Commit 7b367bc9 authored Sep 23, 2020 by Sean Christopherson Committed by Paolo Bonzini Sep 28, 2020

KVM: x86/mmu: Return -EIO if page fault returns RET_PF_INVALID



Exit to userspace with an error if the MMU is buggy and returns
RET_PF_INVALID when servicing a page fault.  This will allow a future
patch to invert the emulation path, i.e. emulate only on RET_PF_EMULATE
instead of emulating on anything but RET_PF_RETRY.  This technically
means that KVM will exit to userspace instead of emulating on
RET_PF_INVALID, but practically speaking it's a nop as the MMU never
returns RET_PF_INVALID.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200923220425.18402-2-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent 2de4085c

arch/x86/kvm/mmu/mmu.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -5462,7 +5462,8 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code,
		if (r == RET_PF_INVALID) {
		r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa,
		lower_32_bits(error_code), false);
		WARN_ON(r == RET_PF_INVALID);
		if (WARN_ON_ONCE(r == RET_PF_INVALID))
		return -EIO;
		}

		if (r == RET_PF_RETRY)

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