linux.git/arch/x86/kernel/cpu/intel.c, branch v6.12 Linux kernel source tree x86/cpu/intel: Replace PAT erratum model/family magic numbers with symbolic IFM references 2024-09-03T09:18:58+00:00 Dave Hansen dave.hansen@linux.intel.com 2024-08-29T22:00:42+00:00 fd82221a59fa5ce9dc7523e11c5e995104a28cb0 There's an erratum that prevents the PAT from working correctly: https://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/pentium-dual-core-specification-update.pdf # Document 316515 Version 010 The kernel currently disables PAT support on those CPUs, but it does it with some magic numbers. Replace the magic numbers with the new "IFM" macros. Make the check refer to the last affected CPU (INTEL_CORE_YONAH) rather than the first fixed one. This makes it easier to find the documentation of the erratum since Intel documents where it is broken and not where it is fixed. I don't think the Pentium Pro (or Pentium II) is actually affected. But the old check included them, so it can't hurt to keep doing the same. I'm also not completely sure about the "Pentium M" CPUs (models 0x9 and 0xd). But, again, they were included in in the old checks and were close Pentium III derivatives, so are likely affected. While we're at it, revise the comment referring to the erratum name and making sure it is a quote of the language from the actual errata doc. That should make it easier to find in the future when the URL inevitably changes. Why bother with this in the first place? It actually gets rid of one of the very few remaining direct references to c->x86{,_model}. No change in functionality intended. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Len Brown <len.brown@intel.com> Link: https://lore.kernel.org/r/20240829220042.1007820-1-dave.hansen@linux.intel.com 
There's an erratum that prevents the PAT from working correctly:

   https://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/pentium-dual-core-specification-update.pdf
   # Document 316515 Version 010

The kernel currently disables PAT support on those CPUs, but it
does it with some magic numbers.

Replace the magic numbers with the new "IFM" macros.

Make the check refer to the last affected CPU (INTEL_CORE_YONAH)
rather than the first fixed one. This makes it easier to find the
documentation of the erratum since Intel documents where it is
broken and not where it is fixed.

I don't think the Pentium Pro (or Pentium II) is actually affected.
But the old check included them, so it can't hurt to keep doing the
same.  I'm also not completely sure about the "Pentium M" CPUs
(models 0x9 and 0xd).  But, again, they were included in in the
old checks and were close Pentium III derivatives, so are likely
affected.

While we're at it, revise the comment referring to the erratum name
and making sure it is a quote of the language from the actual errata
doc.  That should make it easier to find in the future when the URL
inevitably changes.

Why bother with this in the first place? It actually gets rid of one
of the very few remaining direct references to c->x86{,_model}.

No change in functionality intended.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Len Brown <len.brown@intel.com>
Link: https://lore.kernel.org/r/20240829220042.1007820-1-dave.hansen@linux.intel.com
Merge tag 'x86_cpu_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2024-07-16T03:25:16+00:00 Linus Torvalds torvalds@linux-foundation.org 2024-07-16T03:25:16+00:00 d67978318827d06f1c0fa4c31343a279e9df6fde Pull x86 cpu model updates from Borislav Petkov: - Flip the logic to add feature names to /proc/cpuinfo to having to explicitly specify the flag if there's a valid reason to show it in /proc/cpuinfo - Switch a bunch of Intel x86 model checking code to the new CPU model defines - Fixes and cleanups * tag 'x86_cpu_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu/intel: Drop stray FAM6 check with new Intel CPU model defines x86/cpufeatures: Flip the /proc/cpuinfo appearance logic x86/CPU/AMD: Always inline amd_clear_divider() x86/mce/inject: Add missing MODULE_DESCRIPTION() line perf/x86/rapl: Switch to new Intel CPU model defines x86/boot: Switch to new Intel CPU model defines x86/cpu: Switch to new Intel CPU model defines perf/x86/intel: Switch to new Intel CPU model defines x86/virt/tdx: Switch to new Intel CPU model defines x86/PCI: Switch to new Intel CPU model defines x86/cpu/intel: Switch to new Intel CPU model defines x86/platform/intel-mid: Switch to new Intel CPU model defines x86/pconfig: Remove unused MKTME pconfig code x86/cpu: Remove useless work in detect_tme_early() 
Pull x86 cpu model updates from Borislav Petkov:

 - Flip the logic to add feature names to /proc/cpuinfo to having to
   explicitly specify the flag if there's a valid reason to show it in
   /proc/cpuinfo

 - Switch a bunch of Intel x86 model checking code to the new CPU model
   defines

 - Fixes and cleanups

* tag 'x86_cpu_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu/intel: Drop stray FAM6 check with new Intel CPU model defines
  x86/cpufeatures: Flip the /proc/cpuinfo appearance logic
  x86/CPU/AMD: Always inline amd_clear_divider()
  x86/mce/inject: Add missing MODULE_DESCRIPTION() line
  perf/x86/rapl: Switch to new Intel CPU model defines
  x86/boot: Switch to new Intel CPU model defines
  x86/cpu: Switch to new Intel CPU model defines
  perf/x86/intel: Switch to new Intel CPU model defines
  x86/virt/tdx: Switch to new Intel CPU model defines
  x86/PCI: Switch to new Intel CPU model defines
  x86/cpu/intel: Switch to new Intel CPU model defines
  x86/platform/intel-mid: Switch to new Intel CPU model defines
  x86/pconfig: Remove unused MKTME pconfig code
  x86/cpu: Remove useless work in detect_tme_early()
x86/cpu/intel: Drop stray FAM6 check with new Intel CPU model defines 2024-06-29T14:10:37+00:00 Andrew Cooper andrew.cooper3@citrix.com 2024-05-29T18:36:05+00:00 34b3fc558b537bdf99644dcde539e151716f6331 The outer if () should have been dropped when switching to c->x86_vfm. Fixes: 6568fc18c2f6 ("x86/cpu/intel: Switch to new Intel CPU model defines") Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Tony Luck <tony.luck@intel.com> Link: https://lore.kernel.org/r/20240529183605.17520-1-andrew.cooper3@citrix.com 
The outer if () should have been dropped when switching to c->x86_vfm.

Fixes: 6568fc18c2f6 ("x86/cpu/intel: Switch to new Intel CPU model defines")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20240529183605.17520-1-andrew.cooper3@citrix.com
x86/topology/intel: Unlock CPUID before evaluating anything 2024-05-31T18:25:56+00:00 Thomas Gleixner tglx@linutronix.de 2024-05-30T15:29:18+00:00 0c2f6d04619ec2b53ad4b0b591eafc9389786e86 Intel CPUs have a MSR bit to limit CPUID enumeration to leaf two. If this bit is set by the BIOS then CPUID evaluation including topology enumeration does not work correctly as the evaluation code does not try to analyze any leaf greater than two. This went unnoticed before because the original topology code just repeated evaluation several times and managed to overwrite the initial limited information with the correct one later. The new evaluation code does it once and therefore ends up with the limited and wrong information. Cure this by unlocking CPUID right before evaluating anything which depends on the maximum CPUID leaf being greater than two instead of rereading stuff after unlock. Fixes: 22d63660c35e ("x86/cpu: Use common topology code for Intel") Reported-by: Peter Schneider <pschneider1968@googlemail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Peter Schneider <pschneider1968@googlemail.com> Cc: <stable@kernel.org> Link: https://lore.kernel.org/r/fd3f73dc-a86f-4bcf-9c60-43556a21eb42@googlemail.com 
Intel CPUs have a MSR bit to limit CPUID enumeration to leaf two. If
this bit is set by the BIOS then CPUID evaluation including topology
enumeration does not work correctly as the evaluation code does not try
to analyze any leaf greater than two.

This went unnoticed before because the original topology code just
repeated evaluation several times and managed to overwrite the initial
limited information with the correct one later. The new evaluation code
does it once and therefore ends up with the limited and wrong
information.

Cure this by unlocking CPUID right before evaluating anything which
depends on the maximum CPUID leaf being greater than two instead of
rereading stuff after unlock.

Fixes: 22d63660c35e ("x86/cpu: Use common topology code for Intel")
Reported-by: Peter Schneider <pschneider1968@googlemail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Peter Schneider <pschneider1968@googlemail.com>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/fd3f73dc-a86f-4bcf-9c60-43556a21eb42@googlemail.com
x86/cpu/intel: Switch to new Intel CPU model defines 2024-05-28T17:59:02+00:00 Tony Luck tony.luck@intel.com 2024-05-20T22:45:59+00:00 6568fc18c2f62b4f35092e9680fe39f3500f4767 New CPU #defines encode vendor and family as well as model. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lore.kernel.org/all/20240520224620.9480-29-tony.luck%40intel.com 
New CPU #defines encode vendor and family as well as model.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/20240520224620.9480-29-tony.luck%40intel.com
x86/cpu: Remove useless work in detect_tme_early() 2024-05-28T15:45:17+00:00 Alison Schofield alison.schofield@intel.com 2024-05-07T04:24:21+00:00 98b83cf0c1e22390ebfeb96b3c1b40f7189c558a TME (Total Memory Encryption) and MKTME (Multi-Key Total Memory Encryption) BIOS detection were introduced together here [1] and are loosely coupled in the Intel CPU init code. TME is a hardware only feature and its BIOS status is all that needs to be shared with the kernel user: enabled or disabled. The TME algorithm the BIOS is using and whether or not the kernel recognizes that algorithm is useless to the kernel user. MKTME is a hardware feature that requires kernel support. MKTME detection code was added in advance of broader kernel support for MKTME that never followed. So, rather than continuing to spew needless and confusing messages about BIOS MKTME status, remove most of the MKTME pieces from detect_tme_early(). Keep one useful message: alert the user when BIOS enabled MKTME reduces the available physical address bits. Recovery of the MKTME consumed bits requires a reboot with MKTME disabled in BIOS. There is no functional change for the user, only a change in boot messages. Below is one example when both TME and MKTME are enabled in BIOS with AES_XTS_256 which is unknown to the detect tme code. Before: [] x86/tme: enabled by BIOS [] x86/tme: Unknown policy is active: 0x2 [] x86/mktme: No known encryption algorithm is supported: 0x4 [] x86/mktme: enabled by BIOS [] x86/mktme: 127 KeyIDs available After: [] x86/tme: enabled by BIOS [] x86/mktme: BIOS enable: x86_phys_bits reduced by 8 [1] commit cb06d8e3d020 ("x86/tme: Detect if TME and MKTME is activated by BIOS") Signed-off-by: Alison Schofield <alison.schofield@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Link: https://lore.kernel.org/all/86dfdf6ced8c9b790f9376bf6c7e22b5608f47c2.1715054189.git.alison.schofield%40intel.com 
TME (Total Memory Encryption) and MKTME (Multi-Key Total Memory
Encryption) BIOS detection were introduced together here [1] and
are loosely coupled in the Intel CPU init code.

TME is a hardware only feature and its BIOS status is all that needs
to be shared with the kernel user: enabled or disabled. The TME
algorithm the BIOS is using and whether or not the kernel recognizes
that algorithm is useless to the kernel user.

MKTME is a hardware feature that requires kernel support. MKTME
detection code was added in advance of broader kernel support for
MKTME that never followed. So, rather than continuing to spew
needless and confusing messages about BIOS MKTME status, remove
most of the MKTME pieces from detect_tme_early().

Keep one useful message: alert the user when BIOS enabled MKTME
reduces the available physical address bits. Recovery of the MKTME
consumed bits requires a reboot with MKTME disabled in BIOS.

There is no functional change for the user, only a change in boot
messages. Below is one example when both TME and MKTME are enabled
in BIOS with AES_XTS_256 which is unknown to the detect tme code.

Before:
[] x86/tme: enabled by BIOS
[] x86/tme: Unknown policy is active: 0x2
[] x86/mktme: No known encryption algorithm is supported: 0x4
[] x86/mktme: enabled by BIOS
[] x86/mktme: 127 KeyIDs available

After:
[] x86/tme: enabled by BIOS
[] x86/mktme: BIOS enable: x86_phys_bits reduced by 8

[1]
commit cb06d8e3d020 ("x86/tme: Detect if TME and MKTME is activated by BIOS")

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/all/86dfdf6ced8c9b790f9376bf6c7e22b5608f47c2.1715054189.git.alison.schofield%40intel.com
x86/cpu: Clear TME feature flag if TME is not enabled by BIOS 2024-03-26T08:49:32+00:00 Bingsong Si sibs@chinatelecom.cn 2024-03-11T07:19:37+00:00 cd2236c2f49eb46443fd7573d0ddad5373577b11 When TME is disabled by BIOS, the dmesg output is: x86/tme: not enabled by BIOS ... and TME functionality is not enabled by the kernel, but the TME feature is still shown in /proc/cpuinfo. Clear it. [ mingo: Clarified changelog ] Signed-off-by: Bingsong Si <sibs@chinatelecom.cn> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: "Huang, Kai" <kai.huang@intel.com> Link: https://lore.kernel.org/r/20240311071938.13247-1-sibs@chinatelecom.cn 
When TME is disabled by BIOS, the dmesg output is:

  x86/tme: not enabled by BIOS

... and TME functionality is not enabled by the kernel, but the TME feature
is still shown in /proc/cpuinfo.

Clear it.

[ mingo: Clarified changelog ]

Signed-off-by: Bingsong Si <sibs@chinatelecom.cn>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "Huang, Kai" <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20240311071938.13247-1-sibs@chinatelecom.cn
Merge branch 'x86/urgent' into x86/apic, to resolve conflicts 2024-02-27T09:09:49+00:00 Ingo Molnar mingo@kernel.org 2024-02-27T09:09:49+00:00 9b9c280b9af2aa851d83e7d0b79f36a3d869d745 Conflicts: arch/x86/kernel/cpu/common.c arch/x86/kernel/cpu/intel.c Signed-off-by: Ingo Molnar <mingo@kernel.org> 
 Conflicts:
	arch/x86/kernel/cpu/common.c
	arch/x86/kernel/cpu/intel.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
x86/cpu/intel: Detect TME keyid bits before setting MTRR mask registers 2024-02-26T16:16:16+00:00 Paolo Bonzini pbonzini@redhat.com 2024-01-31T23:09:02+00:00 6890cb1ace350b4386c8aee1343dc3b3ddd214da MKTME repurposes the high bit of physical address to key id for encryption key and, even though MAXPHYADDR in CPUID[0x80000008] remains the same, the valid bits in the MTRR mask register are based on the reduced number of physical address bits. detect_tme() in arch/x86/kernel/cpu/intel.c detects TME and subtracts it from the total usable physical bits, but it is called too late. Move the call to early_init_intel() so that it is called in setup_arch(), before MTRRs are setup. This fixes boot on TDX-enabled systems, which until now only worked with "disable_mtrr_cleanup". Without the patch, the values written to the MTRRs mask registers were 52-bit wide (e.g. 0x000fffff_80000800) and the writes failed; with the patch, the values are 46-bit wide, which matches the reduced MAXPHYADDR that is shown in /proc/cpuinfo. Reported-by: Zixi Chen <zixchen@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc:stable@vger.kernel.org Link: https://lore.kernel.org/all/20240131230902.1867092-3-pbonzini%40redhat.com 
MKTME repurposes the high bit of physical address to key id for encryption
key and, even though MAXPHYADDR in CPUID[0x80000008] remains the same,
the valid bits in the MTRR mask register are based on the reduced number
of physical address bits.

detect_tme() in arch/x86/kernel/cpu/intel.c detects TME and subtracts
it from the total usable physical bits, but it is called too late.
Move the call to early_init_intel() so that it is called in setup_arch(),
before MTRRs are setup.

This fixes boot on TDX-enabled systems, which until now only worked with
"disable_mtrr_cleanup".  Without the patch, the values written to the
MTRRs mask registers were 52-bit wide (e.g. 0x000fffff_80000800) and
the writes failed; with the patch, the values are 46-bit wide, which
matches the reduced MAXPHYADDR that is shown in /proc/cpuinfo.

Reported-by: Zixi Chen <zixchen@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc:stable@vger.kernel.org
Link: https://lore.kernel.org/all/20240131230902.1867092-3-pbonzini%40redhat.com
x86/cpu: Use common topology code for Intel 2024-02-15T21:07:37+00:00 Thomas Gleixner tglx@linutronix.de 2024-02-13T21:04:08+00:00 22d63660c35eb751c63a709bf901a64c1726592a Intel CPUs use either topology leaf 0xb/0x1f evaluation or the legacy SMP/HT evaluation based on CPUID leaf 0x1/0x4. Move it over to the consolidated topology code and remove the random topology hacks which are sprinkled into the Intel and the common code. No functional change intended. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juergen Gross <jgross@suse.com> Tested-by: Sohil Mehta <sohil.mehta@intel.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Zhang Rui <rui.zhang@intel.com> Tested-by: Wang Wendy <wendy.wang@intel.com> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com> Link: https://lore.kernel.org/r/20240212153624.893644349@linutronix.de 
Intel CPUs use either topology leaf 0xb/0x1f evaluation or the legacy
SMP/HT evaluation based on CPUID leaf 0x1/0x4.

Move it over to the consolidated topology code and remove the random
topology hacks which are sprinkled into the Intel and the common code.

No functional change intended.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wang Wendy <wendy.wang@intel.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20240212153624.893644349@linutronix.de