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authorMichael S. Tsirkin <mst@redhat.com>2018-05-17 17:54:24 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2018-05-17 19:12:13 +0200
commit633711e82878dc29083fc5d2605166755e25b57a (patch)
tree7abc99cfd5b05e144b41d7b56a4b929cf7a1e19d
parent711702b57cc3c50b84bd648de0f1ca0a378805be (diff)
downloadlinux-633711e82878dc29083fc5d2605166755e25b57a.tar.bz2
kvm: rename KVM_HINTS_DEDICATED to KVM_HINTS_REALTIME
KVM_HINTS_DEDICATED seems to be somewhat confusing: Guest doesn't really care whether it's the only task running on a host CPU as long as it's not preempted. And there are more reasons for Guest to be preempted than host CPU sharing, for example, with memory overcommit it can get preempted on a memory access, post copy migration can cause preemption, etc. Let's call it KVM_HINTS_REALTIME which seems to better match what guests expect. Also, the flag most be set on all vCPUs - current guests assume this. Note so in the documentation. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--Documentation/virtual/kvm/cpuid.txt6
-rw-r--r--arch/x86/include/uapi/asm/kvm_para.h2
-rw-r--r--arch/x86/kernel/kvm.c8
3 files changed, 8 insertions, 8 deletions
diff --git a/Documentation/virtual/kvm/cpuid.txt b/Documentation/virtual/kvm/cpuid.txt
index d4f33eb805dd..ab022dcd0911 100644
--- a/Documentation/virtual/kvm/cpuid.txt
+++ b/Documentation/virtual/kvm/cpuid.txt
@@ -72,8 +72,8 @@ KVM_FEATURE_CLOCKSOURCE_STABLE_BIT || 24 || host will warn if no guest-side
flag || value || meaning
==================================================================================
-KVM_HINTS_DEDICATED || 0 || guest checks this feature bit to
- || || determine if there is vCPU pinning
- || || and there is no vCPU over-commitment,
+KVM_HINTS_REALTIME || 0 || guest checks this feature bit to
+ || || determine that vCPUs are never
+ || || preempted for an unlimited time,
|| || allowing optimizations
----------------------------------------------------------------------------------
diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h
index 4c851ebb3ceb..0ede697c3961 100644
--- a/arch/x86/include/uapi/asm/kvm_para.h
+++ b/arch/x86/include/uapi/asm/kvm_para.h
@@ -29,7 +29,7 @@
#define KVM_FEATURE_PV_TLB_FLUSH 9
#define KVM_FEATURE_ASYNC_PF_VMEXIT 10
-#define KVM_HINTS_DEDICATED 0
+#define KVM_HINTS_REALTIME 0
/* The last 8 bits are used to indicate how to interpret the flags field
* in pvclock structure. If no bits are set, all flags are ignored.
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 7867417cfaff..5b2300b818af 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -457,7 +457,7 @@ static void __init sev_map_percpu_data(void)
static void __init kvm_smp_prepare_cpus(unsigned int max_cpus)
{
native_smp_prepare_cpus(max_cpus);
- if (kvm_para_has_hint(KVM_HINTS_DEDICATED))
+ if (kvm_para_has_hint(KVM_HINTS_REALTIME))
static_branch_disable(&virt_spin_lock_key);
}
@@ -553,7 +553,7 @@ static void __init kvm_guest_init(void)
}
if (kvm_para_has_feature(KVM_FEATURE_PV_TLB_FLUSH) &&
- !kvm_para_has_hint(KVM_HINTS_DEDICATED) &&
+ !kvm_para_has_hint(KVM_HINTS_REALTIME) &&
kvm_para_has_feature(KVM_FEATURE_STEAL_TIME))
pv_mmu_ops.flush_tlb_others = kvm_flush_tlb_others;
@@ -649,7 +649,7 @@ static __init int kvm_setup_pv_tlb_flush(void)
int cpu;
if (kvm_para_has_feature(KVM_FEATURE_PV_TLB_FLUSH) &&
- !kvm_para_has_hint(KVM_HINTS_DEDICATED) &&
+ !kvm_para_has_hint(KVM_HINTS_REALTIME) &&
kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) {
for_each_possible_cpu(cpu) {
zalloc_cpumask_var_node(per_cpu_ptr(&__pv_tlb_mask, cpu),
@@ -745,7 +745,7 @@ void __init kvm_spinlock_init(void)
if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT))
return;
- if (kvm_para_has_hint(KVM_HINTS_DEDICATED))
+ if (kvm_para_has_hint(KVM_HINTS_REALTIME))
return;
__pv_init_lock_hash();