From: Andi Kleen <ak@linux.intel.com>
To: "Michael S. Tsirkin" <mst@redhat.com>,
Kuppuswamy Sathyanarayanan
<sathyanarayanan.kuppuswamy@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Peter Zijlstra <peterz@infradead.org>,
Andy Lutomirski <luto@kernel.org>,
Bjorn Helgaas <bhelgaas@google.com>,
Richard Henderson <rth@twiddle.net>,
Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
James E J Bottomley <James.Bottomley@hansenpartnership.com>,
Helge Deller <deller@gmx.de>,
"David S . Miller" <davem@davemloft.net>,
Arnd Bergmann <arnd@arndb.de>, Jonathan Corbet <corbet@lwn.net>,
Paolo Bonzini <pbonzini@redhat.com>,
David Hildenbrand <david@redhat.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Peter H Anvin <hpa@zytor.com>,
Dave Hansen <dave.hansen@intel.com>,
Tony Luck <tony.luck@intel.com>,
Dan Williams <dan.j.williams@intel.com>,
Kirill Shutemov <kirill.shutemov@linux.intel.com>,
Sean Christopherson <seanjc@google.com>,
Kuppuswamy Sathyanarayanan <knsathya@kernel.org>,
x86@kernel.org, linux-kernel@vger.kernel.org,
linux-pci@vger.kernel.org, linux-alpha@vger.kernel.org,
linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org,
sparclinux@vger.kernel.org, linux-arch@vger.kernel.org,
linux-doc@vger.kernel.org,
virtualization@lists.linux-foundation.org
Subject: Re: [PATCH v5 12/16] PCI: Add pci_iomap_host_shared(), pci_iomap_host_shared_range()
Date: Sun, 10 Oct 2021 15:22:39 -0700 [thread overview]
Message-ID: <cec62ebb-87d7-d725-1096-2c97c5eedbc3@linux.intel.com> (raw)
In-Reply-To: <20211009053103-mutt-send-email-mst@kernel.org>
> To which Andi replied
> One problem with removing the ioremap opt-in is that
> it's still possible for drivers to get at devices without going through probe.
>
> To which Greg replied:
> https://lore.kernel.org/all/YVXBNJ431YIWwZdQ@kroah.com/
> If there are in-kernel PCI drivers that do not do this, they need to be
> fixed today.
>
> Can you guys resolve the differences here?
I addressed this in my other mail, but we may need more discussion.
>
> And once they are resolved, mention this in the commit log so
> I don't get to re-read the series just to find out nothing
> changed in this respect?
>
> I frankly do not believe we are anywhere near being able to harden
> an arbitrary kernel config against attack.
Why not? Device filter and the opt-ins together are a fairly strong
mechanism.
And it's not that they're a lot of code or super complicated either.
You're essentially objecting to a single line change in your subsystem here.
> How about creating a defconfig that makes sense for TDX then?
TDX can be used in many different ways, I don't think a defconfig is
practical.
In theory you could do some Kconfig dependency (at the pain point of
having separate kernel binariees), but why not just do it at run time
then if you maintain the list anyways. That's much easier and saner for
everyone. In the past we usually always ended up with runtime mechanism
for similar things anyways.
Also it turns out that the filter mechanisms are needed for some arch
drivers which are not even configurable, so alone it's probably not enough,
> Anyone deviating from that better know what they are doing,
> this API tweaking is just putting policy into the kernel ...
Hardening drivers is kernel policy. It cannot be done anywhere else.
-Andi
next prev parent reply other threads:[~2021-10-10 22:22 UTC|newest]
Thread overview: 83+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-09 0:36 [PATCH v5 00/16] Add TDX Guest Support (shared-mm support) Kuppuswamy Sathyanarayanan
2021-10-09 0:36 ` [PATCH v5 01/16] x86/mm: Move force_dma_unencrypted() to common code Kuppuswamy Sathyanarayanan
2021-10-20 16:11 ` Tom Lendacky
2021-10-20 16:43 ` Sathyanarayanan Kuppuswamy
2021-10-09 0:36 ` [PATCH v5 02/16] x86/tdx: Get TD execution environment information via TDINFO Kuppuswamy Sathyanarayanan
2021-10-09 0:36 ` [PATCH v5 03/16] x86/tdx: Exclude Shared bit from physical_mask Kuppuswamy Sathyanarayanan
2021-11-05 22:11 ` Sean Christopherson
2021-11-08 14:45 ` Kirill A. Shutemov
2021-10-09 0:36 ` [PATCH v5 04/16] x86/tdx: Make pages shared in ioremap() Kuppuswamy Sathyanarayanan
2021-10-20 16:03 ` Tom Lendacky
2021-10-20 16:41 ` Sathyanarayanan Kuppuswamy
2021-10-09 0:37 ` [PATCH v5 05/16] x86/tdx: Add helper to do MapGPA hypercall Kuppuswamy Sathyanarayanan
2021-10-09 0:37 ` [PATCH v5 06/16] x86/tdx: Make DMA pages shared Kuppuswamy Sathyanarayanan
2021-10-20 16:33 ` Tom Lendacky
2021-10-20 16:45 ` Sathyanarayanan Kuppuswamy
2021-10-20 17:22 ` Tom Lendacky
2021-10-20 17:26 ` Sathyanarayanan Kuppuswamy
2021-10-09 0:37 ` [PATCH v5 07/16] x86/kvm: Use bounce buffers for TD guest Kuppuswamy Sathyanarayanan
2021-10-20 16:39 ` Tom Lendacky
2021-10-20 16:50 ` Sathyanarayanan Kuppuswamy
2021-10-20 17:26 ` Tom Lendacky
2021-10-09 0:37 ` [PATCH v5 08/16] x86/tdx: ioapic: Add shared bit for IOAPIC base address Kuppuswamy Sathyanarayanan
2021-10-09 0:37 ` [PATCH v5 09/16] x86/tdx: Enable shared memory confidential guest flags for TDX guest Kuppuswamy Sathyanarayanan
2021-10-09 0:37 ` [PATCH v5 10/16] PCI: Consolidate pci_iomap_range(), pci_iomap_wc_range() Kuppuswamy Sathyanarayanan
2021-10-09 0:37 ` [PATCH v5 11/16] asm/io.h: Add ioremap_host_shared fallback Kuppuswamy Sathyanarayanan
2021-10-09 0:37 ` [PATCH v5 12/16] PCI: Add pci_iomap_host_shared(), pci_iomap_host_shared_range() Kuppuswamy Sathyanarayanan
2021-10-09 9:53 ` Michael S. Tsirkin
2021-10-09 20:39 ` Dan Williams
2021-10-10 22:11 ` Andi Kleen
2021-10-12 17:42 ` Dan Williams
2021-10-12 18:35 ` Andi Kleen
2021-10-12 21:14 ` Dan Williams
2021-10-12 21:18 ` Michael S. Tsirkin
2021-10-12 21:24 ` Andi Kleen
2021-10-12 21:28 ` Andi Kleen
2021-10-12 22:00 ` Dan Williams
2021-10-18 12:13 ` Greg KH
2021-10-12 18:36 ` Reshetova, Elena
2021-10-12 18:38 ` Andi Kleen
2021-10-12 18:57 ` Reshetova, Elena
2021-10-12 19:13 ` Dan Williams
2021-10-12 19:49 ` Andi Kleen
2021-10-12 21:11 ` Michael S. Tsirkin
2021-10-14 6:32 ` Reshetova, Elena
2021-10-14 6:57 ` Michael S. Tsirkin
2021-10-14 7:27 ` Reshetova, Elena
2021-10-14 9:26 ` Michael S. Tsirkin
2021-10-14 12:33 ` Reshetova, Elena
2021-10-17 22:17 ` Michael S. Tsirkin
2021-10-14 11:49 ` Michael S. Tsirkin
2021-10-17 21:52 ` Thomas Gleixner
2021-10-18 7:03 ` Reshetova, Elena
2021-10-18 0:55 ` Thomas Gleixner
2021-10-18 1:10 ` Thomas Gleixner
2021-10-18 12:08 ` Greg KH
2021-10-10 22:22 ` Andi Kleen [this message]
2021-10-11 11:59 ` Michael S. Tsirkin
2021-10-11 17:32 ` Andi Kleen
2021-10-11 18:22 ` Michael S. Tsirkin
2021-10-18 12:15 ` Greg KH
2021-10-18 13:17 ` Michael S. Tsirkin
2021-10-11 7:58 ` Christoph Hellwig
2021-10-11 17:23 ` Andi Kleen
2021-10-11 19:09 ` Michael S. Tsirkin
2021-10-12 5:31 ` Christoph Hellwig
2021-10-12 18:37 ` Andi Kleen
2021-10-09 0:37 ` [PATCH v5 13/16] PCI: Mark MSI data shared Kuppuswamy Sathyanarayanan
2021-10-09 0:37 ` [PATCH v5 14/16] virtio: Use shared mappings for virtio PCI devices Kuppuswamy Sathyanarayanan
2021-10-09 0:37 ` [PATCH v5 15/16] x86/tdx: Implement ioremap_host_shared for x86 Kuppuswamy Sathyanarayanan
2021-10-09 0:37 ` [PATCH v5 16/16] x86/tdx: Add cmdline option to force use of ioremap_host_shared Kuppuswamy Sathyanarayanan
2021-10-09 1:45 ` Randy Dunlap
2021-10-09 2:10 ` Kuppuswamy, Sathyanarayanan
2021-10-09 11:04 ` Michael S. Tsirkin
2021-10-11 2:39 ` Andi Kleen
2021-10-11 12:04 ` Michael S. Tsirkin
2021-10-11 17:35 ` Andi Kleen
2021-10-11 18:28 ` Michael S. Tsirkin
2021-10-12 17:55 ` Andi Kleen
2021-10-12 20:59 ` Michael S. Tsirkin
2021-10-12 21:18 ` Andi Kleen
2021-10-12 21:30 ` Michael S. Tsirkin
2021-10-15 5:50 ` Andi Kleen
2021-10-15 6:57 ` Michael S. Tsirkin
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