On Mon, Jun 04, 2018 at 02:59:06PM +0100, Andrew Cooper wrote: > c/s 4f36452b63 introduced a write to %dr6 in the #DB intercept case, but the > guests debug registers may be lazy at this point, at which point the guests > later attempt to read %dr6 will discard this value and use the older stale > value. > > Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
Reviewed-by: Roger Pau Monné <roger....@citrix.com> > --- > CC: Jan Beulich <jbeul...@suse.com> > CC: Wei Liu <wei.l...@citrix.com> > CC: Roger Pau Monné <roger....@citrix.com> > CC: Jun Nakajima <jun.nakaj...@intel.com> > CC: Kevin Tian <kevin.t...@intel.com> > --- > xen/arch/x86/hvm/vmx/vmx.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c > index 33d39f6..8dbe838 100644 > --- a/xen/arch/x86/hvm/vmx/vmx.c > +++ b/xen/arch/x86/hvm/vmx/vmx.c > @@ -3696,6 +3696,7 @@ void vmx_vmexit_handler(struct cpu_user_regs *regs) > */ > __vmread(EXIT_QUALIFICATION, &exit_qualification); > HVMTRACE_1D(TRAP_DEBUG, exit_qualification); > + __restore_debug_registers(v); If I understood this correctly, you only call __restore_debug_registers in order to make sure the DR registers are marked as dirty? Thanks, Roger. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
