From 5f8bb004bca43f7b5043c02b4aa5b9b43e15fe50 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Thu, 11 Oct 2018 12:03:12 +0200 Subject: [PATCH] KVM: vmx: hyper-v: don't pass EPT configuration info to vmx_hv_remote_flush_tlb() I'm observing random crashes in multi-vCPU L2 guests running on KVM on Hyper-V. I bisected the issue to the commit 877ad952be3d ("KVM: vmx: Add tlb_remote_flush callback support"). Hyper-V TLFS states: "AddressSpace specifies an address space ID (an EPT PML4 table pointer)" So apparently, Hyper-V doesn't expect us to pass naked EPTP, only PML4 pointer should be used. Strip off EPT configuration information before calling into vmx_hv_remote_flush_tlb(). Fixes: 877ad952be3d ("KVM: vmx: Add tlb_remote_flush callback support") Signed-off-by: Vitaly Kuznetsov Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 612fd17be635..e665aa7167cf 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1572,8 +1572,12 @@ static int vmx_hv_remote_flush_tlb(struct kvm *kvm) goto out; } + /* + * FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE hypercall needs the address of the + * base of EPT PML4 table, strip off EPT configuration information. + */ ret = hyperv_flush_guest_mapping( - to_vmx(kvm_get_vcpu(kvm, 0))->ept_pointer); + to_vmx(kvm_get_vcpu(kvm, 0))->ept_pointer & PAGE_MASK); out: spin_unlock(&to_kvm_vmx(kvm)->ept_pointer_lock);