<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/x86/lib, branch v5.18</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'x86_urgent_for_v5.18_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2022-05-01T17:03:36+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-05-01T17:03:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b2da7df52e16110c8d8dda0602db81c15711e7ff'/>
<id>b2da7df52e16110c8d8dda0602db81c15711e7ff</id>
<content type='text'>
Pull x86 fixes from Borislav Petkov:

 - A fix to disable PCI/MSI[-X] masking for XEN_HVM guests as that is
   solely controlled by the hypervisor

 - A build fix to make the function prototype (__warn()) as visible as
   the definition itself

 - A bunch of objtool annotation fixes which have accumulated over time

 - An ORC unwinder fix to handle bad input gracefully

 - Well, we thought the microcode gets loaded in time in order to
   restore the microcode-emulated MSRs but we thought wrong. So there's
   a fix for that to have the ordering done properly

 - Add new Intel model numbers

 - A spelling fix

* tag 'x86_urgent_for_v5.18_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/pci/xen: Disable PCI/MSI[-X] masking for XEN_HVM guests
  bug: Have __warn() prototype defined unconditionally
  x86/Kconfig: fix the spelling of 'becoming' in X86_KERNEL_IBT config
  objtool: Use offstr() to print address of missing ENDBR
  objtool: Print data address for "!ENDBR" data warnings
  x86/xen: Add ANNOTATE_NOENDBR to startup_xen()
  x86/uaccess: Add ENDBR to __put_user_nocheck*()
  x86/retpoline: Add ANNOTATE_NOENDBR for retpolines
  x86/static_call: Add ANNOTATE_NOENDBR to static call trampoline
  objtool: Enable unreachable warnings for CLANG LTO
  x86,objtool: Explicitly mark idtentry_body()s tail REACHABLE
  x86,objtool: Mark cpu_startup_entry() __noreturn
  x86,xen,objtool: Add UNWIND hint
  lib/strn*,objtool: Enforce user_access_begin() rules
  MAINTAINERS: Add x86 unwinding entry
  x86/unwind/orc: Recheck address range after stack info was updated
  x86/cpu: Load microcode during restore_processor_state()
  x86/cpu: Add new Alderlake and Raptorlake CPU model numbers
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 fixes from Borislav Petkov:

 - A fix to disable PCI/MSI[-X] masking for XEN_HVM guests as that is
   solely controlled by the hypervisor

 - A build fix to make the function prototype (__warn()) as visible as
   the definition itself

 - A bunch of objtool annotation fixes which have accumulated over time

 - An ORC unwinder fix to handle bad input gracefully

 - Well, we thought the microcode gets loaded in time in order to
   restore the microcode-emulated MSRs but we thought wrong. So there's
   a fix for that to have the ordering done properly

 - Add new Intel model numbers

 - A spelling fix

* tag 'x86_urgent_for_v5.18_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/pci/xen: Disable PCI/MSI[-X] masking for XEN_HVM guests
  bug: Have __warn() prototype defined unconditionally
  x86/Kconfig: fix the spelling of 'becoming' in X86_KERNEL_IBT config
  objtool: Use offstr() to print address of missing ENDBR
  objtool: Print data address for "!ENDBR" data warnings
  x86/xen: Add ANNOTATE_NOENDBR to startup_xen()
  x86/uaccess: Add ENDBR to __put_user_nocheck*()
  x86/retpoline: Add ANNOTATE_NOENDBR for retpolines
  x86/static_call: Add ANNOTATE_NOENDBR to static call trampoline
  objtool: Enable unreachable warnings for CLANG LTO
  x86,objtool: Explicitly mark idtentry_body()s tail REACHABLE
  x86,objtool: Mark cpu_startup_entry() __noreturn
  x86,xen,objtool: Add UNWIND hint
  lib/strn*,objtool: Enforce user_access_begin() rules
  MAINTAINERS: Add x86 unwinding entry
  x86/unwind/orc: Recheck address range after stack info was updated
  x86/cpu: Load microcode during restore_processor_state()
  x86/cpu: Add new Alderlake and Raptorlake CPU model numbers
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'objtool_urgent_for_v5.18_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2022-05-01T16:34:54+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-05-01T16:34:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b70ed23c238af025153cb0f5b3c1d0ae5bc30f73'/>
<id>b70ed23c238af025153cb0f5b3c1d0ae5bc30f73</id>
<content type='text'>
Pull objtool fixes from Borislav Petkov:
 "A bunch of objtool fixes to improve unwinding, sibling call detection,
  fallthrough detection and relocation handling of weak symbols when the
  toolchain strips section symbols"

* tag 'objtool_urgent_for_v5.18_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Fix code relocs vs weak symbols
  objtool: Fix type of reloc::addend
  objtool: Fix function fallthrough detection for vmlinux
  objtool: Fix sibling call detection in alternatives
  objtool: Don't set 'jump_dest' for sibling calls
  x86/uaccess: Don't jump between functions
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull objtool fixes from Borislav Petkov:
 "A bunch of objtool fixes to improve unwinding, sibling call detection,
  fallthrough detection and relocation handling of weak symbols when the
  toolchain strips section symbols"

* tag 'objtool_urgent_for_v5.18_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Fix code relocs vs weak symbols
  objtool: Fix type of reloc::addend
  objtool: Fix function fallthrough detection for vmlinux
  objtool: Fix sibling call detection in alternatives
  objtool: Don't set 'jump_dest' for sibling calls
  x86/uaccess: Don't jump between functions
</pre>
</div>
</content>
</entry>
<entry>
<title>x86: __memcpy_flushcache: fix wrong alignment if size &gt; 2^32</title>
<updated>2022-04-20T18:38:49+00:00</updated>
<author>
<name>Mikulas Patocka</name>
<email>mpatocka@redhat.com</email>
</author>
<published>2022-04-19T13:56:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a6823e4e360fe975bd3da4ab156df7c74c8b07f3'/>
<id>a6823e4e360fe975bd3da4ab156df7c74c8b07f3</id>
<content type='text'>
The first "if" condition in __memcpy_flushcache is supposed to align the
"dest" variable to 8 bytes and copy data up to this alignment.  However,
this condition may misbehave if "size" is greater than 4GiB.

The statement min_t(unsigned, size, ALIGN(dest, 8) - dest); casts both
arguments to unsigned int and selects the smaller one.  However, the
cast truncates high bits in "size" and it results in misbehavior.

For example:

	suppose that size == 0x100000001, dest == 0x200000002
	min_t(unsigned, size, ALIGN(dest, 8) - dest) == min_t(0x1, 0xe) == 0x1;
	...
	dest += 0x1;

so we copy just one byte "and" dest remains unaligned.

This patch fixes the bug by replacing unsigned with size_t.

Signed-off-by: Mikulas Patocka &lt;mpatocka@redhat.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The first "if" condition in __memcpy_flushcache is supposed to align the
"dest" variable to 8 bytes and copy data up to this alignment.  However,
this condition may misbehave if "size" is greater than 4GiB.

The statement min_t(unsigned, size, ALIGN(dest, 8) - dest); casts both
arguments to unsigned int and selects the smaller one.  However, the
cast truncates high bits in "size" and it results in misbehavior.

For example:

	suppose that size == 0x100000001, dest == 0x200000002
	min_t(unsigned, size, ALIGN(dest, 8) - dest) == min_t(0x1, 0xe) == 0x1;
	...
	dest += 0x1;

so we copy just one byte "and" dest remains unaligned.

This patch fixes the bug by replacing unsigned with size_t.

Signed-off-by: Mikulas Patocka &lt;mpatocka@redhat.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/uaccess: Don't jump between functions</title>
<updated>2022-04-19T19:58:53+00:00</updated>
<author>
<name>Josh Poimboeuf</name>
<email>jpoimboe@redhat.com</email>
</author>
<published>2022-04-11T23:10:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=02041b32256628aef0d18ec15d3658fe41bc1afe'/>
<id>02041b32256628aef0d18ec15d3658fe41bc1afe</id>
<content type='text'>
For unwinding sanity, a function shouldn't jump to the middle of another
function.  Move the short string user copy code out to a separate
non-function code snippet.

Signed-off-by: Josh Poimboeuf &lt;jpoimboe@redhat.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/9519e4853148b765e047967708f2b61e56c93186.1649718562.git.jpoimboe@redhat.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
For unwinding sanity, a function shouldn't jump to the middle of another
function.  Move the short string user copy code out to a separate
non-function code snippet.

Signed-off-by: Josh Poimboeuf &lt;jpoimboe@redhat.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/9519e4853148b765e047967708f2b61e56c93186.1649718562.git.jpoimboe@redhat.com
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/uaccess: Add ENDBR to __put_user_nocheck*()</title>
<updated>2022-04-19T19:58:49+00:00</updated>
<author>
<name>Josh Poimboeuf</name>
<email>jpoimboe@redhat.com</email>
</author>
<published>2022-04-18T16:50:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7a00829f8ac3f76b3a3aa5c28ce4ddfd2f977bbe'/>
<id>7a00829f8ac3f76b3a3aa5c28ce4ddfd2f977bbe</id>
<content type='text'>
The __put_user_nocheck*() inner labels are exported, so in keeping with
the "allow exported functions to be indirectly called" policy, add
ENDBR.

Fixes: ed53a0d97192 ("x86/alternative: Use .ibt_endbr_seal to seal indirect calls")
Signed-off-by: Josh Poimboeuf &lt;jpoimboe@redhat.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/207f02177a23031091d1a608de6049a9e5e8ff80.1650300597.git.jpoimboe@redhat.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The __put_user_nocheck*() inner labels are exported, so in keeping with
the "allow exported functions to be indirectly called" policy, add
ENDBR.

Fixes: ed53a0d97192 ("x86/alternative: Use .ibt_endbr_seal to seal indirect calls")
Signed-off-by: Josh Poimboeuf &lt;jpoimboe@redhat.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/207f02177a23031091d1a608de6049a9e5e8ff80.1650300597.git.jpoimboe@redhat.com
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/retpoline: Add ANNOTATE_NOENDBR for retpolines</title>
<updated>2022-04-19T19:58:49+00:00</updated>
<author>
<name>Josh Poimboeuf</name>
<email>jpoimboe@redhat.com</email>
</author>
<published>2022-04-18T16:50:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1c0513dec41e4d40eb21402dff397ad84ca13a44'/>
<id>1c0513dec41e4d40eb21402dff397ad84ca13a44</id>
<content type='text'>
The retpolines are exported, so they're referenced by ksymtab sections.
But they're never indirect-branched to, so add ANNOTATE_NOENDBR.

Fixes: ed53a0d97192 ("x86/alternative: Use .ibt_endbr_seal to seal indirect calls")
Signed-off-by: Josh Poimboeuf &lt;jpoimboe@redhat.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/b6ec963dfd9301b6b1d74ef7758fcb0b540d6c6c.1650300597.git.jpoimboe@redhat.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The retpolines are exported, so they're referenced by ksymtab sections.
But they're never indirect-branched to, so add ANNOTATE_NOENDBR.

Fixes: ed53a0d97192 ("x86/alternative: Use .ibt_endbr_seal to seal indirect calls")
Signed-off-by: Josh Poimboeuf &lt;jpoimboe@redhat.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/b6ec963dfd9301b6b1d74ef7758fcb0b540d6c6c.1650300597.git.jpoimboe@redhat.com
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'x86-urgent-2022-04-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2022-04-03T19:15:47+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-04-03T19:15:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8b5656bc4e3707da642cb4a9126f4849fb518423'/>
<id>8b5656bc4e3707da642cb4a9126f4849fb518423</id>
<content type='text'>
Pull x86 fixes from Thomas Gleixner:
 "A set of x86 fixes and updates:

   - Make the prctl() for enabling dynamic XSTATE components correct so
     it adds the newly requested feature to the permission bitmap
     instead of overwriting it. Add a selftest which validates that.

   - Unroll string MMIO for encrypted SEV guests as the hypervisor
     cannot emulate it.

   - Handle supervisor states correctly in the FPU/XSTATE code so it
     takes the feature set of the fpstate buffer into account. The
     feature sets can differ between host and guest buffers. Guest
     buffers do not contain supervisor states. So far this was not an
     issue, but with enabling PASID it needs to be handled in the buffer
     offset calculation and in the permission bitmaps.

   - Avoid a gazillion of repeated CPUID invocations in by caching the
     values early in the FPU/XSTATE code.

   - Enable CONFIG_WERROR in x86 defconfig.

   - Make the X86 defconfigs more useful by adapting them to Y2022
     reality"

* tag 'x86-urgent-2022-04-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu/xstate: Consolidate size calculations
  x86/fpu/xstate: Handle supervisor states in XSTATE permissions
  x86/fpu/xsave: Handle compacted offsets correctly with supervisor states
  x86/fpu: Cache xfeature flags from CPUID
  x86/fpu/xsave: Initialize offset/size cache early
  x86/fpu: Remove unused supervisor only offsets
  x86/fpu: Remove redundant XCOMP_BV initialization
  x86/sev: Unroll string mmio with CC_ATTR_GUEST_UNROLL_STRING_IO
  x86/config: Make the x86 defconfigs a bit more usable
  x86/defconfig: Enable WERROR
  selftests/x86/amx: Update the ARCH_REQ_XCOMP_PERM test
  x86/fpu/xstate: Fix the ARCH_REQ_XCOMP_PERM implementation
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 fixes from Thomas Gleixner:
 "A set of x86 fixes and updates:

   - Make the prctl() for enabling dynamic XSTATE components correct so
     it adds the newly requested feature to the permission bitmap
     instead of overwriting it. Add a selftest which validates that.

   - Unroll string MMIO for encrypted SEV guests as the hypervisor
     cannot emulate it.

   - Handle supervisor states correctly in the FPU/XSTATE code so it
     takes the feature set of the fpstate buffer into account. The
     feature sets can differ between host and guest buffers. Guest
     buffers do not contain supervisor states. So far this was not an
     issue, but with enabling PASID it needs to be handled in the buffer
     offset calculation and in the permission bitmaps.

   - Avoid a gazillion of repeated CPUID invocations in by caching the
     values early in the FPU/XSTATE code.

   - Enable CONFIG_WERROR in x86 defconfig.

   - Make the X86 defconfigs more useful by adapting them to Y2022
     reality"

* tag 'x86-urgent-2022-04-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu/xstate: Consolidate size calculations
  x86/fpu/xstate: Handle supervisor states in XSTATE permissions
  x86/fpu/xsave: Handle compacted offsets correctly with supervisor states
  x86/fpu: Cache xfeature flags from CPUID
  x86/fpu/xsave: Initialize offset/size cache early
  x86/fpu: Remove unused supervisor only offsets
  x86/fpu: Remove redundant XCOMP_BV initialization
  x86/sev: Unroll string mmio with CC_ATTR_GUEST_UNROLL_STRING_IO
  x86/config: Make the x86 defconfigs a bit more usable
  x86/defconfig: Enable WERROR
  selftests/x86/amx: Update the ARCH_REQ_XCOMP_PERM test
  x86/fpu/xstate: Fix the ARCH_REQ_XCOMP_PERM implementation
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs</title>
<updated>2022-04-02T02:57:03+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-04-02T02:57:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=88e6c0207623874922712e162e25d9dafd39661e'/>
<id>88e6c0207623874922712e162e25d9dafd39661e</id>
<content type='text'>
Pull vfs updates from Al Viro:
 "Assorted bits and pieces"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  aio: drop needless assignment in aio_read()
  clean overflow checks in count_mounts() a bit
  seq_file: fix NULL pointer arithmetic warning
  uml/x86: use x86 load_unaligned_zeropad()
  asm/user.h: killed unused macros
  constify struct path argument of finish_automount()/do_add_mount()
  fs: Remove FIXME comment in generic_write_checks()
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull vfs updates from Al Viro:
 "Assorted bits and pieces"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  aio: drop needless assignment in aio_read()
  clean overflow checks in count_mounts() a bit
  seq_file: fix NULL pointer arithmetic warning
  uml/x86: use x86 load_unaligned_zeropad()
  asm/user.h: killed unused macros
  constify struct path argument of finish_automount()/do_add_mount()
  fs: Remove FIXME comment in generic_write_checks()
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/sev: Unroll string mmio with CC_ATTR_GUEST_UNROLL_STRING_IO</title>
<updated>2022-03-29T13:59:16+00:00</updated>
<author>
<name>Joerg Roedel</name>
<email>jroedel@suse.de</email>
</author>
<published>2022-03-21T09:33:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4009a4ac82dd95b8cd2b62bd30019476983f0aff'/>
<id>4009a4ac82dd95b8cd2b62bd30019476983f0aff</id>
<content type='text'>
The io-specific memcpy/memset functions use string mmio accesses to do
their work. Under SEV, the hypervisor can't emulate these instructions
because they read/write directly from/to encrypted memory.

KVM will inject a page fault exception into the guest when it is asked
to emulate string mmio instructions for an SEV guest:

  BUG: unable to handle page fault for address: ffffc90000065068
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 8000100000067 P4D 8000100000067 PUD 80001000fb067 PMD 80001000fc067 PTE 80000000fed40173
  Oops: 0000 [#1] PREEMPT SMP NOPTI
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.0-rc7 #3

As string mmio for an SEV guest can not be supported by the
hypervisor, unroll the instructions for CC_ATTR_GUEST_UNROLL_STRING_IO
enabled kernels.

This issue appears when kernels are launched in recent libvirt-managed
SEV virtual machines, because virt-install started to add a tpm-crb
device to the guest by default and proactively because, raisins:

  https://github.com/virt-manager/virt-manager/commit/eb58c09f488b0633ed1eea012cd311e48864401e

and as that commit says, the default adding of a TPM can be disabled
with "virt-install ... --tpm none".

The kernel driver for tpm-crb uses memcpy_to/from_io() functions to
access MMIO memory, resulting in a page-fault injected by KVM and
crashing the kernel at boot.

  [ bp: Massage and extend commit message. ]

Fixes: d8aa7eea78a1 ('x86/mm: Add Secure Encrypted Virtualization (SEV) support')
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Reviewed-by: Tom Lendacky &lt;thomas.lendacky@amd.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Link: https://lore.kernel.org/r/20220321093351.23976-1-joro@8bytes.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The io-specific memcpy/memset functions use string mmio accesses to do
their work. Under SEV, the hypervisor can't emulate these instructions
because they read/write directly from/to encrypted memory.

KVM will inject a page fault exception into the guest when it is asked
to emulate string mmio instructions for an SEV guest:

  BUG: unable to handle page fault for address: ffffc90000065068
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 8000100000067 P4D 8000100000067 PUD 80001000fb067 PMD 80001000fc067 PTE 80000000fed40173
  Oops: 0000 [#1] PREEMPT SMP NOPTI
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.0-rc7 #3

As string mmio for an SEV guest can not be supported by the
hypervisor, unroll the instructions for CC_ATTR_GUEST_UNROLL_STRING_IO
enabled kernels.

This issue appears when kernels are launched in recent libvirt-managed
SEV virtual machines, because virt-install started to add a tpm-crb
device to the guest by default and proactively because, raisins:

  https://github.com/virt-manager/virt-manager/commit/eb58c09f488b0633ed1eea012cd311e48864401e

and as that commit says, the default adding of a TPM can be disabled
with "virt-install ... --tpm none".

The kernel driver for tpm-crb uses memcpy_to/from_io() functions to
access MMIO memory, resulting in a page-fault injected by KVM and
crashing the kernel at boot.

  [ bp: Massage and extend commit message. ]

Fixes: d8aa7eea78a1 ('x86/mm: Add Secure Encrypted Virtualization (SEV) support')
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Reviewed-by: Tom Lendacky &lt;thomas.lendacky@amd.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Link: https://lore.kernel.org/r/20220321093351.23976-1-joro@8bytes.org
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'x86_core_for_5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2022-03-27T17:17:23+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-03-27T17:17:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7001052160d172f6de06adeffde24dde9935ece8'/>
<id>7001052160d172f6de06adeffde24dde9935ece8</id>
<content type='text'>
Pull x86 CET-IBT (Control-Flow-Integrity) support from Peter Zijlstra:
 "Add support for Intel CET-IBT, available since Tigerlake (11th gen),
  which is a coarse grained, hardware based, forward edge
  Control-Flow-Integrity mechanism where any indirect CALL/JMP must
  target an ENDBR instruction or suffer #CP.

  Additionally, since Alderlake (12th gen)/Sapphire-Rapids, speculation
  is limited to 2 instructions (and typically fewer) on branch targets
  not starting with ENDBR. CET-IBT also limits speculation of the next
  sequential instruction after the indirect CALL/JMP [1].

  CET-IBT is fundamentally incompatible with retpolines, but provides,
  as described above, speculation limits itself"

[1] https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/branch-history-injection.html

* tag 'x86_core_for_5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
  kvm/emulate: Fix SETcc emulation for ENDBR
  x86/Kconfig: Only allow CONFIG_X86_KERNEL_IBT with ld.lld &gt;= 14.0.0
  x86/Kconfig: Only enable CONFIG_CC_HAS_IBT for clang &gt;= 14.0.0
  kbuild: Fixup the IBT kbuild changes
  x86/Kconfig: Do not allow CONFIG_X86_X32_ABI=y with llvm-objcopy
  x86: Remove toolchain check for X32 ABI capability
  x86/alternative: Use .ibt_endbr_seal to seal indirect calls
  objtool: Find unused ENDBR instructions
  objtool: Validate IBT assumptions
  objtool: Add IBT/ENDBR decoding
  objtool: Read the NOENDBR annotation
  x86: Annotate idtentry_df()
  x86,objtool: Move the ASM_REACHABLE annotation to objtool.h
  x86: Annotate call_on_stack()
  objtool: Rework ASM_REACHABLE
  x86: Mark __invalid_creds() __noreturn
  exit: Mark do_group_exit() __noreturn
  x86: Mark stop_this_cpu() __noreturn
  objtool: Ignore extra-symbol code
  objtool: Rename --duplicate to --lto
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 CET-IBT (Control-Flow-Integrity) support from Peter Zijlstra:
 "Add support for Intel CET-IBT, available since Tigerlake (11th gen),
  which is a coarse grained, hardware based, forward edge
  Control-Flow-Integrity mechanism where any indirect CALL/JMP must
  target an ENDBR instruction or suffer #CP.

  Additionally, since Alderlake (12th gen)/Sapphire-Rapids, speculation
  is limited to 2 instructions (and typically fewer) on branch targets
  not starting with ENDBR. CET-IBT also limits speculation of the next
  sequential instruction after the indirect CALL/JMP [1].

  CET-IBT is fundamentally incompatible with retpolines, but provides,
  as described above, speculation limits itself"

[1] https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/branch-history-injection.html

* tag 'x86_core_for_5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
  kvm/emulate: Fix SETcc emulation for ENDBR
  x86/Kconfig: Only allow CONFIG_X86_KERNEL_IBT with ld.lld &gt;= 14.0.0
  x86/Kconfig: Only enable CONFIG_CC_HAS_IBT for clang &gt;= 14.0.0
  kbuild: Fixup the IBT kbuild changes
  x86/Kconfig: Do not allow CONFIG_X86_X32_ABI=y with llvm-objcopy
  x86: Remove toolchain check for X32 ABI capability
  x86/alternative: Use .ibt_endbr_seal to seal indirect calls
  objtool: Find unused ENDBR instructions
  objtool: Validate IBT assumptions
  objtool: Add IBT/ENDBR decoding
  objtool: Read the NOENDBR annotation
  x86: Annotate idtentry_df()
  x86,objtool: Move the ASM_REACHABLE annotation to objtool.h
  x86: Annotate call_on_stack()
  objtool: Rework ASM_REACHABLE
  x86: Mark __invalid_creds() __noreturn
  exit: Mark do_group_exit() __noreturn
  x86: Mark stop_this_cpu() __noreturn
  objtool: Ignore extra-symbol code
  objtool: Rename --duplicate to --lto
  ...
</pre>
</div>
</content>
</entry>
</feed>
