diff mbox series

[7/9] kvm: s390: Add CPU dump functionality

Message ID 20220428130102.230790-8-frankja@linux.ibm.com (mailing list archive)
State New, archived
Headers show
Series kvm: s390: Add PV dump support | expand

Commit Message

Janosch Frank April 28, 2022, 1:01 p.m. UTC
The previous patch introduced the per-VM dump functions now let's
focus on dumping the VCPU state via the newly introduced
KVM_S390_PV_CPU_COMMAND ioctl which mirrors the VM UV ioctl and can be
extended with new commands later.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
---
 arch/s390/kvm/kvm-s390.c | 73 ++++++++++++++++++++++++++++++++++++++++
 arch/s390/kvm/kvm-s390.h |  1 +
 arch/s390/kvm/pv.c       | 16 +++++++++
 include/uapi/linux/kvm.h |  5 +++
 4 files changed, 95 insertions(+)

Comments

Claudio Imbrenda May 9, 2022, 7:11 p.m. UTC | #1
On Thu, 28 Apr 2022 13:01:00 +0000
Janosch Frank <frankja@linux.ibm.com> wrote:

> The previous patch introduced the per-VM dump functions now let's
> focus on dumping the VCPU state via the newly introduced
> KVM_S390_PV_CPU_COMMAND ioctl which mirrors the VM UV ioctl and can be
> extended with new commands later.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
>  arch/s390/kvm/kvm-s390.c | 73 ++++++++++++++++++++++++++++++++++++++++
>  arch/s390/kvm/kvm-s390.h |  1 +
>  arch/s390/kvm/pv.c       | 16 +++++++++
>  include/uapi/linux/kvm.h |  5 +++
>  4 files changed, 95 insertions(+)
> 
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 8984e8db33b4..d15ce38bef14 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -5149,6 +5149,52 @@ long kvm_arch_vcpu_async_ioctl(struct file *filp,
>  	return -ENOIOCTLCMD;
>  }
>  
> +static int kvm_s390_handle_pv_vcpu_dump(struct kvm_vcpu *vcpu,
> +					struct kvm_pv_cmd *cmd)
> +{
> +	struct kvm_s390_pv_dmp dmp;
> +	void *data;
> +	int ret;
> +
> +	/* Dump initialization is a prerequisite */
> +	if (!vcpu->kvm->arch.pv.dumping)
> +		return -EINVAL;
> +
> +	if (copy_from_user(&dmp, (__u8 __user *)cmd->data, sizeof(dmp)))
> +		return -EFAULT;
> +
> +	/* We only handle this subcmd right now */
> +	if (dmp.subcmd != KVM_PV_DUMP_CPU)
> +		return -EINVAL;
> +
> +	/* CPU dump length is the same as create cpu storage donation. */
> +	if (dmp.buff_len != uv_info.guest_cpu_stor_len)
> +		return -EINVAL;
> +
> +	data = vzalloc(uv_info.guest_cpu_stor_len);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	ret = kvm_s390_pv_dump_cpu(vcpu, data, &cmd->rc, &cmd->rrc);
> +
> +	VCPU_EVENT(vcpu, 3, "PROTVIRT DUMP CPU %d rc %x rrc %x",
> +		   vcpu->vcpu_id, cmd->rc, cmd->rrc);
> +
> +	if (ret) {
> +		vfree(data);
> +		return -EINVAL;
> +	}
> +
> +	/* On success copy over the dump data */
> +	if (copy_to_user((__u8 __user *)dmp.buff_addr, data, uv_info.guest_cpu_stor_len)) {
> +		vfree(data);
> +		return -EFAULT;
> +	}
> +
> +	vfree(data);
> +	return 0;
> +}
> +
>  long kvm_arch_vcpu_ioctl(struct file *filp,
>  			 unsigned int ioctl, unsigned long arg)
>  {
> @@ -5313,6 +5359,33 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
>  					   irq_state.len);
>  		break;
>  	}
> +	case KVM_S390_PV_CPU_COMMAND: {
> +		struct kvm_pv_cmd cmd;
> +
> +		r = -EINVAL;
> +		if (!is_prot_virt_host())
> +			break;
> +
> +		r = -EFAULT;
> +		if (copy_from_user(&cmd, argp, sizeof(cmd)))
> +			break;
> +
> +		r = -EINVAL;
> +		if (cmd.flags)
> +			break;
> +
> +		/* We only handle this cmd right now */
> +		if (cmd.cmd != KVM_PV_DUMP)
> +			break;
> +
> +		r = kvm_s390_handle_pv_vcpu_dump(vcpu, &cmd);
> +
> +		/* Always copy over UV rc / rrc data */
> +		if (copy_to_user((__u8 __user *)argp, &cmd.rc,
> +				 sizeof(cmd.rc) + sizeof(cmd.rrc)))
> +			r = -EFAULT;
> +		break;
> +	}
>  	default:
>  		r = -ENOTTY;
>  	}
> diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
> index 2868dd0bba25..a39815184350 100644
> --- a/arch/s390/kvm/kvm-s390.h
> +++ b/arch/s390/kvm/kvm-s390.h
> @@ -250,6 +250,7 @@ int kvm_s390_pv_set_sec_parms(struct kvm *kvm, void *hdr, u64 length, u16 *rc,
>  int kvm_s390_pv_unpack(struct kvm *kvm, unsigned long addr, unsigned long size,
>  		       unsigned long tweak, u16 *rc, u16 *rrc);
>  int kvm_s390_pv_set_cpu_state(struct kvm_vcpu *vcpu, u8 state);
> +int kvm_s390_pv_dump_cpu(struct kvm_vcpu *vcpu, void *buff, u16 *rc, u16 *rrc);
>  int kvm_s390_pv_dump_stor_state(struct kvm *kvm, void __user *buff_user,
>  				u64 *gaddr, u64 buff_user_len, u16 *rc, u16 *rrc);
>  
> diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c
> index d1635ed50078..9ab8192b9b23 100644
> --- a/arch/s390/kvm/pv.c
> +++ b/arch/s390/kvm/pv.c
> @@ -299,6 +299,22 @@ int kvm_s390_pv_set_cpu_state(struct kvm_vcpu *vcpu, u8 state)
>  	return 0;
>  }
>  
> +int kvm_s390_pv_dump_cpu(struct kvm_vcpu *vcpu, void *buff, u16 *rc, u16 *rrc)
> +{
> +	struct uv_cb_dump_cpu uvcb = {
> +		.header.cmd = UVC_CMD_DUMP_CPU,
> +		.header.len = sizeof(uvcb),
> +		.cpu_handle = vcpu->arch.pv.handle,
> +		.dump_area_origin = (u64)buff,
> +	};
> +	int cc;
> +
> +	cc = uv_call_sched(0, (u64)&uvcb);

it's a small amount of data, but you use the _sched variant?

and, why aren't you using the _sched variant in the previous patch (for
DUMP_COMPLETE)?

to be clear: I think the right thing is to always use the _sched
variant unless there is a good reason not to (so please fix the previous
patch)

> +	*rc = uvcb.header.rc;
> +	*rrc = uvcb.header.rrc;
> +	return cc;
> +}
> +
>  /* Size of the cache for the storage state dump data. 1MB for now */
>  #define DUMP_BUFF_LEN HPAGE_SIZE
>  
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index b34850907291..108bc7b7a71b 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -1144,6 +1144,7 @@ struct kvm_ppc_resize_hpt {
>  #define KVM_CAP_S390_MEM_OP_EXTENSION 211
>  #define KVM_CAP_PMU_CAPABILITY 212
>  #define KVM_CAP_DISABLE_QUIRKS2 213
> +#define KVM_CAP_S390_PROTECTED_DUMP 214
>  
>  #ifdef KVM_CAP_IRQ_ROUTING
>  
> @@ -1649,6 +1650,7 @@ enum pv_cmd_dmp_id {
>  	KVM_PV_DUMP_INIT,
>  	KVM_PV_DUMP_CONFIG_STOR_STATE,
>  	KVM_PV_DUMP_COMPLETE,
> +	KVM_PV_DUMP_CPU,
>  };
>  
>  struct kvm_s390_pv_dmp {
> @@ -2110,4 +2112,7 @@ struct kvm_stats_desc {
>  /* Available with KVM_CAP_XSAVE2 */
>  #define KVM_GET_XSAVE2		  _IOR(KVMIO,  0xcf, struct kvm_xsave)
>  
> +/* Available with KVM_CAP_S390_PROTECTED_DUMP */
> +#define KVM_S390_PV_CPU_COMMAND	_IOWR(KVMIO, 0xd0, struct kvm_pv_cmd)
> +
>  #endif /* __LINUX_KVM_H */
Janosch Frank May 10, 2022, 7:26 a.m. UTC | #2
On 5/9/22 21:11, Claudio Imbrenda wrote:
> On Thu, 28 Apr 2022 13:01:00 +0000
> Janosch Frank <frankja@linux.ibm.com> wrote:
> 
>> The previous patch introduced the per-VM dump functions now let's
>> focus on dumping the VCPU state via the newly introduced
>> KVM_S390_PV_CPU_COMMAND ioctl which mirrors the VM UV ioctl and can be
>> extended with new commands later.
>>
>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>> ---
>>   arch/s390/kvm/kvm-s390.c | 73 ++++++++++++++++++++++++++++++++++++++++
>>   arch/s390/kvm/kvm-s390.h |  1 +
>>   arch/s390/kvm/pv.c       | 16 +++++++++
>>   include/uapi/linux/kvm.h |  5 +++
>>   4 files changed, 95 insertions(+)
>>
>> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
>> index 8984e8db33b4..d15ce38bef14 100644
>> --- a/arch/s390/kvm/kvm-s390.c
>> +++ b/arch/s390/kvm/kvm-s390.c
>> @@ -5149,6 +5149,52 @@ long kvm_arch_vcpu_async_ioctl(struct file *filp,
>>   	return -ENOIOCTLCMD;
>>   }
>>   
>> +static int kvm_s390_handle_pv_vcpu_dump(struct kvm_vcpu *vcpu,
>> +					struct kvm_pv_cmd *cmd)
>> +{
>> +	struct kvm_s390_pv_dmp dmp;
>> +	void *data;
>> +	int ret;
>> +
>> +	/* Dump initialization is a prerequisite */
>> +	if (!vcpu->kvm->arch.pv.dumping)
>> +		return -EINVAL;
>> +
>> +	if (copy_from_user(&dmp, (__u8 __user *)cmd->data, sizeof(dmp)))
>> +		return -EFAULT;
>> +
>> +	/* We only handle this subcmd right now */
>> +	if (dmp.subcmd != KVM_PV_DUMP_CPU)
>> +		return -EINVAL;
>> +
>> +	/* CPU dump length is the same as create cpu storage donation. */
>> +	if (dmp.buff_len != uv_info.guest_cpu_stor_len)
>> +		return -EINVAL;
>> +
>> +	data = vzalloc(uv_info.guest_cpu_stor_len);
>> +	if (!data)
>> +		return -ENOMEM;
>> +
>> +	ret = kvm_s390_pv_dump_cpu(vcpu, data, &cmd->rc, &cmd->rrc);
>> +
>> +	VCPU_EVENT(vcpu, 3, "PROTVIRT DUMP CPU %d rc %x rrc %x",
>> +		   vcpu->vcpu_id, cmd->rc, cmd->rrc);
>> +
>> +	if (ret) {
>> +		vfree(data);
>> +		return -EINVAL;
>> +	}
>> +
>> +	/* On success copy over the dump data */
>> +	if (copy_to_user((__u8 __user *)dmp.buff_addr, data, uv_info.guest_cpu_stor_len)) {
>> +		vfree(data);
>> +		return -EFAULT;
>> +	}
>> +
>> +	vfree(data);
>> +	return 0;
>> +}
>> +
>>   long kvm_arch_vcpu_ioctl(struct file *filp,
>>   			 unsigned int ioctl, unsigned long arg)
>>   {
>> @@ -5313,6 +5359,33 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
>>   					   irq_state.len);
>>   		break;
>>   	}
>> +	case KVM_S390_PV_CPU_COMMAND: {
>> +		struct kvm_pv_cmd cmd;
>> +
>> +		r = -EINVAL;
>> +		if (!is_prot_virt_host())
>> +			break;
>> +
>> +		r = -EFAULT;
>> +		if (copy_from_user(&cmd, argp, sizeof(cmd)))
>> +			break;
>> +
>> +		r = -EINVAL;
>> +		if (cmd.flags)
>> +			break;
>> +
>> +		/* We only handle this cmd right now */
>> +		if (cmd.cmd != KVM_PV_DUMP)
>> +			break;
>> +
>> +		r = kvm_s390_handle_pv_vcpu_dump(vcpu, &cmd);
>> +
>> +		/* Always copy over UV rc / rrc data */
>> +		if (copy_to_user((__u8 __user *)argp, &cmd.rc,
>> +				 sizeof(cmd.rc) + sizeof(cmd.rrc)))
>> +			r = -EFAULT;
>> +		break;
>> +	}
>>   	default:
>>   		r = -ENOTTY;
>>   	}
>> diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
>> index 2868dd0bba25..a39815184350 100644
>> --- a/arch/s390/kvm/kvm-s390.h
>> +++ b/arch/s390/kvm/kvm-s390.h
>> @@ -250,6 +250,7 @@ int kvm_s390_pv_set_sec_parms(struct kvm *kvm, void *hdr, u64 length, u16 *rc,
>>   int kvm_s390_pv_unpack(struct kvm *kvm, unsigned long addr, unsigned long size,
>>   		       unsigned long tweak, u16 *rc, u16 *rrc);
>>   int kvm_s390_pv_set_cpu_state(struct kvm_vcpu *vcpu, u8 state);
>> +int kvm_s390_pv_dump_cpu(struct kvm_vcpu *vcpu, void *buff, u16 *rc, u16 *rrc);
>>   int kvm_s390_pv_dump_stor_state(struct kvm *kvm, void __user *buff_user,
>>   				u64 *gaddr, u64 buff_user_len, u16 *rc, u16 *rrc);
>>   
>> diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c
>> index d1635ed50078..9ab8192b9b23 100644
>> --- a/arch/s390/kvm/pv.c
>> +++ b/arch/s390/kvm/pv.c
>> @@ -299,6 +299,22 @@ int kvm_s390_pv_set_cpu_state(struct kvm_vcpu *vcpu, u8 state)
>>   	return 0;
>>   }
>>   
>> +int kvm_s390_pv_dump_cpu(struct kvm_vcpu *vcpu, void *buff, u16 *rc, u16 *rrc)
>> +{
>> +	struct uv_cb_dump_cpu uvcb = {
>> +		.header.cmd = UVC_CMD_DUMP_CPU,
>> +		.header.len = sizeof(uvcb),
>> +		.cpu_handle = vcpu->arch.pv.handle,
>> +		.dump_area_origin = (u64)buff,
>> +	};
>> +	int cc;
>> +
>> +	cc = uv_call_sched(0, (u64)&uvcb);
> 
> it's a small amount of data, but you use the _sched variant?

Who knows what FW will do :)

> 
> and, why aren't you using the _sched variant in the previous patch (for
> DUMP_COMPLETE)?
> 
> to be clear: I think the right thing is to always use the _sched
> variant unless there is a good reason not to (so please fix the previous
> patch)

Yep, will fix.

It might make sense to switch the functions around and make uv_call 
always do a sched and introduce uv_call_nosched() since that's the 
special case. But that's something for the future.

> 
>> +	*rc = uvcb.header.rc;
>> +	*rrc = uvcb.header.rrc;
>> +	return cc;
>> +}
>> +
>>   /* Size of the cache for the storage state dump data. 1MB for now */
>>   #define DUMP_BUFF_LEN HPAGE_SIZE
>>   
>> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
>> index b34850907291..108bc7b7a71b 100644
>> --- a/include/uapi/linux/kvm.h
>> +++ b/include/uapi/linux/kvm.h
>> @@ -1144,6 +1144,7 @@ struct kvm_ppc_resize_hpt {
>>   #define KVM_CAP_S390_MEM_OP_EXTENSION 211
>>   #define KVM_CAP_PMU_CAPABILITY 212
>>   #define KVM_CAP_DISABLE_QUIRKS2 213
>> +#define KVM_CAP_S390_PROTECTED_DUMP 214
>>   
>>   #ifdef KVM_CAP_IRQ_ROUTING
>>   
>> @@ -1649,6 +1650,7 @@ enum pv_cmd_dmp_id {
>>   	KVM_PV_DUMP_INIT,
>>   	KVM_PV_DUMP_CONFIG_STOR_STATE,
>>   	KVM_PV_DUMP_COMPLETE,
>> +	KVM_PV_DUMP_CPU,
>>   };
>>   
>>   struct kvm_s390_pv_dmp {
>> @@ -2110,4 +2112,7 @@ struct kvm_stats_desc {
>>   /* Available with KVM_CAP_XSAVE2 */
>>   #define KVM_GET_XSAVE2		  _IOR(KVMIO,  0xcf, struct kvm_xsave)
>>   
>> +/* Available with KVM_CAP_S390_PROTECTED_DUMP */
>> +#define KVM_S390_PV_CPU_COMMAND	_IOWR(KVMIO, 0xd0, struct kvm_pv_cmd)
>> +
>>   #endif /* __LINUX_KVM_H */
>
Claudio Imbrenda May 10, 2022, 9:14 a.m. UTC | #3
On Tue, 10 May 2022 09:26:50 +0200
Janosch Frank <frankja@linux.ibm.com> wrote:

> On 5/9/22 21:11, Claudio Imbrenda wrote:
> > On Thu, 28 Apr 2022 13:01:00 +0000
> > Janosch Frank <frankja@linux.ibm.com> wrote:
> >   
> >> The previous patch introduced the per-VM dump functions now let's
> >> focus on dumping the VCPU state via the newly introduced
> >> KVM_S390_PV_CPU_COMMAND ioctl which mirrors the VM UV ioctl and can be
> >> extended with new commands later.
> >>
> >> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> >> ---
> >>   arch/s390/kvm/kvm-s390.c | 73 ++++++++++++++++++++++++++++++++++++++++
> >>   arch/s390/kvm/kvm-s390.h |  1 +
> >>   arch/s390/kvm/pv.c       | 16 +++++++++
> >>   include/uapi/linux/kvm.h |  5 +++
> >>   4 files changed, 95 insertions(+)
> >>
> >> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> >> index 8984e8db33b4..d15ce38bef14 100644
> >> --- a/arch/s390/kvm/kvm-s390.c
> >> +++ b/arch/s390/kvm/kvm-s390.c
> >> @@ -5149,6 +5149,52 @@ long kvm_arch_vcpu_async_ioctl(struct file *filp,
> >>   	return -ENOIOCTLCMD;
> >>   }
> >>   
> >> +static int kvm_s390_handle_pv_vcpu_dump(struct kvm_vcpu *vcpu,
> >> +					struct kvm_pv_cmd *cmd)
> >> +{
> >> +	struct kvm_s390_pv_dmp dmp;
> >> +	void *data;
> >> +	int ret;
> >> +
> >> +	/* Dump initialization is a prerequisite */
> >> +	if (!vcpu->kvm->arch.pv.dumping)
> >> +		return -EINVAL;
> >> +
> >> +	if (copy_from_user(&dmp, (__u8 __user *)cmd->data, sizeof(dmp)))
> >> +		return -EFAULT;
> >> +
> >> +	/* We only handle this subcmd right now */
> >> +	if (dmp.subcmd != KVM_PV_DUMP_CPU)
> >> +		return -EINVAL;
> >> +
> >> +	/* CPU dump length is the same as create cpu storage donation. */
> >> +	if (dmp.buff_len != uv_info.guest_cpu_stor_len)
> >> +		return -EINVAL;
> >> +
> >> +	data = vzalloc(uv_info.guest_cpu_stor_len);
> >> +	if (!data)
> >> +		return -ENOMEM;
> >> +
> >> +	ret = kvm_s390_pv_dump_cpu(vcpu, data, &cmd->rc, &cmd->rrc);
> >> +
> >> +	VCPU_EVENT(vcpu, 3, "PROTVIRT DUMP CPU %d rc %x rrc %x",
> >> +		   vcpu->vcpu_id, cmd->rc, cmd->rrc);
> >> +
> >> +	if (ret) {
> >> +		vfree(data);
> >> +		return -EINVAL;
> >> +	}
> >> +
> >> +	/* On success copy over the dump data */
> >> +	if (copy_to_user((__u8 __user *)dmp.buff_addr, data, uv_info.guest_cpu_stor_len)) {
> >> +		vfree(data);
> >> +		return -EFAULT;
> >> +	}
> >> +
> >> +	vfree(data);
> >> +	return 0;
> >> +}
> >> +
> >>   long kvm_arch_vcpu_ioctl(struct file *filp,
> >>   			 unsigned int ioctl, unsigned long arg)
> >>   {
> >> @@ -5313,6 +5359,33 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
> >>   					   irq_state.len);
> >>   		break;
> >>   	}
> >> +	case KVM_S390_PV_CPU_COMMAND: {
> >> +		struct kvm_pv_cmd cmd;
> >> +
> >> +		r = -EINVAL;
> >> +		if (!is_prot_virt_host())
> >> +			break;
> >> +
> >> +		r = -EFAULT;
> >> +		if (copy_from_user(&cmd, argp, sizeof(cmd)))
> >> +			break;
> >> +
> >> +		r = -EINVAL;
> >> +		if (cmd.flags)
> >> +			break;
> >> +
> >> +		/* We only handle this cmd right now */
> >> +		if (cmd.cmd != KVM_PV_DUMP)
> >> +			break;
> >> +
> >> +		r = kvm_s390_handle_pv_vcpu_dump(vcpu, &cmd);
> >> +
> >> +		/* Always copy over UV rc / rrc data */
> >> +		if (copy_to_user((__u8 __user *)argp, &cmd.rc,
> >> +				 sizeof(cmd.rc) + sizeof(cmd.rrc)))
> >> +			r = -EFAULT;
> >> +		break;
> >> +	}
> >>   	default:
> >>   		r = -ENOTTY;
> >>   	}
> >> diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
> >> index 2868dd0bba25..a39815184350 100644
> >> --- a/arch/s390/kvm/kvm-s390.h
> >> +++ b/arch/s390/kvm/kvm-s390.h
> >> @@ -250,6 +250,7 @@ int kvm_s390_pv_set_sec_parms(struct kvm *kvm, void *hdr, u64 length, u16 *rc,
> >>   int kvm_s390_pv_unpack(struct kvm *kvm, unsigned long addr, unsigned long size,
> >>   		       unsigned long tweak, u16 *rc, u16 *rrc);
> >>   int kvm_s390_pv_set_cpu_state(struct kvm_vcpu *vcpu, u8 state);
> >> +int kvm_s390_pv_dump_cpu(struct kvm_vcpu *vcpu, void *buff, u16 *rc, u16 *rrc);
> >>   int kvm_s390_pv_dump_stor_state(struct kvm *kvm, void __user *buff_user,
> >>   				u64 *gaddr, u64 buff_user_len, u16 *rc, u16 *rrc);
> >>   
> >> diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c
> >> index d1635ed50078..9ab8192b9b23 100644
> >> --- a/arch/s390/kvm/pv.c
> >> +++ b/arch/s390/kvm/pv.c
> >> @@ -299,6 +299,22 @@ int kvm_s390_pv_set_cpu_state(struct kvm_vcpu *vcpu, u8 state)
> >>   	return 0;
> >>   }
> >>   
> >> +int kvm_s390_pv_dump_cpu(struct kvm_vcpu *vcpu, void *buff, u16 *rc, u16 *rrc)
> >> +{
> >> +	struct uv_cb_dump_cpu uvcb = {
> >> +		.header.cmd = UVC_CMD_DUMP_CPU,
> >> +		.header.len = sizeof(uvcb),
> >> +		.cpu_handle = vcpu->arch.pv.handle,
> >> +		.dump_area_origin = (u64)buff,
> >> +	};
> >> +	int cc;
> >> +
> >> +	cc = uv_call_sched(0, (u64)&uvcb);  
> > 
> > it's a small amount of data, but you use the _sched variant?  
> 
> Who knows what FW will do :)
> 
> > 
> > and, why aren't you using the _sched variant in the previous patch (for
> > DUMP_COMPLETE)?
> > 
> > to be clear: I think the right thing is to always use the _sched
> > variant unless there is a good reason not to (so please fix the previous
> > patch)  
> 
> Yep, will fix.
> 
> It might make sense to switch the functions around and make uv_call 
> always do a sched and introduce uv_call_nosched() since that's the 
> special case. But that's something for the future.

I was actually thinking the same thing :)

> 
> >   
> >> +	*rc = uvcb.header.rc;
> >> +	*rrc = uvcb.header.rrc;
> >> +	return cc;
> >> +}
> >> +
> >>   /* Size of the cache for the storage state dump data. 1MB for now */
> >>   #define DUMP_BUFF_LEN HPAGE_SIZE
> >>   
> >> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> >> index b34850907291..108bc7b7a71b 100644
> >> --- a/include/uapi/linux/kvm.h
> >> +++ b/include/uapi/linux/kvm.h
> >> @@ -1144,6 +1144,7 @@ struct kvm_ppc_resize_hpt {
> >>   #define KVM_CAP_S390_MEM_OP_EXTENSION 211
> >>   #define KVM_CAP_PMU_CAPABILITY 212
> >>   #define KVM_CAP_DISABLE_QUIRKS2 213
> >> +#define KVM_CAP_S390_PROTECTED_DUMP 214
> >>   
> >>   #ifdef KVM_CAP_IRQ_ROUTING
> >>   
> >> @@ -1649,6 +1650,7 @@ enum pv_cmd_dmp_id {
> >>   	KVM_PV_DUMP_INIT,
> >>   	KVM_PV_DUMP_CONFIG_STOR_STATE,
> >>   	KVM_PV_DUMP_COMPLETE,
> >> +	KVM_PV_DUMP_CPU,
> >>   };
> >>   
> >>   struct kvm_s390_pv_dmp {
> >> @@ -2110,4 +2112,7 @@ struct kvm_stats_desc {
> >>   /* Available with KVM_CAP_XSAVE2 */
> >>   #define KVM_GET_XSAVE2		  _IOR(KVMIO,  0xcf, struct kvm_xsave)
> >>   
> >> +/* Available with KVM_CAP_S390_PROTECTED_DUMP */
> >> +#define KVM_S390_PV_CPU_COMMAND	_IOWR(KVMIO, 0xd0, struct kvm_pv_cmd)
> >> +
> >>   #endif /* __LINUX_KVM_H */  
> >   
>
diff mbox series

Patch

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 8984e8db33b4..d15ce38bef14 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -5149,6 +5149,52 @@  long kvm_arch_vcpu_async_ioctl(struct file *filp,
 	return -ENOIOCTLCMD;
 }
 
+static int kvm_s390_handle_pv_vcpu_dump(struct kvm_vcpu *vcpu,
+					struct kvm_pv_cmd *cmd)
+{
+	struct kvm_s390_pv_dmp dmp;
+	void *data;
+	int ret;
+
+	/* Dump initialization is a prerequisite */
+	if (!vcpu->kvm->arch.pv.dumping)
+		return -EINVAL;
+
+	if (copy_from_user(&dmp, (__u8 __user *)cmd->data, sizeof(dmp)))
+		return -EFAULT;
+
+	/* We only handle this subcmd right now */
+	if (dmp.subcmd != KVM_PV_DUMP_CPU)
+		return -EINVAL;
+
+	/* CPU dump length is the same as create cpu storage donation. */
+	if (dmp.buff_len != uv_info.guest_cpu_stor_len)
+		return -EINVAL;
+
+	data = vzalloc(uv_info.guest_cpu_stor_len);
+	if (!data)
+		return -ENOMEM;
+
+	ret = kvm_s390_pv_dump_cpu(vcpu, data, &cmd->rc, &cmd->rrc);
+
+	VCPU_EVENT(vcpu, 3, "PROTVIRT DUMP CPU %d rc %x rrc %x",
+		   vcpu->vcpu_id, cmd->rc, cmd->rrc);
+
+	if (ret) {
+		vfree(data);
+		return -EINVAL;
+	}
+
+	/* On success copy over the dump data */
+	if (copy_to_user((__u8 __user *)dmp.buff_addr, data, uv_info.guest_cpu_stor_len)) {
+		vfree(data);
+		return -EFAULT;
+	}
+
+	vfree(data);
+	return 0;
+}
+
 long kvm_arch_vcpu_ioctl(struct file *filp,
 			 unsigned int ioctl, unsigned long arg)
 {
@@ -5313,6 +5359,33 @@  long kvm_arch_vcpu_ioctl(struct file *filp,
 					   irq_state.len);
 		break;
 	}
+	case KVM_S390_PV_CPU_COMMAND: {
+		struct kvm_pv_cmd cmd;
+
+		r = -EINVAL;
+		if (!is_prot_virt_host())
+			break;
+
+		r = -EFAULT;
+		if (copy_from_user(&cmd, argp, sizeof(cmd)))
+			break;
+
+		r = -EINVAL;
+		if (cmd.flags)
+			break;
+
+		/* We only handle this cmd right now */
+		if (cmd.cmd != KVM_PV_DUMP)
+			break;
+
+		r = kvm_s390_handle_pv_vcpu_dump(vcpu, &cmd);
+
+		/* Always copy over UV rc / rrc data */
+		if (copy_to_user((__u8 __user *)argp, &cmd.rc,
+				 sizeof(cmd.rc) + sizeof(cmd.rrc)))
+			r = -EFAULT;
+		break;
+	}
 	default:
 		r = -ENOTTY;
 	}
diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index 2868dd0bba25..a39815184350 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -250,6 +250,7 @@  int kvm_s390_pv_set_sec_parms(struct kvm *kvm, void *hdr, u64 length, u16 *rc,
 int kvm_s390_pv_unpack(struct kvm *kvm, unsigned long addr, unsigned long size,
 		       unsigned long tweak, u16 *rc, u16 *rrc);
 int kvm_s390_pv_set_cpu_state(struct kvm_vcpu *vcpu, u8 state);
+int kvm_s390_pv_dump_cpu(struct kvm_vcpu *vcpu, void *buff, u16 *rc, u16 *rrc);
 int kvm_s390_pv_dump_stor_state(struct kvm *kvm, void __user *buff_user,
 				u64 *gaddr, u64 buff_user_len, u16 *rc, u16 *rrc);
 
diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c
index d1635ed50078..9ab8192b9b23 100644
--- a/arch/s390/kvm/pv.c
+++ b/arch/s390/kvm/pv.c
@@ -299,6 +299,22 @@  int kvm_s390_pv_set_cpu_state(struct kvm_vcpu *vcpu, u8 state)
 	return 0;
 }
 
+int kvm_s390_pv_dump_cpu(struct kvm_vcpu *vcpu, void *buff, u16 *rc, u16 *rrc)
+{
+	struct uv_cb_dump_cpu uvcb = {
+		.header.cmd = UVC_CMD_DUMP_CPU,
+		.header.len = sizeof(uvcb),
+		.cpu_handle = vcpu->arch.pv.handle,
+		.dump_area_origin = (u64)buff,
+	};
+	int cc;
+
+	cc = uv_call_sched(0, (u64)&uvcb);
+	*rc = uvcb.header.rc;
+	*rrc = uvcb.header.rrc;
+	return cc;
+}
+
 /* Size of the cache for the storage state dump data. 1MB for now */
 #define DUMP_BUFF_LEN HPAGE_SIZE
 
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index b34850907291..108bc7b7a71b 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1144,6 +1144,7 @@  struct kvm_ppc_resize_hpt {
 #define KVM_CAP_S390_MEM_OP_EXTENSION 211
 #define KVM_CAP_PMU_CAPABILITY 212
 #define KVM_CAP_DISABLE_QUIRKS2 213
+#define KVM_CAP_S390_PROTECTED_DUMP 214
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
@@ -1649,6 +1650,7 @@  enum pv_cmd_dmp_id {
 	KVM_PV_DUMP_INIT,
 	KVM_PV_DUMP_CONFIG_STOR_STATE,
 	KVM_PV_DUMP_COMPLETE,
+	KVM_PV_DUMP_CPU,
 };
 
 struct kvm_s390_pv_dmp {
@@ -2110,4 +2112,7 @@  struct kvm_stats_desc {
 /* Available with KVM_CAP_XSAVE2 */
 #define KVM_GET_XSAVE2		  _IOR(KVMIO,  0xcf, struct kvm_xsave)
 
+/* Available with KVM_CAP_S390_PROTECTED_DUMP */
+#define KVM_S390_PV_CPU_COMMAND	_IOWR(KVMIO, 0xd0, struct kvm_pv_cmd)
+
 #endif /* __LINUX_KVM_H */