Messages in this thread Patch in this message | | | From | Eric B Munson <> | Subject | [PATCH 2/5 V5] Add functions to check if the host has stopped the vm | Date | Mon, 5 Dec 2011 15:19:01 -0500 |
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When a host stops or suspends a VM it will set a flag to show this. The watchdog will use these functions to determine if a softlockup is real, or the result of a suspended VM.
Signed-off-by: Eric B Munson <emunson@mgebm.net> Cc: mingo@redhat.com Cc: hpa@zytor.com Cc: arnd@arndb.de Cc: ryanh@linux.vnet.ibm.com Cc: aliguori@us.ibm.com Cc: mtosatti@redhat.com Cc: jeremy.fitzhardinge@citrix.com Cc: levinsasha928@gmail.com Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: kvm@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: x86@kernel.org Cc: linux-kernel@vger.kernel.org --- arch/x86/include/asm/kvm_para.h | 1 + arch/x86/kernel/kvmclock.c | 21 +++++++++++++++++++++ 2 files changed, 22 insertions(+), 0 deletions(-)
diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h index 734c376..e9d63a6 100644 --- a/arch/x86/include/asm/kvm_para.h +++ b/arch/x86/include/asm/kvm_para.h @@ -95,6 +95,7 @@ struct kvm_vcpu_pv_apf_data { extern void kvmclock_init(void); extern int kvm_register_clock(char *txt); +bool kvm_check_and_clear_guest_paused(int cpu); /* This instruction is vmcall. On non-VT architectures, it will generate a * trap that we will then rewrite to the appropriate instruction. diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index 44842d7..f0c0599 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -22,6 +22,7 @@ #include <asm/msr.h> #include <asm/apic.h> #include <linux/percpu.h> +#include <linux/hardirq.h> #include <asm/x86_init.h> #include <asm/reboot.h> @@ -114,6 +115,26 @@ static void kvm_get_preset_lpj(void) preset_lpj = lpj; } +bool kvm_check_and_clear_guest_paused(int cpu) +{ + bool ret = false; + struct pvclock_vcpu_time_info *src; + + /* + * per_cpu() is safe here because this function is only called from + * timer functions where preemption is already disabled. + */ + WARN_ON(!in_atomic()); + src = &per_cpu(hv_clock, cpu); + if ((src->flags & PVCLOCK_GUEST_STOPPED) != 0) { + src->flags = src->flags & (~PVCLOCK_GUEST_STOPPED); + ret = true; + } + + return ret; +} +EXPORT_SYMBOL_GPL(kvm_check_and_clear_guest_paused); + static struct clocksource kvm_clock = { .name = "kvm-clock", .read = kvm_clock_get_cycles, -- 1.7.5.4
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