On Tue, 2 Feb 2021 17:36:12 -0800 Sean Christopherson wrote:
> On Wed, Feb 03, 2021, Edgecombe, Rick P wrote:
> > On Tue, 2021-01-26 at 22:31 +1300, Kai Huang wrote:
> > > +static int handle_encls_ecreate(struct kvm_vcpu *vcpu)
> > > +{
> > > + unsigned long a_hva, m_hva, x_hva, s_hva, secs_hva;
> > > + struct kvm_cpuid_entry2 *sgx_12_0, *sgx_12_1;
> > > + gpa_t metadata_gpa, contents_gpa, secs_gpa;
> > > + struct sgx_pageinfo pageinfo;
> > > + gva_t pageinfo_gva, secs_gva;
> > > + u64 attributes, xfrm, size;
> > > + struct x86_exception ex;
> > > + u8 max_size_log2;
> > > + u32 miscselect;
> > > + int trapnr, r;
> > > +
> > > + sgx_12_0 = kvm_find_cpuid_entry(vcpu, 0x12, 0);
> > > + sgx_12_1 = kvm_find_cpuid_entry(vcpu, 0x12, 1);
> > > + if (!sgx_12_0 || !sgx_12_1) {
> > > + kvm_inject_gp(vcpu, 0);
> > > + return 1;
> > > + }
> > > +
> > > + if (sgx_get_encls_gva(vcpu, kvm_rbx_read(vcpu), 32, 32,
> > > &pageinfo_gva) ||
> > > + sgx_get_encls_gva(vcpu, kvm_rcx_read(vcpu), 4096, 4096,
> > > &secs_gva))
> > > + return 1;
> > > +
> > > + /*
> > > + * Copy the PAGEINFO to local memory, its pointers need to be
> > > + * translated, i.e. we need to do a deep copy/translate.
> > > + */
> > > + r = kvm_read_guest_virt(vcpu, pageinfo_gva, &pageinfo,
> > > + sizeof(pageinfo), &ex);
> > > + if (r == X86EMUL_PROPAGATE_FAULT) {
> > > + kvm_inject_emulated_page_fault(vcpu, &ex);
> > > + return 1;
> > > + } else if (r != X86EMUL_CONTINUE) {
> > > + sgx_handle_emulation_failure(vcpu, pageinfo_gva,
> > > size);
> > > + return 0;
> > > + }
> > > +
> > > + /*
> > > + * Verify alignment early. This conveniently avoids having
> > > to worry
> > > + * about page splits on userspace addresses.
> > > + */
> > > + if (!IS_ALIGNED(pageinfo.metadata, 64) ||
> > > + !IS_ALIGNED(pageinfo.contents, 4096)) {
> > > + kvm_inject_gp(vcpu, 0);
> > > + return 1;
> > > + }
> > > +
> > > + /*
> > > + * Translate the SECINFO, SOURCE and SECS pointers from GVA
> > > to GPA.
> > > + * Resume the guest on failure to inject a #PF.
> > > + */
> > > + if (sgx_gva_to_gpa(vcpu, pageinfo.metadata, false,
> > > &metadata_gpa) ||
> > > + sgx_gva_to_gpa(vcpu, pageinfo.contents, false,
> > > &contents_gpa) ||
> > > + sgx_gva_to_gpa(vcpu, secs_gva, true, &secs_gpa))
> > > + return 1;
> > > +
> >
> > Do pageinfo.metadata and pageinfo.contents need cannonical checks here?
>
> Bugger, yes. So much boilerplate needed in this code :-/
>
> Maybe add yet another helper to do alignment+canonical checks, up where the
> IS_ALIGNED() calls are?
sgx_get_encls_gva() already does canonical check. Couldn't we just use it?
For instance:
if (sgx_get_encls_gva(vcpu, pageinfo.metadata, 64, 64 &metadata_gva) ||
sgx_get_encls_gva(vcpu, pageinfo.contents, 4096, 4096,
&contents_gva))
return 1;
