[Qemu-devel] Bug in option parsing
Hi everybody,
while coding the support for Jason's dump-guest-core option I realized
there is (probably) a problem with the way QEMU parses additional
machine options ('dump-guest-core', 'kvm_shadow_mem' etc.). Running QEMU
with option to -machine works ok, but using '-M' (as libvirt does) works
only w/o additional options, otherwise it ends in an error (the whole
string is probably parsed as a machine name).
Is '-M' so obsolete it shouldn't be used at all or is it just an bug? We
still use '-M' everywhere I know and '-machine' isn't compatible with
older versions and different builds of QEMU.
Should I file a bug or do we have to drop '-M' for this situations?
Have a nice day,
Martin
Re: [Qemu-devel] Bug in option parsing
On 2012-08-22 17:05, Martin Kletzander wrote:
Hi everybody,
while coding the support for Jason's dump-guest-core option I realized
there is (probably) a problem with the way QEMU parses additional
machine options ('dump-guest-core', 'kvm_shadow_mem' etc.). Running QEMU
with option to -machine works ok, but using '-M' (as libvirt does) works
only w/o additional options, otherwise it ends in an error (the whole
string is probably parsed as a machine name).
Is '-M' so obsolete it shouldn't be used at all or is it just an bug? We
still use '-M' everywhere I know and '-machine' isn't compatible with
older versions and different builds of QEMU.
Should I file a bug or do we have to drop '-M' for this situations?
If libvirt uses -M just like -machine, i.e. with more than a machine
name, that would be a libvirt bug (but that would have been noticed much
earlier - did you patch something?). QEMU only keeps -M machine-name
around to please existing users that didn't switch yet. It is NOT an
alias for -machine.
Jan
--
Siemens AG, Corporate Technology, CT RTC ITP SDP-DE
Corporate Competence Center Embedded Linux
Re: [Qemu-devel] Bug in option parsing
On 08/22/2012 05:15 PM, Jan Kiszka wrote:
On 2012-08-22 17:05, Martin Kletzander wrote:
Hi everybody,
while coding the support for Jason's dump-guest-core option I realized
there is (probably) a problem with the way QEMU parses additional
machine options ('dump-guest-core', 'kvm_shadow_mem' etc.). Running QEMU
with option to -machine works ok, but using '-M' (as libvirt does) works
only w/o additional options, otherwise it ends in an error (the whole
string is probably parsed as a machine name).
Is '-M' so obsolete it shouldn't be used at all or is it just an bug? We
still use '-M' everywhere I know and '-machine' isn't compatible with
older versions and different builds of QEMU.
Should I file a bug or do we have to drop '-M' for this situations?
If libvirt uses -M just like -machine, i.e. with more than a machine
name, that would be a libvirt bug (but that would have been noticed much
earlier - did you patch something?). QEMU only keeps -M machine-name
around to please existing users that didn't switch yet. It is NOT an
alias for -machine.
There is no option *yet* that libvirt would like to use as an additional
option for machine type, but I'm working on the first one and I've hit this.
So your suggestion would be to use -machine wherever it's possible and
fallback to -M only when -machine is not supported?
Martin
Re: [Qemu-devel] Bug in option parsing
On 2012-08-22 17:58, Martin Kletzander wrote:
On 08/22/2012 05:15 PM, Jan Kiszka wrote:
On 2012-08-22 17:05, Martin Kletzander wrote:
Hi everybody,
while coding the support for Jason's dump-guest-core option I realized
there is (probably) a problem with the way QEMU parses additional
machine options ('dump-guest-core', 'kvm_shadow_mem' etc.). Running QEMU
with option to -machine works ok, but using '-M' (as libvirt does) works
only w/o additional options, otherwise it ends in an error (the whole
string is probably parsed as a machine name).
Is '-M' so obsolete it shouldn't be used at all or is it just an bug? We
still use '-M' everywhere I know and '-machine' isn't compatible with
older versions and different builds of QEMU.
Should I file a bug or do we have to drop '-M' for this situations?
If libvirt uses -M just like -machine, i.e. with more than a machine
name, that would be a libvirt bug (but that would have been noticed much
earlier - did you patch something?). QEMU only keeps -M machine-name
around to please existing users that didn't switch yet. It is NOT an
alias for -machine.
There is no option *yet* that libvirt would like to use as an additional
option for machine type, but I'm working on the first one and I've hit this.
So your suggestion would be to use -machine wherever it's possible and
fallback to -M only when -machine is not supported?
Yep.
Jan
--
Siemens AG, Corporate Technology, CT RTC ITP SDP-DE
Corporate Competence Center Embedded Linux
