Commit Graph
23 Commits
Author SHA1 Message Date
Demi Marie Obenour 8752ad83e7 xen/ucode: Make Intel's microcode_sanity_check() stricter
The SDM states that data size must be a multiple of 4, but Xen doesn't check
this propery.

This is liable to cause a later failures, but should be checked explicitly.

Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-09-24 18:57:38 +01:00
Demi Marie Obenour a8bf14f6f3 xen/ucode: Fix buffer under-run when parsing AMD containers
The AMD container format has no formal spec.  It is, at best, precision
guesswork based on AMD's prior contributions to open source projects.  The
Equivalence Table has both an explicit length, and an expectation of having a
NULL entry at the end.

Xen was sanity checking the NULL entry, but without confirming that an entry
was present, resulting in a read off the front of the buffer.  With some
manual debugging/annotations this manifests as:

  (XEN) *** Buf ffff83204c00b19c, eq ffff83204c00b194
  (XEN) *** eq: 0c 00 00 00 44 4d 41 00 00 00 00 00 00 00 00 00 aa aa aa aa
                            ^-Actual buffer-------------------^
  (XEN) *** installed_cpu: 000c
  (XEN) microcode: Bad equivalent cpu table
  (XEN) Parsing microcode blob error -22

When loaded by hypercall, the 4 bytes interpreted as installed_cpu happen to
be the containing struct ucode_buf's len field, and luckily will be nonzero.

When loaded at boot, it's possible for the access to #PF if the module happens
to have been placed on a 2M boundary by the bootloader.  Under Linux, it will
commonly be the end of the CPIO header.

Drop the probe of the NULL entry; Nothing else cares.  A container without one
is well formed, insofar that we can still parse it correctly.  With this
dropped, the same container results in:

  (XEN) microcode: couldn't find any matching ucode in the provided blob!

Fixes: 4de936a38a ("x86/ucode/amd: Rework parsing logic in cpu_request_microcode()")
Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-09-13 15:23:30 +01:00
Demi Marie Obenour 531d3bea5e libxl: Fix handling XenStore errors in device creation
If xenstored runs out of memory it is possible for it to fail operations
that should succeed.  libxl wasn't robust against this, and could fail
to ensure that the TTY path of a non-initial console was created and
read-only for guests.  This doesn't qualify for an XSA because guests
should not be able to run xenstored out of memory, but it still needs to
be fixed.

Add the missing error checks to ensure that all errors are properly
handled and that at no point can a guest make the TTY path of its
frontend directory writable.

Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
2024-05-11 00:13:43 +01:00
Demi Marie Obenour 054acfc444 misc: Replace git:// and http:// with https://
Obtaining code over an insecure transport is a terrible idea for
blatently obvious reasons.  Even for non-executable data, insecure
transports are considered deprecated.

This patch enforces the use of secure transports in misc places.
All URLs are known to work.

Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
2023-03-24 16:29:15 +00:00
Demi Marie Obenour 04988f1c59 configure: Replace git:// and http:// with https://
Obtaining code over an insecure transport is a terrible idea for
blatently obvious reasons.  Even for non-executable data, insecure
transports are considered deprecated.

This patch enforces the use of secure transports in the build system.
Some URLs returned 301 or 302 redirects, so I replaced them with the
URLs that were redirected to.

Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
2023-03-24 16:29:15 +00:00
Demi Marie Obenour 47ee23f05a configure: Do not try to use broken links
The upstream URLs for zlib, PolarSSL, and the TPM emulator do not work
anymore, so do not attempt to use them.

Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
2023-03-24 16:29:15 +00:00
Demi Marie Obenour e1d7508444 build: Change remaining xenbits.xen.org link to HTTPS
Obtaining code over an insecure transport is a terrible idea for
blatently obvious reasons.  Even for non-executable data, insecure
transports are considered deprecated.

This patch enforces the use of secure transports for all xenbits.xen.org
URLs.  All altered links have been tested and are known to work.

Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
2023-03-24 16:29:15 +00:00
Demi Marie Obenour eb23eef476 build: Use HTTPS for all xenbits.xen.org Git repos
Obtaining code over an insecure transport is a terrible idea for
blatently obvious reasons.  Even for non-executable data, insecure
transports are considered deprecated.

This patch enforces the use of secure transports for all xenbits git
repositories.  It was generated with the following shell script:

    git ls-files -z |
    xargs -0 -- sed -Ei -- 's@(git://xenbits\.xen\.org|http://xenbits\.xen\.org/git-http)/@https://xenbits.xen.org/git-http/@g'

All altered links have been tested and are known to work.

Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
2023-03-24 16:29:13 +00:00
Demi Marie Obenour a4557f515f change assorted xenbits.xen.org links to HTTPS
Also switch to xenbits.xenproject.org at this occasion.

Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2023-02-28 14:52:14 +01:00
Demi Marie Obenour 40b05620e2 x86/mm: avoid hard-coding PAT in get_page_from_l1e()
get_page_from_l1e() relied on Xen's choice of PAT, which is brittle in
the face of future PAT changes.  Instead, compute the actual cacheability
used by the CPU and switch on that, as this will work no matter what PAT
Xen uses.

No functional change intended.  This code is itself questionable and may
be removed in the future, but removing it would be an observable
behavior change and so is out of scope for this patch series.

Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2023-01-05 16:19:43 +01:00
Demi Marie Obenour 4b40d68e66 x86: derive XEN_MSR_PAT from its individual entries
This avoids it being a magic constant that is difficult for humans to
decode.  Use BUILD_BUG_ON to check that the old and new values are
identical.

Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2022-12-20 16:51:55 +01:00
Demi Marie Obenour b7dd0f590a x86: replace EPT_EMT_* constants with X86_MT_*
This allows eliminating the former.  No functional change intended.

Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2022-12-20 16:51:18 +01:00
Demi Marie Obenour 6eaaa1fcb9 x86: replace MTRR_* constants with X86_MT_* constants
This allows eliminating of the former, with the exception of
MTRR_NUM_TYPES.  MTRR_NUM_TYPES is kept, as due to a quirk of the x86
architecture X86_MT_UCM (7) is not valid in an MTRR.

Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2022-12-20 16:50:38 +01:00
Demi Marie Obenour 60b8f9a739 x86: replace PAT_* with X86_MT_*
This allows eliminating the former.

Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2022-12-20 16:49:35 +01:00
Demi Marie Obenour 4714ae256f x86: add memory type constants
These are not currently used, so there is no functional change.  Future
patches will use these constants.

Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2022-12-20 16:49:16 +01:00
Demi Marie Obenour 32b61bcafc efi: avoid hard-coding the various PAT constants
This makes the code much easier to understand, and avoids problems if
Xen's PAT ever changes in the future.

Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2022-12-15 17:04:40 +01:00
Demi Marie Obenour 1ca8af08df p2m-pt: avoid hard-coding Xen's PAT
This makes the code much easier to understand.  No functional change
intended.  As per Andrew Cooper, the existing logic is questionable, but
this does not make it any worse.

Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2022-12-15 17:03:45 +01:00
Demi Marie Obenour 8d7acf3f7d EFI: relocate the ESRT when booting via multiboot2
This was missed in the initial patchset.

Move efi_relocate_esrt() up to avoid adding a forward declaration.

Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2022-12-14 12:00:35 +01:00
Demi Marie Obenour d7669c1014 Use EfiACPIReclaimMemory for ESRT
A previous patch tried to get Linux to use the ESRT under Xen if it is
in memory of type EfiRuntimeServicesData.  However, this turns out to be
a bad idea.  Ard Biesheuvel pointed out that EfiRuntimeServices* memory
winds up fragmenting both the EFI page tables and the direct map, and
that EfiACPIReclaimMemory is a much better choice for this purpose.

Link: https://lists.xenproject.org/archives/html/xen-devel/2022-09/msg01365.html
Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2022-12-08 18:00:22 +00:00
Demi Marie Obenour a6da84524c x86/mm/shadow: do not open-code PAGE_CACHE_ATTRS
This makes the code easier to understand.

Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2022-12-06 13:55:07 +01:00
Demi Marie Obenour 53ba5e1b48 x86/mm/shadow: avoid assuming a specific Xen PAT
This makes the code easier to understand and more robust if Xen's PAT
ever changes.

Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
2022-12-06 13:54:33 +01:00
Demi Marie Obenour dc7da0874b EFI: preserve the System Resource Table for dom0
The EFI System Resource Table (ESRT) is necessary for fwupd to identify
firmware updates to install.  According to the UEFI specification §23.4,
the ESRT shall be stored in memory of type EfiBootServicesData.  However,
memory of type EfiBootServicesData is considered general-purpose memory
by Xen, so the ESRT needs to be moved somewhere where Xen will not
overwrite it.  Copy the ESRT to memory of type EfiRuntimeServicesData,
which Xen will not reuse.  dom0 can use the ESRT if (and only if) it is
in memory of type EfiRuntimeServicesData.

Earlier versions of this patch reserved the memory in which the ESRT was
located.  This created awkward alignment problems, and required either
splitting the E820 table or wasting memory.  It also would have required
a new platform op for dom0 to use to indicate if the ESRT is reserved.
By copying the ESRT into EfiRuntimeServicesData memory, the E820 table
does not need to be modified, and dom0 can just check the type of the
memory region containing the ESRT.  The copy is only done if the ESRT is
not already in EfiRuntimeServicesData memory, avoiding memory leaks on
repeated kexec.

See https://lore.kernel.org/xen-devel/20200818184018.GN1679@mail-itl/T/
for details.

Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Tested-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2022-07-12 08:39:19 +02:00
Demi Marie Obenour 8d410ac2c1 EFI: preserve the System Resource Table for dom0
The EFI System Resource Table (ESRT) is necessary for fwupd to identify
firmware updates to install.  According to the UEFI specification §23.4,
the ESRT shall be stored in memory of type EfiBootServicesData.  However,
memory of type EfiBootServicesData is considered general-purpose memory
by Xen, so the ESRT needs to be moved somewhere where Xen will not
overwrite it.  Copy the ESRT to memory of type EfiRuntimeServicesData,
which Xen will not reuse.  dom0 can use the ESRT if (and only if) it is
in memory of type EfiRuntimeServicesData.

Earlier versions of this patch reserved the memory in which the ESRT was
located.  This created awkward alignment problems, and required either
splitting the E820 table or wasting memory.  It also would have required
a new platform op for dom0 to use to indicate if the ESRT is reserved.
By copying the ESRT into EfiRuntimeServicesData memory, the E820 table
does not need to be modified, and dom0 can just check the type of the
memory region containing the ESRT.  The copy is only done if the ESRT is
not already in EfiRuntimeServicesData memory, avoiding memory leaks on
repeated kexec.

See https://lore.kernel.org/xen-devel/20200818184018.GN1679@mail-itl/T/
for details.

Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2022-07-05 13:10:46 +02:00