ++++++++++++++
target/ppc/kvm_ppc.h | 6 ++++++
3 files changed, 35 insertions(+)
diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
index fb594a4..939f428 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,
@@ -354,6 +355,20 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
target_ulong args,
uint32_t nret, target_ulong rets)
{
+ int ret;
+
+ 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->mc_reset = 0;
spapr->guest_machine_check_addr = rtas_ld(args, 1);
rtas_st(rets, 0, RTAS_OUT_SUCCESS);
diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index a593448..161b45e 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -93,6 +93,7 @@ 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;
@@ -155,6 +156,7 @@ 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.
@@ -2091,6 +2093,18 @@ 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;
diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h
index df5e85f..cf7b24f 100644
--- a/target/ppc/kvm_ppc.h
+++ b/target/ppc/kvm_ppc.h
@@ -27,6 +27,7 @@ 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);
int kvmppc_smt_threads(void);
void kvmppc_hint_smt_possible(Error **errp);
int kvmppc_set_smt_threads(int smt);
@@ -158,6 +159,11 @@ static inline void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
{
}
+int kvmppc_fwnmi_enable(PowerPCCPU *cpu)
+{
+ return 1;
+}
+
static inline int kvmppc_smt_threads(void)
{
return 1;
On Fri, Mar 22, 2019 at 12:04:16PM +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.
>
> Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
> ---
> hw/ppc/spapr_rtas.c | 15 +++++++++++++++
> target/ppc/kvm.c | 14 ++++++++++++++
> target/ppc/kvm_ppc.h | 6 ++++++
> 3 files changed, 35 insertions(+)
>
> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
> index fb594a4..939f428 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,
> @@ -354,6 +355,20 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
> target_ulong args,
> uint32_t nret, target_ulong rets)
> {
> + int ret;
> +
> + ret = kvmppc_fwnmi_enable(cpu);
> +
> + if (ret == 1) {
> + rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
Urgh, we're here making a guest visible different to the environment
depending on a host (KVM) capability. What happens if you start a
guest and it registers fwnmi support, then migrate it to a host that
lacks the necessary KVM support?
> + return;
> + }
> +
> + if (ret < 0) {
> + rtas_st(rets, 0, RTAS_OUT_HW_ERROR);
> + return;
> + }
> +
> spapr->mc_reset = 0;
> spapr->guest_machine_check_addr = rtas_ld(args, 1);
> rtas_st(rets, 0, RTAS_OUT_SUCCESS);
> diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
> index a593448..161b45e 100644
> --- a/target/ppc/kvm.c
> +++ b/target/ppc/kvm.c
> @@ -93,6 +93,7 @@ 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;
>
> @@ -155,6 +156,7 @@ 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.
> @@ -2091,6 +2093,18 @@ 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;
> diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h
> index df5e85f..cf7b24f 100644
> --- a/target/ppc/kvm_ppc.h
> +++ b/target/ppc/kvm_ppc.h
> @@ -27,6 +27,7 @@ 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);
> int kvmppc_smt_threads(void);
> void kvmppc_hint_smt_possible(Error **errp);
> int kvmppc_set_smt_threads(int smt);
> @@ -158,6 +159,11 @@ static inline void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
> {
> }
>
> +int kvmppc_fwnmi_enable(PowerPCCPU *cpu)
> +{
> + return 1;
> +}
> +
> 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
On Monday 25 March 2019 12:02 PM, David Gibson wrote:
> On Fri, Mar 22, 2019 at 12:04:16PM +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.
>>
>> Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
>> ---
>> hw/ppc/spapr_rtas.c | 15 +++++++++++++++
>> target/ppc/kvm.c | 14 ++++++++++++++
>> target/ppc/kvm_ppc.h | 6 ++++++
>> 3 files changed, 35 insertions(+)
>>
>> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
>> index fb594a4..939f428 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,
>> @@ -354,6 +355,20 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
>> target_ulong args,
>> uint32_t nret, target_ulong rets)
>> {
>> + int ret;
>> +
>> + ret = kvmppc_fwnmi_enable(cpu);
>> +
>> + if (ret == 1) {
>> + rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
>
> Urgh, we're here making a guest visible different to the environment
> depending on a host (KVM) capability. What happens if you start a
> guest and it registers fwnmi support, then migrate it to a host that
> lacks the necessary KVM support?
I just checked how such scenarios are handled for other KVM
capabilities. Should I need to add an Spapr cap for this?
Regards,
Aravinda
>
>> + return;
>> + }
>> +
>> + if (ret < 0) {
>> + rtas_st(rets, 0, RTAS_OUT_HW_ERROR);
>> + return;
>> + }
>> +
>> spapr->mc_reset = 0;
>> spapr->guest_machine_check_addr = rtas_ld(args, 1);
>> rtas_st(rets, 0, RTAS_OUT_SUCCESS);
>> diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
>> index a593448..161b45e 100644
>> --- a/target/ppc/kvm.c
>> +++ b/target/ppc/kvm.c
>> @@ -93,6 +93,7 @@ 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;
>>
>> @@ -155,6 +156,7 @@ 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.
>> @@ -2091,6 +2093,18 @@ 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;
>> diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h
>> index df5e85f..cf7b24f 100644
>> --- a/target/ppc/kvm_ppc.h
>> +++ b/target/ppc/kvm_ppc.h
>> @@ -27,6 +27,7 @@ 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);
>> int kvmppc_smt_threads(void);
>> void kvmppc_hint_smt_possible(Error **errp);
>> int kvmppc_set_smt_threads(int smt);
>> @@ -158,6 +159,11 @@ static inline void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
>> {
>> }
>>
>> +int kvmppc_fwnmi_enable(PowerPCCPU *cpu)
>> +{
>> + return 1;
>> +}
>> +
>> static inline int kvmppc_smt_threads(void)
>> {
>> return 1;
>>
>
--
Regards,
Aravinda
On Mon, Mar 25, 2019 at 02:27:45PM +0530, Aravinda Prasad wrote:
>
>
> On Monday 25 March 2019 12:02 PM, David Gibson wrote:
> > On Fri, Mar 22, 2019 at 12:04:16PM +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.
> >>
> >> Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
> >> ---
> >> hw/ppc/spapr_rtas.c | 15 +++++++++++++++
> >> target/ppc/kvm.c | 14 ++++++++++++++
> >> target/ppc/kvm_ppc.h | 6 ++++++
> >> 3 files changed, 35 insertions(+)
> >>
> >> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
> >> index fb594a4..939f428 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,
> >> @@ -354,6 +355,20 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
> >> target_ulong args,
> >> uint32_t nret, target_ulong rets)
> >> {
> >> + int ret;
> >> +
> >> + ret = kvmppc_fwnmi_enable(cpu);
> >> +
> >> + if (ret == 1) {
> >> + rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
> >
> > Urgh, we're here making a guest visible different to the environment
> > depending on a host (KVM) capability. What happens if you start a
> > guest and it registers fwnmi support, then migrate it to a host that
> > lacks the necessary KVM support?
>
> I just checked how such scenarios are handled for other KVM
> capabilities. Should I need to add an Spapr cap for this?
Yes, I think that's what we'll need to do.
--
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
On Tuesday 26 March 2019 05:03 AM, David Gibson wrote:
> On Mon, Mar 25, 2019 at 02:27:45PM +0530, Aravinda Prasad wrote:
>>
>>
>> On Monday 25 March 2019 12:02 PM, David Gibson wrote:
>>> On Fri, Mar 22, 2019 at 12:04:16PM +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.
>>>>
>>>> Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
>>>> ---
>>>> hw/ppc/spapr_rtas.c | 15 +++++++++++++++
>>>> target/ppc/kvm.c | 14 ++++++++++++++
>>>> target/ppc/kvm_ppc.h | 6 ++++++
>>>> 3 files changed, 35 insertions(+)
>>>>
>>>> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
>>>> index fb594a4..939f428 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,
>>>> @@ -354,6 +355,20 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
>>>> target_ulong args,
>>>> uint32_t nret, target_ulong rets)
>>>> {
>>>> + int ret;
>>>> +
>>>> + ret = kvmppc_fwnmi_enable(cpu);
>>>> +
>>>> + if (ret == 1) {
>>>> + rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
>>>
>>> Urgh, we're here making a guest visible different to the environment
>>> depending on a host (KVM) capability. What happens if you start a
>>> guest and it registers fwnmi support, then migrate it to a host that
>>> lacks the necessary KVM support?
>>
>> I just checked how such scenarios are handled for other KVM
>> capabilities. Should I need to add an Spapr cap for this?
>
> Yes, I think that's what we'll need to do.
Ok I will update the patch.
>
--
Regards,
Aravinda
On Tuesday 26 March 2019 05:03 AM, David Gibson wrote:
> On Mon, Mar 25, 2019 at 02:27:45PM +0530, Aravinda Prasad wrote:
>>
>>
>> On Monday 25 March 2019 12:02 PM, David Gibson wrote:
>>> On Fri, Mar 22, 2019 at 12:04:16PM +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.
>>>>
>>>> Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
>>>> ---
>>>> hw/ppc/spapr_rtas.c | 15 +++++++++++++++
>>>> target/ppc/kvm.c | 14 ++++++++++++++
>>>> target/ppc/kvm_ppc.h | 6 ++++++
>>>> 3 files changed, 35 insertions(+)
>>>>
>>>> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
>>>> index fb594a4..939f428 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,
>>>> @@ -354,6 +355,20 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
>>>> target_ulong args,
>>>> uint32_t nret, target_ulong rets)
>>>> {
>>>> + int ret;
>>>> +
>>>> + ret = kvmppc_fwnmi_enable(cpu);
>>>> +
>>>> + if (ret == 1) {
>>>> + rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
>>>
>>> Urgh, we're here making a guest visible different to the environment
>>> depending on a host (KVM) capability. What happens if you start a
>>> guest and it registers fwnmi support, then migrate it to a host that
>>> lacks the necessary KVM support?
>>
>> I just checked how such scenarios are handled for other KVM
>> capabilities. Should I need to add an Spapr cap for this?
>
> Yes, I think that's what we'll need to do.
I was looking into SPAPR Cap, and I am not sure that the following code
will help in handling the migration. I need some help here.
diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
index edc5ed0..ef96192 100644
--- a/hw/ppc/spapr_caps.c
+++ b/hw/ppc/spapr_caps.c
@@ -473,6 +473,15 @@ static void cap_ccf_assist_apply(SpaprMachineState
*spapr, uint8_t val,
}
}
+static void cap_machine_check_apply(SpaprMachineState *spapr, uint8_t val,
+ Error **errp)
+{
+ if (kvm_enabled()) {
+ if (kvmppc_fwnmi_enable(cpu)) {
+ error_setg(errp, "Unable to enable fwnmi capability");
+ }
+}
+
SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
[SPAPR_CAP_HTM] = {
.name = "htm",
@@ -571,6 +580,15 @@ SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
.type = "bool",
.apply = cap_ccf_assist_apply,
},
+ [SPAPR_CAP_MACHINE_CHECK] = {
+ .name = "machine-check",
+ .description = "Handle machine check exceptions",
+ .index = SPAPR_CAP_MACHINE_CHECK,
+ .get = spapr_cap_get_bool,
+ .set = spapr_cap_set_bool,
+ .type = "bool",
+ .apply = cap_machine_check_apply,
+ },
};
static SpaprCapabilities default_caps_with_cpu(SpaprMachineState *spapr,
@@ -706,6 +724,7 @@ SPAPR_CAP_MIG_STATE(ibs, SPAPR_CAP_IBS);
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(mce, SPAPR_CAP_MACHINE_CHECK);
void spapr_caps_init(SpaprMachineState *spapr)
{
Or is it that just adding SPAPR_CAP_MIG_STATE(mce,
SPAPR_CAP_MACHINE_CHECK); is enough as it is checking or cap values?
>
--
Regards,
Aravinda
On Mon, Apr 15, 2019 at 03:42:46PM +0530, Aravinda Prasad wrote:
>
>
> On Tuesday 26 March 2019 05:03 AM, David Gibson wrote:
> > On Mon, Mar 25, 2019 at 02:27:45PM +0530, Aravinda Prasad wrote:
> >>
> >>
> >> On Monday 25 March 2019 12:02 PM, David Gibson wrote:
> >>> On Fri, Mar 22, 2019 at 12:04:16PM +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.
> >>>>
> >>>> Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
> >>>> ---
> >>>> hw/ppc/spapr_rtas.c | 15 +++++++++++++++
> >>>> target/ppc/kvm.c | 14 ++++++++++++++
> >>>> target/ppc/kvm_ppc.h | 6 ++++++
> >>>> 3 files changed, 35 insertions(+)
> >>>>
> >>>> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
> >>>> index fb594a4..939f428 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,
> >>>> @@ -354,6 +355,20 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
> >>>> target_ulong args,
> >>>> uint32_t nret, target_ulong rets)
> >>>> {
> >>>> + int ret;
> >>>> +
> >>>> + ret = kvmppc_fwnmi_enable(cpu);
> >>>> +
> >>>> + if (ret == 1) {
> >>>> + rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
> >>>
> >>> Urgh, we're here making a guest visible different to the environment
> >>> depending on a host (KVM) capability. What happens if you start a
> >>> guest and it registers fwnmi support, then migrate it to a host that
> >>> lacks the necessary KVM support?
> >>
> >> I just checked how such scenarios are handled for other KVM
> >> capabilities. Should I need to add an Spapr cap for this?
> >
> > Yes, I think that's what we'll need to do.
>
> I was looking into SPAPR Cap, and I am not sure that the following code
> will help in handling the migration. I need some help here.
>
> diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
> index edc5ed0..ef96192 100644
> --- a/hw/ppc/spapr_caps.c
> +++ b/hw/ppc/spapr_caps.c
> @@ -473,6 +473,15 @@ static void cap_ccf_assist_apply(SpaprMachineState
> *spapr, uint8_t val,
> }
> }
>
> +static void cap_machine_check_apply(SpaprMachineState *spapr, uint8_t val,
> + Error **errp)
> +{
> + if (kvm_enabled()) {
> + if (kvmppc_fwnmi_enable(cpu)) {
> + error_setg(errp, "Unable to enable fwnmi capability");
> + }
> +}
> +
> SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
> [SPAPR_CAP_HTM] = {
> .name = "htm",
> @@ -571,6 +580,15 @@ SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
> .type = "bool",
> .apply = cap_ccf_assist_apply,
> },
> + [SPAPR_CAP_MACHINE_CHECK] = {
> + .name = "machine-check",
> + .description = "Handle machine check exceptions",
> + .index = SPAPR_CAP_MACHINE_CHECK,
> + .get = spapr_cap_get_bool,
> + .set = spapr_cap_set_bool,
> + .type = "bool",
> + .apply = cap_machine_check_apply,
> + },
> };
>
> static SpaprCapabilities default_caps_with_cpu(SpaprMachineState *spapr,
> @@ -706,6 +724,7 @@ SPAPR_CAP_MIG_STATE(ibs, SPAPR_CAP_IBS);
> 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(mce, SPAPR_CAP_MACHINE_CHECK);
>
> void spapr_caps_init(SpaprMachineState *spapr)
> {
>
>
> Or is it that just adding SPAPR_CAP_MIG_STATE(mce,
> SPAPR_CAP_MACHINE_CHECK); is enough as it is checking or cap values?
No, the change you have above looks mostly good. You'll also need to
set default values for the cap in spapr_machine_class_init(), and
probably compat values in some of the earlier machine type variants.
I also don't like the cap name: there's at least some kind of handling
of machine checks before this, this is more specifically about the
fwnmi scheme, AIUI.
--
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
Aravinda Prasad <aravinda@linux.vnet.ibm.com> writes:
(...)
> diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h
> index df5e85f..cf7b24f 100644
> --- a/target/ppc/kvm_ppc.h
> +++ b/target/ppc/kvm_ppc.h
> @@ -27,6 +27,7 @@ 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);
Building for all architectures results in:
In file included from qemu/hw/ppc/ppc.c:36:
qemu/target/ppc/kvm_ppc.h:162:5: error: no previous prototype for
‘kvmppc_fwnmi_enable’ [-Werror=missing-prototypes]
int kvmppc_fwnmi_enable(PowerPCCPU *cpu)
^~~~~~~~~~~~~~~~~~~
> int kvmppc_smt_threads(void);
> void kvmppc_hint_smt_possible(Error **errp);
> int kvmppc_set_smt_threads(int smt);
> @@ -158,6 +159,11 @@ static inline void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
> {
> }
>
> +int kvmppc_fwnmi_enable(PowerPCCPU *cpu)
> +{
> + return 1;
> +}
> +
> static inline int kvmppc_smt_threads(void)
> {
> return 1;
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