From 5527233db7f7d989f0bc7459c23869ed08f5ad62 Mon Sep 17 00:00:00 2001 From: Glauber Costa Date: Mon, 17 Mar 2008 16:08:40 -0300 Subject: [PATCH] --- yaml --- r: 93831 b: refs/heads/master c: 1e977aa12dd4f80688b1f243762212e75c6d7fe8 h: refs/heads/master i: 93829: 92478aeb18d2d6c22203b82e2dbdfec057e7a50b 93827: 26d44d5d994e661d564a47ad575391d4ef4f2bd1 93823: b18bb3476d574daf8d5eca140824e47c6659c94e v: v3 --- [refs] | 2 +- trunk/arch/x86/kernel/kvmclock.c | 27 +++++++++++++++++++++++++++ 2 files changed, 28 insertions(+), 1 deletion(-) diff --git a/[refs] b/[refs] index 82d91aa37384..d1942e827236 100644 --- a/[refs] +++ b/[refs] @@ -1,2 +1,2 @@ --- -refs/heads/master: 3c62c62502bea24448d4e82aa1f33c7dbca61a32 +refs/heads/master: 1e977aa12dd4f80688b1f243762212e75c6d7fe8 diff --git a/trunk/arch/x86/kernel/kvmclock.c b/trunk/arch/x86/kernel/kvmclock.c index b999f5e5b3bf..ddee04043aeb 100644 --- a/trunk/arch/x86/kernel/kvmclock.c +++ b/trunk/arch/x86/kernel/kvmclock.c @@ -22,6 +22,7 @@ #include #include #include +#include #define KVM_SCALE 22 @@ -143,6 +144,28 @@ static void kvm_setup_secondary_clock(void) setup_secondary_APIC_clock(); } +/* + * After the clock is registered, the host will keep writing to the + * registered memory location. If the guest happens to shutdown, this memory + * won't be valid. In cases like kexec, in which you install a new kernel, this + * means a random memory location will be kept being written. So before any + * kind of shutdown from our side, we unregister the clock by writting anything + * that does not have the 'enable' bit set in the msr + */ +#ifdef CONFIG_KEXEC +static void kvm_crash_shutdown(struct pt_regs *regs) +{ + native_write_msr_safe(MSR_KVM_SYSTEM_TIME, 0, 0); + native_machine_crash_shutdown(regs); +} +#endif + +static void kvm_shutdown(void) +{ + native_write_msr_safe(MSR_KVM_SYSTEM_TIME, 0, 0); + native_machine_shutdown(); +} + void __init kvmclock_init(void) { if (!kvm_para_available()) @@ -155,6 +178,10 @@ void __init kvmclock_init(void) pv_time_ops.set_wallclock = kvm_set_wallclock; pv_time_ops.sched_clock = kvm_clock_read; pv_apic_ops.setup_secondary_clock = kvm_setup_secondary_clock; + machine_ops.shutdown = kvm_shutdown; +#ifdef CONFIG_KEXEC + machine_ops.crash_shutdown = kvm_crash_shutdown; +#endif clocksource_register(&kvm_clock); } }