Yang, Sheng wrote: > From: Sheng Yang <[EMAIL PROTECTED]> > Date: Thu, 31 Jul 2008 13:43:58 +0800 > Subject: [PATCH] KVM: Fix QEmu interrupted HLT emulation > > QEmu can interrupt VCPU from HLT emulation without setting mp_state to > MP_STATE_RUNNABLE, when it kick vcpus which are doing HLT emulation to > do something like "stop" or "info cpus". Here are two issues of this > behaviour: > > First, if vcpu exit to QEmu with MP_STATE_HALTED, it would keep in > this state later for vcpu_run(), which is eerie... > > Second, a practical problem: bios load AP boot up code to 0x10000 > (now), and AP is running HLT there. But later grub load it's stage2 > code to the same address. Then if the halting vcpu was forced exit to > QEmu in grub, and come back for vcpu_run later, it can't execute HLT > instruction anymore, just because the bios code is not there, > and it would follow a piece of code of grub, which would cause > completely chaos... > > The second issue directly lead to guest crash or SMP linux can't boot > up AP later if we "stop" or "info cpus" in grub. Though I also sent a > patch for BIOS, it's necessary to get correct behavior here. >
Going over my backlog it looks like I missed this. But I think Marcelo's rework obsoletes this patch? -- Do not meddle in the internals of kernels, for they are subtle and quick to panic. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
