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KVM: vmx: hyper-v: don't pass EPT configuration info to vmx_hv_remote_flush_tlb()
authorVitaly Kuznetsov <vkuznets@redhat.com>
Thu, 11 Oct 2018 10:03:12 +0000 (12:03 +0200)
committerPaolo Bonzini <pbonzini@redhat.com>
Sat, 13 Oct 2018 09:38:54 +0000 (11:38 +0200)
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 <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
arch/x86/kvm/vmx.c

index 612fd17..e665aa7 100644 (file)
@@ -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);