diff options
| author | Nina Schoetterl-Glausch <nsg@linux.ibm.com> | 2023-12-19 15:08:51 +0100 |
|---|---|---|
| committer | Janosch Frank <frankja@linux.ibm.com> | 2023-12-23 10:41:09 +0100 |
| commit | 682dbf430d27bc0e23d8d6921116b4f77f5dc9c6 (patch) | |
| tree | 7d15afcec67aafd2fd7027251e61c14c032adddf /arch/s390/kvm/vsie.c | |
| parent | 2731d605d5478052a10ac5a7c80f7aa7e1788cc5 (diff) | |
KVM: s390: vsie: Fix length of facility list shadowed
The length of the facility list accessed when interpretively executing
STFLE is the same as the hosts facility list (in case of format-0)
The memory following the facility list doesn't need to be accessible.
The current VSIE implementation accesses a fixed length that exceeds the
guest/host facility list length and can therefore wrongly inject a
validity intercept.
Instead, find out the host facility list length by running STFLE and
copy only as much as necessary when shadowing.
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20231219140854.1042599-3-nsg@linux.ibm.com
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Message-ID: <20231219140854.1042599-3-nsg@linux.ibm.com>
Diffstat (limited to 'arch/s390/kvm/vsie.c')
| -rw-r--r-- | arch/s390/kvm/vsie.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c index 3cf95bc0401d..aa8f4ab11e33 100644 --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -19,6 +19,7 @@ #include <asm/nmi.h> #include <asm/dis.h> #include <asm/fpu/api.h> +#include <asm/facility.h> #include "kvm-s390.h" #include "gaccess.h" @@ -990,6 +991,10 @@ static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; __u32 fac = READ_ONCE(vsie_page->scb_o->fac); + /* + * Alternate-STFLE-Interpretive-Execution facilities are not supported + * -> format-0 flcb + */ if (fac && test_kvm_facility(vcpu->kvm, 7)) { retry_vsie_icpt(vsie_page); /* @@ -997,8 +1002,13 @@ static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) * so we need to mask here before reading. */ fac = fac & 0x7ffffff8U; + /* + * format-0 -> size of nested guest's facility list == guest's size + * guest's size == host's size, since STFLE is interpretatively executed + * using a format-0 for the guest, too. + */ if (read_guest_real(vcpu, fac, &vsie_page->fac, - sizeof(vsie_page->fac))) + stfle_size() * sizeof(u64))) return set_validity_icpt(scb_s, 0x1090U); scb_s->fac = (__u32)(__u64) &vsie_page->fac; } |