Bug 1179578

Summary: QEMU fail to do SG_IO INQUIRY checking when pass-through(scsi-block) a LVM to KVM guest
Product: Red Hat Enterprise Linux 7 Reporter: Sibiao Luo <sluo>
Component: qemu-kvmAssignee: Ademar Reis <areis>
Status: CLOSED CANTFIX QA Contact: Virtualization Bugs <virt-bugs>
Severity: medium Docs Contact:
Priority: medium    
Version: 7.1CC: chayang, famz, juzhang, knoel, kwolf, michen, pbonzini, qzhang, rbalakri, virt-bugs, virt-maint, xfu
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: 1179577 Environment:
Last Closed: 2015-01-08 18:15:21 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:
Bug Depends On: 1179577    
Bug Blocks:    

Comment 1 Sibiao Luo 2015-01-07 07:01:10 UTC 
host info:
# uname -r && rpm -q qemu-kvm
3.10.0-220.el7.x86_64
qemu-kvm-1.5.3-84.el7.x86_64
guest info:
# uname -r
3.10.0-220.el7.x86_64
Comment 2 Paolo Bonzini 2015-01-08 18:15:21 UTC 
This is unfortunately expected behavior when CAP_SYS_RAWIO is valid.  The patch that was applied to RHEL6 was rejected upstream and is not in RHEL7.  Example:

# capsh --drop=cap_sys_rawio -- -c '/usr/libexec/qemu-kvm -M pc -enable-kvm -m 2048 -smp 2 -drive file=/dev/vg-root/rhel5-x86-64,id=root,if=none -device virtio-scsi-pci -device scsi-block,drive=root -S'
qemu-kvm: -device scsi-block,drive=root: scsi-block: INQUIRY failed
qemu-kvm: -device scsi-block,drive=root: Device initialization failed.
qemu-kvm: -device scsi-block,drive=root: Device 'scsi-block' could not be initialized

(put the capsh command on a single line).