<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/s390, branch v6.12</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>crash, powerpc: default to CRASH_DUMP=n on PPC_BOOK3S_32</title>
<updated>2024-11-15T06:43:48+00:00</updated>
<author>
<name>Dave Vasilevsky</name>
<email>dave@vasilevsky.ca</email>
</author>
<published>2024-09-17T16:37:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=31daa34315d45d3fe77f2158d889d523d78852ea'/>
<id>31daa34315d45d3fe77f2158d889d523d78852ea</id>
<content type='text'>
Fixes boot failures on 6.9 on PPC_BOOK3S_32 machines using Open Firmware. 
On these machines, the kernel refuses to boot from non-zero
PHYSICAL_START, which occurs when CRASH_DUMP is on.

Since most PPC_BOOK3S_32 machines boot via Open Firmware, it should
default to off for them.  Users booting via some other mechanism can still
turn it on explicitly.

Does not change the default on any other architectures for the
time being.

Link: https://lkml.kernel.org/r/20240917163720.1644584-1-dave@vasilevsky.ca
Fixes: 75bc255a7444 ("crash: clean up kdump related config items")
Signed-off-by: Dave Vasilevsky &lt;dave@vasilevsky.ca&gt;
Reported-by: Reimar Döffinger &lt;Reimar.Doeffinger@gmx.de&gt;
Closes: https://lists.debian.org/debian-powerpc/2024/07/msg00001.html
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;	[powerpc]
Acked-by: Baoquan He &lt;bhe@redhat.com&gt;
Cc: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Cc: John Paul Adrian Glaubitz &lt;glaubitz@physik.fu-berlin.de&gt;
Cc: Reimar Döffinger &lt;Reimar.Doeffinger@gmx.de&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fixes boot failures on 6.9 on PPC_BOOK3S_32 machines using Open Firmware. 
On these machines, the kernel refuses to boot from non-zero
PHYSICAL_START, which occurs when CRASH_DUMP is on.

Since most PPC_BOOK3S_32 machines boot via Open Firmware, it should
default to off for them.  Users booting via some other mechanism can still
turn it on explicitly.

Does not change the default on any other architectures for the
time being.

Link: https://lkml.kernel.org/r/20240917163720.1644584-1-dave@vasilevsky.ca
Fixes: 75bc255a7444 ("crash: clean up kdump related config items")
Signed-off-by: Dave Vasilevsky &lt;dave@vasilevsky.ca&gt;
Reported-by: Reimar Döffinger &lt;Reimar.Doeffinger@gmx.de&gt;
Closes: https://lists.debian.org/debian-powerpc/2024/07/msg00001.html
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;	[powerpc]
Acked-by: Baoquan He &lt;bhe@redhat.com&gt;
Cc: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Cc: John Paul Adrian Glaubitz &lt;glaubitz@physik.fu-berlin.de&gt;
Cc: Reimar Döffinger &lt;Reimar.Doeffinger@gmx.de&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 's390-6.12-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux</title>
<updated>2024-10-18T14:01:59+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-10-18T14:01:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c91c14618fcf4ae3cf3475e5461ea8b41bf76f6d'/>
<id>c91c14618fcf4ae3cf3475e5461ea8b41bf76f6d</id>
<content type='text'>
Pull s390 fixes from Heiko Carstens:

 - Fix PCI error recovery by handling error events correctly

 - Fix CCA crypto card behavior within protected execution environment

 - Two KVM commits which fix virtual vs physical address handling bugs
   in KVM pfault handling

 - Fix return code handling in pckmo_key2protkey()

 - Deactivate sclp console as late as possible so that outstanding
   messages appear on the console instead of being dropped on reboot

 - Convert newlines to CRLF instead of LFCR for the sclp vt220 driver,
   as required by the vt220 specification

 - Initialize also psw mask in perf_arch_fetch_caller_regs() to make
   sure that user_mode(regs) will return false

 - Update defconfigs

* tag 's390-6.12-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390: Update defconfigs
  s390: Initialize psw mask in perf_arch_fetch_caller_regs()
  s390/sclp_vt220: Convert newlines to CRLF instead of LFCR
  s390/sclp: Deactivate sclp after all its users
  s390/pkey_pckmo: Return with success for valid protected key types
  KVM: s390: Change virtual to physical address access in diag 0x258 handler
  KVM: s390: gaccess: Check if guest address is in memslot
  s390/ap: Fix CCA crypto card behavior within protected execution environment
  s390/pci: Handle PCI error codes other than 0x3a
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull s390 fixes from Heiko Carstens:

 - Fix PCI error recovery by handling error events correctly

 - Fix CCA crypto card behavior within protected execution environment

 - Two KVM commits which fix virtual vs physical address handling bugs
   in KVM pfault handling

 - Fix return code handling in pckmo_key2protkey()

 - Deactivate sclp console as late as possible so that outstanding
   messages appear on the console instead of being dropped on reboot

 - Convert newlines to CRLF instead of LFCR for the sclp vt220 driver,
   as required by the vt220 specification

 - Initialize also psw mask in perf_arch_fetch_caller_regs() to make
   sure that user_mode(regs) will return false

 - Update defconfigs

* tag 's390-6.12-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390: Update defconfigs
  s390: Initialize psw mask in perf_arch_fetch_caller_regs()
  s390/sclp_vt220: Convert newlines to CRLF instead of LFCR
  s390/sclp: Deactivate sclp after all its users
  s390/pkey_pckmo: Return with success for valid protected key types
  KVM: s390: Change virtual to physical address access in diag 0x258 handler
  KVM: s390: gaccess: Check if guest address is in memslot
  s390/ap: Fix CCA crypto card behavior within protected execution environment
  s390/pci: Handle PCI error codes other than 0x3a
</pre>
</div>
</content>
</entry>
<entry>
<title>s390: Update defconfigs</title>
<updated>2024-10-16T09:32:32+00:00</updated>
<author>
<name>Heiko Carstens</name>
<email>hca@linux.ibm.com</email>
</author>
<published>2024-10-14T10:07:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b4fa00fd428bf7648d4ac5d0c8b61882902ec516'/>
<id>b4fa00fd428bf7648d4ac5d0c8b61882902ec516</id>
<content type='text'>
Signed-off-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>s390: Initialize psw mask in perf_arch_fetch_caller_regs()</title>
<updated>2024-10-16T09:32:32+00:00</updated>
<author>
<name>Heiko Carstens</name>
<email>hca@linux.ibm.com</email>
</author>
<published>2024-10-10T15:52:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=223e7fb979fa06934f1595b6ad0ae1d4ead1147f'/>
<id>223e7fb979fa06934f1595b6ad0ae1d4ead1147f</id>
<content type='text'>
Also initialize regs-&gt;psw.mask in perf_arch_fetch_caller_regs().
This way user_mode(regs) will return false, like it should.

It looks like all current users initialize regs to zero, so that this
doesn't fix a bug currently. However it is better to not rely on callers
to do this.

Fixes: 914d52e46490 ("s390: implement perf_arch_fetch_caller_regs")
Signed-off-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Also initialize regs-&gt;psw.mask in perf_arch_fetch_caller_regs().
This way user_mode(regs) will return false, like it should.

It looks like all current users initialize regs to zero, so that this
doesn't fix a bug currently. However it is better to not rely on callers
to do this.

Fixes: 914d52e46490 ("s390: implement perf_arch_fetch_caller_regs")
Signed-off-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: s390: Change virtual to physical address access in diag 0x258 handler</title>
<updated>2024-10-10T13:31:55+00:00</updated>
<author>
<name>Michael Mueller</name>
<email>mimu@linux.ibm.com</email>
</author>
<published>2024-09-17T15:18:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=cad4b3d4ab1f062708fff33f44d246853f51e966'/>
<id>cad4b3d4ab1f062708fff33f44d246853f51e966</id>
<content type='text'>
The parameters for the diag 0x258 are real addresses, not virtual, but
KVM was using them as virtual addresses. This only happened to work, since
the Linux kernel as a guest used to have a 1:1 mapping for physical vs
virtual addresses.

Fix KVM so that it correctly uses the addresses as real addresses.

Cc: stable@vger.kernel.org
Fixes: 8ae04b8f500b ("KVM: s390: Guest's memory access functions get access registers")
Suggested-by: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Signed-off-by: Michael Mueller &lt;mimu@linux.ibm.com&gt;
Signed-off-by: Nico Boehr &lt;nrb@linux.ibm.com&gt;
Reviewed-by: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Reviewed-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Link: https://lore.kernel.org/r/20240917151904.74314-3-nrb@linux.ibm.com
Acked-by: Janosch Frank &lt;frankja@linux.ibm.com&gt;
Signed-off-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The parameters for the diag 0x258 are real addresses, not virtual, but
KVM was using them as virtual addresses. This only happened to work, since
the Linux kernel as a guest used to have a 1:1 mapping for physical vs
virtual addresses.

Fix KVM so that it correctly uses the addresses as real addresses.

Cc: stable@vger.kernel.org
Fixes: 8ae04b8f500b ("KVM: s390: Guest's memory access functions get access registers")
Suggested-by: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Signed-off-by: Michael Mueller &lt;mimu@linux.ibm.com&gt;
Signed-off-by: Nico Boehr &lt;nrb@linux.ibm.com&gt;
Reviewed-by: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Reviewed-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Link: https://lore.kernel.org/r/20240917151904.74314-3-nrb@linux.ibm.com
Acked-by: Janosch Frank &lt;frankja@linux.ibm.com&gt;
Signed-off-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: s390: gaccess: Check if guest address is in memslot</title>
<updated>2024-10-10T13:31:55+00:00</updated>
<author>
<name>Nico Boehr</name>
<email>nrb@linux.ibm.com</email>
</author>
<published>2024-09-17T15:18:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e8061f06185be0a06a73760d6526b8b0feadfe52'/>
<id>e8061f06185be0a06a73760d6526b8b0feadfe52</id>
<content type='text'>
Previously, access_guest_page() did not check whether the given guest
address is inside of a memslot. This is not a problem, since
kvm_write_guest_page/kvm_read_guest_page return -EFAULT in this case.

However, -EFAULT is also returned when copy_to/from_user fails.

When emulating a guest instruction, the address being outside a memslot
usually means that an addressing exception should be injected into the
guest.

Failure in copy_to/from_user however indicates that something is wrong
in userspace and hence should be handled there.

To be able to distinguish these two cases, return PGM_ADDRESSING in
access_guest_page() when the guest address is outside guest memory. In
access_guest_real(), populate vcpu-&gt;arch.pgm.code such that
kvm_s390_inject_prog_cond() can be used in the caller for injecting into
the guest (if applicable).

Since this adds a new return value to access_guest_page(), we need to make
sure that other callers are not confused by the new positive return value.

There are the following users of access_guest_page():
- access_guest_with_key() does the checking itself (in
  guest_range_to_gpas()), so this case should never happen. Even if, the
  handling is set up properly.
- access_guest_real() just passes the return code to its callers, which
  are:
    - read_guest_real() - see below
    - write_guest_real() - see below

There are the following users of read_guest_real():
- ar_translation() in gaccess.c which already returns PGM_*
- setup_apcb10(), setup_apcb00(), setup_apcb11() in vsie.c which always
  return -EFAULT on read_guest_read() nonzero return - no change
- shadow_crycb(), handle_stfle() always present this as validity, this
  could be handled better but doesn't change current behaviour - no change

There are the following users of write_guest_real():
- kvm_s390_store_status_unloaded() always returns -EFAULT on
  write_guest_real() failure.

Fixes: 2293897805c2 ("KVM: s390: add architecture compliant guest access functions")
Cc: stable@vger.kernel.org
Signed-off-by: Nico Boehr &lt;nrb@linux.ibm.com&gt;
Reviewed-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Link: https://lore.kernel.org/r/20240917151904.74314-2-nrb@linux.ibm.com
Acked-by: Janosch Frank &lt;frankja@linux.ibm.com&gt;
Signed-off-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Previously, access_guest_page() did not check whether the given guest
address is inside of a memslot. This is not a problem, since
kvm_write_guest_page/kvm_read_guest_page return -EFAULT in this case.

However, -EFAULT is also returned when copy_to/from_user fails.

When emulating a guest instruction, the address being outside a memslot
usually means that an addressing exception should be injected into the
guest.

Failure in copy_to/from_user however indicates that something is wrong
in userspace and hence should be handled there.

To be able to distinguish these two cases, return PGM_ADDRESSING in
access_guest_page() when the guest address is outside guest memory. In
access_guest_real(), populate vcpu-&gt;arch.pgm.code such that
kvm_s390_inject_prog_cond() can be used in the caller for injecting into
the guest (if applicable).

Since this adds a new return value to access_guest_page(), we need to make
sure that other callers are not confused by the new positive return value.

There are the following users of access_guest_page():
- access_guest_with_key() does the checking itself (in
  guest_range_to_gpas()), so this case should never happen. Even if, the
  handling is set up properly.
- access_guest_real() just passes the return code to its callers, which
  are:
    - read_guest_real() - see below
    - write_guest_real() - see below

There are the following users of read_guest_real():
- ar_translation() in gaccess.c which already returns PGM_*
- setup_apcb10(), setup_apcb00(), setup_apcb11() in vsie.c which always
  return -EFAULT on read_guest_read() nonzero return - no change
- shadow_crycb(), handle_stfle() always present this as validity, this
  could be handled better but doesn't change current behaviour - no change

There are the following users of write_guest_real():
- kvm_s390_store_status_unloaded() always returns -EFAULT on
  write_guest_real() failure.

Fixes: 2293897805c2 ("KVM: s390: add architecture compliant guest access functions")
Cc: stable@vger.kernel.org
Signed-off-by: Nico Boehr &lt;nrb@linux.ibm.com&gt;
Reviewed-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Link: https://lore.kernel.org/r/20240917151904.74314-2-nrb@linux.ibm.com
Acked-by: Janosch Frank &lt;frankja@linux.ibm.com&gt;
Signed-off-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>s390/pci: Handle PCI error codes other than 0x3a</title>
<updated>2024-10-10T13:31:55+00:00</updated>
<author>
<name>Niklas Schnelle</name>
<email>schnelle@linux.ibm.com</email>
</author>
<published>2024-04-11T12:01:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3cd03ea57e8e16cc78cc357d5e9f26078426f236'/>
<id>3cd03ea57e8e16cc78cc357d5e9f26078426f236</id>
<content type='text'>
The Linux implementation of PCI error recovery for s390 was based on the
understanding that firmware error recovery is a two step process with an
optional initial error event to indicate the cause of the error if known
followed by either error event 0x3A (Success) or 0x3B (Failure) to
indicate whether firmware was able to recover. While this has been the
case in testing and the error cases seen in the wild it turns out this
is not correct. Instead firmware only generates 0x3A for some error and
service scenarios and expects the OS to perform recovery for all PCI
events codes except for those indicating permanent error (0x3B, 0x40)
and those indicating errors on the function measurement block (0x2A,
0x2B, 0x2C). Align Linux behavior with these expectations.

Fixes: 4cdf2f4e24ff ("s390/pci: implement minimal PCI error recovery")
Reviewed-by: Gerd Bayer &lt;gbayer@linux.ibm.com&gt;
Signed-off-by: Niklas Schnelle &lt;schnelle@linux.ibm.com&gt;
Signed-off-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The Linux implementation of PCI error recovery for s390 was based on the
understanding that firmware error recovery is a two step process with an
optional initial error event to indicate the cause of the error if known
followed by either error event 0x3A (Success) or 0x3B (Failure) to
indicate whether firmware was able to recover. While this has been the
case in testing and the error cases seen in the wild it turns out this
is not correct. Instead firmware only generates 0x3A for some error and
service scenarios and expects the OS to perform recovery for all PCI
events codes except for those indicating permanent error (0x3B, 0x40)
and those indicating errors on the function measurement block (0x2A,
0x2B, 0x2C). Align Linux behavior with these expectations.

Fixes: 4cdf2f4e24ff ("s390/pci: implement minimal PCI error recovery")
Reviewed-by: Gerd Bayer &lt;gbayer@linux.ibm.com&gt;
Signed-off-by: Niklas Schnelle &lt;schnelle@linux.ibm.com&gt;
Signed-off-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fs/proc/kcore.c: allow translation of physical memory addresses</title>
<updated>2024-10-09T19:47:19+00:00</updated>
<author>
<name>Alexander Gordeev</name>
<email>agordeev@linux.ibm.com</email>
</author>
<published>2024-09-30T12:21:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3d5854d75e3187147613130561b58f0b06166172'/>
<id>3d5854d75e3187147613130561b58f0b06166172</id>
<content type='text'>
When /proc/kcore is read an attempt to read the first two pages results in
HW-specific page swap on s390 and another (so called prefix) pages are
accessed instead.  That leads to a wrong read.

Allow architecture-specific translation of memory addresses using
kc_xlate_dev_mem_ptr() and kc_unxlate_dev_mem_ptr() callbacks similarily
to /dev/mem xlate_dev_mem_ptr() and unxlate_dev_mem_ptr() callbacks.  That
way an architecture can deal with specific physical memory ranges.

Re-use the existing /dev/mem callback implementation on s390, which
handles the described prefix pages swapping correctly.

For other architectures the default callback is basically NOP.  It is
expected the condition (vaddr == __va(__pa(vaddr))) always holds true for
KCORE_RAM memory type.

Link: https://lkml.kernel.org/r/20240930122119.1651546-1-agordeev@linux.ibm.com
Signed-off-by: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Suggested-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When /proc/kcore is read an attempt to read the first two pages results in
HW-specific page swap on s390 and another (so called prefix) pages are
accessed instead.  That leads to a wrong read.

Allow architecture-specific translation of memory addresses using
kc_xlate_dev_mem_ptr() and kc_unxlate_dev_mem_ptr() callbacks similarily
to /dev/mem xlate_dev_mem_ptr() and unxlate_dev_mem_ptr() callbacks.  That
way an architecture can deal with specific physical memory ranges.

Re-use the existing /dev/mem callback implementation on s390, which
handles the described prefix pages swapping correctly.

For other architectures the default callback is basically NOP.  It is
expected the condition (vaddr == __va(__pa(vaddr))) always holds true for
KCORE_RAM memory type.

Link: https://lkml.kernel.org/r/20240930122119.1651546-1-agordeev@linux.ibm.com
Signed-off-by: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Suggested-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm</title>
<updated>2024-09-28T16:20:14+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-09-28T16:20:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3efc57369a0ce8f76bf0804f7e673982384e4ac9'/>
<id>3efc57369a0ce8f76bf0804f7e673982384e4ac9</id>
<content type='text'>
Pull x86 kvm updates from Paolo Bonzini:
 "x86:

   - KVM currently invalidates the entirety of the page tables, not just
     those for the memslot being touched, when a memslot is moved or
     deleted.

     This does not traditionally have particularly noticeable overhead,
     but Intel's TDX will require the guest to re-accept private pages
     if they are dropped from the secure EPT, which is a non starter.

     Actually, the only reason why this is not already being done is a
     bug which was never fully investigated and caused VM instability
     with assigned GeForce GPUs, so allow userspace to opt into the new
     behavior.

   - Advertise AVX10.1 to userspace (effectively prep work for the
     "real" AVX10 functionality that is on the horizon)

   - Rework common MSR handling code to suppress errors on userspace
     accesses to unsupported-but-advertised MSRs

     This will allow removing (almost?) all of KVM's exemptions for
     userspace access to MSRs that shouldn't exist based on the vCPU
     model (the actual cleanup is non-trivial future work)

   - Rework KVM's handling of x2APIC ICR, again, because AMD (x2AVIC)
     splits the 64-bit value into the legacy ICR and ICR2 storage,
     whereas Intel (APICv) stores the entire 64-bit value at the ICR
     offset

   - Fix a bug where KVM would fail to exit to userspace if one was
     triggered by a fastpath exit handler

   - Add fastpath handling of HLT VM-Exit to expedite re-entering the
     guest when there's already a pending wake event at the time of the
     exit

   - Fix a WARN caused by RSM entering a nested guest from SMM with
     invalid guest state, by forcing the vCPU out of guest mode prior to
     signalling SHUTDOWN (the SHUTDOWN hits the VM altogether, not the
     nested guest)

   - Overhaul the "unprotect and retry" logic to more precisely identify
     cases where retrying is actually helpful, and to harden all retry
     paths against putting the guest into an infinite retry loop

   - Add support for yielding, e.g. to honor NEED_RESCHED, when zapping
     rmaps in the shadow MMU

   - Refactor pieces of the shadow MMU related to aging SPTEs in
     prepartion for adding multi generation LRU support in KVM

   - Don't stuff the RSB after VM-Exit when RETPOLINE=y and AutoIBRS is
     enabled, i.e. when the CPU has already flushed the RSB

   - Trace the per-CPU host save area as a VMCB pointer to improve
     readability and cleanup the retrieval of the SEV-ES host save area

   - Remove unnecessary accounting of temporary nested VMCB related
     allocations

   - Set FINAL/PAGE in the page fault error code for EPT violations if
     and only if the GVA is valid. If the GVA is NOT valid, there is no
     guest-side page table walk and so stuffing paging related metadata
     is nonsensical

   - Fix a bug where KVM would incorrectly synthesize a nested VM-Exit
     instead of emulating posted interrupt delivery to L2

   - Add a lockdep assertion to detect unsafe accesses of vmcs12
     structures

   - Harden eVMCS loading against an impossible NULL pointer deref
     (really truly should be impossible)

   - Minor SGX fix and a cleanup

   - Misc cleanups

  Generic:

   - Register KVM's cpuhp and syscore callbacks when enabling
     virtualization in hardware, as the sole purpose of said callbacks
     is to disable and re-enable virtualization as needed

   - Enable virtualization when KVM is loaded, not right before the
     first VM is created

     Together with the previous change, this simplifies a lot the logic
     of the callbacks, because their very existence implies
     virtualization is enabled

   - Fix a bug that results in KVM prematurely exiting to userspace for
     coalesced MMIO/PIO in many cases, clean up the related code, and
     add a testcase

   - Fix a bug in kvm_clear_guest() where it would trigger a buffer
     overflow _if_ the gpa+len crosses a page boundary, which thankfully
     is guaranteed to not happen in the current code base. Add WARNs in
     more helpers that read/write guest memory to detect similar bugs

  Selftests:

   - Fix a goof that caused some Hyper-V tests to be skipped when run on
     bare metal, i.e. NOT in a VM

   - Add a regression test for KVM's handling of SHUTDOWN for an SEV-ES
     guest

   - Explicitly include one-off assets in .gitignore. Past Sean was
     completely wrong about not being able to detect missing .gitignore
     entries

   - Verify userspace single-stepping works when KVM happens to handle a
     VM-Exit in its fastpath

   - Misc cleanups"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (127 commits)
  Documentation: KVM: fix warning in "make htmldocs"
  s390: Enable KVM_S390_UCONTROL config in debug_defconfig
  selftests: kvm: s390: Add VM run test case
  KVM: SVM: let alternatives handle the cases when RSB filling is required
  KVM: VMX: Set PFERR_GUEST_{FINAL,PAGE}_MASK if and only if the GVA is valid
  KVM: x86/mmu: Use KVM_PAGES_PER_HPAGE() instead of an open coded equivalent
  KVM: x86/mmu: Add KVM_RMAP_MANY to replace open coded '1' and '1ul' literals
  KVM: x86/mmu: Fold mmu_spte_age() into kvm_rmap_age_gfn_range()
  KVM: x86/mmu: Morph kvm_handle_gfn_range() into an aging specific helper
  KVM: x86/mmu: Honor NEED_RESCHED when zapping rmaps and blocking is allowed
  KVM: x86/mmu: Add a helper to walk and zap rmaps for a memslot
  KVM: x86/mmu: Plumb a @can_yield parameter into __walk_slot_rmaps()
  KVM: x86/mmu: Move walk_slot_rmaps() up near for_each_slot_rmap_range()
  KVM: x86/mmu: WARN on MMIO cache hit when emulating write-protected gfn
  KVM: x86/mmu: Detect if unprotect will do anything based on invalid_list
  KVM: x86/mmu: Subsume kvm_mmu_unprotect_page() into the and_retry() version
  KVM: x86: Rename reexecute_instruction()=&gt;kvm_unprotect_and_retry_on_failure()
  KVM: x86: Update retry protection fields when forcing retry on emulation failure
  KVM: x86: Apply retry protection to "unprotect on failure" path
  KVM: x86: Check EMULTYPE_WRITE_PF_TO_SP before unprotecting gfn
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 kvm updates from Paolo Bonzini:
 "x86:

   - KVM currently invalidates the entirety of the page tables, not just
     those for the memslot being touched, when a memslot is moved or
     deleted.

     This does not traditionally have particularly noticeable overhead,
     but Intel's TDX will require the guest to re-accept private pages
     if they are dropped from the secure EPT, which is a non starter.

     Actually, the only reason why this is not already being done is a
     bug which was never fully investigated and caused VM instability
     with assigned GeForce GPUs, so allow userspace to opt into the new
     behavior.

   - Advertise AVX10.1 to userspace (effectively prep work for the
     "real" AVX10 functionality that is on the horizon)

   - Rework common MSR handling code to suppress errors on userspace
     accesses to unsupported-but-advertised MSRs

     This will allow removing (almost?) all of KVM's exemptions for
     userspace access to MSRs that shouldn't exist based on the vCPU
     model (the actual cleanup is non-trivial future work)

   - Rework KVM's handling of x2APIC ICR, again, because AMD (x2AVIC)
     splits the 64-bit value into the legacy ICR and ICR2 storage,
     whereas Intel (APICv) stores the entire 64-bit value at the ICR
     offset

   - Fix a bug where KVM would fail to exit to userspace if one was
     triggered by a fastpath exit handler

   - Add fastpath handling of HLT VM-Exit to expedite re-entering the
     guest when there's already a pending wake event at the time of the
     exit

   - Fix a WARN caused by RSM entering a nested guest from SMM with
     invalid guest state, by forcing the vCPU out of guest mode prior to
     signalling SHUTDOWN (the SHUTDOWN hits the VM altogether, not the
     nested guest)

   - Overhaul the "unprotect and retry" logic to more precisely identify
     cases where retrying is actually helpful, and to harden all retry
     paths against putting the guest into an infinite retry loop

   - Add support for yielding, e.g. to honor NEED_RESCHED, when zapping
     rmaps in the shadow MMU

   - Refactor pieces of the shadow MMU related to aging SPTEs in
     prepartion for adding multi generation LRU support in KVM

   - Don't stuff the RSB after VM-Exit when RETPOLINE=y and AutoIBRS is
     enabled, i.e. when the CPU has already flushed the RSB

   - Trace the per-CPU host save area as a VMCB pointer to improve
     readability and cleanup the retrieval of the SEV-ES host save area

   - Remove unnecessary accounting of temporary nested VMCB related
     allocations

   - Set FINAL/PAGE in the page fault error code for EPT violations if
     and only if the GVA is valid. If the GVA is NOT valid, there is no
     guest-side page table walk and so stuffing paging related metadata
     is nonsensical

   - Fix a bug where KVM would incorrectly synthesize a nested VM-Exit
     instead of emulating posted interrupt delivery to L2

   - Add a lockdep assertion to detect unsafe accesses of vmcs12
     structures

   - Harden eVMCS loading against an impossible NULL pointer deref
     (really truly should be impossible)

   - Minor SGX fix and a cleanup

   - Misc cleanups

  Generic:

   - Register KVM's cpuhp and syscore callbacks when enabling
     virtualization in hardware, as the sole purpose of said callbacks
     is to disable and re-enable virtualization as needed

   - Enable virtualization when KVM is loaded, not right before the
     first VM is created

     Together with the previous change, this simplifies a lot the logic
     of the callbacks, because their very existence implies
     virtualization is enabled

   - Fix a bug that results in KVM prematurely exiting to userspace for
     coalesced MMIO/PIO in many cases, clean up the related code, and
     add a testcase

   - Fix a bug in kvm_clear_guest() where it would trigger a buffer
     overflow _if_ the gpa+len crosses a page boundary, which thankfully
     is guaranteed to not happen in the current code base. Add WARNs in
     more helpers that read/write guest memory to detect similar bugs

  Selftests:

   - Fix a goof that caused some Hyper-V tests to be skipped when run on
     bare metal, i.e. NOT in a VM

   - Add a regression test for KVM's handling of SHUTDOWN for an SEV-ES
     guest

   - Explicitly include one-off assets in .gitignore. Past Sean was
     completely wrong about not being able to detect missing .gitignore
     entries

   - Verify userspace single-stepping works when KVM happens to handle a
     VM-Exit in its fastpath

   - Misc cleanups"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (127 commits)
  Documentation: KVM: fix warning in "make htmldocs"
  s390: Enable KVM_S390_UCONTROL config in debug_defconfig
  selftests: kvm: s390: Add VM run test case
  KVM: SVM: let alternatives handle the cases when RSB filling is required
  KVM: VMX: Set PFERR_GUEST_{FINAL,PAGE}_MASK if and only if the GVA is valid
  KVM: x86/mmu: Use KVM_PAGES_PER_HPAGE() instead of an open coded equivalent
  KVM: x86/mmu: Add KVM_RMAP_MANY to replace open coded '1' and '1ul' literals
  KVM: x86/mmu: Fold mmu_spte_age() into kvm_rmap_age_gfn_range()
  KVM: x86/mmu: Morph kvm_handle_gfn_range() into an aging specific helper
  KVM: x86/mmu: Honor NEED_RESCHED when zapping rmaps and blocking is allowed
  KVM: x86/mmu: Add a helper to walk and zap rmaps for a memslot
  KVM: x86/mmu: Plumb a @can_yield parameter into __walk_slot_rmaps()
  KVM: x86/mmu: Move walk_slot_rmaps() up near for_each_slot_rmap_range()
  KVM: x86/mmu: WARN on MMIO cache hit when emulating write-protected gfn
  KVM: x86/mmu: Detect if unprotect will do anything based on invalid_list
  KVM: x86/mmu: Subsume kvm_mmu_unprotect_page() into the and_retry() version
  KVM: x86: Rename reexecute_instruction()=&gt;kvm_unprotect_and_retry_on_failure()
  KVM: x86: Update retry protection fields when forcing retry on emulation failure
  KVM: x86: Apply retry protection to "unprotect on failure" path
  KVM: x86: Check EMULTYPE_WRITE_PF_TO_SP before unprotecting gfn
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 's390-6.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux</title>
<updated>2024-09-28T16:11:46+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-09-28T16:11:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e08d227840bb9366c6321ae1e480b37ba5eec29b'/>
<id>e08d227840bb9366c6321ae1e480b37ba5eec29b</id>
<content type='text'>
Pull more s390 updates from Vasily Gorbik:

 - Clean up and improve vdso code: use SYM_* macros for function and
   data annotations, add CFI annotations to fix GDB unwinding, optimize
   the chacha20 implementation

 - Add vfio-ap driver feature advertisement for use by libvirt and
   mdevctl

* tag 's390-6.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/vfio-ap: Driver feature advertisement
  s390/vdso: Use one large alternative instead of an alternative branch
  s390/vdso: Use SYM_DATA_START_LOCAL()/SYM_DATA_END() for data objects
  tools: Add additional SYM_*() stubs to linkage.h
  s390/vdso: Use macros for annotation of asm functions
  s390/vdso: Add CFI annotations to __arch_chacha20_blocks_nostack()
  s390/vdso: Fix comment within __arch_chacha20_blocks_nostack()
  s390/vdso: Get rid of permutation constants
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull more s390 updates from Vasily Gorbik:

 - Clean up and improve vdso code: use SYM_* macros for function and
   data annotations, add CFI annotations to fix GDB unwinding, optimize
   the chacha20 implementation

 - Add vfio-ap driver feature advertisement for use by libvirt and
   mdevctl

* tag 's390-6.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/vfio-ap: Driver feature advertisement
  s390/vdso: Use one large alternative instead of an alternative branch
  s390/vdso: Use SYM_DATA_START_LOCAL()/SYM_DATA_END() for data objects
  tools: Add additional SYM_*() stubs to linkage.h
  s390/vdso: Use macros for annotation of asm functions
  s390/vdso: Add CFI annotations to __arch_chacha20_blocks_nostack()
  s390/vdso: Fix comment within __arch_chacha20_blocks_nostack()
  s390/vdso: Get rid of permutation constants
</pre>
</div>
</content>
</entry>
</feed>
