Re: absolute firmware path made relocatable in qemu 5.2.0

[Paolo Bonzini <pbonzini@redhat.com>]

[-- Attachment #1: Type: text/plain, Size: 2717 bytes --]

Il mar 12 gen 2021, 17:48 Dave <dave@0bits.com> ha scritto:

> Hi Paolo,
>
> While this (option 2) partially works, it will still search for
> /nonexistent/libexec/qemu-bridge-helper for example so seems that some
> paths are still absolute and some relative.
>

Ok, that's a bug that can be fixed in 5.2.1. Are there other instances?


> To explain, what we are expecting that we compile one binary with the
> relevant options, test that and then it goes into production. If we
> compile with --prefix=/usr (it's final resting place will be /usr/bin)
> then everything works as expected once it is in production (since
> /usr/share/qemu, /usr/libexec, /etc/qemu exists as expected).  However
> when we are testing the binary in a directory /root/qemu/5.2.0 with
> --prefix=/usr it breaks since it converts the firmware and bios paths to
> /root/qemu/5.2.0/../share/qemu. This means we need to recompile twice
> with relevant prefixes since if i use --prefix=/nonexistent then we
> can't find the qemu-bridge-helper when the binary goes into production.
>
> It would be nicer with the relocatable binary took some fixed paths from
> /etc/qemu.conf for the bridge-helper, firmware, bios, qemu-ifup/down.
>
> thanks
> Dave
>
>
> On 12/01/2021 18:48, Paolo Bonzini wrote:
> > On 12/01/21 15:05, Dave wrote:
> >> Is seem that absolute firmwarepath compilation option is converted  to
> >> relocatable in 5.2.0 qemu.
> >>
> >> # QEMU configure log Tue 12 Jan 14:46:41 GST 2021
> >> # Configured with: '../configure' '--prefix=/usr'
> >> '--sysconfdir=/etc/qemu' '--disable-bochs'
> >> '*--firmwarepath=/usr/share/qemu:/usr/share/qemu-firmware*'
> >> #
> >
> > Yes, all paths within the prefix are relocated.  The workaround is
> > simply to configure the intended prefix with configure:
> >
> > ./configure --prefix=/root/qemu ...
> >
> > or if you don't know the prefix:
> >
> > ./configure --prefix=/nonexistent ...
> >
> > Because /usr/share/qemu and /usr/share/qemu-firmware are outside /usr,
> > they will be treated as absolute just like /etc/qemu.
> >
> > Thanks,
> >
> > Paolo
> >
> >> And trying to run the executable
> >>
> >>     bash-5.1# ./qemu-system-x86_64
> >>     qemu: could not load PC BIOS 'bios-256k.bin'
> >>
> >> If i print out the resultant binary paths
> >>
> >>     bash-5.1# ./qemu-system-x86_64 -L help
> >>     /root/qemu/../share/qemu
> >>     /root/qemu/../share/qemu-firmware
> >>
> >> So there is no way to have a absolute path for firmware /bios and all
> >> qemu's that we test need to be at the right directory nesting to find
> >> firmware, bios etc or else they all need their own duplicate firmware
> >> files. Firmware path needs to honor the absolute paths i believe.
> >>
> >
>
>

[-- Attachment #2: Type: text/html, Size: 3789 bytes --]