On Thu, Nov 22, 2012 at 04:22:26PM +0800, Zhang Yanfei wrote: > Currently, kdump just makes all the logical processors leave VMX operation by > executing VMXOFF instruction, so any VMCSs active on the logical processors may > be corrupted. But, sometimes, we need the VMCSs to debug guest images contained > in the host vmcore. To prevent the corruption, we should VMCLEAR the VMCSs before > executing the VMXOFF instruction. > > The patch set provides a way to VMCLEAR vmcss related to guests on all cpus before > executing the VMXOFF when doing kdump. This is used to ensure the VMCSs in the > vmcore updated and non-corrupted. > Looks fine to me, but kexec part should get acks from exec maintainers. > Changelog from v7 to v8: > 1. KEXEC: regression for using name crash_notifier_list > and remove comments related to KVM > and just call function atomic_notifier_call_chain directly. > > Changelog from v6 to v7: > 1. KVM-INTEL: in hardware_disable, we needn't disable the > vmclear, so remove it. > > Changelog from v5 to v6: > 1. KEXEC: the atomic notifier list renamed: > crash_notifier_list --> vmclear_notifier_list > 2. KVM-INTEL: provide empty functions if CONFIG_KEXEC is > not defined and remove unnecessary #ifdef's. > > Changelog from v4 to v5: > 1. use an atomic notifier instead of function call, so > have all the vmclear codes in vmx.c. > > Changelog from v3 to v4: > 1. add a new percpu variable vmclear_skipped to skip > vmclear in kdump in some conditions. > > Changelog from v2 to v3: > 1. remove unnecessary conditions in function > cpu_emergency_clear_loaded_vmcss as Marcelo suggested. > > Changelog from v1 to v2: > 1. remove the sysctl and clear VMCSs unconditionally. > > Zhang Yanfei (2): > x86/kexec: add a new atomic notifier list for kdump > KVM-INTEL: add a notifier and a bitmap to support VMCLEAR in kdump > > arch/x86/include/asm/kexec.h | 2 + > arch/x86/kernel/crash.c | 9 +++++ > arch/x86/kvm/vmx.c | 70 ++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 81 insertions(+), 0 deletions(-) -- Gleb.
