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 <[email protected]> --- CC: Jan Beulich <[email protected]> CC: Wei Liu <[email protected]> CC: Roger Pau Monné <[email protected]> CC: Jun Nakajima <[email protected]> CC: Kevin Tian <[email protected]> --- 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); write_debugreg(6, exit_qualification | DR_STATUS_RESERVED_ONE); if ( !v->domain->debugger_attached ) { -- 2.1.4 _______________________________________________ Xen-devel mailing list [email protected] https://lists.xenproject.org/mailman/listinfo/xen-devel
