From 8aba09588d2af37c6cc1a781b87d1d91ebf389ae Mon Sep 17 00:00:00 2001 From: Janosch Frank Date: Tue, 17 May 2022 16:36:25 +0000 Subject: [PATCH] KVM: s390: Add CPU dump functionality 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 Reviewed-by: Claudio Imbrenda Link: https://lore.kernel.org/r/20220517163629.3443-8-frankja@linux.ibm.com Message-Id: <20220517163629.3443-8-frankja@linux.ibm.com> Signed-off-by: Christian Borntraeger --- arch/s390/kvm/kvm-s390.c | 69 ++++++++++++++++++++++++++++++++++++++++ arch/s390/kvm/kvm-s390.h | 1 + arch/s390/kvm/pv.c | 16 ++++++++++ include/uapi/linux/kvm.h | 4 +++ 4 files changed, 90 insertions(+) diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 1d00aead6bc5..37be2a33edb5 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -5096,6 +5096,48 @@ 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 = kvzalloc(uv_info.guest_cpu_stor_len, GFP_KERNEL); + 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) + ret = -EINVAL; + + /* On success copy over the dump data */ + if (!ret && copy_to_user((__u8 __user *)dmp.buff_addr, data, uv_info.guest_cpu_stor_len)) + ret = -EFAULT; + + kvfree(data); + return ret; +} + long kvm_arch_vcpu_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { @@ -5260,6 +5302,33 @@ 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 2c11eb5ba3ef..dd01d989816f 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); int kvm_s390_pv_dump_complete(struct kvm *kvm, void __user *buff_user, diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c index e9912113879c..b4a499b10b67 100644 --- a/arch/s390/kvm/pv.c +++ b/arch/s390/kvm/pv.c @@ -300,6 +300,22 @@ 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 673be2061c6c..af5d254f8061 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1664,6 +1664,7 @@ 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 { @@ -2168,4 +2169,7 @@ 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 */