kvm_read_guest_virt returning unexpected data

[KVM Man <kvmman602@xxxxxxxxx>]

Hi,

I'm making changes to KVM on linux 5.11.4 while using qemu 5.0.0 and
having issues using kvm_read_guest_virt successfully with an x86_64 VM
guest.

I call kvm_read_guest_virt in a VM exit handler, and it returns data
that's unexpected, as compared to what I see with a kernel debugger
attached to the guest. The function returns a successful error code
(X86EMUL_CONTINUE), and I've verified that virtual to physical address
translation is working properly when kvm_read_guest_virt_helper calls
vcpu->arch.walk_mmu->gva_to_gpa.

Are there any reasons that this function would not work as expected?

Thanks.