On Tue, Aug 30, 2011 at 06:26, Marcelo Tosatti <mtosatti@xxxxxxxxxx> wrote: > On Mon, Aug 29, 2011 at 05:27:11PM -0600, Eric B Munson wrote: >> Currently, when qemu stops a guest kernel that guest will issue a soft lockup >> message when it resumes. This set provides the ability for qemu to comminucate >> to the guest that it has been stopped. When the guest hits the watchdog on >> resume it will check if it was suspended before issuing the warning. >> >> Eric B Munson (4): >> Add flag to indicate that a vm was stopped by the host >> Add functions to check if the host has stopped the vm >> Add generic stubs for kvm stop check functions >> Add check for suspended vm in softlockup detector >> >> arch/x86/include/asm/pvclock-abi.h | 1 + >> arch/x86/include/asm/pvclock.h | 2 ++ >> arch/x86/kernel/kvmclock.c | 14 ++++++++++++++ >> include/asm-generic/pvclock.h | 14 ++++++++++++++ >> kernel/watchdog.c | 12 ++++++++++++ >> 5 files changed, 43 insertions(+), 0 deletions(-) >> create mode 100644 include/asm-generic/pvclock.h >> >> -- >> 1.7.4.1 > > How is the host supposed to set this flag? The hypervisor will set the flag (the second bit in the struct pvclock_vcpu_time_info.flags field) when it stops the guest. I could be reading pvclock-abi.h incorrectly, but the way I understand it is that this structure is used to communicate between hypervisor and guest. > > As mentioned previously, if you save save/restore the offset added to > kvmclock on stop/cont (and the TSC MSR, forgot to mention that), no > paravirt infrastructure is required. Which means the issue is also fixed > for older guests. > -- 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
