Fix splat below.  Lock is short hold, make it raw.

[15528.614216] BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:995
[15528.614218] in_atomic(): 0, irqs_disabled(): 1, pid: 19619, name: qemu-system-x86
[15528.614218] no locks held by qemu-system-x86/19619.
[15528.614219] irq event stamp: 321840
[15528.614224] hardirqs last  enabled at (321839): [<ffffffff816a8467>] entry_SYSCALL_64_fastpath+0x5/0xc2
[15528.614244] hardirqs last disabled at (321840): [<ffffffffa08578f4>] kvm_arch_vm_ioctl+0x234/0xda0 [kvm]
[15528.614246] softirqs last  enabled at (0): [<ffffffff81077e8a>] copy_process.part.36+0x5ba/0x20b0
[15528.614247] softirqs last disabled at (0): [<          (null)>]           (null)
[15528.614250] CPU: 7 PID: 19619 Comm: qemu-system-x86 Tainted: G            E   4.9.0-rt1-virgin #1
[15528.614250] Hardware name: MEDION MS-7848/MS-7848, BIOS M7848W08.20C 09/23/2013
[15528.614253]  ffffc9000b98bc30 ffffffff8136874d 0000000000000000 ffff8803e76db200
[15528.614255]  ffffc9000b98bc68 ffffffff810abe9d ffff8800353472d0 ffff8800353472d0
[15528.614257]  00007ffc53dbc2b0 000000000000000b 00007ffc53dbc2b0 ffffc9000b98bc88
[15528.614257] Call Trace:
[15528.614262]  [<ffffffff8136874d>] dump_stack+0x85/0xc8
[15528.614266]  [<ffffffff810abe9d>] ___might_sleep+0x15d/0x260
[15528.614268]  [<ffffffff816a7ca4>] rt_spin_lock+0x24/0x80
[15528.614283]  [<ffffffffa084b212>] __get_kvmclock_ns+0x22/0xf0 [kvm]
[15528.614297]  [<ffffffffa08578fc>] kvm_arch_vm_ioctl+0x23c/0xda0 [kvm]
[15528.614300]  [<ffffffff810dc5d5>] ? __lock_acquire+0x305/0x16a0
[15528.614301]  [<ffffffff8107d916>] ? unpin_current_cpu+0x16/0x70
[15528.614314]  [<ffffffffa08409dd>] kvm_vm_ioctl+0x9d/0x920 [kvm]
[15528.614316]  [<ffffffff8127b547>] ? __fget+0x107/0x220
[15528.614318]  [<ffffffff810da5f9>] ? __lock_is_held+0x49/0x70
[15528.614320]  [<ffffffff8126e9b6>] do_vfs_ioctl+0x96/0x6c0
[15528.614321]  [<ffffffff8127b564>] ? __fget+0x124/0x220
[15528.614322]  [<ffffffff8127b445>] ? __fget+0x5/0x220
[15528.614324]  [<ffffffff8126f021>] SyS_ioctl+0x41/0x70
[15528.614326]  [<ffffffff816a8481>] entry_SYSCALL_64_fastpath+0x1f/0xc2

Signed-off-by: Mike Galbraith <efault@gmx.de>
---
 arch/x86/include/asm/kvm_host.h |    2 +-
 arch/x86/kvm/x86.c              |   20 ++++++++++----------
 2 files changed, 11 insertions(+), 11 deletions(-)

Index: linux-4.18.7-rt5/arch/x86/include/asm/kvm_host.h
===================================================================
--- linux-4.18.7-rt5.orig/arch/x86/include/asm/kvm_host.h
+++ linux-4.18.7-rt5/arch/x86/include/asm/kvm_host.h
@@ -826,7 +826,7 @@ struct kvm_arch {
        u64 cur_tsc_generation;
        int nr_vcpus_matched_tsc;
 
-       spinlock_t pvclock_gtod_sync_lock;
+       raw_spinlock_t pvclock_gtod_sync_lock;
        bool use_master_clock;
        u64 master_kernel_ns;
        u64 master_cycle_now;
Index: linux-4.18.7-rt5/arch/x86/kvm/x86.c
===================================================================
--- linux-4.18.7-rt5.orig/arch/x86/kvm/x86.c
+++ linux-4.18.7-rt5/arch/x86/kvm/x86.c
@@ -1689,7 +1689,7 @@ void kvm_write_tsc(struct kvm_vcpu *vcpu
        kvm_vcpu_write_tsc_offset(vcpu, offset);
        raw_spin_unlock_irqrestore(&kvm->arch.tsc_write_lock, flags);
 
-       spin_lock(&kvm->arch.pvclock_gtod_sync_lock);
+       raw_spin_lock(&kvm->arch.pvclock_gtod_sync_lock);
        if (!matched) {
                kvm->arch.nr_vcpus_matched_tsc = 0;
        } else if (!already_matched) {
@@ -1697,7 +1697,7 @@ void kvm_write_tsc(struct kvm_vcpu *vcpu
        }
 
        kvm_track_tsc_matching(vcpu);
-       spin_unlock(&kvm->arch.pvclock_gtod_sync_lock);
+       raw_spin_unlock(&kvm->arch.pvclock_gtod_sync_lock);
 }
 
 EXPORT_SYMBOL_GPL(kvm_write_tsc);
@@ -1921,7 +1921,7 @@ static void kvm_gen_update_masterclock(s
        struct kvm_vcpu *vcpu;
        struct kvm_arch *ka = &kvm->arch;
 
-       spin_lock(&ka->pvclock_gtod_sync_lock);
+       raw_spin_lock(&ka->pvclock_gtod_sync_lock);
        kvm_make_mclock_inprogress_request(kvm);
        /* no guest entries from this point */
        pvclock_update_vm_gtod_copy(kvm);
@@ -1933,7 +1933,7 @@ static void kvm_gen_update_masterclock(s
        kvm_for_each_vcpu(i, vcpu, kvm)
                kvm_clear_request(KVM_REQ_MCLOCK_INPROGRESS, vcpu);
 
-       spin_unlock(&ka->pvclock_gtod_sync_lock);
+       raw_spin_unlock(&ka->pvclock_gtod_sync_lock);
 #endif
 }
 
@@ -1943,15 +1943,15 @@ u64 get_kvmclock_ns(struct kvm *kvm)
        struct pvclock_vcpu_time_info hv_clock;
        u64 ret;
 
-       spin_lock(&ka->pvclock_gtod_sync_lock);
+       raw_spin_lock(&ka->pvclock_gtod_sync_lock);
        if (!ka->use_master_clock) {
-               spin_unlock(&ka->pvclock_gtod_sync_lock);
+               raw_spin_unlock(&ka->pvclock_gtod_sync_lock);
                return ktime_get_boot_ns() + ka->kvmclock_offset;
        }
 
        hv_clock.tsc_timestamp = ka->master_cycle_now;
        hv_clock.system_time = ka->master_kernel_ns + ka->kvmclock_offset;
-       spin_unlock(&ka->pvclock_gtod_sync_lock);
+       raw_spin_unlock(&ka->pvclock_gtod_sync_lock);
 
        /* both __this_cpu_read() and rdtsc() should be on the same cpu */
        get_cpu();
@@ -2043,13 +2043,13 @@ static int kvm_guest_time_update(struct
         * If the host uses TSC clock, then passthrough TSC as stable
         * to the guest.
         */
-       spin_lock(&ka->pvclock_gtod_sync_lock);
+       raw_spin_lock(&ka->pvclock_gtod_sync_lock);
        use_master_clock = ka->use_master_clock;
        if (use_master_clock) {
                host_tsc = ka->master_cycle_now;
                kernel_ns = ka->master_kernel_ns;
        }
-       spin_unlock(&ka->pvclock_gtod_sync_lock);
+       raw_spin_unlock(&ka->pvclock_gtod_sync_lock);
 
        /* Keep irq disabled to prevent changes to the clock */
        local_irq_save(flags);
@@ -8764,7 +8764,7 @@ int kvm_arch_init_vm(struct kvm *kvm, un
 
        raw_spin_lock_init(&kvm->arch.tsc_write_lock);
        mutex_init(&kvm->arch.apic_map_lock);
-       spin_lock_init(&kvm->arch.pvclock_gtod_sync_lock);
+       raw_spin_lock_init(&kvm->arch.pvclock_gtod_sync_lock);
 
        kvm->arch.kvmclock_offset = -ktime_get_boot_ns();
        pvclock_update_vm_gtod_copy(kvm);