| Message ID | 20200515221935.18775-4-walling@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Use DIAG318 to set Control Program Name & Version Codes | expand |
On 16.05.20 00:19, Collin Walling wrote: > DIAGNOSE 0x318 (diag 318) sets information regarding the environment > the VM is running in (Linux, z/VM, etc) and is observed via > firmware/service events. > > This is a privileged s390x instruction that must be intercepted by > SIE. Userspace handling is required, so let's introduce some functions > to communicate between userspace and KVM via ioctls. These will be used > to get/set the diag 318 related information. > > The Control Program Name Code (CPNC) is stored in the SIE block. The > CPNC along with the Control Program Version Code (CPVC) are stored in > the kvm_arch struct. > > Signed-off-by: Collin Walling <walling@linux.ibm.com> > --- > Documentation/virt/kvm/devices/vm.rst | 21 +++++++ > arch/s390/include/asm/kvm_host.h | 5 +- > arch/s390/include/uapi/asm/kvm.h | 4 ++ > arch/s390/kvm/kvm-s390.c | 82 +++++++++++++++++++++++++++ > arch/s390/kvm/vsie.c | 2 + > 5 files changed, 113 insertions(+), 1 deletion(-) > > diff --git a/Documentation/virt/kvm/devices/vm.rst b/Documentation/virt/kvm/devices/vm.rst > index 0aa5b1cfd700..52cc906dd7bd 100644 > --- a/Documentation/virt/kvm/devices/vm.rst > +++ b/Documentation/virt/kvm/devices/vm.rst > @@ -314,3 +314,24 @@ Allows userspace to query the status of migration mode. > if it is enabled > :Returns: -EFAULT if the given address is not accessible from kernel space; > 0 in case of success. > + > +6. GROUP: KVM_S390_VM_MISC > +========================== > + > +:Architectures: s390 > + > +6.1. KVM_S390_VM_MISC_DIAG_318 (r/w) > +----------------------------------- > + > +Allows userspace to retrieve and set the DIAGNOSE 0x318 information, > +which consists of a 1-byte "Control Program Name Code" and a 7-byte > +"Control Program Version Code" (a 64 bit value all in all). This > +information is set by the guest (usually during IPL). This interface is > +intended to allow retrieving and setting it during migration; while no > +real harm is done if the information is changed outside of migration, > +it is strongly discouraged. > + > +:Parameters: address of a buffer in user space (u64), where the > + information is read from or stored into > +:Returns: -EFAULT if the given address is not accessible from kernel space; > + 0 in case of success An alternative would be a new sync_reg value + KVM capability.
On 5/18/20 5:15 AM, Christian Borntraeger wrote: > > > On 16.05.20 00:19, Collin Walling wrote: >> DIAGNOSE 0x318 (diag 318) sets information regarding the environment >> the VM is running in (Linux, z/VM, etc) and is observed via >> firmware/service events. >> >> This is a privileged s390x instruction that must be intercepted by >> SIE. Userspace handling is required, so let's introduce some functions >> to communicate between userspace and KVM via ioctls. These will be used >> to get/set the diag 318 related information. >> >> The Control Program Name Code (CPNC) is stored in the SIE block. The >> CPNC along with the Control Program Version Code (CPVC) are stored in >> the kvm_arch struct. >> >> Signed-off-by: Collin Walling <walling@linux.ibm.com> >> --- >> Documentation/virt/kvm/devices/vm.rst | 21 +++++++ >> arch/s390/include/asm/kvm_host.h | 5 +- >> arch/s390/include/uapi/asm/kvm.h | 4 ++ >> arch/s390/kvm/kvm-s390.c | 82 +++++++++++++++++++++++++++ >> arch/s390/kvm/vsie.c | 2 + >> 5 files changed, 113 insertions(+), 1 deletion(-) >> >> diff --git a/Documentation/virt/kvm/devices/vm.rst b/Documentation/virt/kvm/devices/vm.rst >> index 0aa5b1cfd700..52cc906dd7bd 100644 >> --- a/Documentation/virt/kvm/devices/vm.rst >> +++ b/Documentation/virt/kvm/devices/vm.rst >> @@ -314,3 +314,24 @@ Allows userspace to query the status of migration mode. >> if it is enabled >> :Returns: -EFAULT if the given address is not accessible from kernel space; >> 0 in case of success. >> + >> +6. GROUP: KVM_S390_VM_MISC >> +========================== >> + >> +:Architectures: s390 >> + >> +6.1. KVM_S390_VM_MISC_DIAG_318 (r/w) >> +----------------------------------- >> + >> +Allows userspace to retrieve and set the DIAGNOSE 0x318 information, >> +which consists of a 1-byte "Control Program Name Code" and a 7-byte >> +"Control Program Version Code" (a 64 bit value all in all). This >> +information is set by the guest (usually during IPL). This interface is >> +intended to allow retrieving and setting it during migration; while no >> +real harm is done if the information is changed outside of migration, >> +it is strongly discouraged. >> + >> +:Parameters: address of a buffer in user space (u64), where the >> + information is read from or stored into >> +:Returns: -EFAULT if the given address is not accessible from kernel space; >> + 0 in case of success > > > An alternative would be a new sync_reg value + KVM capability. > > I did some investigation into this (new grounds for me) sync_reg would handle the migration part, and then we'd just need the ioctl so the diag instruction handler can set the data. Does that sound right?
On 21.05.20 08:15, Collin Walling wrote: > On 5/18/20 5:15 AM, Christian Borntraeger wrote: >> >> >> On 16.05.20 00:19, Collin Walling wrote: >>> DIAGNOSE 0x318 (diag 318) sets information regarding the environment >>> the VM is running in (Linux, z/VM, etc) and is observed via >>> firmware/service events. >>> >>> This is a privileged s390x instruction that must be intercepted by >>> SIE. Userspace handling is required, so let's introduce some functions >>> to communicate between userspace and KVM via ioctls. These will be used >>> to get/set the diag 318 related information. >>> >>> The Control Program Name Code (CPNC) is stored in the SIE block. The >>> CPNC along with the Control Program Version Code (CPVC) are stored in >>> the kvm_arch struct. >>> >>> Signed-off-by: Collin Walling <walling@linux.ibm.com> >>> --- >>> Documentation/virt/kvm/devices/vm.rst | 21 +++++++ >>> arch/s390/include/asm/kvm_host.h | 5 +- >>> arch/s390/include/uapi/asm/kvm.h | 4 ++ >>> arch/s390/kvm/kvm-s390.c | 82 +++++++++++++++++++++++++++ >>> arch/s390/kvm/vsie.c | 2 + >>> 5 files changed, 113 insertions(+), 1 deletion(-) >>> >>> diff --git a/Documentation/virt/kvm/devices/vm.rst b/Documentation/virt/kvm/devices/vm.rst >>> index 0aa5b1cfd700..52cc906dd7bd 100644 >>> --- a/Documentation/virt/kvm/devices/vm.rst >>> +++ b/Documentation/virt/kvm/devices/vm.rst >>> @@ -314,3 +314,24 @@ Allows userspace to query the status of migration mode. >>> if it is enabled >>> :Returns: -EFAULT if the given address is not accessible from kernel space; >>> 0 in case of success. >>> + >>> +6. GROUP: KVM_S390_VM_MISC >>> +========================== >>> + >>> +:Architectures: s390 >>> + >>> +6.1. KVM_S390_VM_MISC_DIAG_318 (r/w) >>> +----------------------------------- >>> + >>> +Allows userspace to retrieve and set the DIAGNOSE 0x318 information, >>> +which consists of a 1-byte "Control Program Name Code" and a 7-byte >>> +"Control Program Version Code" (a 64 bit value all in all). This >>> +information is set by the guest (usually during IPL). This interface is >>> +intended to allow retrieving and setting it during migration; while no >>> +real harm is done if the information is changed outside of migration, >>> +it is strongly discouraged. >>> + >>> +:Parameters: address of a buffer in user space (u64), where the >>> + information is read from or stored into >>> +:Returns: -EFAULT if the given address is not accessible from kernel space; >>> + 0 in case of success >> >> >> An alternative would be a new sync_reg value + KVM capability. >> >> > > I did some investigation into this (new grounds for me) > > sync_reg would handle the migration part, and then we'd just need the > ioctl so the diag instruction handler can set the data. Does that sound > right? We would not even need the ioctl. We could just export/import this all the time. See the sync_regs and store_regs functions.
diff --git a/Documentation/virt/kvm/devices/vm.rst b/Documentation/virt/kvm/devices/vm.rst index 0aa5b1cfd700..52cc906dd7bd 100644 --- a/Documentation/virt/kvm/devices/vm.rst +++ b/Documentation/virt/kvm/devices/vm.rst @@ -314,3 +314,24 @@ Allows userspace to query the status of migration mode. if it is enabled :Returns: -EFAULT if the given address is not accessible from kernel space; 0 in case of success. + +6. GROUP: KVM_S390_VM_MISC +========================== + +:Architectures: s390 + +6.1. KVM_S390_VM_MISC_DIAG_318 (r/w) +----------------------------------- + +Allows userspace to retrieve and set the DIAGNOSE 0x318 information, +which consists of a 1-byte "Control Program Name Code" and a 7-byte +"Control Program Version Code" (a 64 bit value all in all). This +information is set by the guest (usually during IPL). This interface is +intended to allow retrieving and setting it during migration; while no +real harm is done if the information is changed outside of migration, +it is strongly discouraged. + +:Parameters: address of a buffer in user space (u64), where the + information is read from or stored into +:Returns: -EFAULT if the given address is not accessible from kernel space; + 0 in case of success diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index d6bcd34f3ec3..c03222051043 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -260,7 +260,8 @@ struct kvm_s390_sie_block { __u32 scaol; /* 0x0064 */ __u8 sdf; /* 0x0068 */ __u8 epdx; /* 0x0069 */ - __u8 reserved6a[2]; /* 0x006a */ + __u8 cpnc; /* 0x006a */ + __u8 reserved6b; /* 0x006b */ __u32 todpr; /* 0x006c */ #define GISA_FORMAT1 0x00000001 __u32 gd; /* 0x0070 */ @@ -938,6 +939,7 @@ struct kvm_arch{ int user_sigp; int user_stsi; int user_instr0; + int use_diag_318; struct s390_io_adapter *adapters[MAX_S390_IO_ADAPTERS]; wait_queue_head_t ipte_wq; int ipte_lock_count; @@ -956,6 +958,7 @@ struct kvm_arch{ DECLARE_BITMAP(idle_mask, KVM_MAX_VCPUS); struct kvm_s390_gisa_interrupt gisa_int; struct kvm_s390_pv pv; + union diag_318_info diag_318_info; }; #define KVM_HVA_ERR_BAD (-1UL) diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h index 436ec7636927..2ce8e6f72206 100644 --- a/arch/s390/include/uapi/asm/kvm.h +++ b/arch/s390/include/uapi/asm/kvm.h @@ -74,6 +74,7 @@ struct kvm_s390_io_adapter_req { #define KVM_S390_VM_CRYPTO 2 #define KVM_S390_VM_CPU_MODEL 3 #define KVM_S390_VM_MIGRATION 4 +#define KVM_S390_VM_MISC 5 /* kvm attributes for mem_ctrl */ #define KVM_S390_VM_MEM_ENABLE_CMMA 0 @@ -171,6 +172,9 @@ struct kvm_s390_vm_cpu_subfunc { #define KVM_S390_VM_MIGRATION_START 1 #define KVM_S390_VM_MIGRATION_STATUS 2 +/* kvm attributes for KVM_S390_VM_MISC */ +#define KVM_S390_VM_MISC_DIAG_318 0 + /* for KVM_GET_REGS and KVM_SET_REGS */ struct kvm_regs { /* general purpose regs for s390 */ diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index d05bb040fd42..cf8a3f1be839 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -1243,6 +1243,70 @@ static int kvm_s390_get_tod(struct kvm *kvm, struct kvm_device_attr *attr) return ret; } +static int kvm_s390_set_diag_318_info(struct kvm *kvm, __u64 addr) +{ + struct kvm_vcpu *vcpu; + u64 info; + int i; + + if (get_user(info, (u64 __user *)addr)) + return -EFAULT; + + kvm->arch.diag_318_info.val = info; + + if (sclp.has_diag_318) { + kvm_for_each_vcpu(i, vcpu, kvm) { + vcpu->arch.sie_block->cpnc = kvm->arch.diag_318_info.cpnc; + } + } + + VM_EVENT(kvm, 3, "SET: CPNC: 0x%x CPVC: 0x%llx", + kvm->arch.diag_318_info.cpnc, (u64)kvm->arch.diag_318_info.cpvc); + + return 0; +} + +static int kvm_s390_vm_set_misc(struct kvm *kvm, struct kvm_device_attr *attr) +{ + int ret; + + switch (attr->attr) { + case KVM_S390_VM_MISC_DIAG_318: + ret = kvm_s390_set_diag_318_info(kvm, attr->addr); + break; + default: + ret = -ENXIO; + break; + } + return ret; +} + +static int kvm_s390_get_diag_318_info(struct kvm *kvm, __u64 addr) +{ + if (put_user(kvm->arch.diag_318_info.val, (u64 __user *)addr)) + return -EFAULT; + + VM_EVENT(kvm, 3, "QUERY: CPNC: 0x%x, CPVC: 0x%llx", + kvm->arch.diag_318_info.cpnc, (u64)kvm->arch.diag_318_info.cpvc); + + return 0; +} + +static int kvm_s390_get_misc(struct kvm *kvm, struct kvm_device_attr *attr) +{ + int ret; + + switch (attr->attr) { + case KVM_S390_VM_MISC_DIAG_318: + ret = kvm_s390_get_diag_318_info(kvm, attr->addr); + break; + default: + ret = -ENXIO; + break; + } + return ret; +} + static int kvm_s390_set_processor(struct kvm *kvm, struct kvm_device_attr *attr) { struct kvm_s390_vm_cpu_processor *proc; @@ -1689,6 +1753,9 @@ static int kvm_s390_vm_set_attr(struct kvm *kvm, struct kvm_device_attr *attr) case KVM_S390_VM_MIGRATION: ret = kvm_s390_vm_set_migration(kvm, attr); break; + case KVM_S390_VM_MISC: + ret = kvm_s390_vm_set_misc(kvm, attr); + break; default: ret = -ENXIO; break; @@ -1714,6 +1781,9 @@ static int kvm_s390_vm_get_attr(struct kvm *kvm, struct kvm_device_attr *attr) case KVM_S390_VM_MIGRATION: ret = kvm_s390_vm_get_migration(kvm, attr); break; + case KVM_S390_VM_MISC: + ret = kvm_s390_get_misc(kvm, attr); + break; default: ret = -ENXIO; break; @@ -1787,6 +1857,16 @@ static int kvm_s390_vm_has_attr(struct kvm *kvm, struct kvm_device_attr *attr) case KVM_S390_VM_MIGRATION: ret = 0; break; + case KVM_S390_VM_MISC: + switch (attr->attr) { + case KVM_S390_VM_MISC_DIAG_318: + ret = 0; + break; + default: + ret = -ENXIO; + break; + } + break; default: ret = -ENXIO; break; @@ -3075,6 +3155,8 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu) vcpu->arch.sie_block->ictl |= ICTL_OPEREXC; /* make vcpu_load load the right gmap on the first trigger */ vcpu->arch.enabled_gmap = vcpu->arch.gmap; + if (sclp.has_diag_318) + vcpu->arch.sie_block->cpnc = vcpu->kvm->arch.diag_318_info.cpnc; } static bool kvm_has_pckmo_subfunc(struct kvm *kvm, unsigned long nr) diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c index 4f6c22d72072..a6820267e661 100644 --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -548,6 +548,8 @@ static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) scb_s->ecd |= scb_o->ecd & ECD_ETOKENF; scb_s->hpid = HPID_VSIE; + if (sclp.has_diag_318) + scb_s->cpnc = scb_o->cpnc; prepare_ibc(vcpu, vsie_page); rc = shadow_crycb(vcpu, vsie_page);
DIAGNOSE 0x318 (diag 318) sets information regarding the environment the VM is running in (Linux, z/VM, etc) and is observed via firmware/service events. This is a privileged s390x instruction that must be intercepted by SIE. Userspace handling is required, so let's introduce some functions to communicate between userspace and KVM via ioctls. These will be used to get/set the diag 318 related information. The Control Program Name Code (CPNC) is stored in the SIE block. The CPNC along with the Control Program Version Code (CPVC) are stored in the kvm_arch struct. Signed-off-by: Collin Walling <walling@linux.ibm.com> --- Documentation/virt/kvm/devices/vm.rst | 21 +++++++ arch/s390/include/asm/kvm_host.h | 5 +- arch/s390/include/uapi/asm/kvm.h | 4 ++ arch/s390/kvm/kvm-s390.c | 82 +++++++++++++++++++++++++++ arch/s390/kvm/vsie.c | 2 + 5 files changed, 113 insertions(+), 1 deletion(-)