Messages in this thread | | | Date | Mon, 7 Feb 2022 10:40:28 +0100 | Subject | Re: [PATCH v7 03/17] KVM: s390: pv: handle secure storage exceptions for normal guests | From | Janosch Frank <> |
| |
On 2/4/22 16:53, Claudio Imbrenda wrote: > With upcoming patches, normal guests might touch secure pages. > > This patch extends the existing exception handler to convert the pages > to non secure also when the exception is triggered by a normal guest. > > This can happen for example when a secure guest reboots; the first > stage of a secure guest is non secure, and in general a secure guest > can reboot into non-secure mode. > > If the secure memory of the previous boot has not been cleared up > completely yet (which will be allowed to happen in an upcoming patch), > a non-secure guest might touch secure memory, which will need to be > handled properly. > > Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Once you fix the compiler warning: Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
> --- > arch/s390/mm/fault.c | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c > index 47b52e5384f8..bbd37e2c7962 100644 > --- a/arch/s390/mm/fault.c > +++ b/arch/s390/mm/fault.c > @@ -770,6 +770,7 @@ void do_secure_storage_access(struct pt_regs *regs) > struct vm_area_struct *vma; > struct mm_struct *mm; > struct page *page; > + struct gmap *gmap; > int rc; > > /* > @@ -799,6 +800,16 @@ void do_secure_storage_access(struct pt_regs *regs) > } > > switch (get_fault_type(regs)) { > + case GMAP_FAULT: > + gmap = (struct gmap *)S390_lowcore.gmap; > + mmap_read_lock(mm); > + addr = __gmap_translate(gmap, addr); > + mmap_read_unlock(mm); > + if (IS_ERR_VALUE(addr)) { > + do_fault_error(regs, VM_ACCESS_FLAGS, VM_FAULT_BADMAP); > + break; > + } > + fallthrough; > case USER_FAULT: > mm = current->mm; > mmap_read_lock(mm); > @@ -827,7 +838,6 @@ void do_secure_storage_access(struct pt_regs *regs) > if (rc) > BUG(); > break; > - case GMAP_FAULT: > default: > do_fault_error(regs, VM_READ | VM_WRITE, VM_FAULT_BADMAP); > WARN_ON_ONCE(1); >
| |