| Message ID | 20240319164420.4053380-3-nsg@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: s390: Fix V!=R bug in STFLE shadowing | expand |
On 19.03.24 17:44, Nina Schoetterl-Glausch wrote: > In order for SIE to interpretively execute STFLE, it requires the real > or absolute address of a facility-list control block. > Before writing the location into the shadow SIE control block, convert > it from a virtual address. > We currently do not run into this bug because the lower 31 bits are the > same for virtual and physical addresses. So it's not a bug (yet) :) But certainly the right thing to do and more future-proof. Reviewed-by: David Hildenbrand <david@redhat.com>
diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c index 3af3bd20ac7b..da2819112e1d 100644 --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -12,6 +12,7 @@ #include <linux/list.h> #include <linux/bitmap.h> #include <linux/sched/signal.h> +#include <linux/io.h> #include <asm/gmap.h> #include <asm/mmu_context.h> @@ -1006,7 +1007,7 @@ static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) if (read_guest_real(vcpu, fac, &vsie_page->fac, stfle_size() * sizeof(u64))) return set_validity_icpt(scb_s, 0x1090U); - scb_s->fac = (__u32)(__u64) &vsie_page->fac; + scb_s->fac = (u32)virt_to_phys(&vsie_page->fac); } return 0; }
In order for SIE to interpretively execute STFLE, it requires the real or absolute address of a facility-list control block. Before writing the location into the shadow SIE control block, convert it from a virtual address. We currently do not run into this bug because the lower 31 bits are the same for virtual and physical addresses. Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com> --- arch/s390/kvm/vsie.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)