Re: [PATCH Part2 v6 41/49] KVM: SVM: Add support to handle the RMP nested page fault

[Jarkko Sakkinen]

On Mon, Jun 20, 2022 at 11:13:03PM +0000, Ashish Kalra wrote:
> From: Brijesh Singh <brijesh.singh@xxxxxxx>
> 
> When SEV-SNP is enabled in the guest, the hardware places restrictions on
> all memory accesses based on the contents of the RMP table. When hardware
> encounters RMP check failure caused by the guest memory access it raises
> the #NPF. The error code contains additional information on the access
> type. See the APM volume 2 for additional information.
> 
> Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
> ---
>  arch/x86/kvm/svm/sev.c | 76 ++++++++++++++++++++++++++++++++++++++++++
>  arch/x86/kvm/svm/svm.c | 14 +++++---
>  2 files changed, 86 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
> index 4ed90331bca0..7fc0fad87054 100644
> --- a/arch/x86/kvm/svm/sev.c
> +++ b/arch/x86/kvm/svm/sev.c
> @@ -4009,3 +4009,79 @@ void sev_post_unmap_gfn(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn)
>  
>  	spin_unlock(&sev->psc_lock);
>  }
> +
> +void handle_rmp_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code)
> +{
> +	int rmp_level, npt_level, rc, assigned;
> +	struct kvm *kvm = vcpu->kvm;
> +	gfn_t gfn = gpa_to_gfn(gpa);
> +	bool need_psc = false;
> +	enum psc_op psc_op;
> +	kvm_pfn_t pfn;
> +	bool private;
> +
> +	write_lock(&kvm->mmu_lock);
> +
> +	if (unlikely(!kvm_mmu_get_tdp_walk(vcpu, gpa, &pfn, &npt_level)))

This function does not exist. Should it be kvm_mmu_get_tdp_page?

BR, Jarkko