From 344c6c804703841d2bff4d68d7390ba726053874 Mon Sep 17 00:00:00 2001 From: Tianyu Lan Date: Thu, 22 Aug 2019 22:30:20 +0800 Subject: KVM/Hyper-V: Add new KVM capability KVM_CAP_HYPERV_DIRECT_TLBFLUSH Hyper-V direct tlb flush function should be enabled for guest that only uses Hyper-V hypercall. User space hypervisor(e.g, Qemu) can disable KVM identification in CPUID and just exposes Hyper-V identification to make sure the precondition. Add new KVM capability KVM_CAP_ HYPERV_DIRECT_TLBFLUSH for user space to enable Hyper-V direct tlb function and this function is default to be disabled in KVM. Signed-off-by: Tianyu Lan Signed-off-by: Paolo Bonzini --- arch/x86/kvm/x86.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'arch/x86/kvm') diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index bb93771e4170..5becc6753280 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3282,6 +3282,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = kvm_x86_ops->get_nested_state ? kvm_x86_ops->get_nested_state(NULL, NULL, 0) : 0; break; + case KVM_CAP_HYPERV_DIRECT_TLBFLUSH: + r = kvm_x86_ops->enable_direct_tlbflush ? 1 : 0; + break; default: break; } @@ -4055,6 +4058,11 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu, r = -EFAULT; } return r; + case KVM_CAP_HYPERV_DIRECT_TLBFLUSH: + if (!kvm_x86_ops->enable_direct_tlbflush) + return -ENOTTY; + + return kvm_x86_ops->enable_direct_tlbflush(vcpu); default: return -EINVAL; -- cgit