On 17/01/13 11:27, Daniel Kiper wrote: > On Wed, Jan 16, 2013 at 04:29:03PM +0000, David Vrabel wrote: >> This series of patches improves the kexec hypercall in the Xen >> hypervisor. It is an incomplete prototype but I posting it early for >> comments on the proposed ABI/API. >> >> This allows a privileged Xen guest to load kexec images into the >> hypervisor from a userspace tool without using the Linux kernel's >> kexec subsystem. It is the first step to supporting kexec of crash >> kernels from a pv-ops dom0 kernel (the required kernel and kexec-tools >> patches will be posted later). >> >> The kernel will require a kexec hypercall somewhere in the >> crash_kexec() path to actually exec the loaded image. Any preferences >> on how the hook for this should be implemented? Note that the kernel > This should be implemented as stub which be called by machine_kexec() > and later it would call relevant hypercall. > >> won't be aware that an image as been loaded as it is loaded directly >> into the hypervisor and not via the kernel's kexec_load system call. > Maybe we should have sepcial kexec hypercall function which allow us > to ask hypervisor that image is loaded or not. But we already have this information. If the kexec crash hypercall returns back to dom0 then a crash kernel is not loaded. One could certainly argue that even if a crash kernel is not loaded, a kexec crash hypercall means that dom0 is in bad state and Xen should panic() anyway, which is the case on any other form of dom0 crash. ~Andrew > >> Since the kexec hypercall is for use by dom0 I have removed the >> implementation of the old load/unload ops and thus guests will require >> updated kexec-tools to load images. Is this acceptable? > Not yet. I think that old interface should stay as long as Xen Linux Kernel > could run on latest versions of hypervisor. > > Daniel > > _______________________________________________ > Xen-devel mailing list > Xen-devel at lists.xen.org > http://lists.xen.org/xen-devel
