Bug 1003756
| Summary: | balloon device PCI class code should be 0x5 for older RHEL machine types | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Qian Guo <qiguo> |
| Component: | qemu-kvm | Assignee: | Luiz Capitulino <lcapitulino> |
| Status: | CLOSED DUPLICATE | QA Contact: | Virtualization Bugs <virt-bugs> |
| Severity: | medium | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 7.0 | CC: | acathrow, amit.shah, armbru, chayang, hhuang, juzhang, lcapitulino, michen, virt-maint |
| Target Milestone: | rc | Keywords: | Reopened |
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2013-09-06 12:10:37 UTC | Type: | Bug |
| 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
Qian Guo
2013-09-03 07:06:29 UTC
(In reply to Qian Guo from comment #0) > > > Additional info: > > Contrast with guest in RHEL7 host, that the result is: Sorry, typo here, RHEL7 should be RHEL6.4GA > 00:05.0 RAM memory: Red Hat, Inc Virtio memory balloon Until QEMU v1.0 the balloon device had the PCI class 0x5 (Memory Controller) assigned to it. However, it has been found that having this class was problematic in some platforms, because the system would try to operate the balloon device as a memory controller, which it isn't (see upstream commit 2ba1d381c2f5f5868fe071b45977c2ed459d78f0). So in QEMU v1.1 the balloon device class has been changed from 0x5 to 0xff which, according to the PCI spec, means "Device does not fit in any defined classes". This is really the best we can do for the balloon device I guess, because it's a device that doesn't exist in real life and as such there's no PCI class that can describe it better than 0xff. You see the friendlier string in RHEL6 because RHEL6's qemu-kvm has been forked before QEMU v1.1, but I'd say that it's RHEL6 that needs fixing instead! Closing as CANTFIX. (In reply to Luiz Capitulino from comment #3) > Until QEMU v1.0 the balloon device had the PCI class 0x5 (Memory Controller) > assigned to it. However, it has been found that having this class was > problematic in some platforms, because the system would try to operate the > balloon device as a memory controller, which it isn't (see upstream commit > 2ba1d381c2f5f5868fe071b45977c2ed459d78f0). So in QEMU v1.1 the balloon > device class has been changed from 0x5 to 0xff which, according to the PCI > spec, means "Device does not fit in any defined classes". > > This is really the best we can do for the balloon device I guess, because > it's a device that doesn't exist in real life and as such there's no PCI > class that can describe it better than 0xff. > > You see the friendlier string in RHEL6 because RHEL6's qemu-kvm has been > forked before QEMU v1.1, but I'd say that it's RHEL6 that needs fixing > instead! However, for migration compatibility, we may have to continue advertising the older PCI class for machines started with -M rhel6x and older (stable guest ABI). We could use this bug to do that. Oh, good catch! That problem didn't occur to me. I'd prefer creating a new, clearer bz, but patching this one works too. It turns out that this is already fixed. The tracking bz is bug 983991, closing as duplicated. *** This bug has been marked as a duplicate of bug 983991 *** Fixed in upstream commit 2ba1d38 for the upstream machine types, and RHEL-7 commit 69018e8 for the RHEL machine types. |