[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 08/11] x86/hvm: RFC - PROBABLY BROKEN - Defer all debugging/monitor actions to {svm, vmx}_inject_event()
On Mon, Jun 04, 2018 at 02:59:12PM +0100, Andrew Cooper wrote: > Currently, there is a lot of functionality in the #DB intercepts, and some > repeated functionality in the *_inject_event() logic. > > The gdbsx code is implemented at both levels (albeit differently for #BP, > which is presumably due to the fact that the old emulator behaviour used to be > to move %rip forwards for traps), while the monitor behaviour only exists at > the intercept level. > > Updating of %dr6 is implemented (buggily) at both levels, but having it at > both levels is problematic to implement correctly. > > Rearrange the logic to have nothing interesting at the intercept level, and > everything implemented at the injection level. Amongst other things, this > means that the monitor subsystem will pick up debug actions from emulated > events. > > Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx> > @@ -1797,16 +1803,39 @@ static void vmx_inject_event(const struct x86_event > *event) > __vmread(GUEST_IA32_DEBUGCTL, &val); > __vmwrite(GUEST_IA32_DEBUGCTL, val & ~IA32_DEBUGCTLMSR_LBR); > } > - if ( cpu_has_monitor_trap_flag ) > - break; > + > /* fall through */ > case TRAP_int3: > if ( curr->domain->debugger_attached ) > { > /* Debug/Int3: Trap to debugger. */ > + if ( _event.vector == TRAP_int3 ) > + { > + /* N.B. Can't use __update_guest_eip() for risk of recusion. > */ > + regs->rip += _event.insn_len; > + regs->eflags &= ~X86_EFLAGS_RF; > + curr->arch.gdbsx_vcpu_event = TRAP_int3; > + } > + > domain_pause_for_debugger(); > return; > } > + else > + { > + int rc = hvm_monitor_debug(regs->rip, > + _event.vector == TRAP_debug > + ? HVM_MONITOR_DEBUG_EXCEPTION > + : HVM_MONITOR_SOFTWARE_BREAKPOINT, > + _event.type, _event.insn_len); > + if ( rc < 0 ) > + { > + gprintk(XENLOG_ERR, "Monitor debug error %d\n", rc); > + domain_crash(curr->domain); > + return; > + } > + if ( rc ) > + return; /* VCPU paused. Wait for monitor. */ > + } > break; This look fairly similar to the svm_inject_event code, I wonder if those could be merged somehow (or certain part of it shared). Roger. _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/xen-devel
|
![]() |
Lists.xenproject.org is hosted with RackSpace, monitoring our |