* Marcelo Tosatti <mtosatti@xxxxxxxxxx> [2011-08-30 07:35]: > 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? > > 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. How is saving the offset going to prevent a large jump from triggering the softlock message? Won't we still have not touched the watchdog for that long period of time? -- Ryan Harper Software Engineer; Linux Technology Center IBM Corp., Austin, Tx ryanh@xxxxxxxxxx -- 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
