Commit 5f8bb004 authored Oct 11, 2018 by Vitaly Kuznetsov Committed by Paolo Bonzini Oct 13, 2018

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 877ad952 ("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: 877ad952 ("KVM: vmx: Add tlb_remote_flush callback support")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent 4cebf459

arch/x86/kvm/vmx.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -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);

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