[v7,2/2] target: arm: Add support for VCPU event states

This patch extends the qemu-kvm state sync logic with support for
KVM_GET/SET_VCPU_EVENTS, giving access to yet missing SError exception.
And also it can support the exception state migration.

Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
---
change since v6:
1. Add cover letter
2. Change name "cpu/ras" to "cpu/serror"
3. Add some comments and check the ioctl return value for kvm_put_vcpu_events()

Change since v5:
address Peter's comments:
1. Move the "struct serror" before the "end_reset_fields" in CPUARMState
2. Remove ARM_FEATURE_RAS_EXT and add a variable have_inject_serror_esr
3. Use the variable have_inject_serror_esr to track whether the kernel has state we need to migrate
4. Remove printf() in kvm_arch_put_registers()
5. ras_needed/vmstate_ras to serror_needed/vmstate_serror
6. Check to use "return env.serror.pending != 0" instead of "arm_feature(env, ARM_FEATURE_RAS_EXT)" in the ras_needed()

Change since v4:
1. Rebase the code to latest

Change since v3:
1. Add a new new subsection with a suitable 'ras_needed' function
   controlling whether it is present
2. Add a ARM_FEATURE_RAS feature bit for CPUARMState
---
 target/arm/cpu.h     |  7 ++++++
 target/arm/kvm64.c   | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 target/arm/machine.c | 22 +++++++++++++++++
 3 files changed, 97 insertions(+)

Hi,

On 8/28/2018 4:46 AM, Dongjiu Geng wrote:
> This patch extends the qemu-kvm state sync logic with support for
> KVM_GET/SET_VCPU_EVENTS, giving access to yet missing SError exception.
> And also it can support the exception state migration.
> 
> Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
> ---
> change since v6:
> 1. Add cover letter
> 2. Change name "cpu/ras" to "cpu/serror"
> 3. Add some comments and check the ioctl return value for kvm_put_vcpu_events()
> 
> Change since v5:
> address Peter's comments:
> 1. Move the "struct serror" before the "end_reset_fields" in CPUARMState
> 2. Remove ARM_FEATURE_RAS_EXT and add a variable have_inject_serror_esr
> 3. Use the variable have_inject_serror_esr to track whether the kernel has state we need to migrate
> 4. Remove printf() in kvm_arch_put_registers()
> 5. ras_needed/vmstate_ras to serror_needed/vmstate_serror
> 6. Check to use "return env.serror.pending != 0" instead of "arm_feature(env, ARM_FEATURE_RAS_EXT)" in the ras_needed()
> 
> Change since v4:
> 1. Rebase the code to latest
> 
> Change since v3:
> 1. Add a new new subsection with a suitable 'ras_needed' function
>     controlling whether it is present
> 2. Add a ARM_FEATURE_RAS feature bit for CPUARMState
> ---
>   target/arm/cpu.h     |  7 ++++++
>   target/arm/kvm64.c   | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>   target/arm/machine.c | 22 +++++++++++++++++
>   3 files changed, 97 insertions(+)
> 
> diff --git a/target/arm/cpu.h b/target/arm/cpu.h
> index 62c36b4..7030680 100644
> --- a/target/arm/cpu.h
> +++ b/target/arm/cpu.h
> @@ -530,6 +530,13 @@ typedef struct CPUARMState {
>            */
>       } exception;
>   
> +    /* Information associated with an SError */
> +    struct {
> +        uint32_t pending;
> +        uint32_t has_esr;
why use uint32_t for a bool parameter here while it's u8 in the kernel 
header?

> +        uint64_t esr;
> +    } serror;
> +
>       /* Thumb-2 EE state.  */
>       uint32_t teecr;
>       uint32_t teehbr;
> diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c
> index e0b8246..6e0252c 100644
> --- a/target/arm/kvm64.c
> +++ b/target/arm/kvm64.c
> @@ -29,6 +29,7 @@
>   #include "hw/arm/arm.h"
>   
>   static bool have_guest_debug;
> +static bool have_inject_serror_esr;
>   
>   /*
>    * Although the ARM implementation of hardware assisted debugging
> @@ -546,6 +547,10 @@ int kvm_arch_init_vcpu(CPUState *cs)
>   
>       kvm_arm_init_debug(cs);
>   
> +    /* Check whether userspace can specify guest syndrome value */
> +    have_inject_serror_esr = kvm_check_extension(cs->kvm_state,
> +                                                 KVM_CAP_ARM_INJECT_SERROR_ESR);
> +
>       return kvm_arm_init_cpreg_list(cpu);
>   }
>   
> @@ -600,6 +605,59 @@ int kvm_arm_cpreg_level(uint64_t regidx)
>   #define AARCH64_SIMD_CTRL_REG(x)   (KVM_REG_ARM64 | KVM_REG_SIZE_U32 | \
>                    KVM_REG_ARM_CORE | KVM_REG_ARM_CORE_REG(x))
>   
> +static int kvm_put_vcpu_events(ARMCPU *cpu)
> +{
> +    CPUARMState *env = &cpu->env;
> +    struct kvm_vcpu_events events = {};
> +    int ret;
> +
> +    if (!kvm_has_vcpu_events()) {
> +        return 0;
> +    }
> +
> +    memset(&events, 0, sizeof(events));
> +    events.exception.serror_pending = env->serror.pending;
> +
> +    /* Inject SError to guest with specified syndrome if host kernel
> +     * supports it, otherwise inject SError without syndrome.
> +     */
> +    if (have_inject_serror_esr) {
> +        events.exception.serror_has_esr = env->serror.has_esr;
> +        events.exception.serror_esr = env->serror.esr;
> +    }
> +
> +    ret = kvm_vcpu_ioctl(CPU(cpu), KVM_SET_VCPU_EVENTS, &events);
> +    if (ret) {
> +        error_report("failed to put vcpu events");
> +    }
> +
> +    return ret;
> +}
> +
> +static int kvm_get_vcpu_events(ARMCPU *cpu)
> +{
> +    CPUARMState *env = &cpu->env;
> +    struct kvm_vcpu_events events;
> +    int ret;
> +
> +    if (!kvm_has_vcpu_events()) {
> +        return 0;
> +    }
> +
> +    memset(&events, 0, sizeof(events));
> +    ret = kvm_vcpu_ioctl(CPU(cpu), KVM_GET_VCPU_EVENTS, &events);
> +
> +    if (ret < 0) {
like the put function, it's better to add a error_report here.

Thanks,
Shannon
> +        return ret;
> +    }
> +
> +    env->serror.pending = events.exception.serror_pending;
> +    env->serror.has_esr = events.exception.serror_has_esr;
> +    env->serror.esr = events.exception.serror_esr;
> +
> +    return 0;
> +}
> +
>   int kvm_arch_put_registers(CPUState *cs, int level)
>   {
>       struct kvm_one_reg reg;
> @@ -727,6 +785,11 @@ int kvm_arch_put_registers(CPUState *cs, int level)
>           return ret;
>       }
>   
> +    ret = kvm_put_vcpu_events(cpu);
> +    if (ret) {
> +        return ret;
> +    }
> +
>       if (!write_list_to_kvmstate(cpu, level)) {
>           return EINVAL;
>       }
> @@ -863,6 +926,11 @@ int kvm_arch_get_registers(CPUState *cs)
>       }
>       vfp_set_fpcr(env, fpr);
>   
> +    ret = kvm_get_vcpu_events(cpu);
> +    if (ret) {
> +        return ret;
> +    }
> +
>       if (!write_kvmstate_to_list(cpu)) {
>           return EINVAL;
>       }
> diff --git a/target/arm/machine.c b/target/arm/machine.c
> index ff4ec22..d6dadf1 100644
> --- a/target/arm/machine.c
> +++ b/target/arm/machine.c
> @@ -172,6 +172,27 @@ static const VMStateDescription vmstate_sve = {
>   };
>   #endif /* AARCH64 */
>   
> +static bool serror_needed(void *opaque)
> +{
> +    ARMCPU *cpu = opaque;
> +    CPUARMState *env = &cpu->env;
> +
> +    return env->serror.pending != 0;
> +}
> +
> +static const VMStateDescription vmstate_serror = {
> +    .name = "cpu/serror",
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .needed = serror_needed,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_UINT32(env.serror.pending, ARMCPU),
> +        VMSTATE_UINT32(env.serror.has_esr, ARMCPU),
> +        VMSTATE_UINT64(env.serror.esr, ARMCPU),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
>   static bool m_needed(void *opaque)
>   {
>       ARMCPU *cpu = opaque;
> @@ -726,6 +747,7 @@ const VMStateDescription vmstate_arm_cpu = {
>   #ifdef TARGET_AARCH64
>           &vmstate_sve,
>   #endif
> +        &vmstate_serror,
>           NULL
>       }
>   };
>

Hi Shannon
   Ｉhave changed it according to your comments and repost the patches, thanks for the review.

> 
> Hi,
> 
> On 8/28/2018 4:46 AM, Dongjiu Geng wrote:
> > This patch extends the qemu-kvm state sync logic with support for
> > KVM_GET/SET_VCPU_EVENTS, giving access to yet missing SError exception.
> > And also it can support the exception state migration.
> >
> > Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
> > ---
> > change since v6:
> > 1. Add cover letter
> > 2. Change name "cpu/ras" to "cpu/serror"
> > 3. Add some comments and check the ioctl return value for
> > kvm_put_vcpu_events()
> >
> > Change since v5:
> > address Peter's comments:
> > 1. Move the "struct serror" before the "end_reset_fields" in
> > CPUARMState 2. Remove ARM_FEATURE_RAS_EXT and add a variable
> > have_inject_serror_esr 3. Use the variable have_inject_serror_esr to
> > track whether the kernel has state we need to migrate 4. Remove
> > printf() in kvm_arch_put_registers() 5. ras_needed/vmstate_ras to
> > serror_needed/vmstate_serror 6. Check to use "return
> > env.serror.pending != 0" instead of "arm_feature(env,
> > ARM_FEATURE_RAS_EXT)" in the ras_needed()
> >
> > Change since v4:
> > 1. Rebase the code to latest
> >
> > Change since v3:
> > 1. Add a new new subsection with a suitable 'ras_needed' function
> >     controlling whether it is present
> > 2. Add a ARM_FEATURE_RAS feature bit for CPUARMState
> > ---
> >   target/arm/cpu.h     |  7 ++++++
> >   target/arm/kvm64.c   | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> >   target/arm/machine.c | 22 +++++++++++++++++
> >   3 files changed, 97 insertions(+)
> >
> > diff --git a/target/arm/cpu.h b/target/arm/cpu.h index
> > 62c36b4..7030680 100644
> > --- a/target/arm/cpu.h
> > +++ b/target/arm/cpu.h
> > @@ -530,6 +530,13 @@ typedef struct CPUARMState {
> >            */
> >       } exception;
> >
> > +    /* Information associated with an SError */
> > +    struct {
> > +        uint32_t pending;
> > +        uint32_t has_esr;
> why use uint32_t for a bool parameter here while it's u8 in the kernel header?
> 
> > +        uint64_t esr;
> > +    } serror;
> > +
> >       /* Thumb-2 EE state.  */
> >       uint32_t teecr;
> >       uint32_t teehbr;
> > diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c index
> > e0b8246..6e0252c 100644
> > --- a/target/arm/kvm64.c
> > +++ b/target/arm/kvm64.c
> > @@ -29,6 +29,7 @@
> >   #include "hw/arm/arm.h"
> >
> >   static bool have_guest_debug;
> > +static bool have_inject_serror_esr;
> >
> >   /*
> >    * Although the ARM implementation of hardware assisted debugging @@
> > -546,6 +547,10 @@ int kvm_arch_init_vcpu(CPUState *cs)
> >
> >       kvm_arm_init_debug(cs);
> >
> > +    /* Check whether userspace can specify guest syndrome value */
> > +    have_inject_serror_esr = kvm_check_extension(cs->kvm_state,
> > +
> > + KVM_CAP_ARM_INJECT_SERROR_ESR);
> > +
> >       return kvm_arm_init_cpreg_list(cpu);
> >   }
> >
> > @@ -600,6 +605,59 @@ int kvm_arm_cpreg_level(uint64_t regidx)
> >   #define AARCH64_SIMD_CTRL_REG(x)   (KVM_REG_ARM64 | KVM_REG_SIZE_U32 | \
> >                    KVM_REG_ARM_CORE | KVM_REG_ARM_CORE_REG(x))
> >
> > +static int kvm_put_vcpu_events(ARMCPU *cpu) {
> > +    CPUARMState *env = &cpu->env;
> > +    struct kvm_vcpu_events events = {};
> > +    int ret;
> > +
> > +    if (!kvm_has_vcpu_events()) {
> > +        return 0;
> > +    }
> > +
> > +    memset(&events, 0, sizeof(events));
> > +    events.exception.serror_pending = env->serror.pending;
> > +
> > +    /* Inject SError to guest with specified syndrome if host kernel
> > +     * supports it, otherwise inject SError without syndrome.
> > +     */
> > +    if (have_inject_serror_esr) {
> > +        events.exception.serror_has_esr = env->serror.has_esr;
> > +        events.exception.serror_esr = env->serror.esr;
> > +    }
> > +
> > +    ret = kvm_vcpu_ioctl(CPU(cpu), KVM_SET_VCPU_EVENTS, &events);
> > +    if (ret) {
> > +        error_report("failed to put vcpu events");
> > +    }
> > +
> > +    return ret;
> > +}
> > +
> > +static int kvm_get_vcpu_events(ARMCPU *cpu) {
> > +    CPUARMState *env = &cpu->env;
> > +    struct kvm_vcpu_events events;
> > +    int ret;
> > +
> > +    if (!kvm_has_vcpu_events()) {
> > +        return 0;
> > +    }
> > +
> > +    memset(&events, 0, sizeof(events));
> > +    ret = kvm_vcpu_ioctl(CPU(cpu), KVM_GET_VCPU_EVENTS, &events);
> > +
> > +    if (ret < 0) {
> like the put function, it's better to add a error_report here.
> 
> Thanks,
> Shannon
> > +        return ret;
> > +    }
> > +
> > +    env->serror.pending = events.exception.serror_pending;
> > +    env->serror.has_esr = events.exception.serror_has_esr;
> > +    env->serror.esr = events.exception.serror_esr;
> > +
> > +    return 0;
> > +}
> > +
> >   int kvm_arch_put_registers(CPUState *cs, int level)
> >   {
> >       struct kvm_one_reg reg;
> > @@ -727,6 +785,11 @@ int kvm_arch_put_registers(CPUState *cs, int level)
> >           return ret;
> >       }
> >
> > +    ret = kvm_put_vcpu_events(cpu);
> > +    if (ret) {
> > +        return ret;
> > +    }
> > +
> >       if (!write_list_to_kvmstate(cpu, level)) {
> >           return EINVAL;
> >       }
> > @@ -863,6 +926,11 @@ int kvm_arch_get_registers(CPUState *cs)
> >       }
> >       vfp_set_fpcr(env, fpr);
> >
> > +    ret = kvm_get_vcpu_events(cpu);
> > +    if (ret) {
> > +        return ret;
> > +    }
> > +
> >       if (!write_kvmstate_to_list(cpu)) {
> >           return EINVAL;
> >       }
> > diff --git a/target/arm/machine.c b/target/arm/machine.c index
> > ff4ec22..d6dadf1 100644
> > --- a/target/arm/machine.c
> > +++ b/target/arm/machine.c
> > @@ -172,6 +172,27 @@ static const VMStateDescription vmstate_sve = {
> >   };
> >   #endif /* AARCH64 */
> >
> > +static bool serror_needed(void *opaque) {
> > +    ARMCPU *cpu = opaque;
> > +    CPUARMState *env = &cpu->env;
> > +
> > +    return env->serror.pending != 0;
> > +}
> > +
> > +static const VMStateDescription vmstate_serror = {
> > +    .name = "cpu/serror",
> > +    .version_id = 1,
> > +    .minimum_version_id = 1,
> > +    .needed = serror_needed,
> > +    .fields = (VMStateField[]) {
> > +        VMSTATE_UINT32(env.serror.pending, ARMCPU),
> > +        VMSTATE_UINT32(env.serror.has_esr, ARMCPU),
> > +        VMSTATE_UINT64(env.serror.esr, ARMCPU),
> > +        VMSTATE_END_OF_LIST()
> > +    }
> > +};
> > +
> >   static bool m_needed(void *opaque)
> >   {
> >       ARMCPU *cpu = opaque;
> > @@ -726,6 +747,7 @@ const VMStateDescription vmstate_arm_cpu = {
> >   #ifdef TARGET_AARCH64
> >           &vmstate_sve,
> >   #endif
> > +        &vmstate_serror,
> >           NULL
> >       }
> >   };
> >