Tweaks to avoid ide timeouts under qemu?

[Paul Ripke <stix%stix.id.au@localhost>]

Just wondering what other people are doing to avoid ide timeouts when
running qemu? My disk image is on spinning rust, and when the /etc/daily
jobs run on the host, the qemu emulated netbsd kernel tends to see
timeouts and ultimately hang. Eg:

piixide0:0:0: lost interrupt
[ 20336.2698191]        type: ata tc_bcount: 512 tc_skip: 0
[ 20336.2698191] wd0a: device timeout writing fsbn 1796064 (wd0 bn 1796127; cn 877 tn 0 sn 31), xfer 38, retry 2
[ 20344.0331985] wd0: soft error (corrected) xfer 38 piixide0:0:0: lost interrupt
[ 20366.1480635]        type: ata tc_bcount: 65536 tc_skip: 0
[ 20366.1480635] wd0a: device timeout reading fsbn 3336544 of 3336544-3336671 (wd0 bn 3336607; cn 1629 tn 12 sn 31), xfer 38, retry 0
[ 20372.0147313] wd0: soft error (corrected) xfer 38 piixide0:0:0: lost interrupt
[ 20391.3896284]        type: ata tc_bcount: 512 tc_skip: 0
[ 20391.3896284] wd0a: device timeout writing fsbn 1799043 (wd0 bn 1799106; cn 878 tn 30 sn 2), xfer 38, retry 0
[ 20398.9681696] wd0: soft error (corrected) xfer 38
[ 20412.0882013] piixide0:0:0: not ready, st=0xd0, err=0x00
[ 20412.0882013] wd0a: device timeout writing fsbn 1799168 of 1799168-1799171 (wd0 bn 1799231; cn 878 tn 33 sn 31), xfer 38, retry 0
[ 20419.6539492] wd0: soft error (corrected) xfer 38
[ 20432.8541192] piixide0:0:0: not ready, st=0xd0, err=0x00
[ 20432.8541192] wd0a: device timeout writing fsbn 1799188 of 1799172-1799203 (wd0 bn 1799251; cn 878 tn 34 sn 19), xfer 38, retry 0
[ 20444.2739035] piixide0:0:0: timeout waiting for DRQ, st=0xd0, err=0x00

Cheers,
--
Paul Ripke
"Great minds discuss ideas, average minds discuss events, small minds
discuss people."
-- Disputed: Often attributed to Eleanor Roosevelt. 1948.