Bug 447636
Summary: | Cannot instal RHEL4 x86_64 guest on AMD | ||||||
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Product: | [Fedora] Fedora | Reporter: | Daniel Berrangé <berrange> | ||||
Component: | kvm | Assignee: | Glauber Costa <gcosta> | ||||
Status: | CLOSED CURRENTRELEASE | QA Contact: | Fedora Extras Quality Assurance <extras-qa> | ||||
Severity: | low | Docs Contact: | |||||
Priority: | low | ||||||
Version: | 9 | CC: | berrange, clalance, djuran, dsmith, katzj, mniranja | ||||
Target Milestone: | --- | ||||||
Target Release: | --- | ||||||
Hardware: | All | ||||||
OS: | Linux | ||||||
Whiteboard: | |||||||
Fixed In Version: | Doc Type: | Bug Fix | |||||
Doc Text: | Story Points: | --- | |||||
Clone Of: | Environment: | ||||||
Last Closed: | 2008-10-20 11:17:57 UTC | Type: | --- | ||||
Regression: | --- | Mount Type: | --- | ||||
Documentation: | --- | CRM: | |||||
Verified Versions: | Category: | --- | |||||
oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||
Cloudforms Team: | --- | Target Upstream Version: | |||||
Embargoed: | |||||||
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Description
Daniel Berrangé
2008-05-20 21:54:07 UTC
Created attachment 306190 [details] upstream msr write fix This was fixed in upstream commit 854d17ee91e87903dc42e8b4506ffd9d023ed47a. Launching scratch build to verify fix: http://koji.fedoraproject.org/koji/taskinfo?taskID=621934 What Chris says is true, however, I believe the problem is deeper. I believe the above fix works for AMD, but you will still have problems on Intel, in a similar piece of code. This started happening on RHEL-4 U7 because of the backported NMI code, basically so it could share the perfctr registers with oprofile. Before U7, what would happen is that RHEL-4 would attempt to access the EVNTSEL register; since KVM didn't support it, it would inject a GPF, which RHEL-4 would then catch, and then give up on NMI watchdog support and go on with life. In U7, however, that attempt to access the EVNTSEL register no longer traps the GPF, so when you actually hit the GPF, it crashes the guest. My suggestion is two-fold: 1. Fix RHEL-4 U7 (and probably upstream) to re-add the "check MSR with GPF fixup", so that if you boot on a version of KVM (or bare-metal, or any other virtualization solution for that matter) that doesn't support these MSR's, the guest just won't enable NMI watchdog and won't crash. 2. Fix KVM on the Intel side so that you properly emulate-n-drop writes to these MSR's, so we won't have this problem going forward. Chris Lalancette I checked "The Book" (tm), for some light, and it says, under the rdpmc instruction that a gpf is generated if the instruction attempts to access an invalid perfctr index. So, although nothing at all is said about perfctrs being optional, how many of them there are, seem to be variant across architectures. Given this, it seems the correct thing to me to check for a possible GPF when reading it. RHEL4 kernel-2.6.9-78.0.5 now works fine with kvm-65-9.fc9 |