s/Introduce/Use
This doesn't "introduce" anything, in the sense that it's an AMD-defined error
code flag. That matters because KVM *did* introduce/define PFERR_IMPLICIT_ACCESS.
On Thu, Jul 20, 2023, isaku.yamahata@xxxxxxxxx wrote:
> From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
>
> Add two PFERR codes to designate that the page fault is private and that
> it requires looking up memory attributes. The vendor kvm page fault
> handler should set PFERR_GUEST_ENC_MASK bit based on their fault
> information. It may or may not use the hardware value directly or
> parse the hardware value to set the bit.
>
> For KVM_X86_PROTECTED_VM, ask memory attributes for the fault privateness.
...
> +static inline bool kvm_is_fault_private(struct kvm *kvm, gpa_t gpa, u64 error_code)
> +{
> + /*
> + * This is racy with mmu_seq. If we hit a race, it would result in a
> + * spurious KVM_EXIT_MEMORY_FAULT.
> + */
> + if (kvm->arch.vm_type == KVM_X86_SW_PROTECTED_VM)
> + return kvm_mem_is_private(kvm, gpa_to_gfn(gpa));
Please synthesize the error code flag for SW-protected VMs, same as TDX, e.g.
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 20e289e872eb..de9e0a9c41e6 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5751,6 +5751,10 @@ int noinline kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 err
if (WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root.hpa)))
return RET_PF_RETRY;
+ if (vcpu->kvm->arch.vm_type == KVM_X86_SW_PROTECTED_VM &&
+ kvm_mem_is_private(vcpu->kvm, gpa_to_gfn(cr2_or_gpa)))
+ error_code |= PFERR_GUEST_ENC_MASK;
+
r = RET_PF_INVALID;
if (unlikely(error_code & PFERR_RSVD_MASK)) {
r = handle_mmio_page_fault(vcpu, cr2_or_gpa, direct);
Functionally it's the same, but I want all VM types to have the same source of
truth for private versus shared, and I really don't want kvm_is_fault_private()
to exist.
