From: Sean Christopherson <seanjc@google.com>
To: Kai Huang <kai.huang@intel.com>
Cc: kvm@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org,
linux-kernel@vger.kernel.org, jarkko@kernel.org, luto@kernel.org,
dave.hansen@intel.com, 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: [PATCH 03/25] x86/sgx: Wipe out EREMOVE from sgx_free_epc_page()
Date: Mon, 1 Mar 2021 09:29:46 -0800 [thread overview]
Message-ID: <YD0kinxqJF1w+BZf@google.com> (raw)
In-Reply-To: <9c2c83ccc7324390bfb302bd327d9236b890c679.1614590788.git.kai.huang@intel.com>
On Mon, Mar 01, 2021, Kai Huang wrote:
> diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
> index 7449ef33f081..a7dc86e87a09 100644
> --- a/arch/x86/kernel/cpu/sgx/encl.c
> +++ b/arch/x86/kernel/cpu/sgx/encl.c
> @@ -381,6 +381,26 @@ const struct vm_operations_struct sgx_vm_ops = {
> .access = sgx_vma_access,
> };
>
> +static void sgx_encl_free_epc_page(struct sgx_epc_page *epc_page)
> +{
> + int ret;
> +
> + WARN_ON_ONCE(epc_page->flags & SGX_EPC_PAGE_RECLAIMER_TRACKED);
> +
> + ret = __eremove(sgx_get_epc_virt_addr(epc_page));
> + if (WARN_ONCE(ret, "EREMOVE returned %d (0x%x)", ret, ret)) {
This can be ENCLS_WARN, especially if you're printing a separate error message
about leaking the page. That being said, I'm not sure a seperate error message
is a good idea. If other stuff gets dumped to the kernel log between the WARN
and the pr_err_once(), it may not be clear to admins that the two events are
directly connected. It's even possible the prints could come from two different
CPUs.
Why not dump a short blurb in the WARN itself? The error message can be thrown
in a define if the line length is too obnoxious (it's ~109 chars if embedded
directly).
#define EREMOVE_ERROR_MESSAGE \
"EREMOVE returned %d (0x%x). EPC page leaked, reboot recommended."
if (WARN_ONCE(ret, EREMOVE_ERROR_MESSAGE, ret, ret))
> + /*
> + * Give a message to remind EPC page is leaked, and requires
> + * machine reboot to get leaked pages back. This can be improved
> + * in the future by adding stats of leaked pages, etc.
> + */
> + pr_err_once("EPC page is leaked. Require machine reboot to get leaked pages back.\n");
> + return;
> + }
> +
> + sgx_free_epc_page(epc_page);
> +}
> +
> /**
> * sgx_encl_release - Destroy an enclave instance
> * @kref: address of a kref inside &sgx_encl
next prev parent reply other threads:[~2021-03-01 22:13 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-01 9:44 [PATCH 00/25] KVM SGX virtualization support Kai Huang
2021-03-01 9:44 ` [PATCH 01/25] x86/cpufeatures: Make SGX_LC feature bit depend on SGX bit Kai Huang
2021-03-01 9:44 ` [PATCH 02/25] x86/cpufeatures: Add SGX1 and SGX2 sub-features Kai Huang
2021-03-01 10:00 ` Borislav Petkov
2021-03-01 10:19 ` Kai Huang
2021-03-01 10:30 ` Borislav Petkov
2021-03-01 10:40 ` Kai Huang
2021-03-01 10:53 ` Borislav Petkov
2021-03-01 11:28 ` Kai Huang
2021-03-01 11:32 ` Borislav Petkov
2021-03-01 11:43 ` Kai Huang
2021-03-01 11:58 ` Borislav Petkov
2021-03-01 12:08 ` Kai Huang
2021-03-02 15:48 ` Haitao Huang
2021-03-02 15:58 ` Dave Hansen
2021-03-07 22:49 ` Kai Huang
2021-03-10 15:30 ` Jarkko Sakkinen
2021-03-02 16:02 ` Sean Christopherson
2021-03-02 17:53 ` Boris Petkov
2021-03-02 18:27 ` Kai Huang
2021-03-01 9:44 ` [PATCH 03/25] x86/sgx: Wipe out EREMOVE from sgx_free_epc_page() Kai Huang
2021-03-01 17:29 ` Sean Christopherson [this message]
2021-03-02 0:32 ` Kai Huang
2021-03-01 9:44 ` [PATCH 04/25] x86/sgx: Add SGX_CHILD_PRESENT hardware error code Kai Huang
2021-03-01 9:44 ` [PATCH 05/25] x86/sgx: Introduce virtual EPC for use by KVM guests Kai Huang
2021-03-01 16:21 ` Sean Christopherson
2021-03-02 0:33 ` Kai Huang
2021-03-01 9:45 ` [PATCH 06/25] x86/cpu/intel: Allow SGX virtualization without Launch Control support Kai Huang
2021-03-05 17:29 ` Borislav Petkov
2021-03-07 23:50 ` Kai Huang
2021-03-08 0:19 ` Kai Huang
2021-03-10 15:32 ` Jarkko Sakkinen
2021-03-01 9:45 ` [PATCH 07/25] x86/sgx: Initialize virtual EPC driver even when SGX driver is disabled Kai Huang
2021-03-01 9:45 ` [PATCH 08/25] x86/sgx: Expose SGX architectural definitions to the kernel Kai Huang
2021-03-01 9:45 ` [PATCH 09/25] x86/sgx: Move ENCLS leaf definitions to sgx.h Kai Huang
2021-03-01 16:25 ` Sean Christopherson
2021-03-02 0:34 ` Kai Huang
2021-03-01 9:45 ` [PATCH 10/25] x86/sgx: Add SGX2 ENCLS leaf definitions (EAUG, EMODPR and EMODT) Kai Huang
2021-03-01 9:45 ` [PATCH 11/25] x86/sgx: Add encls_faulted() helper Kai Huang
2021-03-01 9:45 ` [PATCH 12/25] x86/sgx: Add helper to update SGX_LEPUBKEYHASHn MSRs Kai Huang
2021-03-01 16:57 ` Sean Christopherson
2021-03-02 0:34 ` Kai Huang
2021-03-01 9:45 ` [PATCH 13/25] x86/sgx: Add helpers to expose ECREATE and EINIT to KVM Kai Huang
2021-03-01 9:45 ` [PATCH 14/25] x86/sgx: Move provisioning device creation out of SGX driver Kai Huang
2021-03-01 9:45 ` [PATCH 15/25] KVM: x86: Export kvm_mmu_gva_to_gpa_{read,write}() for SGX (VMX) Kai Huang
2021-03-01 9:45 ` [PATCH 16/25] KVM: x86: Define new #PF SGX error code bit Kai Huang
2021-03-01 9:45 ` [PATCH 17/25] KVM: x86: Add support for reverse CPUID lookup of scattered features Kai Huang
2021-03-01 9:45 ` [PATCH 18/25] KVM: x86: Add reverse-CPUID lookup support for scattered SGX features Kai Huang
2021-03-01 9:45 ` [PATCH 19/25] KVM: VMX: Add basic handling of VM-Exit from SGX enclave Kai Huang
2021-03-01 16:52 ` Sean Christopherson
2021-03-02 0:50 ` Kai Huang
2021-03-01 9:45 ` [PATCH 20/25] KVM: VMX: Frame in ENCLS handler for SGX virtualization Kai Huang
2021-03-01 9:45 ` [PATCH 21/25] KVM: VMX: Add SGX ENCLS[ECREATE] handler to enforce CPUID restrictions Kai Huang
2021-03-01 17:20 ` Sean Christopherson
2021-03-02 0:54 ` Kai Huang
2021-03-02 5:34 ` Kai Huang
2021-03-02 8:44 ` Kai Huang
2021-03-01 9:45 ` [PATCH 22/25] KVM: VMX: Add emulation of SGX Launch Control LE hash MSRs Kai Huang
2021-03-01 9:45 ` [PATCH 23/25] KVM: VMX: Add ENCLS[EINIT] handler to support SGX Launch Control (LC) Kai Huang
2021-03-01 9:45 ` [PATCH 24/25] KVM: VMX: Enable SGX virtualization for SGX1, SGX2 and LC Kai Huang
2021-03-01 9:46 ` [PATCH 25/25] KVM: x86: Add capability to grant VM access to privileged SGX attribute Kai Huang
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