Date: Sun, 05 Apr 2009 11:23:39 -0500 (CDT) From: Sergey Babkin <babkin@verizon.net> To: ivoras@freebsd.org Cc: freebsd-hackers@freebsd.org Subject: Re: Patch for MS Hyper V (virtualization) Message-ID: <1366225354.253456.1238948619308.JavaMail.root@vms124.mailsrvcs.net>
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Apr 4, 2009 02:10:23 PM, ivoras@freebsd.org wrote: >Can someo= ne please review and commit (if appropriate) the tweak for >Hyper-V shu= tdown issue at http://shell.peach.ne.jp/aoyama/archives/40 >? > = >>The problem is: the VM appears to hang on shutdown without it (hanging >the Hyper-V VM with it so the host also can't shutdown or reboot >re= liably - someone at MS skipped the part where an error in the VM >isn't= supposed to bring the host down with it) I don't have the commit = permission any more but I can review :-) Yes, Hyper-V does not like th= e writes into the PCI config space. Very specifically, writing the base= register window address of the simulated 21140 screws up something tha= t prevents the VM from shutting down. Interestingly, even reading and writi= ng back the same value has this effect. So the patch is valid. = >I don't particularly like the hackish checking for the 21140 chip, and I'= m not sure if if would break some real 21140 chip out there. If the dri= ver does the same as another one I've seen, the driver tries to align t= he register window to 0x80, and in the simulated 21140 it's already ali= gned. I've had a quick look but couldn't say it for sure. I'd do it dif= ferently: check if the value being written is the same that was read, = and skip the write in this case. Let me see, maybe I'll make a dif= ferent patch. -SB
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