On Mon, 2025-06-09 at 22:13 +0300, Kirill A. Shutemov wrote:
> int tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn,
> enum pg_level level, kvm_pfn_t pfn)
> {
> + struct kvm_vcpu *vcpu = kvm_get_running_vcpu();
This is unfortunate. In practice, all of the callers will be in a vCPU context,
but __tdp_mmu_set_spte_atomic() can be called for zap's which is why there is no
vCPU.
We don't want to split the tdp mmu calling code to introduce a variant that has
a vCPU.
What about a big comment? Or checking for NULL and returning -EINVAL like
PG_LEVEL_4K below? I guess in this case a NULL pointer will be plenty loud. So
probably a comment is enough.
Hmm, the only reason we need the vCPU here is to get at the the per-vCPU pamt
page cache. This is also the reason for the strange callback scheme I was
complaining about in the other patch. It kind of seems like there are two
friction points in this series:
1. How to allocate dpamt pages
2. How to serialize the global DPAMT resource inside a read lock
I'd like to try to figure out a better solution for (1). (2) seems good. But I'm
still processing.
> struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
> struct page *page = pfn_to_page(pfn);
> + int ret;
> +
> + ret = tdx_pamt_get(page, level, tdx_alloc_pamt_page_atomic, vcpu);
> + if (ret)
> + return ret;
