github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-23 06:31:58 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

KVM: s390: vsie: Allow non-zarch guests

Browse Source 
Linux/KVM runs in z/Architecture-only mode. Although z/Architecture
is built upon a long history of hardware refinements, any other
CPU mode is not permitted.

Allow a userspace to explicitly enable the use of ESA mode for
nested guests, otherwise usage will be rejected.

Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
This commit is contained in:
Eric Farman 2026-04-01 17:12:18 +02:00 committed by Janosch Frank
parent 1653545abc
commit b0ad874d98
2 changed files with 6 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/s390/include/asm/kvm_host.h
View File

@ -656,6 +656,7 @@ struct kvm_arch {
int user_stsi;
int user_instr0;
int user_operexec;
int allow_vsie_esamode;
struct s390_io_adapter *adapters[MAX_S390_IO_ADAPTERS];
wait_queue_head_t ipte_wq;
int ipte_lock_count;

8
arch/s390/kvm/vsie.c
View File

@ -125,8 +125,8 @@ static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
int newflags, cpuflags = atomic_read(&scb_o->cpuflags);
/* we don't allow ESA/390 guests */
if (!(cpuflags & CPUSTAT_ZARCH))
/* we don't allow ESA/390 guests unless explicitly enabled */
if (!(cpuflags & CPUSTAT_ZARCH) && !vcpu->kvm->arch.allow_vsie_esamode)
return set_validity_icpt(scb_s, 0x0001U);
if (cpuflags & (CPUSTAT_RRF | CPUSTAT_MCDS))
@ -135,7 +135,9 @@ static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
return set_validity_icpt(scb_s, 0x0007U);
/* intervention requests will be set later */
newflags = CPUSTAT_ZARCH;
newflags = 0;
if (cpuflags & CPUSTAT_ZARCH)
newflags = CPUSTAT_ZARCH;
if (cpuflags & CPUSTAT_GED && test_kvm_facility(vcpu->kvm, 8))
newflags |= CPUSTAT_GED;
if (cpuflags & CPUSTAT_GED2 && test_kvm_facility(vcpu->kvm, 78)) {