Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "x86 guest:

   - Tweaks to the paravirtualization code, to avoid using them when
     they're pointless or harmful

  x86 host:

   - Fix for SRCU lockdep splat

   - Brown paper bag fix for the propagation of errno"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: pull kvm->srcu read-side to kvm_arch_vcpu_ioctl_run
  KVM: x86/mmu: Passing up the error state of mmu_alloc_shadow_roots()
  KVM: x86: Yield to IPI target vCPU only if it is busy
  x86/kvmclock: Fix Hyper-V Isolated VM's boot issue when vCPUs > 64
  x86/kvm: Don't waste memory if kvmclock is disabled
  x86/kvm: Don't use PV TLB/yield when mwait is advertised

2 files changed, 6 insertions, 1 deletions

diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index f734e3b0cfec..d77481ecb0d5 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -463,6 +463,7 @@ static bool pv_tlb_flush_supported(void)
 	return (kvm_para_has_feature(KVM_FEATURE_PV_TLB_FLUSH) &&
 		!kvm_para_has_hint(KVM_HINTS_REALTIME) &&
 		kvm_para_has_feature(KVM_FEATURE_STEAL_TIME) &&
+		!boot_cpu_has(X86_FEATURE_MWAIT) &&
 		(num_possible_cpus() != 1));
 }
 
@@ -477,6 +478,7 @@ static bool pv_sched_yield_supported(void)
 	return (kvm_para_has_feature(KVM_FEATURE_PV_SCHED_YIELD) &&
 		!kvm_para_has_hint(KVM_HINTS_REALTIME) &&
 	    kvm_para_has_feature(KVM_FEATURE_STEAL_TIME) &&
+	    !boot_cpu_has(X86_FEATURE_MWAIT) &&
 	    (num_possible_cpus() != 1));
 }
 
@@ -622,7 +624,7 @@ static void kvm_smp_send_call_func_ipi(const struct cpumask *mask)
 
 	/* Make sure other vCPUs get a chance to run if they need to. */
 	for_each_cpu(cpu, mask) {
-		if (vcpu_is_preempted(cpu)) {
+		if (!idle_cpu(cpu) && vcpu_is_preempted(cpu)) {
 			kvm_hypercall1(KVM_HC_SCHED_YIELD, per_cpu(x86_cpu_to_apicid, cpu));
 			break;
 		}
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index a35cbf9107af..c5caa7311bd8 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -239,6 +239,9 @@ static void __init kvmclock_init_mem(void)
 
 static int __init kvm_setup_vsyscall_timeinfo(void)
 {
+	if (!kvm_para_available() || !kvmclock)
+		return 0;
+
 	kvmclock_init_mem();
 
 #ifdef CONFIG_X86_64