Dave Voutila <d...@sisu.io> writes:
> Looking for folks that use the serial console connection in vmd(8) and > experience the host CPU spikes & delays associated with things like > hitting the up key (to cycle shell command history) or copy/paste in X. > > vmd(8) approximates edge triggered interrupts with the emulated i8259 > interrupt controller. Some core devices (serial console, rtc, timer) try > "toggling" an irq...but it's pointless in how our emulated i8259 is > implemented. The deassert does nothing for edge triggered interrupts > other than causing race conditions and extra syscalls. > > I've tested on two of my machines and this resolves the issue I've been > seeing off and on. It should fix the report[1] on bugs@ from months ago. Still looking for testers as the origin bug reporter has not responded. > > -dv > > [1] https://marc.info/?l=openbsd-bugs&m=169669132915760&w=2 > > diff refs/heads/master refs/heads/vmd-edge > commit - 7869b2fdaac7e118bfd1783874fe25ce3b8b0f09 > commit + 00d448cdbe2461f27419aaf79520a0cef720aefc > blob - b98e7bdc69ac6a12eb84eaaf97ec43ecdbe83733 > blob + 248e3b161e88be505a88411156dc57a2772bd4fa > --- usr.sbin/vmd/i8253.c > +++ usr.sbin/vmd/i8253.c > @@ -371,7 +371,6 @@ i8253_fire(int fd, short type, void *arg) > struct i8253_channel *ctr = (struct i8253_channel *)arg; > > vcpu_assert_pic_irq(ctr->vm_id, 0, 0); > - vcpu_deassert_pic_irq(ctr->vm_id, 0, 0); > > if (ctr->mode != TIMER_INTTC) { > timerclear(&tv); > blob - 43dce7b10d1467a5b7ac7f3308d01e32b4d0b9ee > blob + 4fc147b19c99627e386ab26355b8f90a6ae5872b > --- usr.sbin/vmd/mc146818.c > +++ usr.sbin/vmd/mc146818.c > @@ -150,7 +150,6 @@ rtc_fireper(int fd, short type, void *arg) > rtc.regs[MC_REGC] |= MC_REGC_PF; > > vcpu_assert_pic_irq((ptrdiff_t)arg, 0, 8); > - vcpu_deassert_pic_irq((ptrdiff_t)arg, 0, 8); > > evtimer_add(&rtc.per, &rtc.per_tv); > } > blob - bc23876bf0392312335da0d00e143583a87549af > blob + 98ed7dbecf2120ccbf9a16198ee479cb15aebc5f > --- usr.sbin/vmd/ns8250.c > +++ usr.sbin/vmd/ns8250.c > @@ -82,7 +82,6 @@ ratelimit(int fd, short type, void *arg) > com1_dev.regs.iir &= ~IIR_NOPEND; > > vcpu_assert_pic_irq(com1_dev.vmid, 0, com1_dev.irq); > - vcpu_deassert_pic_irq(com1_dev.vmid, 0, com1_dev.irq); > mutex_unlock(&com1_dev.mutex); > } > > @@ -160,7 +159,6 @@ com_rcv_event(int fd, short kind, void *arg) > if ((com1_dev.regs.iir & IIR_NOPEND) == 0) { > /* XXX: vcpu_id */ > vcpu_assert_pic_irq((uintptr_t)arg, 0, com1_dev.irq); > - vcpu_deassert_pic_irq((uintptr_t)arg, 0, com1_dev.irq); > } > > mutex_unlock(&com1_dev.mutex);