pcifront (CONFIG_XEN_PCIDEV_FRONTEND=m) support in RHEL 4.5

[Teo En Ming]

 Dear All,

The production server supports Intel Virtualization Technology. Processor is
an Intel Xeon 1.86 GHz Quad Core. 8 GB DDR2 memory.

There is also an Emulex LightPulse Fiber Channel HBA adapter.

The host operating system (Dom 0) is RHEL 5 x86 with Xen Virtualization
technology. Dom 0 kernel is 2.6.18-8.el5xen. I have recompiled the Dom 0
kernel so that pciback (CONFIG_XEN_PCIDEV_BACKEND=y) is compiled statically
into the kernel. Upon parsing the pciback.hide parameter on the Dom 0 kernel
command line, I am able to hide a port of the fiber channel HBA card from
Dom 0.

Now, I have a RHEL 4 Update 5 x86 running as a para-virtualized guest. The
Dom U kernel is kernel-xenU-2.6.9-55.el4. I intend to allow the PV guest to
have direct access to a port on the HBA card. However, there are no PCIFRONT
and LPFC kernel modules in the xenU kernel. Only BLKFRONT and NETFRONT are
supported by default. LPFC is a kernel module for the Emulex HBA card. To
compile these two kernel modules, I downloaded and installed
kernel-2.6.9-55.el5.src.rpm, which is the full kernel sources (with xen
patches) for RHEL 4.5. However, compiling pcifront and lpfc against the
kernel sources did not succeed. CONFIG_XEN_PCIDEV_FRONTEND=m and
CONFIG_SCSI_LPFC=m. These kernel modules do not have any dependencies. It
appears that CONFIG_XEN_PCIDEV_FRONTEND is not supported in the
2.6.9-55kernel source code for RHEL
4.5.

Due to production requirements, I have to stick to RHEL 4.5 as a guest. The
alternative is to use the 2.6.18-8 xen kernel that shipped with RHEL 5 to
boot the RHEL 4.5 guest. To do this, however, I have to upgrade the glibc,
udev, initscripts, and other core packages in RHEL 4.5 guest. This makes the
RHEL 4.5 effectively NOT a RHEL 4.5 anymore. I have to stick to production
requirements as Symantec ESM, SCSP, Antivirus, and siteminder agent may not
work with a newer GLIBC and kernel. Have an incompatible GLIBC may cause
segmentation faults with certain softwares.

Please advise me on what I should do.

Thank you very much.