From: Dave Hansen <dave.hansen@intel.com>
To: Kai Huang <kai.huang@intel.com>,
linux-sgx@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org
Cc: seanjc@google.com, jarkko@kernel.org, luto@kernel.org,
rick.p.edgecombe@intel.com, haitao.huang@intel.com,
pbonzini@redhat.com, bp@alien8.de, tglx@linutronix.de,
mingo@redhat.com, hpa@zytor.com
Subject: Re: [RFC PATCH v6 13/25] x86/sgx: Add helpers to expose ECREATE and EINIT to KVM
Date: Fri, 5 Mar 2021 09:51:56 -0800 [thread overview]
Message-ID: <64a2d65f-ddf9-b42b-5b51-76bb3b79a30e@intel.com> (raw)
In-Reply-To: <14908104a7ff5724b6fb4e4c7df6e675adafe5a7.1614338774.git.kai.huang@intel.com>
On 2/26/21 4:15 AM, Kai Huang wrote:
> +int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs,
> + int *trapnr)
> +{
> + int ret;
> +
> + /*
> + * @secs is userspace address, and it's not guaranteed @secs points at
> + * an actual EPC page.
There are four cases that I can think of:
1. @secs points to an EPC page. Good, return 0 and go on with life.
2. @secs points to a non-EPC page. It will fault and permanently error
out
3. @secs points to a Present=0 PTE. It will fault, but we need to call
the fault handler to get a page in here.
4. @secs points to a kernel address
#1 and #2 are handled and described.
#4 is probably impossible because the address comes out of some
gpa_to_hva() KVM code. But, it still _looks_ wonky here. I wouldn't
hate an access_ok() check on it.
/*
* @secs is an untrusted, userspace-provided address. It comes
* from KVM and is assumed to point somewhere in userspace.
* This can fault and call SGX or other fault handlers.
*/
You can also spend a moment to describe the kinds of faults that are
handled and what is fatal.
> + * to physical EPC page by resolving PFN but using __uaccess_xx() is
> + * simpler.
> + */
I'd leave the justification for the changelog.
> + __uaccess_begin();
> + ret = __ecreate(pageinfo, (void *)secs);
> + __uaccess_end();
> +
> + if (encls_faulted(ret)) {
> + *trapnr = ENCLS_TRAPNR(ret);
> + return -EFAULT;
> + }
next prev parent reply other threads:[~2021-03-05 17:52 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-26 12:14 [RFC PATCH v6 00/25] KVM SGX virtualization support Kai Huang
2021-02-26 12:14 ` [RFC PATCH v6 01/25] x86/cpufeatures: Make SGX_LC feature bit depend on SGX bit Kai Huang
2021-02-26 12:14 ` [RFC PATCH v6 02/25] x86/cpufeatures: Add SGX1 and SGX2 sub-features Kai Huang
2021-02-26 12:14 ` [RFC PATCH v6 03/25] x86/sgx: Wipe out EREMOVE from sgx_free_epc_page() Kai Huang
2021-02-26 17:08 ` Dave Hansen
2021-02-26 19:52 ` Sean Christopherson
2021-02-26 20:12 ` Dave Hansen
2021-02-26 22:34 ` Sean Christopherson
2021-03-01 6:13 ` Kai Huang
2021-02-26 12:14 ` [RFC PATCH v6 04/25] x86/sgx: Add SGX_CHILD_PRESENT hardware error code Kai Huang
2021-02-26 12:14 ` [RFC PATCH v6 05/25] x86/sgx: Introduce virtual EPC for use by KVM guests Kai Huang
2021-02-26 12:14 ` [RFC PATCH v6 06/25] x86/cpu/intel: Allow SGX virtualization without Launch Control support Kai Huang
2021-02-26 12:15 ` [RFC PATCH v6 07/25] x86/sgx: Initialize virtual EPC driver even when SGX driver is disabled Kai Huang
2021-02-26 12:15 ` [RFC PATCH v6 08/25] x86/sgx: Expose SGX architectural definitions to the kernel Kai Huang
2021-02-26 17:09 ` Dave Hansen
2021-02-26 12:15 ` [RFC PATCH v6 09/25] x86/sgx: Move ENCLS leaf definitions to sgx.h Kai Huang
2021-02-26 12:15 ` [RFC PATCH v6 10/25] x86/sgx: Add SGX2 ENCLS leaf definitions (EAUG, EMODPR and EMODT) Kai Huang
2021-02-26 12:15 ` [RFC PATCH v6 11/25] x86/sgx: Add encls_faulted() helper Kai Huang
2021-02-26 12:15 ` [RFC PATCH v6 12/25] x86/sgx: Add helper to update SGX_LEPUBKEYHASHn MSRs Kai Huang
2021-02-26 12:15 ` [RFC PATCH v6 13/25] x86/sgx: Add helpers to expose ECREATE and EINIT to KVM Kai Huang
2021-03-05 17:51 ` Dave Hansen [this message]
2021-03-08 9:30 ` Kai Huang
2021-02-26 12:15 ` [RFC PATCH v6 14/25] x86/sgx: Move provisioning device creation out of SGX driver Kai Huang
2021-03-05 17:45 ` Dave Hansen
2021-02-26 12:15 ` [RFC PATCH v6 15/25] KVM: x86: Export kvm_mmu_gva_to_gpa_{read,write}() for SGX (VMX) Kai Huang
2021-02-26 12:15 ` [RFC PATCH v6 16/25] KVM: x86: Define new #PF SGX error code bit Kai Huang
2021-02-26 12:15 ` [RFC PATCH v6 17/25] KVM: x86: Add support for reverse CPUID lookup of scattered features Kai Huang
2021-02-26 12:15 ` [RFC PATCH v6 18/25] KVM: x86: Add reverse-CPUID lookup support for scattered SGX features Kai Huang
2021-02-26 12:15 ` [RFC PATCH v6 19/25] KVM: VMX: Add basic handling of VM-Exit from SGX enclave Kai Huang
2021-02-26 12:15 ` [RFC PATCH v6 20/25] KVM: VMX: Frame in ENCLS handler for SGX virtualization Kai Huang
2021-02-26 12:15 ` [RFC PATCH v6 21/25] KVM: VMX: Add SGX ENCLS[ECREATE] handler to enforce CPUID restrictions Kai Huang
2021-02-26 12:15 ` [RFC PATCH v6 22/25] KVM: VMX: Add emulation of SGX Launch Control LE hash MSRs Kai Huang
2021-02-26 12:15 ` [RFC PATCH v6 23/25] KVM: VMX: Add ENCLS[EINIT] handler to support SGX Launch Control (LC) Kai Huang
2021-02-26 12:15 ` [RFC PATCH v6 24/25] KVM: VMX: Enable SGX virtualization for SGX1, SGX2 and LC Kai Huang
2021-02-26 12:16 ` [RFC PATCH v6 25/25] KVM: x86: Add capability to grant VM access to privileged SGX attribute Kai Huang
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