>>> On 22.11.16 at 17:46, <andrew.coop...@citrix.com> wrote: > 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.
Oh, yes, that's better. > Either way, Reviewed-by: Andrew Cooper <andrew.coop...@citrix.com> Thanks, Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
