From: Wanpeng Li <wanpengli@xxxxxxxxxxx>
Expose PV_SEND_IPI feature bit to guest, the guest can check this feature
bit before using paravirtualized send IPIs.
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Radim Krčmář <rkrcmar@xxxxxxxxxx>
Cc: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Signed-off-by: Wanpeng Li <wanpengli@xxxxxxxxxxx>
---
Documentation/virtual/kvm/cpuid.txt | 4 ++++
arch/x86/kvm/cpuid.c | 3 ++-
2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/Documentation/virtual/kvm/cpuid.txt b/Documentation/virtual/kvm/cpuid.txt
index ab022dc..97ca194 100644
--- a/Documentation/virtual/kvm/cpuid.txt
+++ b/Documentation/virtual/kvm/cpuid.txt
@@ -62,6 +62,10 @@ KVM_FEATURE_ASYNC_PF_VMEXIT || 10 || paravirtualized async PF VM exit
|| || can be enabled by setting bit 2
|| || when writing to msr 0x4b564d02
------------------------------------------------------------------------------
+KVM_FEATURE_PV_SEND_IPI || 11 || guest checks this feature bit
+ || || before using paravirtualized
+ || || send IPIs.
+------------------------------------------------------------------------------
KVM_FEATURE_CLOCKSOURCE_STABLE_BIT || 24 || host will warn if no guest-side
|| || per-cpu warps are expected in
|| || kvmclock.
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 7e042e3..7bcfa61 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -621,7 +621,8 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
(1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) |
(1 << KVM_FEATURE_PV_UNHALT) |
(1 << KVM_FEATURE_PV_TLB_FLUSH) |
- (1 << KVM_FEATURE_ASYNC_PF_VMEXIT);
+ (1 << KVM_FEATURE_ASYNC_PF_VMEXIT) |
+ (1 << KVM_FEATURE_PV_SEND_IPI);
if (sched_info_on())
entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
--
2.7.4
