Konrad Rzeszutek Wilk
2015-May-13 15:57 UTC
[Pkg-xen-devel] Bug#785187: Bug#785187: xen-hypervisor-4.5-amd64: Option ucode=scan is not working
> > according to the documentation the option ucode=scan should tell XEN to > > look for a microcode update in an uncompressed initrd. > > > > While I don?t use the Debian kernel the tools to generate the initrd are > > part of Debian. The command ?cpio -i < /boot/initrd.img-4.0.2-Dom0? > > creates the directory structure ?kernel/x86/microcode/GenuineIntel.bin?, > > so I think the initrd is allright.Is the initramfs compressed? The scanning code can't deal if the initramfs is compressed - so you either have to glue the compressed initramfs and the cpio with the microcode together (where the microcode has to go first).
Ian Campbell
2015-May-13 18:03 UTC
[Pkg-xen-devel] Bug#785187: Bug#785187: xen-hypervisor-4.5-amd64: Option ucode=scan is not working
On Wed, 2015-05-13 at 11:57 -0400, Konrad Rzeszutek Wilk wrote:> > > according to the documentation the option ucode=scan should tell XEN to > > > look for a microcode update in an uncompressed initrd. > > > > > > While I don?t use the Debian kernel the tools to generate the initrd are > > > part of Debian. The command ?cpio -i < /boot/initrd.img-4.0.2-Dom0? > > > creates the directory structure ?kernel/x86/microcode/GenuineIntel.bin?, > > > so I think the initrd is allright. > > > Is the initramfs compressed?The successful use of "cpio -i < /boot/initrd.img" would suggest not, I don't think cpio knows how to decompress things by itself. Ian.
Stephan Seitz
2015-May-14 20:45 UTC
[Pkg-xen-devel] Bug#785187: Bug#785187: xen-hypervisor-4.5-amd64: Option ucode=scan is not working
On Wed, May 13, 2015 at 11:57:55AM -0400, Konrad Rzeszutek Wilk wrote:>> > according to the documentation the option ucode=scan should tell XEN to >> > look for a microcode update in an uncompressed initrd. >> > >> > While I don?t use the Debian kernel the tools to generate the initrd are >> > part of Debian. The command ?cpio -i < /boot/initrd.img-4.0.2-Dom0? >> > creates the directory structure ?kernel/x86/microcode/GenuineIntel.bin?, >> > so I think the initrd is allright. >Is the initramfs compressed? The scanning code can't deal if the[stse at osgiliath]: file /boot/initrd.img-4.0.2-Dom0 /boot/initrd.img-4.0.2-Dom0: ASCII cpio archive (SVR4 with no CRC) I don?t think the initrd is compressed. http://lists.xen.org/archives/html/xen-users/2014-05/msg00053.html says that I have to use ?cpio -H newc? not ?cpio -o c?, but I don?t know how the Debian tools create the initrd. Shade and sweet water! Stephan -- | Stephan Seitz E-Mail: stse at fsing.rootsland.net | | Public Keys: http://fsing.rootsland.net/~stse/keys.html | -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/x-pkcs7-signature Size: 3735 bytes Desc: not available URL: <http://lists.alioth.debian.org/pipermail/pkg-xen-devel/attachments/20150514/75791c38/attachment.bin>
Ian Campbell
2015-May-15 07:26 UTC
[Pkg-xen-devel] Bug#785187: Bug#785187: xen-hypervisor-4.5-amd64: Option ucode=scan is not working
On Thu, 2015-05-14 at 22:45 +0200, Stephan Seitz wrote:> On Wed, May 13, 2015 at 11:57:55AM -0400, Konrad Rzeszutek Wilk wrote: > >> > according to the documentation the option ucode=scan should tell XEN to > >> > look for a microcode update in an uncompressed initrd. > >> > > >> > While I don?t use the Debian kernel the tools to generate the initrd are > >> > part of Debian. The command ?cpio -i < /boot/initrd.img-4.0.2-Dom0? > >> > creates the directory structure ?kernel/x86/microcode/GenuineIntel.bin?, > >> > so I think the initrd is allright. > >Is the initramfs compressed? The scanning code can't deal if the > > [stse at osgiliath]: file /boot/initrd.img-4.0.2-Dom0 > /boot/initrd.img-4.0.2-Dom0: ASCII cpio archive (SVR4 with no CRC) > > I don?t think the initrd is compressed. > > http://lists.xen.org/archives/html/xen-users/2014-05/msg00053.html says > that I have to use ?cpio -H newc? not ?cpio -o c?, but I don?t know how > the Debian tools create the initrd.The intel-microcode package contains: /usr/share/initramfs-tools/hooks/intel_microcode which will be called during initamfs generation. It seems to call iucode_tool, from the iucode-tool package. That's a binary tool which seems to include its own cpio writer implementation, I've no idea if that is like a 'newc' or not. However: ijc at dagon:tmp$ find iucode-tool/ | cpio -o > normal.cpio 828 blocks ijc at dagon:tmp$ find iucode-tool/ | cpio -o -H newc > newc.cpio 840 blocks ijc at dagon:tmp$ file *.cpio newc.cpio: ASCII cpio archive (SVR4 with no CRC) normal.cpio: cpio archive So the fact that yours reports the same as newc.cpio makes me reasonably confident it is in the correct form. So I think the issue must be elsewhere. In iucode_tool.c I found: /* Gross hack to work around a Linux kernel bug: for file * entries, force file data into a 16-byte alignment by * appending NULs to the file name. Verified to be compatible * with GNU pax, and GNU cpio */ s = (size) ? (16 - (*pos + bufsize) % 16) % 16 : 0; I wonder if perhaps this confuses Xen? I doubt it somehow. Here's an idea. First extract the real initrd from the back half of the initrd: ijc at dagon:tmp$ cat /boot/initrd.img | ( cpio -t >&2 ; cat ) > initrd.real kernel kernel/x86 kernel/x86/microcode kernel/x86/microcode/GenuineIntel.bin 16 blocks ijc at dagon:tmp$ file initrd.real initrd.real: gzip compressed data, last modified: Sun Apr 19 16:31:17 2015, from Unix ijc at dagon:tmp$ zcat initrd.real | cpio -t | head -n 5 . etc etc/ld.so.conf.d etc/ld.so.conf.d/fakeroot-x86_64-linux-gnu.conf etc/ld.so.conf.d/x86_64-linux-gnu.conf Now you can experiment with regenerating the ucode bit with whatever commands are recommended and reconcatenating the two. If that works then we know there is some incompatibility between iucode-tools's output and Xen's cpio reader (could be a bug in either or both I think). Ian.
Possibly Parallel Threads
- Bug#785187: Bug#785187: xen-hypervisor-4.5-amd64: Option ucode=scan is not working
- Bug#785187: Bug#785187: xen-hypervisor-4.5-amd64: Option ucode=scan is not working
- Bug#785187: Bug#785187: xen-hypervisor-4.5-amd64: Option ucode=scan is not working
- Bug#785187: [Xen-devel] Bug#785187: xen-hypervisor-4.5-amd64: Option ucode=scan is not working
- Bug#785187: Bug#785187: xen-hypervisor-4.5-amd64: Option ucode=scan is not working