On 22/11/16 13:55, Jan Beulich wrote: > The only fields modified are EIP, EFLAGS, GPRs, and segment selectors. > CR3 in particular is not supposed to be updated. > > Signed-off-by: Jan Beulich <jbeul...@suse.com> > > --- a/xen/arch/x86/hvm/hvm.c > +++ b/xen/arch/x86/hvm/hvm.c > @@ -2952,7 +2952,6 @@ void hvm_task_switch( > if ( taskswitch_reason == TSW_iret ) > eflags &= ~X86_EFLAGS_NT; > > - tss.cr3 = v->arch.hvm_vcpu.guest_cr[3]; > tss.eip = regs->eip; > tss.eflags = eflags; > tss.eax = regs->eax; > @@ -2979,8 +2978,10 @@ void hvm_task_switch( > hvm_get_segment_register(v, x86_seg_ldtr, &segr); > tss.ldt = segr.sel; > > - rc = hvm_copy_to_guest_virt( > - prev_tr.base, &tss, sizeof(tss), PFEC_page_present); > + rc = hvm_copy_to_guest_virt(prev_tr.base + offsetof(typeof(tss), eip), > + &tss.eip, > + (void *)&tss.trace - (void *)&tss.eip,
How about offsetof(typeof(tss), trace) - offsetof(typeof(tss), eip)? It avoids some casts and void pointer arithmetic. Either way, Reviewed-by: Andrew Cooper <andrew.coop...@citrix.com> _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
