On Thu, Dec 15, 2011 at 11:21:37AM +0800, Liu ping fan wrote: > On Tue, Dec 13, 2011 at 7:36 PM, Marcelo Tosatti <mtosatti@xxxxxxxxxx> wrote: > > On Mon, Dec 12, 2011 at 10:41:23AM +0800, Liu Ping Fan wrote: > >> From: Liu Ping Fan <pingfank@xxxxxxxxxxxxxxxxxx> > >> > >> Currently, vcpu can be destructed only when kvm instance destroyed. > >> Change this to vcpu's destruction taken when its refcnt is zero, > >> and then vcpu MUST and CAN be destroyed before kvm's destroy. > >> > >> Signed-off-by: Liu Ping Fan <pingfank@xxxxxxxxxxxxxxxxxx> > >> --- > >> arch/x86/kvm/i8254.c | 10 ++++-- > >> arch/x86/kvm/i8259.c | 12 +++++-- > >> arch/x86/kvm/mmu.c | 7 ++-- > >> arch/x86/kvm/x86.c | 54 +++++++++++++++++++---------------- > >> include/linux/kvm_host.h | 71 ++++++++++++++++++++++++++++++++++++++++++---- > >> virt/kvm/irq_comm.c | 7 +++- > >> virt/kvm/kvm_main.c | 62 +++++++++++++++++++++++++++++++++------ > >> 7 files changed, 170 insertions(+), 53 deletions(-) > > > > This needs a full audit of paths that access vcpus. See for one example > > bsp_vcpu pointer. > > > Yes, I had missed it and just paid attention to the access path to > vcpu in kvm_lapic and the path used in async_pf. I will correct it > later. > BTW, I want to make it sure that because kvm_lapic will be destroyed > before vcpu, so it is safe to bypass the access path there, and the > situation is the same in async_pf for we have called > kvm_clear_async_pf_completion_queue before zapping vcpu. Am I right? > > As to the scene like bsp_vcpu, I think that introducing refcount like > in V2 can handle it easier. Please help to review these changes in V4 > which I will send a little later. > Since bsp_vcpu pointer will never be released or re-assigned introducing reference count to keep the pointer valid is not necessary. The counter will never reach 0 and bsp vcpu will never be freed. Just disallow removal of bsp_vcpu. Or better get rid of bsp_vcpu at all since its only use is invalid anyway. -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
