Skip to content

Commit

Permalink
s390/kvm: diagnose 0x318 sync and reset
Browse files Browse the repository at this point in the history 
DIAGNOSE 0x318 (diag318) 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 handles the instruction as well as migration. Data
is communicated via VCPU register synchronization.

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_vcpu_arch struct.

This data is reset on load normal and clear resets.

Signed-off-by: Collin Walling <walling@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20200622154636.5499-3-walling@linux.ibm.com
[borntraeger@de.ibm.com: fix sync_reg position]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
  • Loading branch information
Collin Walling authored and Christian Borntraeger committed Jun 23, 2020
1 parent a23816f commit 23a60f8
Show file tree
Hide file tree
Showing 5 changed files with 20 additions and 4 deletions.
4 changes: 3 additions & 1 deletion arch/s390/include/asm/kvm_host.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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 */
Expand Down Expand Up @@ -745,6 +746,7 @@ struct kvm_vcpu_arch {
bool gs_enabled;
bool skey_enabled;
struct kvm_s390_pv_vcpu pv;
union diag318_info diag318_info;
};

struct kvm_vm_stat {
Expand Down
7 changes: 5 additions & 2 deletions arch/s390/include/uapi/asm/kvm.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -231,11 +231,13 @@ struct kvm_guest_debug_arch {
#define KVM_SYNC_GSCB (1UL << 9)
#define KVM_SYNC_BPBC (1UL << 10)
#define KVM_SYNC_ETOKEN (1UL << 11)
#define KVM_SYNC_DIAG318 (1UL << 12)

#define KVM_SYNC_S390_VALID_FIELDS \
(KVM_SYNC_PREFIX | KVM_SYNC_GPRS | KVM_SYNC_ACRS | KVM_SYNC_CRS | \
KVM_SYNC_ARCH0 | KVM_SYNC_PFAULT | KVM_SYNC_VRS | KVM_SYNC_RICCB | \
KVM_SYNC_FPRS | KVM_SYNC_GSCB | KVM_SYNC_BPBC | KVM_SYNC_ETOKEN)
KVM_SYNC_FPRS | KVM_SYNC_GSCB | KVM_SYNC_BPBC | KVM_SYNC_ETOKEN | \
KVM_SYNC_DIAG318)

/* length and alignment of the sdnx as a power of two */
#define SDNXC 8
Expand Down Expand Up @@ -264,7 +266,8 @@ struct kvm_sync_regs {
__u8 reserved2 : 7;
__u8 padding1[51]; /* riccb needs to be 64byte aligned */
__u8 riccb[64]; /* runtime instrumentation controls block */
__u8 padding2[192]; /* sdnx needs to be 256byte aligned */
__u64 diag318; /* diagnose 0x318 info */
__u8 padding2[184]; /* sdnx needs to be 256byte aligned */
union {
__u8 sdnx[SDNXL]; /* state description annex */
struct {
Expand Down
11 changes: 10 additions & 1 deletion arch/s390/kvm/kvm-s390.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -545,6 +545,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_S390_AIS_MIGRATION:
case KVM_CAP_S390_VCPU_RESETS:
case KVM_CAP_SET_GUEST_DEBUG:
case KVM_CAP_S390_DIAG318:
r = 1;
break;
case KVM_CAP_S390_HPAGE_1M:
Expand Down Expand Up @@ -3267,7 +3268,8 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
KVM_SYNC_ACRS |
KVM_SYNC_CRS |
KVM_SYNC_ARCH0 |
KVM_SYNC_PFAULT;
KVM_SYNC_PFAULT |
KVM_SYNC_DIAG318;
kvm_s390_set_prefix(vcpu, 0);
if (test_kvm_facility(vcpu->kvm, 64))
vcpu->run->kvm_valid_regs |= KVM_SYNC_RICCB;
Expand Down Expand Up @@ -3562,6 +3564,7 @@ static void kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu)
vcpu->arch.sie_block->pp = 0;
vcpu->arch.sie_block->fpf &= ~FPF_BPBC;
vcpu->arch.sie_block->todpr = 0;
vcpu->arch.sie_block->cpnc = 0;
}
}

Expand All @@ -3579,6 +3582,7 @@ static void kvm_arch_vcpu_ioctl_clear_reset(struct kvm_vcpu *vcpu)

regs->etoken = 0;
regs->etoken_extension = 0;
regs->diag318 = 0;
}

int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
Expand Down Expand Up @@ -4196,6 +4200,10 @@ static void sync_regs_fmt2(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
if (vcpu->arch.pfault_token == KVM_S390_PFAULT_TOKEN_INVALID)
kvm_clear_async_pf_completion_queue(vcpu);
}
if (kvm_run->kvm_dirty_regs & KVM_SYNC_DIAG318) {
vcpu->arch.diag318_info.val = kvm_run->s.regs.diag318;
vcpu->arch.sie_block->cpnc = vcpu->arch.diag318_info.cpnc;
}
/*
* If userspace sets the riccb (e.g. after migration) to a valid state,
* we should enable RI here instead of doing the lazy enablement.
Expand Down Expand Up @@ -4297,6 +4305,7 @@ static void store_regs_fmt2(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
kvm_run->s.regs.pp = vcpu->arch.sie_block->pp;
kvm_run->s.regs.gbea = vcpu->arch.sie_block->gbea;
kvm_run->s.regs.bpbc = (vcpu->arch.sie_block->fpf & FPF_BPBC) == FPF_BPBC;
kvm_run->s.regs.diag318 = vcpu->arch.diag318_info.val;
if (MACHINE_HAS_GS) {
__ctl_set_bit(2, 4);
if (vcpu->arch.gs_enabled)
Expand Down
1 change: 1 addition & 0 deletions arch/s390/kvm/vsie.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -548,6 +548,7 @@ 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;
scb_s->cpnc = scb_o->cpnc;

prepare_ibc(vcpu, vsie_page);
rc = shadow_crycb(vcpu, vsie_page);
Expand Down
1 change: 1 addition & 0 deletions include/uapi/linux/kvm.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1031,6 +1031,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_PPC_SECURE_GUEST 181
#define KVM_CAP_HALT_POLL 182
#define KVM_CAP_ASYNC_PF_INT 183
#define KVM_CAP_S390_DIAG318 184

#ifdef KVM_CAP_IRQ_ROUTING

Expand Down

0 comments on commit 23a60f8

Please sign in to comment.