JustKernel

Ray Of Hope

July, 2014

QEMU + CPU Hotunplug design

The basic design decision that we have taken while designing cpu hotunplug functionality for qemu is that the kernel mode fd (in KVM) associated with the usermode vcpu will not be deleted. It will remain there. Only the mmapped memory associated the usermode thread (vcpu) will be deleted from the kernel. If we get a […]

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QEMU + VCPU architecture.

Whenever a new CPU is added to the QEMU, call flow goes like this. Realize the x86 Device : target-i386/cpu.c:x86_cpu_realizefn -> cpus.c:qemu_init_vcpu() and target-i386/cpu.c:x86_cpu_realizefn -> xcc->parent_Realizefn(). qemu_init_vcpu checks if the kvm is enabled and it calls cpus.c: qemu_kvm_start_vcpu() . qemu_kvm_start_vcpu allocates the memory for the thread, specify its halting condition and calls qemu_thread_create with the […]

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