Commit graph

27 commits

Author SHA1 Message Date
Linus Torvalds
c00b285024 hyperv-next for v6.16
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Merge tag 'hyperv-next-signed-20250602' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv updates from Wei Liu:

 - Support for Virtual Trust Level (VTL) on arm64 (Roman Kisel)

 - Fixes for Hyper-V UIO driver (Long Li)

 - Fixes for Hyper-V PCI driver (Michael Kelley)

 - Select CONFIG_SYSFB for Hyper-V guests (Michael Kelley)

 - Documentation updates for Hyper-V VMBus (Michael Kelley)

 - Enhance logging for hv_kvp_daemon (Shradha Gupta)

* tag 'hyperv-next-signed-20250602' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (23 commits)
  Drivers: hv: Always select CONFIG_SYSFB for Hyper-V guests
  Drivers: hv: vmbus: Add comments about races with "channels" sysfs dir
  Documentation: hyperv: Update VMBus doc with new features and info
  PCI: hv: Remove unnecessary flex array in struct pci_packet
  Drivers: hv: Remove hv_alloc/free_* helpers
  Drivers: hv: Use kzalloc for panic page allocation
  uio_hv_generic: Align ring size to system page
  uio_hv_generic: Use correct size for interrupt and monitor pages
  Drivers: hv: Allocate interrupt and monitor pages aligned to system page boundary
  arch/x86: Provide the CPU number in the wakeup AP callback
  x86/hyperv: Fix APIC ID and VP index confusion in hv_snp_boot_ap()
  PCI: hv: Get vPCI MSI IRQ domain from DeviceTree
  ACPI: irq: Introduce acpi_get_gsi_dispatcher()
  Drivers: hv: vmbus: Introduce hv_get_vmbus_root_device()
  Drivers: hv: vmbus: Get the IRQ number from DeviceTree
  dt-bindings: microsoft,vmbus: Add interrupt and DMA coherence properties
  arm64, x86: hyperv: Report the VTL the system boots in
  arm64: hyperv: Initialize the Virtual Trust Level field
  Drivers: hv: Provide arch-neutral implementation of get_vtl()
  Drivers: hv: Enable VTL mode for arm64
  ...
2025-06-03 08:39:20 -07:00
Roman Kisel
43cb39ad26 arch/x86: Provide the CPU number in the wakeup AP callback
When starting APs, confidential guests and paravisor guests
need to know the CPU number, and the pattern of using the linear
search has emerged in several places. With N processors that leads
to the O(N^2) time complexity.

Provide the CPU number in the AP wake up callback so that one can
get the CPU number in constant time.

Suggested-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20250507182227.7421-3-romank@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250507182227.7421-3-romank@linux.microsoft.com>
2025-05-23 16:30:56 +00:00
Roman Kisel
86c48271e0 x86/hyperv: Fix APIC ID and VP index confusion in hv_snp_boot_ap()
To start an application processor in SNP-isolated guest, a hypercall
is used that takes a virtual processor index. The hv_snp_boot_ap()
function uses that START_VP hypercall but passes as VP index to it
what it receives as a wakeup_secondary_cpu_64 callback: the APIC ID.

As those two aren't generally interchangeable, that may lead to hung
APs if the VP index and the APIC ID don't match up.

Update the parameter names to avoid confusion as to what the parameter
is. Use the APIC ID to the VP index conversion to provide the correct
input to the hypercall.

Cc: stable@vger.kernel.org
Fixes: 44676bb9d5 ("x86/hyperv: Add smp support for SEV-SNP guest")
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/20250507182227.7421-2-romank@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250507182227.7421-2-romank@linux.microsoft.com>
2025-05-23 16:30:56 +00:00
Roman Kisel
e956ee9491 arm64, x86: hyperv: Report the VTL the system boots in
The hyperv guest code might run in various Virtual Trust Levels.

Report the level when the kernel boots in the non-default (0)
one.

Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/20250428210742.435282-7-romank@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250428210742.435282-7-romank@linux.microsoft.com>
2025-05-23 16:30:55 +00:00
Xin Li (Intel)
3204877d05 x86/msr: Convert __rdmsr() uses to native_rdmsrq() uses
__rdmsr() is the lowest level MSR write API, with native_rdmsr()
and native_rdmsrq() serving as higher-level wrappers around it.

  #define native_rdmsr(msr, val1, val2)                   \
  do {                                                    \
          u64 __val = __rdmsr((msr));                     \
          (void)((val1) = (u32)__val);                    \
          (void)((val2) = (u32)(__val >> 32));            \
  } while (0)

  static __always_inline u64 native_rdmsrq(u32 msr)
  {
          return __rdmsr(msr);
  }

However, __rdmsr() continues to be utilized in various locations.

MSR APIs are designed for different scenarios, such as native or
pvops, with or without trace, and safe or non-safe.  Unfortunately,
the current MSR API names do not adequately reflect these factors,
making it challenging to select the most appropriate API for
various situations.

To pave the way for improving MSR API names, convert __rdmsr()
uses to native_rdmsrq() to ensure consistent usage.  Later, these
APIs can be renamed to better reflect their implications, such as
native or pvops, with or without trace, and safe or non-safe.

No functional change intended.

Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20250427092027.1598740-10-xin@zytor.com
2025-05-02 10:36:35 +02:00
Xin Li (Intel)
efef7f184f x86/msr: Add explicit includes of <asm/msr.h>
For historic reasons there are some TSC-related functions in the
<asm/msr.h> header, even though there's an <asm/tsc.h> header.

To facilitate the relocation of rdtsc{,_ordered}() from <asm/msr.h>
to <asm/tsc.h> and to eventually eliminate the inclusion of
<asm/msr.h> in <asm/tsc.h>, add an explicit <asm/msr.h> dependency
to the source files that reference definitions from <asm/msr.h>.

[ mingo: Clarified the changelog. ]

Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Link: https://lore.kernel.org/r/20250501054241.1245648-1-xin@zytor.com
2025-05-02 10:23:47 +02:00
Linus Torvalds
a5b3d8660b hyperv-next for 6.15
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Merge tag 'hyperv-next-signed-20250324' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv updates from Wei Liu:

 - Add support for running as the root partition in Hyper-V (Microsoft
   Hypervisor) by exposing /dev/mshv (Nuno and various people)

 - Add support for CPU offlining in Hyper-V (Hamza Mahfooz)

 - Misc fixes and cleanups (Roman Kisel, Tianyu Lan, Wei Liu, Michael
   Kelley, Thorsten Blum)

* tag 'hyperv-next-signed-20250324' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (24 commits)
  x86/hyperv: fix an indentation issue in mshyperv.h
  x86/hyperv: Add comments about hv_vpset and var size hypercall input args
  Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs
  hyperv: Add definitions for root partition driver to hv headers
  x86: hyperv: Add mshv_handler() irq handler and setup function
  Drivers: hv: Introduce per-cpu event ring tail
  Drivers: hv: Export some functions for use by root partition module
  acpi: numa: Export node_to_pxm()
  hyperv: Introduce hv_recommend_using_aeoi()
  arm64/hyperv: Add some missing functions to arm64
  x86/mshyperv: Add support for extended Hyper-V features
  hyperv: Log hypercall status codes as strings
  x86/hyperv: Fix check of return value from snp_set_vmsa()
  x86/hyperv: Add VTL mode callback for restarting the system
  x86/hyperv: Add VTL mode emergency restart callback
  hyperv: Remove unused union and structs
  hyperv: Add CONFIG_MSHV_ROOT to gate root partition support
  hyperv: Change hv_root_partition into a function
  hyperv: Convert hypercall statuses to linux error codes
  drivers/hv: add CPU offlining support
  ...
2025-03-25 14:47:04 -07:00
Roman Kisel
07b74192e6 x86/hyperv: Add VTL mode callback for restarting the system
The kernel runs as a firmware in the VTL mode, and the only way
to restart in the VTL mode on x86 is to triple fault. Thus, one
has to always supply "reboot=t" on the kernel command line in the
VTL mode, and missing that renders rebooting not working.

Define the machine restart callback to always use the triple
fault to provide the robust configuration by default.

Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Link: https://lore.kernel.org/r/20250227214728.15672-3-romank@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250227214728.15672-3-romank@linux.microsoft.com>
2025-03-20 21:23:03 +00:00
Roman Kisel
ced518ad55 x86/hyperv: Add VTL mode emergency restart callback
By default, X86(-64) systems use the emergecy restart routine
in the course of which the code unconditionally writes to
the physical address of 0x472 to indicate the boot mode
to the firmware (BIOS or UEFI).

When the kernel itself runs as a firmware in the VTL mode,
that write corrupts the memory of the guest upon emergency
restarting. Preserving the state intact in that situation
is important for debugging, at least.

Define the specialized machine callback to avoid that write
and use the triple fault to perform emergency restart.

Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Link: https://lore.kernel.org/r/20250227214728.15672-2-romank@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250227214728.15672-2-romank@linux.microsoft.com>
2025-03-20 21:23:03 +00:00
Naman Jain
59115e2e25 x86/hyperv/vtl: Stop kernel from probing VTL0 low memory
For Linux, running in Hyper-V VTL (Virtual Trust Level), kernel in VTL2
tries to access VTL0 low memory in probe_roms. This memory is not
described in the e820 map. Initialize probe_roms call to no-ops
during boot for VTL2 kernel to avoid this. The issue got identified
in OpenVMM which detects invalid accesses initiated from kernel running
in VTL2.

Co-developed-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Signed-off-by: Naman Jain <namjain@linux.microsoft.com>
Tested-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Roman Kisel <romank@linux.microsoft.com>
Link: https://lore.kernel.org/r/20250116061224.1701-1-namjain@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250116061224.1701-1-namjain@linux.microsoft.com>
2025-02-12 02:16:56 +00:00
Roman Kisel
f285d99574 hyperv: Do not overlap the hvcall IO areas in hv_vtl_apicid_to_vp_id()
The Top-Level Functional Specification for Hyper-V, Section 3.6 [1, 2],
disallows overlapping of the input and output hypercall areas, and
hv_vtl_apicid_to_vp_id() overlaps them.

Use the output hypercall page of the current vCPU for the hypercall.

[1] https://learn.microsoft.com/en-us/virtualization/hyper-v-on-windows/tlfs/hypercall-interface
[2] https://github.com/MicrosoftDocs/Virtualization-Documentation/tree/main/tlfs

Reported-by: Michael Kelley <mhklinux@outlook.com>
Closes: https://lore.kernel.org/lkml/SN6PR02MB4157B98CD34781CC87A9D921D40D2@SN6PR02MB4157.namprd02.prod.outlook.com/
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Link: https://lore.kernel.org/r/20250108222138.1623703-6-romank@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250108222138.1623703-6-romank@linux.microsoft.com>
2025-01-10 00:54:21 +00:00
Saurabh Sengar
222408cde4 x86/of: Set the parse_smp_cfg for all the DeviceTree platforms by default
x86_dtb_parse_smp_config() must be set by DeviceTree platform for
parsing SMP configuration. Set the parse_smp_cfg pointer to
x86_dtb_parse_smp_config() by default so that all the dtb platforms
need not to assign it explicitly. Today there are only two platforms
using DeviceTree in x86, ce4100 and hv_vtl. Remove the explicit
assignment of x86_dtb_parse_smp_config() function from these.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/1712068830-4513-3-git-send-email-ssengar@linux.microsoft.com
2024-04-03 08:46:08 +02:00
Saurabh Sengar
fe5e6b599f x86/hyperv/vtl: Correct x86_init.mpparse.parse_smp_cfg assignment
VTL platform uses DeviceTree for fetching SMP configuration, assign
the correct parsing function x86_dtb_parse_smp_config() for it to
parse_smp_cfg.

Fixes: c22e19cd2c ("x86/hyperv/vtl: Prepare for separate mpparse callbacks")
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/1712068830-4513-2-git-send-email-ssengar@linux.microsoft.com
2024-04-03 08:46:08 +02:00
Linus Torvalds
cfce216e14 hyperv-next for v6.9
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Merge tag 'hyperv-next-signed-20240320' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv updates from Wei Liu:

 - Use Hyper-V entropy to seed guest random number generator (Michael
   Kelley)

 - Convert to platform remove callback returning void for vmbus (Uwe
   Kleine-König)

 - Introduce hv_get_hypervisor_version function (Nuno Das Neves)

 - Rename some HV_REGISTER_* defines for consistency (Nuno Das Neves)

 - Change prefix of generic HV_REGISTER_* MSRs to HV_MSR_* (Nuno Das
   Neves)

 - Cosmetic changes for hv_spinlock.c (Purna Pavan Chandra Aekkaladevi)

 - Use per cpu initial stack for vtl context (Saurabh Sengar)

* tag 'hyperv-next-signed-20240320' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  x86/hyperv: Use Hyper-V entropy to seed guest random number generator
  x86/hyperv: Cosmetic changes for hv_spinlock.c
  hyperv-tlfs: Rename some HV_REGISTER_* defines for consistency
  hv: vmbus: Convert to platform remove callback returning void
  mshyperv: Introduce hv_get_hypervisor_version function
  x86/hyperv: Use per cpu initial stack for vtl context
  hyperv-tlfs: Change prefix of generic HV_REGISTER_* MSRs to HV_MSR_*
2024-03-21 10:01:02 -07:00
Linus Torvalds
ca7e917769 Rework of APIC enumeration and topology evaluation:
The current implementation has a couple of shortcomings:
 
   - It fails to handle hybrid systems correctly.
 
   - The APIC registration code which handles CPU number assignents is in
     the middle of the APIC code and detached from the topology evaluation.
 
   - The various mechanisms which enumerate APICs, ACPI, MPPARSE and guest
     specific ones, tweak global variables as they see fit or in case of
     XENPV just hack around the generic mechanisms completely.
 
   - The CPUID topology evaluation code is sprinkled all over the vendor
     code and reevaluates global variables on every hotplug operation.
 
   - There is no way to analyze topology on the boot CPU before bringing up
     the APs. This causes problems for infrastructure like PERF which needs
     to size certain aspects upfront or could be simplified if that would be
     possible.
 
   - The APIC admission and CPU number association logic is incomprehensible
     and overly complex and needs to be kept around after boot instead of
     completing this right after the APIC enumeration.
 
 This update addresses these shortcomings with the following changes:
 
   - Rework the CPUID evaluation code so it is common for all vendors and
     provides information about the APIC ID segments in a uniform way
     independent of the number of segments (Thread, Core, Module, ..., Die,
     Package) so that this information can be computed instead of rewriting
     global variables of dubious value over and over.
 
   - A few cleanups and simplifcations of the APIC, IO/APIC and related
     interfaces to prepare for the topology evaluation changes.
 
   - Seperation of the parser stages so the early evaluation which tries to
     find the APIC address can be seperately overridden from the late
     evaluation which enumerates and registers the local APIC as further
     preparation for sanitizing the topology evaluation.
 
   - A new registration and admission logic which
 
      - encapsulates the inner workings so that parsers and guest logic
        cannot longer fiddle in it
 
      - uses the APIC ID segments to build topology bitmaps at registration
        time
 
      - provides a sane admission logic
 
      - allows to detect the crash kernel case, where CPU0 does not run on
        the real BSP, automatically. This is required to prevent sending
        INIT/SIPI sequences to the real BSP which would reset the whole
        machine. This was so far handled by a tedious command line
        parameter, which does not even work in nested crash scenarios.
 
      - Associates CPU number after the enumeration completed and prevents
        the late registration of APICs, which was somehow tolerated before.
 
   - Converting all parsers and guest enumeration mechanisms over to the
     new interfaces.
 
     This allows to get rid of all global variable tweaking from the parsers
     and enumeration mechanisms and sanitizes the XEN[PV] handling so it can
     use CPUID evaluation for the first time.
 
   - Mopping up existing sins by taking the information from the APIC ID
     segment bitmaps.
 
     This evaluates hybrid systems correctly on the boot CPU and allows for
     cleanups and fixes in the related drivers, e.g. PERF.
 
 The series has been extensively tested and the minimal late fallout due to
 a broken ACPI/MADT table has been addressed by tightening the admission
 logic further.
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Merge tag 'x86-apic-2024-03-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 APIC updates from Thomas Gleixner:
 "Rework of APIC enumeration and topology evaluation.

  The current implementation has a couple of shortcomings:

   - It fails to handle hybrid systems correctly.

   - The APIC registration code which handles CPU number assignents is
     in the middle of the APIC code and detached from the topology
     evaluation.

   - The various mechanisms which enumerate APICs, ACPI, MPPARSE and
     guest specific ones, tweak global variables as they see fit or in
     case of XENPV just hack around the generic mechanisms completely.

   - The CPUID topology evaluation code is sprinkled all over the vendor
     code and reevaluates global variables on every hotplug operation.

   - There is no way to analyze topology on the boot CPU before bringing
     up the APs. This causes problems for infrastructure like PERF which
     needs to size certain aspects upfront or could be simplified if
     that would be possible.

   - The APIC admission and CPU number association logic is
     incomprehensible and overly complex and needs to be kept around
     after boot instead of completing this right after the APIC
     enumeration.

  This update addresses these shortcomings with the following changes:

   - Rework the CPUID evaluation code so it is common for all vendors
     and provides information about the APIC ID segments in a uniform
     way independent of the number of segments (Thread, Core, Module,
     ..., Die, Package) so that this information can be computed instead
     of rewriting global variables of dubious value over and over.

   - A few cleanups and simplifcations of the APIC, IO/APIC and related
     interfaces to prepare for the topology evaluation changes.

   - Seperation of the parser stages so the early evaluation which tries
     to find the APIC address can be seperately overridden from the late
     evaluation which enumerates and registers the local APIC as further
     preparation for sanitizing the topology evaluation.

   - A new registration and admission logic which

       - encapsulates the inner workings so that parsers and guest logic
         cannot longer fiddle in it

       - uses the APIC ID segments to build topology bitmaps at
         registration time

       - provides a sane admission logic

       - allows to detect the crash kernel case, where CPU0 does not run
         on the real BSP, automatically. This is required to prevent
         sending INIT/SIPI sequences to the real BSP which would reset
         the whole machine. This was so far handled by a tedious command
         line parameter, which does not even work in nested crash
         scenarios.

       - Associates CPU number after the enumeration completed and
         prevents the late registration of APICs, which was somehow
         tolerated before.

   - Converting all parsers and guest enumeration mechanisms over to the
     new interfaces.

     This allows to get rid of all global variable tweaking from the
     parsers and enumeration mechanisms and sanitizes the XEN[PV]
     handling so it can use CPUID evaluation for the first time.

   - Mopping up existing sins by taking the information from the APIC ID
     segment bitmaps.

     This evaluates hybrid systems correctly on the boot CPU and allows
     for cleanups and fixes in the related drivers, e.g. PERF.

  The series has been extensively tested and the minimal late fallout
  due to a broken ACPI/MADT table has been addressed by tightening the
  admission logic further"

* tag 'x86-apic-2024-03-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (76 commits)
  x86/topology: Ignore non-present APIC IDs in a present package
  x86/apic: Build the x86 topology enumeration functions on UP APIC builds too
  smp: Provide 'setup_max_cpus' definition on UP too
  smp: Avoid 'setup_max_cpus' namespace collision/shadowing
  x86/bugs: Use fixed addressing for VERW operand
  x86/cpu/topology: Get rid of cpuinfo::x86_max_cores
  x86/cpu/topology: Provide __num_[cores|threads]_per_package
  x86/cpu/topology: Rename topology_max_die_per_package()
  x86/cpu/topology: Rename smp_num_siblings
  x86/cpu/topology: Retrieve cores per package from topology bitmaps
  x86/cpu/topology: Use topology logical mapping mechanism
  x86/cpu/topology: Provide logical pkg/die mapping
  x86/cpu/topology: Simplify cpu_mark_primary_thread()
  x86/cpu/topology: Mop up primary thread mask handling
  x86/cpu/topology: Use topology bitmaps for sizing
  x86/cpu/topology: Let XEN/PV use topology from CPUID/MADT
  x86/xen/smp_pv: Count number of vCPUs early
  x86/cpu/topology: Assign hotpluggable CPUIDs during init
  x86/cpu/topology: Reject unknown APIC IDs on ACPI hotplug
  x86/topology: Add a mechanism to track topology via APIC IDs
  ...
2024-03-11 15:45:55 -07:00
Saurabh Sengar
2b4b90e053 x86/hyperv: Use per cpu initial stack for vtl context
Currently, the secondary CPUs in Hyper-V VTL context lack support for
parallel startup. Therefore, relying on the single initial_stack fetched
from the current task structure suffices for all vCPUs.

However, common initial_stack risks stack corruption when parallel startup
is enabled. In order to facilitate parallel startup, use the initial_stack
from the per CPU idle thread instead of the current task.

Fixes: 3be1bc2fe9 ("x86/hyperv: VTL support for Hyper-V")
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/1709452896-13342-1-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <1709452896-13342-1-git-send-email-ssengar@linux.microsoft.com>
2024-03-08 23:40:09 +00:00
Saurabh Sengar
0d63e4c0eb x86/hyperv: Allow 15-bit APIC IDs for VTL platforms
The current method for signaling the compatibility of a Hyper-V host
with MSIs featuring 15-bit APIC IDs relies on a synthetic cpuid leaf.
However, for higher VTLs, this leaf is not reported, due to the absence
of an IO-APIC.

As an alternative, assume that when running at a high VTL, the host
supports 15-bit APIC IDs. This assumption is safe, as Hyper-V does not
employ any architectural MSIs at higher VTLs

This unblocks startup of VTL2 environments with more than 256 CPUs.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/1705341460-18394-1-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <1705341460-18394-1-git-send-email-ssengar@linux.microsoft.com>
2024-03-01 08:36:22 +00:00
Thomas Gleixner
dcb7600849 x86/mpparse: Switch to new init callbacks
Now that all platforms have the new split SMP configuration callbacks set
up, flip the switch and remove the old callback pointer and mop up the
platform code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240212154639.870883080@linutronix.de
2024-02-15 22:07:41 +01:00
Thomas Gleixner
c22e19cd2c x86/hyperv/vtl: Prepare for separate mpparse callbacks
Initialize the new callbacks in preparation for switching the core code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240212154639.808238769@linutronix.de
2024-02-15 22:07:41 +01:00
Linus Torvalds
eb55307e67 X86 core code updates:
- Limit the hardcoded topology quirk for Hygon CPUs to those which have a
     model ID less than 4. The newer models have the topology CPUID leaf 0xB
     correctly implemented and are not affected.
 
   - Make SMT control more robust against enumeration failures
 
     SMT control was added to allow controlling SMT at boottime or
     runtime. The primary purpose was to provide a simple mechanism to
     disable SMT in the light of speculation attack vectors.
 
     It turned out that the code is sensible to enumeration failures and
     worked only by chance for XEN/PV. XEN/PV has no real APIC enumeration
     which means the primary thread mask is not set up correctly. By chance
     a XEN/PV boot ends up with smp_num_siblings == 2, which makes the
     hotplug control stay at its default value "enabled". So the mask is
     never evaluated.
 
     The ongoing rework of the topology evaluation caused XEN/PV to end up
     with smp_num_siblings == 1, which sets the SMT control to "not
     supported" and the empty primary thread mask causes the hotplug core to
     deny the bringup of the APS.
 
     Make the decision logic more robust and take 'not supported' and 'not
     implemented' into account for the decision whether a CPU should be
     booted or not.
 
   - Fake primary thread mask for XEN/PV
 
     Pretend that all XEN/PV vCPUs are primary threads, which makes the
     usage of the primary thread mask valid on XEN/PV. That is consistent
     with because all of the topology information on XEN/PV is fake or even
     non-existent.
 
   - Encapsulate topology information in cpuinfo_x86
 
     Move the randomly scattered topology data into a separate data
     structure for readability and as a preparatory step for the topology
     evaluation overhaul.
 
   - Consolidate APIC ID data type to u32
 
     It's fixed width hardware data and not randomly u16, int, unsigned long
     or whatever developers decided to use.
 
   - Cure the abuse of cpuinfo for persisting logical IDs.
 
     Per CPU cpuinfo is used to persist the logical package and die
     IDs. That's really not the right place simply because cpuinfo is
     subject to be reinitialized when a CPU goes through an offline/online
     cycle.
 
     Use separate per CPU data for the persisting to enable the further
     topology management rework. It will be removed once the new topology
     management is in place.
 
   - Provide a debug interface for inspecting topology information
 
     Useful in general and extremly helpful for validating the topology
     management rework in terms of correctness or "bug" compatibility.
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Merge tag 'x86-core-2023-10-29-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 core updates from Thomas Gleixner:

 - Limit the hardcoded topology quirk for Hygon CPUs to those which have
   a model ID less than 4.

   The newer models have the topology CPUID leaf 0xB correctly
   implemented and are not affected.

 - Make SMT control more robust against enumeration failures

   SMT control was added to allow controlling SMT at boottime or
   runtime. The primary purpose was to provide a simple mechanism to
   disable SMT in the light of speculation attack vectors.

   It turned out that the code is sensible to enumeration failures and
   worked only by chance for XEN/PV. XEN/PV has no real APIC enumeration
   which means the primary thread mask is not set up correctly. By
   chance a XEN/PV boot ends up with smp_num_siblings == 2, which makes
   the hotplug control stay at its default value "enabled". So the mask
   is never evaluated.

   The ongoing rework of the topology evaluation caused XEN/PV to end up
   with smp_num_siblings == 1, which sets the SMT control to "not
   supported" and the empty primary thread mask causes the hotplug core
   to deny the bringup of the APS.

   Make the decision logic more robust and take 'not supported' and 'not
   implemented' into account for the decision whether a CPU should be
   booted or not.

 - Fake primary thread mask for XEN/PV

   Pretend that all XEN/PV vCPUs are primary threads, which makes the
   usage of the primary thread mask valid on XEN/PV. That is consistent
   with because all of the topology information on XEN/PV is fake or
   even non-existent.

 - Encapsulate topology information in cpuinfo_x86

   Move the randomly scattered topology data into a separate data
   structure for readability and as a preparatory step for the topology
   evaluation overhaul.

 - Consolidate APIC ID data type to u32

   It's fixed width hardware data and not randomly u16, int, unsigned
   long or whatever developers decided to use.

 - Cure the abuse of cpuinfo for persisting logical IDs.

   Per CPU cpuinfo is used to persist the logical package and die IDs.
   That's really not the right place simply because cpuinfo is subject
   to be reinitialized when a CPU goes through an offline/online cycle.

   Use separate per CPU data for the persisting to enable the further
   topology management rework. It will be removed once the new topology
   management is in place.

 - Provide a debug interface for inspecting topology information

   Useful in general and extremly helpful for validating the topology
   management rework in terms of correctness or "bug" compatibility.

* tag 'x86-core-2023-10-29-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  x86/apic, x86/hyperv: Use u32 in hv_snp_boot_ap() too
  x86/cpu: Provide debug interface
  x86/cpu/topology: Cure the abuse of cpuinfo for persisting logical ids
  x86/apic: Use u32 for wakeup_secondary_cpu[_64]()
  x86/apic: Use u32 for [gs]et_apic_id()
  x86/apic: Use u32 for phys_pkg_id()
  x86/apic: Use u32 for cpu_present_to_apicid()
  x86/apic: Use u32 for check_apicid_used()
  x86/apic: Use u32 for APIC IDs in global data
  x86/apic: Use BAD_APICID consistently
  x86/cpu: Move cpu_l[l2]c_id into topology info
  x86/cpu: Move logical package and die IDs into topology info
  x86/cpu: Remove pointless evaluation of x86_coreid_bits
  x86/cpu: Move cu_id into topology info
  x86/cpu: Move cpu_core_id into topology info
  hwmon: (fam15h_power) Use topology_core_id()
  scsi: lpfc: Use topology_core_id()
  x86/cpu: Move cpu_die_id into topology info
  x86/cpu: Move phys_proc_id into topology info
  x86/cpu: Encapsulate topology information in cpuinfo_x86
  ...
2023-10-30 17:37:47 -10:00
Thomas Gleixner
db4a4086a2 x86/apic: Use u32 for wakeup_secondary_cpu[_64]()
APIC IDs are used with random data types u16, u32, int, unsigned int,
unsigned long.

Make it all consistently use u32 because that reflects the hardware
register width.

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 <mikelley@microsoft.com>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Reviewed-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230814085113.233274223@linutronix.de
2023-10-10 14:38:19 +02:00
Saurabh Sengar
14058f72cf x86/hyperv: Remove hv_vtl_early_init initcall
There has been cases reported where HYPERV_VTL_MODE is enabled by mistake,
on a non Hyper-V platforms. This causes the hv_vtl_early_init function to
be called in an non Hyper-V/VTL platforms which results the memory
corruption.

Remove the early_initcall for hv_vtl_early_init and call it at the end of
hyperv_init to make sure it is never called in a non Hyper-V platform by
mistake.

Reported-by: Mathias Krause <minipli@grsecurity.net>
Closes: https://lore.kernel.org/lkml/40467722-f4ab-19a5-4989-308225b1f9f0@grsecurity.net/
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Acked-by: Mathias Krause <minipli@grsecurity.net>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/1695358720-27681-1-git-send-email-ssengar@linux.microsoft.com
2023-09-22 18:41:29 +00:00
Linus Torvalds
1687d8aca5 * Rework apic callbacks, getting rid of unnecessary ones and
coalescing lots of silly duplicates.
  * Use static_calls() instead of indirect calls for apic->foo()
  * Tons of cleanups an crap removal along the way
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Merge tag 'x86_apic_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 apic updates from Dave Hansen:
 "This includes a very thorough rework of the 'struct apic' handlers.
  Quite a variety of them popped up over the years, especially in the
  32-bit days when odd apics were much more in vogue.

  The end result speaks for itself, which is a removal of a ton of code
  and static calls to replace indirect calls.

  If there's any breakage here, it's likely to be around the 32-bit
  museum pieces that get light to no testing these days.

  Summary:

   - Rework apic callbacks, getting rid of unnecessary ones and
     coalescing lots of silly duplicates.

   - Use static_calls() instead of indirect calls for apic->foo()

   - Tons of cleanups an crap removal along the way"

* tag 'x86_apic_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits)
  x86/apic: Turn on static calls
  x86/apic: Provide static call infrastructure for APIC callbacks
  x86/apic: Wrap IPI calls into helper functions
  x86/apic: Mark all hotpath APIC callback wrappers __always_inline
  x86/xen/apic: Mark apic __ro_after_init
  x86/apic: Convert other overrides to apic_update_callback()
  x86/apic: Replace acpi_wake_cpu_handler_update() and apic_set_eoi_cb()
  x86/apic: Provide apic_update_callback()
  x86/xen/apic: Use standard apic driver mechanism for Xen PV
  x86/apic: Provide common init infrastructure
  x86/apic: Wrap apic->native_eoi() into a helper
  x86/apic: Nuke ack_APIC_irq()
  x86/apic: Remove pointless arguments from [native_]eoi_write()
  x86/apic/noop: Tidy up the code
  x86/apic: Remove pointless NULL initializations
  x86/apic: Sanitize APIC ID range validation
  x86/apic: Prepare x2APIC for using apic::max_apic_id
  x86/apic: Simplify X2APIC ID validation
  x86/apic: Add max_apic_id member
  x86/apic: Wrap APIC ID validation into an inline
  ...
2023-08-30 10:44:46 -07:00
Thomas Gleixner
2744a7ce34 x86/apic: Replace acpi_wake_cpu_handler_update() and apic_set_eoi_cb()
Switch them over to apic_update_callback() and remove the code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Juergen Gross <jgross@suse.com> # Xen PV (dom0 and unpriv. guest)
2023-08-09 12:00:46 -07:00
Saurabh Sengar
9e2d0c3365 x86/hyperv: add noop functions to x86_init mpparse functions
Hyper-V can run VMs at different privilege "levels" known as Virtual
Trust Levels (VTL). Sometimes, it chooses to run two different VMs
at different levels but they share some of their address space. In
such setups VTL2 (higher level VM) has visibility of all of the
VTL0 (level 0) memory space.

When the CONFIG_X86_MPPARSE is enabled for VTL2, the VTL2 kernel
performs a search within the low memory to locate MP tables. However,
in systems where VTL0 manages the low memory and may contain valid
tables, this scanning can result in incorrect MP table information
being provided to the VTL2 kernel, mistakenly considering VTL0's MP
table as its own

Add noop functions to avoid MP parse scan by VTL2.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/r/1687537688-5397-1-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2023-08-02 23:09:53 +00:00
Saurabh Sengar
cb6aeeb69a x86/hyperv/vtl: Add noop for realmode pointers
Assign the realmode pointers to noop, instead of NULL to fix kernel panic.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1682331016-22561-1-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2023-05-08 16:46:43 +00:00
Saurabh Sengar
3be1bc2fe9 x86/hyperv: VTL support for Hyper-V
Virtual Trust Levels (VTL) helps enable Hyper-V Virtual Secure Mode (VSM)
feature. VSM is a set of hypervisor capabilities and enlightenments
offered to host and guest partitions which enable the creation and
management of new security boundaries within operating system software.
VSM achieves and maintains isolation through VTLs.

Add early initialization for Virtual Trust Levels (VTL). This includes
initializing the x86 platform for VTL and enabling boot support for
secondary CPUs to start in targeted VTL context. For now, only enable
the code for targeted VTL level as 2.

When starting an AP at a VTL other than VTL0, the AP must start directly
in 64-bit mode, bypassing the usual 16-bit -> 32-bit -> 64-bit mode
transition sequence that occurs after waking up an AP with SIPI whose
vector points to the 16-bit AP startup trampoline code.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Stanislav Kinsburskii <stanislav.kinsburskii@gmail.com>
Link: https://lore.kernel.org/r/1681192532-15460-6-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2023-04-18 17:29:52 +00:00