From: Wanpeng Li <wanpengli@xxxxxxxxxxx>
Allow to disable ioport intercept by userspace.
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Radim Krčmář <rkrcmar@xxxxxxxxxx>
Cc: Tim Shearer <tshearer@xxxxxxxxxxxxxxx>
Cc: Liran Alon <liran.alon@xxxxxxxxxx>
Signed-off-by: Wanpeng Li <wanpengli@xxxxxxxxxxx>
---
Documentation/virtual/kvm/api.txt | 11 +++++++++++
arch/x86/include/asm/kvm_host.h | 2 ++
arch/x86/kvm/x86.c | 5 +++++
include/uapi/linux/kvm.h | 1 +
4 files changed, 19 insertions(+)
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 1c7958b..3d0488e 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -4378,6 +4378,17 @@ all such vmexits.
Do not enable KVM_FEATURE_PV_UNHALT if you disable HLT exits.
+7.14 KVM_CAP_IOPORT_DISABLE_INTERCEPT
+
+Architectures: x86
+Parameters: args[0] defines whether ioport intercept
+
+When disable intercept (args[0] == 1), some ioports which frequently
+access will not be intercepted.
+
+When enable intercept (args[0] == 0), behavior is as if this facility
+is unsupported.
+
8. Other capabilities.
----------------------
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index c25775f..2f29f64 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -808,6 +808,8 @@ struct kvm_arch {
bool hlt_in_guest;
bool pause_in_guest;
+ bool ioport_disable_intercept;
+
unsigned long irq_sources_bitmap;
s64 kvmclock_offset;
raw_spinlock_t tsc_write_lock;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 51ecd38..044e314 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2881,6 +2881,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_SPLIT_IRQCHIP:
case KVM_CAP_IMMEDIATE_EXIT:
case KVM_CAP_GET_MSR_FEATURES:
+ case KVM_CAP_IOPORT_DISABLE_INTERCEPT:
r = 1;
break;
case KVM_CAP_SYNC_REGS:
@@ -4250,6 +4251,10 @@ static int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
kvm->arch.pause_in_guest = true;
r = 0;
break;
+ case KVM_CAP_IOPORT_DISABLE_INTERCEPT:
+ kvm->arch.ioport_disable_intercept = cap->args[0];
+ r = 0;
+ break;
default:
r = -EINVAL;
break;
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 1065006..92730d8 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -941,6 +941,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_S390_BPB 152
#define KVM_CAP_GET_MSR_FEATURES 153
#define KVM_CAP_HYPERV_EVENTFD 154
+#define KVM_CAP_IOPORT_DISABLE_INTERCEPT 155
#ifdef KVM_CAP_IRQ_ROUTING
--
2.7.4
