Re: [kvm-devel] [RFC] Stable kvm userspace interface

2007-01-12 Thread Pavel Machek
Hi! > >>Can we please avoid adding a ton of new ioctls? > >>ioctls inevitably require 64-bit compat code for > >>certain architectures, whereas sysfs/procfs does not. > > > >For performance reasons, an ascii string based > >interface is not > >desireable here, some of these calls should be >

Re: [kvm-devel] [RFC] Stable kvm userspace interface

2007-01-11 Thread David Lang
On Thu, 11 Jan 2007, Arnd Bergmann wrote: On Tuesday 09 January 2007 14:47, Jeff Garzik wrote: Can we please avoid adding a ton of new ioctls?  ioctls inevitably require 64-bit compat code for certain architectures, whereas sysfs/procfs does not. For performance reasons, an ascii string based

Re: [kvm-devel] [RFC] Stable kvm userspace interface

2007-01-11 Thread Avi Kivity
Jeff Garzik wrote: > Arnd Bergmann wrote: >> On Tuesday 09 January 2007 14:47, Jeff Garzik wrote: >>> Can we please avoid adding a ton of new ioctls? ioctls inevitably >>> require 64-bit compat code for certain architectures, whereas >>> sysfs/procfs does not. >> >> For performance reasons, an a

Re: [kvm-devel] [RFC] Stable kvm userspace interface

2007-01-11 Thread Jeff Garzik
Arnd Bergmann wrote: > On Tuesday 09 January 2007 14:47, Jeff Garzik wrote: >> Can we please avoid adding a ton of new ioctls? ioctls inevitably >> require 64-bit compat code for certain architectures, whereas >> sysfs/procfs does not. > > For performance reasons, an ascii string based interfac

Re: [kvm-devel] [RFC] Stable kvm userspace interface

2007-01-11 Thread Avi Kivity
Arnd Bergmann wrote: > I still think that in the long term, we should migrate to > new system calls and a special file system for kvm, which > might be non-mountable. The inode-per-vm and inode-per-vcpu approach sort-of-implies a nonmountable special filesystem, so with the proposed change, we'l

Re: [kvm-devel] [RFC] Stable kvm userspace interface

2007-01-11 Thread Avi Kivity
Arnd Bergmann wrote: > On Tuesday 09 January 2007 14:37, Avi Kivity wrote: > >> struct kvm_vcpu_area { >> u32 vcpu_area_size; >> u32 exit_reason; >> >> sigset_t sigmask; // for use during vcpu execution >> > > Since Jeff brought up the point of 32 bit compatibility: > When this

Re: [kvm-devel] [RFC] Stable kvm userspace interface

2007-01-10 Thread Arnd Bergmann
On Tuesday 09 January 2007 14:47, Jeff Garzik wrote: > Can we please avoid adding a ton of new ioctls?  ioctls inevitably > require 64-bit compat code for certain architectures, whereas > sysfs/procfs does not. For performance reasons, an ascii string based interface is not desireable here, some

Re: [kvm-devel] [RFC] Stable kvm userspace interface

2007-01-10 Thread Arnd Bergmann
On Tuesday 09 January 2007 14:37, Avi Kivity wrote: > struct kvm_vcpu_area { >     u32 vcpu_area_size; >     u32 exit_reason; > >     sigset_t sigmask;  // for use during vcpu execution Since Jeff brought up the point of 32 bit compatibility: When this structure is shared between 64 bit kernel an

Re: [kvm-devel] [RFC] Stable kvm userspace interface

2007-01-09 Thread Avi Kivity
Jeff Garzik wrote: > Can we please avoid adding a ton of new ioctls? ioctls inevitably > require 64-bit compat code for certain architectures, whereas > sysfs/procfs does not. > I don't see how the procfs or sysfs models fit kvm. wrt compat code, the current kvm abi (also ioctl based) is 32/6

Re: [kvm-devel] [RFC] Stable kvm userspace interface

2007-01-09 Thread James Morris
On Tue, 9 Jan 2007, Jeff Garzik wrote: > Can we please avoid adding a ton of new ioctls? ioctls inevitably > require 64-bit compat code for certain architectures, whereas > sysfs/procfs does not. I guess ioctl is not as important now if the API is now always talking to one VM. - James -- J

Re: [kvm-devel] [RFC] Stable kvm userspace interface

2007-01-09 Thread Jeff Garzik
Can we please avoid adding a ton of new ioctls? ioctls inevitably require 64-bit compat code for certain architectures, whereas sysfs/procfs does not. Jeff - Take Surveys. Earn Cash. Influence the Future of IT J