On Wed, Mar 27, 2024 at 12:27:03AM +0000,
"Edgecombe, Rick P" <rick.p.edgecombe@xxxxxxxxx> wrote:
> On Mon, 2024-02-26 at 00:25 -0800, isaku.yamahata@xxxxxxxxx wrote:
> > +/* VMM can pass one 64bit auxiliary data to vcpu via RCX for guest BIOS. */
> > +static int tdx_td_vcpu_init(struct kvm_vcpu *vcpu, u64 vcpu_rcx)
> > +{
> > + struct kvm_tdx *kvm_tdx = to_kvm_tdx(vcpu->kvm);
> > + struct vcpu_tdx *tdx = to_tdx(vcpu);
> > + unsigned long *tdvpx_pa = NULL;
> > + unsigned long tdvpr_pa;
>
>
> I think we could drop theselocal variables and just use tdx->tdvpr_pa and tdx->tdvpx_pa. Then we
> don't have to have the assignments later.
Yes, let me clean it up. The old version acquired spin lock in the middle. Now
we don't have it.
> > + unsigned long va;
> > + int ret, i;
> > + u64 err;
> > +
> > + if (is_td_vcpu_created(tdx))
> > + return -EINVAL;
> > +
> > + /*
> > + * vcpu_free method frees allocated pages. Avoid partial setup so
> > + * that the method can't handle it.
> > + */
> > + va = __get_free_page(GFP_KERNEL_ACCOUNT);
> > + if (!va)
> > + return -ENOMEM;
> > + tdvpr_pa = __pa(va);
> > +
> > + tdvpx_pa = kcalloc(tdx_info->nr_tdvpx_pages, sizeof(*tdx->tdvpx_pa),
> > + GFP_KERNEL_ACCOUNT);
> > + if (!tdvpx_pa) {
> > + ret = -ENOMEM;
> > + goto free_tdvpr;
> > + }
> > + for (i = 0; i < tdx_info->nr_tdvpx_pages; i++) {
> > + va = __get_free_page(GFP_KERNEL_ACCOUNT);
> > + if (!va) {
> > + ret = -ENOMEM;
> > + goto free_tdvpx;
> > + }
> > + tdvpx_pa[i] = __pa(va);
> > + }
> > +
> > + err = tdh_vp_create(kvm_tdx->tdr_pa, tdvpr_pa);
> > + if (KVM_BUG_ON(err, vcpu->kvm)) {
> > + ret = -EIO;
> > + pr_tdx_error(TDH_VP_CREATE, err, NULL);
> > + goto free_tdvpx;
> > + }
> > + tdx->tdvpr_pa = tdvpr_pa;
> > +
> > + tdx->tdvpx_pa = tdvpx_pa;
>
> Or alternatively let's move these to right before they are used. (in the current branch
>
> > + for (i = 0; i < tdx_info->nr_tdvpx_pages; i++) {
> > + err = tdh_vp_addcx(tdx->tdvpr_pa, tdvpx_pa[i]);
> > + if (KVM_BUG_ON(err, vcpu->kvm)) {
> > + pr_tdx_error(TDH_VP_ADDCX, err, NULL);
> > + for (; i < tdx_info->nr_tdvpx_pages; i++) {
> > + free_page((unsigned long)__va(tdvpx_pa[i]));
> > + tdvpx_pa[i] = 0;
> > + }
> > + /* vcpu_free method frees TDVPX and TDR donated to TDX */
> > + return -EIO;
> > + }
> > + }
> >
> >
> In the current branch tdh_vp_init() takes struct vcpu_tdx, so they would be moved right here.
>
> What do you think?
Yes, I should revise the error recovery path.
--
Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
