Commit Graph

44868 Commits

Author SHA1 Message Date
Jiri Olsa f64b2dc8a4 bpf: Fix prog_array_map_poke_run map poke update
commit 4b7de801606e504e69689df71475d27e35336fb3 upstream.

Lee pointed out issue found by syscaller [0] hitting BUG in prog array
map poke update in prog_array_map_poke_run function due to error value
returned from bpf_arch_text_poke function.

There's race window where bpf_arch_text_poke can fail due to missing
bpf program kallsym symbols, which is accounted for with check for
-EINVAL in that BUG_ON call.

The problem is that in such case we won't update the tail call jump
and cause imbalance for the next tail call update check which will
fail with -EBUSY in bpf_arch_text_poke.

I'm hitting following race during the program load:

  CPU 0                             CPU 1

  bpf_prog_load
    bpf_check
      do_misc_fixups
        prog_array_map_poke_track

                                    map_update_elem
                                      bpf_fd_array_map_update_elem
                                        prog_array_map_poke_run

                                          bpf_arch_text_poke returns -EINVAL

    bpf_prog_kallsyms_add

After bpf_arch_text_poke (CPU 1) fails to update the tail call jump, the next
poke update fails on expected jump instruction check in bpf_arch_text_poke
with -EBUSY and triggers the BUG_ON in prog_array_map_poke_run.

Similar race exists on the program unload.

Fixing this by moving the update to bpf_arch_poke_desc_update function which
makes sure we call __bpf_arch_text_poke that skips the bpf address check.

Each architecture has slightly different approach wrt looking up bpf address
in bpf_arch_text_poke, so instead of splitting the function or adding new
'checkip' argument in previous version, it seems best to move the whole
map_poke_run update as arch specific code.

  [0] https://syzkaller.appspot.com/bug?extid=97a4fe20470e9bc30810

Fixes: ebf7d1f508 ("bpf, x64: rework pro/epilogue and tailcall handling in JIT")
Reported-by: syzbot+97a4fe20470e9bc30810@syzkaller.appspotmail.com
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Cc: Lee Jones <lee@kernel.org>
Cc: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20231206083041.1306660-2-jolsa@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-01 12:42:23 +00:00
Fangrui Song 06f61af802 x86/speculation, objtool: Use absolute relocations for annotations
commit b8ec60e1186cdcfce41e7db4c827cb107e459002 upstream.

.discard.retpoline_safe sections do not have the SHF_ALLOC flag.  These
sections referencing text sections' STT_SECTION symbols with PC-relative
relocations like R_386_PC32 [0] is conceptually not suitable.  Newer
LLD will report warnings for REL relocations even for relocatable links [1]:

    ld.lld: warning: vmlinux.a(drivers/i2c/busses/i2c-i801.o):(.discard.retpoline_safe+0x120): has non-ABS relocation R_386_PC32 against symbol ''

Switch to absolute relocations instead, which indicate link-time
addresses.  In a relocatable link, these addresses are also output
section offsets, used by checks in tools/objtool/check.c.  When linking
vmlinux, these .discard.* sections will be discarded, therefore it is
not a problem that R_X86_64_32 cannot represent a kernel address.

Alternatively, we could set the SHF_ALLOC flag for .discard.* sections,
but I think non-SHF_ALLOC for sections to be discarded makes more sense.

Note: if we decide to never support REL architectures (e.g. arm, i386),
we can utilize R_*_NONE relocations (.reloc ., BFD_RELOC_NONE, sym),
making .discard.* sections zero-sized.  That said, the section content
waste is 4 bytes per entry, much smaller than sizeof(Elf{32,64}_Rel).

  [0] commit 1c0c1faf56 ("objtool: Use relative pointers for annotations")
  [1] https://github.com/ClangBuiltLinux/linux/issues/1937

Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20230920001728.1439947-1-maskray@google.com
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-20 17:02:06 +01:00
Saurabh Sengar 54d8c1d326 x86/hyperv: Fix the detection of E820_TYPE_PRAM in a Gen2 VM
[ Upstream commit 7e8037b099c0bbe8f2109dc452dbcab8d400fc53 ]

A Gen2 VM doesn't support legacy PCI/PCIe, so both raw_pci_ops and
raw_pci_ext_ops are NULL, and pci_subsys_init() -> pcibios_init()
doesn't call pcibios_resource_survey() -> e820__reserve_resources_late();
as a result, any emulated persistent memory of E820_TYPE_PRAM (12) via
the kernel parameter memmap=nn[KMG]!ss is not added into iomem_resource
and hence can't be detected by register_e820_pmem().

Fix this by directly calling e820__reserve_resources_late() in
hv_pci_init(), which is called from arch_initcall(pci_arch_init).

It's ok to move a Gen2 VM's e820__reserve_resources_late() from
subsys_initcall(pci_subsys_init) to arch_initcall(pci_arch_init) because
the code in-between doesn't depend on the E820 resources.
e820__reserve_resources_late() depends on e820__reserve_resources(),
which has been called earlier from setup_arch().

For a Gen-2 VM, the new hv_pci_init() also adds any memory of
E820_TYPE_PMEM (7) into iomem_resource, and acpi_nfit_register_region() ->
acpi_nfit_insert_resource() -> region_intersects() returns
REGION_INTERSECTS, so the memory of E820_TYPE_PMEM won't get added twice.

Changed the local variable "int gen2vm" to "bool gen2vm".

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <1699691867-9827-1-git-send-email-ssengar@linux.microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-12-20 17:01:55 +01:00
Sean Christopherson dea8cfe773 KVM: SVM: Update EFER software model on CR0 trap for SEV-ES
commit 4cdf351d3630a640ab6a05721ef055b9df62277f upstream.

In general, activating long mode involves setting the EFER_LME bit in
the EFER register and then enabling the X86_CR0_PG bit in the CR0
register. At this point, the EFER_LMA bit will be set automatically by
hardware.

In the case of SVM/SEV guests where writes to CR0 are intercepted, it's
necessary for the host to set EFER_LMA on behalf of the guest since
hardware does not see the actual CR0 write.

In the case of SEV-ES guests where writes to CR0 are trapped instead of
intercepted, the hardware *does* see/record the write to CR0 before
exiting and passing the value on to the host, so as part of enabling
SEV-ES support commit f1c6366e30 ("KVM: SVM: Add required changes to
support intercepts under SEV-ES") dropped special handling of the
EFER_LMA bit with the understanding that it would be set automatically.

However, since the guest never explicitly sets the EFER_LMA bit, the
host never becomes aware that it has been set. This becomes problematic
when userspace tries to get/set the EFER values via
KVM_GET_SREGS/KVM_SET_SREGS, since the EFER contents tracked by the host
will be missing the EFER_LMA bit, and when userspace attempts to pass
the EFER value back via KVM_SET_SREGS it will fail a sanity check that
asserts that EFER_LMA should always be set when X86_CR0_PG and EFER_LME
are set.

Fix this by always inferring the value of EFER_LMA based on X86_CR0_PG
and EFER_LME, regardless of whether or not SEV-ES is enabled.

Fixes: f1c6366e30 ("KVM: SVM: Add required changes to support intercepts under SEV-ES")
Reported-by: Peter Gonda <pgonda@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210507165947.2502412-2-seanjc@google.com>
[A two year old patch that was revived after we noticed the failure in
 KVM_SET_SREGS and a similar patch was posted by Michael Roth.  This is
 Sean's patch, but with Michael's more complete commit message. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-13 18:45:34 +01:00
Borislav Petkov (AMD) 903a1a1949 x86/CPU/AMD: Check vendor in the AMD microcode callback
commit 9b8493dc43044376716d789d07699f17d538a7c4 upstream.

Commit in Fixes added an AMD-specific microcode callback. However, it
didn't check the CPU vendor the kernel runs on explicitly.

The only reason the Zenbleed check in it didn't run on other x86 vendors
hardware was pure coincidental luck:

  if (!cpu_has_amd_erratum(c, amd_zenbleed))
	  return;

gives true on other vendors because they don't have those families and
models.

However, with the removal of the cpu_has_amd_erratum() in

  05f5f73936fa ("x86/CPU/AMD: Drop now unused CPU erratum checking function")

that coincidental condition is gone, leading to the zenbleed check
getting executed on other vendors too.

Add the explicit vendor check for the whole callback as it should've
been done in the first place.

Fixes: 522b1d6921 ("x86/cpu/amd: Add a Zenbleed fix")
Cc: <stable@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20231201184226.16749-1-bp@alien8.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-13 18:45:33 +01:00
Ashwin Dayanand Kamat 73bbca1298 x86/sev: Fix kernel crash due to late update to read-only ghcb_version
[ Upstream commit 27d25348d42161837be08fc63b04a2559d2e781c ]

A write-access violation page fault kernel crash was observed while running
cpuhotplug LTP testcases on SEV-ES enabled systems. The crash was
observed during hotplug, after the CPU was offlined and the process
was migrated to different CPU. setup_ghcb() is called again which
tries to update ghcb_version in sev_es_negotiate_protocol(). Ideally this
is a read_only variable which is initialised during booting.

Trying to write it results in a pagefault:

  BUG: unable to handle page fault for address: ffffffffba556e70
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0003) - permissions violation
  [ ...]
  Call Trace:
   <TASK>
   ? __die_body.cold+0x1a/0x1f
   ? __die+0x2a/0x35
   ? page_fault_oops+0x10c/0x270
   ? setup_ghcb+0x71/0x100
   ? __x86_return_thunk+0x5/0x6
   ? search_exception_tables+0x60/0x70
   ? __x86_return_thunk+0x5/0x6
   ? fixup_exception+0x27/0x320
   ? kernelmode_fixup_or_oops+0xa2/0x120
   ? __bad_area_nosemaphore+0x16a/0x1b0
   ? kernel_exc_vmm_communication+0x60/0xb0
   ? bad_area_nosemaphore+0x16/0x20
   ? do_kern_addr_fault+0x7a/0x90
   ? exc_page_fault+0xbd/0x160
   ? asm_exc_page_fault+0x27/0x30
   ? setup_ghcb+0x71/0x100
   ? setup_ghcb+0xe/0x100
   cpu_init_exception_handling+0x1b9/0x1f0

The fix is to call sev_es_negotiate_protocol() only in the BSP boot phase,
and it only needs to be done once in any case.

[ mingo: Refined the changelog. ]

Fixes: 95d33bfaa3 ("x86/sev: Register GHCB memory when SEV-SNP is active")
Suggested-by: Tom Lendacky <thomas.lendacky@amd.com>
Co-developed-by: Bo Gan <bo.gan@broadcom.com>
Signed-off-by: Bo Gan <bo.gan@broadcom.com>
Signed-off-by: Ashwin Dayanand Kamat <ashwin.kamat@broadcom.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/1701254429-18250-1-git-send-email-kashwindayan@vmware.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-12-13 18:45:30 +01:00
Kirill A. Shutemov 239bff0171 x86/tdx: Allow 32-bit emulation by default
[ upstream commit f4116bfc44621882556bbf70f5284fbf429a5cf6 ]

32-bit emulation was disabled on TDX to prevent a possible attack by
a VMM injecting an interrupt on vector 0x80.

Now that int80_emulation() has a check for external interrupts the
limitation can be lifted.

To distinguish software interrupts from external ones, int80_emulation()
checks the APIC ISR bit relevant to the 0x80 vector. For
software interrupts, this bit will be 0.

On TDX, the VAPIC state (including ISR) is protected and cannot be
manipulated by the VMM. The ISR bit is set by the microcode flow during
the handling of posted interrupts.

[ dhansen: more changelog tweaks ]

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@vger.kernel.org> # v6.0+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-13 18:45:02 +01:00
Thomas Gleixner 22ca647c8f x86/entry: Do not allow external 0x80 interrupts
[ upstream commit 55617fb991df535f953589586468612351575704 ]

The INT 0x80 instruction is used for 32-bit x86 Linux syscalls. The
kernel expects to receive a software interrupt as a result of the INT
0x80 instruction. However, an external interrupt on the same vector
also triggers the same codepath.

An external interrupt on vector 0x80 will currently be interpreted as a
32-bit system call, and assuming that it was a user context.

Panic on external interrupts on the vector.

To distinguish software interrupts from external ones, the kernel checks
the APIC ISR bit relevant to the 0x80 vector. For software interrupts,
this bit will be 0.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@vger.kernel.org> # v6.0+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-13 18:45:02 +01:00
Thomas Gleixner 4591766ff6 x86/entry: Convert INT 0x80 emulation to IDTENTRY
[ upstream commit be5341eb0d43b1e754799498bd2e8756cc167a41 ]

There is no real reason to have a separate ASM entry point implementation
for the legacy INT 0x80 syscall emulation on 64-bit.

IDTENTRY provides all the functionality needed with the only difference
that it does not:

  - save the syscall number (AX) into pt_regs::orig_ax
  - set pt_regs::ax to -ENOSYS

Both can be done safely in the C code of an IDTENTRY before invoking any of
the syscall related functions which depend on this convention.

Aside of ASM code reduction this prepares for detecting and handling a
local APIC injected vector 0x80.

[ kirill.shutemov: More verbose comments ]
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@vger.kernel.org> # v6.0+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-13 18:45:02 +01:00
Kirill A. Shutemov 34c686e5be x86/coco: Disable 32-bit emulation by default on TDX and SEV
[ upstream commit b82a8dbd3d2f4563156f7150c6f2ecab6e960b30 ]

The INT 0x80 instruction is used for 32-bit x86 Linux syscalls. The
kernel expects to receive a software interrupt as a result of the INT
0x80 instruction. However, an external interrupt on the same vector
triggers the same handler.

The kernel interprets an external interrupt on vector 0x80 as a 32-bit
system call that came from userspace.

A VMM can inject external interrupts on any arbitrary vector at any
time.  This remains true even for TDX and SEV guests where the VMM is
untrusted.

Put together, this allows an untrusted VMM to trigger int80 syscall
handling at any given point. The content of the guest register file at
that moment defines what syscall is triggered and its arguments. It
opens the guest OS to manipulation from the VMM side.

Disable 32-bit emulation by default for TDX and SEV. User can override
it with the ia32_emulation=y command line option.

[ dhansen: reword the changelog ]

Reported-by: Supraja Sridhara <supraja.sridhara@inf.ethz.ch>
Reported-by: Benedict Schlüter <benedict.schlueter@inf.ethz.ch>
Reported-by: Mark Kuhne <mark.kuhne@inf.ethz.ch>
Reported-by: Andrin Bertschi <andrin.bertschi@inf.ethz.ch>
Reported-by: Shweta Shinde <shweta.shinde@inf.ethz.ch>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@vger.kernel.org> # 6.0+: 1da5c9b x86: Introduce ia32_enabled()
Cc: <stable@vger.kernel.org> # 6.0+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-13 18:45:02 +01:00
Nikolay Borisov f259af26ee x86: Introduce ia32_enabled()
[ upstream commit 1da5c9bc119d3a749b519596b93f9b2667e93c4a ]

IA32 support on 64bit kernels depends on whether CONFIG_IA32_EMULATION
is selected or not. As it is a compile time option it doesn't
provide the flexibility to have distributions set their own policy for
IA32 support and give the user the flexibility to override it.

As a first step introduce ia32_enabled() which abstracts whether IA32
compat is turned on or off. Upcoming patches will implement
the ability to set IA32 compat state at boot time.

Signed-off-by: Nikolay Borisov <nik.borisov@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230623111409.3047467-2-nik.borisov@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-13 18:45:02 +01:00
Juergen Gross 602aa0efcf x86/xen: fix percpu vcpu_info allocation
[ Upstream commit db2832309a82b9acc4b8cc33a1831d36507ec13e ]

Today the percpu struct vcpu_info is allocated via DEFINE_PER_CPU(),
meaning that it could cross a page boundary. In this case registering
it with the hypervisor will fail, resulting in a panic().

This can easily be fixed by using DEFINE_PER_CPU_ALIGNED() instead,
as struct vcpu_info is guaranteed to have a size of 64 bytes, matching
the cache line size of x86 64-bit processors (Xen doesn't support
32-bit processors).

Fixes: 5ead97c84f ("xen: Core Xen implementation")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.con>
Link: https://lore.kernel.org/r/20231124074852.25161-1-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-12-08 08:52:25 +01:00
Josh Poimboeuf b4166941c0 x86/srso: Move retbleed IBPB check into existing 'has_microcode' code block
commit 351236947a45a512c517153bbe109fe868d05e6d upstream.

Simplify the code flow a bit by moving the retbleed IBPB check into the
existing 'has_microcode' block.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/0a22b86b1f6b07f9046a9ab763fc0e0d1b7a91d4.1693889988.git.jpoimboe@kernel.org
Cc: Caleb Jorden <cjorden@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:20:16 +00:00
Roger Pau Monne 32ca78deed acpi/processor: sanitize _OSC/_PDC capabilities for Xen dom0
commit bfa993b355d33a438a746523e7129391c8664e8a upstream.

The Processor capability bits notify ACPI of the OS capabilities, and
so ACPI can adjust the return of other Processor methods taking the OS
capabilities into account.

When Linux is running as a Xen dom0, the hypervisor is the entity
in charge of processor power management, and hence Xen needs to make
sure the capabilities reported by _OSC/_PDC match the capabilities of
the driver in Xen.

Introduce a small helper to sanitize the buffer when running as Xen
dom0.

When Xen supports HWP, this serves as the equivalent of commit
a21211672c ("ACPI / processor: Request native thermal interrupt
handling via _OSC") to avoid SMM crashes.  Xen will set bit
ACPI_PROC_CAP_COLLAB_PROC_PERF (bit 12) in the capability bits and the
_OSC/_PDC call will apply it.

[ jandryuk: Mention Xen HWP's need.  Support _OSC & _PDC ]
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Michal Wilczynski <michal.wilczynski@intel.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20231108212517.72279-1-jandryuk@gmail.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:19:57 +00:00
Haitao Shan 7de33b0fc9 KVM: x86: Fix lapic timer interrupt lost after loading a snapshot.
commit 9cfec6d097c607e36199cf0cfbb8cf5acbd8e9b2 upstream.

When running android emulator (which is based on QEMU 2.12) on
certain Intel hosts with kernel version 6.3-rc1 or above, guest
will freeze after loading a snapshot. This is almost 100%
reproducible. By default, the android emulator will use snapshot
to speed up the next launching of the same android guest. So
this breaks the android emulator badly.

I tested QEMU 8.0.4 from Debian 12 with an Ubuntu 22.04 guest by
running command "loadvm" after "savevm". The same issue is
observed. At the same time, none of our AMD platforms is impacted.
More experiments show that loading the KVM module with
"enable_apicv=false" can workaround it.

The issue started to show up after commit 8e6ed96cdd ("KVM: x86:
fire timer when it is migrated and expired, and in oneshot mode").
However, as is pointed out by Sean Christopherson, it is introduced
by commit 967235d320 ("KVM: vmx: clear pending interrupts on
KVM_SET_LAPIC"). commit 8e6ed96cdd ("KVM: x86: fire timer when
it is migrated and expired, and in oneshot mode") just makes it
easier to hit the issue.

Having both commits, the oneshot lapic timer gets fired immediately
inside the KVM_SET_LAPIC call when loading the snapshot. On Intel
platforms with APIC virtualization and posted interrupt processing,
this eventually leads to setting the corresponding PIR bit. However,
the whole PIR bits get cleared later in the same KVM_SET_LAPIC call
by apicv_post_state_restore. This leads to timer interrupt lost.

The fix is to move vmx_apicv_post_state_restore to the beginning of
the KVM_SET_LAPIC call and rename to vmx_apicv_pre_state_restore.
What vmx_apicv_post_state_restore does is actually clearing any
former apicv state and this behavior is more suitable to carry out
in the beginning.

Fixes: 967235d320 ("KVM: vmx: clear pending interrupts on KVM_SET_LAPIC")
Cc: stable@vger.kernel.org
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Haitao Shan <hshan@google.com>
Link: https://lore.kernel.org/r/20230913000215.478387-1-hshan@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:19:56 +00:00
Tao Su fb05c7b93c KVM: x86: Clear bit12 of ICR after APIC-write VM-exit
commit 629d3698f6958ee6f8131ea324af794f973b12ac upstream.

When IPI virtualization is enabled, a WARN is triggered if bit12 of ICR
MSR is set after APIC-write VM-exit. The reason is kvm_apic_send_ipi()
thinks the APIC_ICR_BUSY bit should be cleared because KVM has no delay,
but kvm_apic_write_nodecode() doesn't clear the APIC_ICR_BUSY bit.

Under the x2APIC section, regarding ICR, the SDM says:

  It remains readable only to aid in debugging; however, software should
  not assume the value returned by reading the ICR is the last written
  value.

I.e. the guest is allowed to set bit 12.  However, the SDM also gives KVM
free reign to do whatever it wants with the bit, so long as KVM's behavior
doesn't confuse userspace or break KVM's ABI.

Clear bit 12 so that it reads back as '0'. This approach is safer than
"do nothing" and is consistent with the case where IPI virtualization is
disabled or not supported, i.e.,

  handle_fastpath_set_x2apic_icr_irqoff() -> kvm_x2apic_icr_write()

Opportunistically replace the TODO with a comment calling out that eating
the write is likely faster than a conditional branch around the busy bit.

Link: https://lore.kernel.org/all/ZPj6iF0Q7iynn62p@google.com/
Fixes: 5413bcba7e ("KVM: x86: Add support for vICR APIC-write VM-Exits in x2APIC mode")
Cc: stable@vger.kernel.org
Signed-off-by: Tao Su <tao1.su@linux.intel.com>
Tested-by: Yi Lai <yi1.lai@intel.com>
Reviewed-by: Chao Gao <chao.gao@intel.com>
Link: https://lore.kernel.org/r/20230914055504.151365-1-tao1.su@linux.intel.com
[sean: tweak changelog, replace TODO with comment, drop local "val"]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:19:56 +00:00
Maciej S. Szmigiero d3719df92e KVM: x86: Ignore MSR_AMD64_TW_CFG access
commit 2770d4722036d6bd24bcb78e9cd7f6e572077d03 upstream.

Hyper-V enabled Windows Server 2022 KVM VM cannot be started on Zen1 Ryzen
since it crashes at boot with SYSTEM_THREAD_EXCEPTION_NOT_HANDLED +
STATUS_PRIVILEGED_INSTRUCTION (in other words, because of an unexpected #GP
in the guest kernel).

This is because Windows tries to set bit 8 in MSR_AMD64_TW_CFG and can't
handle receiving a #GP when doing so.

Give this MSR the same treatment that commit 2e32b71906
("x86, kvm: Add MSR_AMD64_BU_CFG2 to the list of ignored MSRs") gave
MSR_AMD64_BU_CFG2 under justification that this MSR is baremetal-relevant
only.
Although apparently it was then needed for Linux guests, not Windows as in
this case.

With this change, the aforementioned guest setup is able to finish booting
successfully.

This issue can be reproduced either on a Summit Ridge Ryzen (with
just "-cpu host") or on a Naples EPYC (with "-cpu host,stepping=1" since
EPYC is ordinarily stepping 2).

Alternatively, userspace could solve the problem by using MSR filters, but
forcing every userspace to define a filter isn't very friendly and doesn't
add much, if any, value.  The only potential hiccup is if one of these
"baremetal-only" MSRs ever requires actual emulation and/or has F/M/S
specific behavior.  But if that happens, then KVM can still punt *that*
handling to userspace since userspace MSR filters "win" over KVM's default
handling.

Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1ce85d9c7c9e9632393816cf19c902e0a3f411f1.1697731406.git.maciej.szmigiero@oracle.com
[sean: call out MSR filtering alternative]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:19:56 +00:00
Nicolas Saenz Julienne e0c63803d7 KVM: x86: hyper-v: Don't auto-enable stimer on write from user-space
commit d6800af51c76b6dae20e6023bbdc9b3da3ab5121 upstream.

Don't apply the stimer's counter side effects when modifying its
value from user-space, as this may trigger spurious interrupts.

For example:
 - The stimer is configured in auto-enable mode.
 - The stimer's count is set and the timer enabled.
 - The stimer expires, an interrupt is injected.
 - The VM is live migrated.
 - The stimer config and count are deserialized, auto-enable is ON, the
   stimer is re-enabled.
 - The stimer expires right away, and injects an unwarranted interrupt.

Cc: stable@vger.kernel.org
Fixes: 1f4b34f825 ("kvm/x86: Hyper-V SynIC timers")
Signed-off-by: Nicolas Saenz Julienne <nsaenz@amazon.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20231017155101.40677-1-nsaenz@amazon.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:19:56 +00:00
Pu Wen 8e780a58c1 x86/cpu/hygon: Fix the CPU topology evaluation for real
commit ee545b94d39a00c93dc98b1dbcbcf731d2eadeb4 upstream.

Hygon processors with a model ID > 3 have CPUID leaf 0xB correctly
populated and don't need the fixed package ID shift workaround. The fixup
is also incorrect when running in a guest.

Fixes: e0ceeae708 ("x86/CPU/hygon: Fix phys_proc_id calculation logic for multi-die processors")
Signed-off-by: Pu Wen <puwen@hygon.cn>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/tencent_594804A808BD93A4EBF50A994F228E3A7F07@qq.com
Link: https://lore.kernel.org/r/20230814085112.089607918@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:19:56 +00:00
Koichiro Den 119f7373b0 x86/apic/msi: Fix misconfigured non-maskable MSI quirk
commit b56ebe7c896dc78b5865ec2c4b1dae3c93537517 upstream.

commit ef8dd01538 ("genirq/msi: Make interrupt allocation less
convoluted"), reworked the code so that the x86 specific quirk for affinity
setting of non-maskable PCI/MSI interrupts is not longer activated if
necessary.

This could be solved by restoring the original logic in the core MSI code,
but after a deeper analysis it turned out that the quirk flag is not
required at all.

The quirk is only required when the PCI/MSI device cannot mask the MSI
interrupts, which in turn also prevents reservation mode from being enabled
for the affected interrupt.

This allows ot remove the NOMASK quirk bit completely as msi_set_affinity()
can instead check whether reservation mode is enabled for the interrupt,
which gives exactly the same answer.

Even in the momentary non-existing case that the reservation mode would be
not set for a maskable MSI interrupt this would not cause any harm as it
just would cause msi_set_affinity() to go needlessly through the
functionaly equivalent slow path, which works perfectly fine with maskable
interrupts as well.

Rework msi_set_affinity() to query the reservation mode and remove all
NOMASK quirk logic from the core code.

[ tglx: Massaged changelog ]

Fixes: ef8dd01538 ("genirq/msi: Make interrupt allocation less convoluted")
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Koichiro Den <den@valinux.co.jp>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20231026032036.2462428-1-den@valinux.co.jp
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:19:56 +00:00
Mario Limonciello 3f6154cb29 x86/PCI: Avoid PME from D3hot/D3cold for AMD Rembrandt and Phoenix USB4
commit 7d08f21f8c6307cb05cabb8d86e90ff6ccba57e9 upstream.

Iain reports that USB devices can't be used to wake a Lenovo Z13 from
suspend.  This occurs because on some AMD platforms, even though the Root
Ports advertise PME_Support for D3hot and D3cold, wakeup events from
devices on a USB4 controller don't result in wakeup interrupts from the
Root Port when amd-pmc has put the platform in a hardware sleep state.

If amd-pmc will be involved in the suspend, remove D3hot and D3cold from
the PME_Support mask of Root Ports above USB4 controllers so we avoid those
states if we need wakeups.

Restore D3 support at resume so that it can be used by runtime suspend.

This affects both AMD Rembrandt and Phoenix SoCs.

"pm_suspend_target_state == PM_SUSPEND_ON" means we're doing runtime
suspend, and amd-pmc will not be involved.  In that case PMEs work as
advertised in D3hot/D3cold, so we don't need to do anything.

Note that amd-pmc is technically optional, and there's no need for this
quirk if it's not present, but we assume it's always present because power
consumption is so high without it.

Fixes: 9d26d3a8f1 ("PCI: Put PCIe ports into D3 during suspend")
Link: https://lore.kernel.org/r/20231004144959.158840-1-mario.limonciello@amd.com
Reported-by: Iain Lane <iain@orangesquash.org.uk>
Closes: https://forums.lenovo.com/t5/Ubuntu/Z13-can-t-resume-from-suspend-with-external-USB-keyboard/m-p/5217121
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
[bhelgaas: commit log, move to arch/x86/pci/fixup.c, add #includes]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:19:56 +00:00
Roxana Nicolescu 20b951fcdc crypto: x86/sha - load modules based on CPU features
commit 1c43c0f1f84aa59dfc98ce66f0a67b2922aa7f9d upstream.

x86 optimized crypto modules are built as modules rather than build-in and
they are not loaded when the crypto API is initialized, resulting in the
generic builtin module (sha1-generic) being used instead.

It was discovered when creating a sha1/sha256 checksum of a 2Gb file by
using kcapi-tools because it would take significantly longer than creating
a sha512 checksum of the same file. trace-cmd showed that for sha1/256 the
generic module was used, whereas for sha512 the optimized module was used
instead.

Add module aliases() for these x86 optimized crypto modules based on CPU
feature bits so udev gets a chance to load them later in the boot
process. This resulted in ~3x decrease in the real-time execution of
kcapi-dsg.

Fix is inspired from commit
aa031b8f70 ("crypto: x86/sha512 - load based on CPU features")
where a similar fix was done for sha512.

Cc: stable@vger.kernel.org # 5.15+
Suggested-by: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Suggested-by: Julian Andres Klode <julian.klode@canonical.com>
Signed-off-by: Roxana Nicolescu <roxana.nicolescu@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:19:56 +00:00
Rick Edgecombe 4cb2be4c73 x86/shstk: Delay signal entry SSP write until after user accesses
commit 31255e072b2e91f97645d792d25b2db744186dd1 upstream.

When a signal is being delivered, the kernel needs to make accesses to
userspace. These accesses could encounter an access error, in which case
the signal delivery itself will trigger a segfault. Usually this would
result in the kernel killing the process. But in the case of a SEGV signal
handler being configured, the failure of the first signal delivery will
result in *another* signal getting delivered. The second signal may
succeed if another thread has resolved the issue that triggered the
segfault (i.e. a well timed mprotect()/mmap()), or the second signal is
being delivered to another stack (i.e. an alt stack).

On x86, in the non-shadow stack case, all the accesses to userspace are
done before changes to the registers (in pt_regs). The operation is
aborted when an access error occurs, so although there may be writes done
for the first signal, control flow changes for the signal (regs->ip,
regs->sp, etc) are not committed until all the accesses have already
completed successfully. This means that the second signal will be
delivered as if it happened at the time of the first signal. It will
effectively replace the first aborted signal, overwriting the half-written
frame of the aborted signal. So on sigreturn from the second signal,
control flow will resume happily from the point of control flow where the
original signal was delivered.

The problem is, when shadow stack is active, the shadow stack SSP
register/MSR is updated *before* some of the userspace accesses. This
means if the earlier accesses succeed and the later ones fail, the second
signal will not be delivered at the same spot on the shadow stack as the
first one. So on sigreturn from the second signal, the SSP will be
pointing to the wrong location on the shadow stack (off by a frame).

Pengfei privately reported that while using a shadow stack enabled glibc,
the “signal06” test in the LTP test-suite hung. It turns out it is
testing the above described double signal scenario. When this test was
compiled with shadow stack, the first signal pushed a shadow stack
sigframe, then the second pushed another. When the second signal was
handled, the SSP was at the first shadow stack signal frame instead of
the original location. The test then got stuck as the #CP from the twice
incremented SSP was incorrect and generated segfaults in a loop.

Fix this by adjusting the SSP register only after any userspace accesses,
such that there can be no failures after the SSP is adjusted. Do this by
moving the shadow stack sigframe push logic to happen after all other
userspace accesses.

Note, sigreturn (as opposed to the signal delivery dealt with in this
patch) has ordering behavior that could lead to similar failures. The
ordering issues there extend beyond shadow stack to include the alt stack
restoration. Fixing that would require cross-arch changes, and the
ordering today does not cause any known test or apps breakages. So leave
it as is, for now.

[ dhansen: minor changelog/subject tweak ]

Fixes: 05e36022c0 ("x86/shstk: Handle signals for shadow stack")
Reported-by: Pengfei Xu <pengfei.xu@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Cc:stable@vger.kernel.org
Link: https://lore.kernel.org/all/20231107182251.91276-1-rick.p.edgecombe%40intel.com
Link: https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/syscalls/signal/signal06.c
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:19:55 +00:00
Mike Rapoport (IBM) 0f32b0b2bd x86/mm: Drop the 4 MB restriction on minimal NUMA node memory size
[ Upstream commit a1e2b8b36820d8c91275f207e77e91645b7c6836 ]

Qi Zheng reported crashes in a production environment and provided a
simplified example as a reproducer:

 |  For example, if we use Qemu to start a two NUMA node kernel,
 |  one of the nodes has 2M memory (less than NODE_MIN_SIZE),
 |  and the other node has 2G, then we will encounter the
 |  following panic:
 |
 |    BUG: kernel NULL pointer dereference, address: 0000000000000000
 |    <...>
 |    RIP: 0010:_raw_spin_lock_irqsave+0x22/0x40
 |    <...>
 |    Call Trace:
 |      <TASK>
 |      deactivate_slab()
 |      bootstrap()
 |      kmem_cache_init()
 |      start_kernel()
 |      secondary_startup_64_no_verify()

The crashes happen because of inconsistency between the nodemask that
has nodes with less than 4MB as memoryless, and the actual memory fed
into the core mm.

The commit:

  9391a3f9c7 ("[PATCH] x86_64: Clear more state when ignoring empty node in SRAT parsing")

... that introduced minimal size of a NUMA node does not explain why
a node size cannot be less than 4MB and what boot failures this
restriction might fix.

Fixes have been submitted to the core MM code to tighten up the
memory topologies it accepts and to not crash on weird input:

  mm: page_alloc: skip memoryless nodes entirely
  mm: memory_hotplug: drop memoryless node from fallback lists

Andrew has accepted them into the -mm tree, but there are no
stable SHA1's yet.

This patch drops the limitation for minimal node size on x86:

  - which works around the crash without the fixes to the core MM.
  - makes x86 topologies less weird,
  - removes an arbitrary and undocumented limitation on NUMA topologies.

[ mingo: Improved changelog clarity. ]

Reported-by: Qi Zheng <zhengqi.arch@bytedance.com>
Tested-by: Mario Casquero <mcasquer@redhat.com>
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Rik van Riel <riel@surriel.com>
Link: https://lore.kernel.org/r/ZS+2qqjEO5/867br@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-28 17:19:36 +00:00
Yazen Ghannam 28e7c108c0 x86/amd_nb: Use Family 19h Models 60h-7Fh Function 4 IDs
commit 2a565258b3f4bbdc7a3c09cd02082cb286a7bffc upstream.

Three PCI IDs for DF Function 4 were defined but not used.

Add them to the "link" list.

Fixes: f8faf34966 ("x86/amd_nb: Add AMD PCI IDs for SMN communication")
Fixes: 23a5b8bb02 ("x86/amd_nb: Add PCI ID for family 19h model 78h")
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230803150430.3542854-1-yazen.ghannam@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-20 11:59:38 +01:00
Kai Huang de4c5bacca x86/tdx: Zero out the missing RSI in TDX_HYPERCALL macro
[ Upstream commit 5d092b66119d774853cc9308522620299048a662 ]

In the TDX_HYPERCALL asm, after the TDCALL instruction returns from the
untrusted VMM, the registers that the TDX guest shares to the VMM need
to be cleared to avoid speculative execution of VMM-provided values.

RSI is specified in the bitmap of those registers, but it is missing
when zeroing out those registers in the current TDX_HYPERCALL.

It was there when it was originally added in commit 752d13305c
("x86/tdx: Expand __tdx_hypercall() to handle more arguments"), but was
later removed in commit 1e70c68037 ("x86/tdx: Do not corrupt
frame-pointer in __tdx_hypercall()"), which was correct because %rsi is
later restored in the "pop %rsi".  However a later commit 7a3a401874
("x86/tdx: Drop flags from __tdx_hypercall()") removed that "pop %rsi"
but forgot to add the "xor %rsi, %rsi" back.

Fix by adding it back.

Fixes: 7a3a401874 ("x86/tdx: Drop flags from __tdx_hypercall()")
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/e7d1157074a0b45d34564d5f17f3e0ffee8115e9.1692096753.git.kai.huang%40intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:59:09 +01:00
Leon Hwang 8f873cc3f6 bpf, x64: Fix tailcall infinite loop
[ Upstream commit 2b5dcb31a19a2e0acd869b12c9db9b2d696ef544 ]

From commit ebf7d1f508 ("bpf, x64: rework pro/epilogue and tailcall
handling in JIT"), the tailcall on x64 works better than before.

From commit e411901c0b ("bpf: allow for tailcalls in BPF subprograms
for x64 JIT"), tailcall is able to run in BPF subprograms on x64.

From commit 5b92a28aae ("bpf: Support attaching tracing BPF program
to other BPF programs"), BPF program is able to trace other BPF programs.

How about combining them all together?

1. FENTRY/FEXIT on a BPF subprogram.
2. A tailcall runs in the BPF subprogram.
3. The tailcall calls the subprogram's caller.

As a result, a tailcall infinite loop comes up. And the loop would halt
the machine.

As we know, in tail call context, the tail_call_cnt propagates by stack
and rax register between BPF subprograms. So do in trampolines.

Fixes: ebf7d1f508 ("bpf, x64: rework pro/epilogue and tailcall handling in JIT")
Fixes: e411901c0b ("bpf: allow for tailcalls in BPF subprograms for x64 JIT")
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Leon Hwang <hffilwlqm@gmail.com>
Link: https://lore.kernel.org/r/20230912150442.2009-3-hffilwlqm@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:58:55 +01:00
Paul E. McKenney 2112a9df40 x86/nmi: Fix out-of-order NMI nesting checks & false positive warning
[ Upstream commit f44075ecafb726830e63d33fbca29413149eeeb8 ]

The ->idt_seq and ->recv_jiffies variables added by:

  1a3ea611fc ("x86/nmi: Accumulate NMI-progress evidence in exc_nmi()")

... place the exit-time check of the bottom bit of ->idt_seq after the
this_cpu_dec_return() that re-enables NMI nesting.  This can result in
the following sequence of events on a given CPU in kernels built with
CONFIG_NMI_CHECK_CPU=y:

  o   An NMI arrives, and ->idt_seq is incremented to an odd number.
      In addition, nmi_state is set to NMI_EXECUTING==1.

  o   The NMI is processed.

  o   The this_cpu_dec_return(nmi_state) zeroes nmi_state and returns
      NMI_EXECUTING==1, thus opting out of the "goto nmi_restart".

  o   Another NMI arrives and ->idt_seq is incremented to an even
      number, triggering the warning.  But all is just fine, at least
      assuming we don't get so many closely spaced NMIs that the stack
      overflows or some such.

Experience on the fleet indicates that the MTBF of this false positive
is about 70 years.  Or, for those who are not quite that patient, the
MTBF appears to be about one per week per 4,000 systems.

Fix this false-positive warning by moving the "nmi_restart" label before
the initial ->idt_seq increment/check and moving the this_cpu_dec_return()
to follow the final ->idt_seq increment/check.  This way, all nested NMIs
that get past the NMI_NOT_RUNNING check get a clean ->idt_seq slate.
And if they don't get past that check, they will set nmi_state to
NMI_LATCHED, which will cause the this_cpu_dec_return(nmi_state)
to restart.

Fixes: 1a3ea611fc ("x86/nmi: Accumulate NMI-progress evidence in exc_nmi()")
Reported-by: Chris Mason <clm@fb.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/0cbff831-6e3d-431c-9830-ee65ee7787ff@paulmck-laptop
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:58:53 +01:00
Thomas Gleixner e0621d5d9e x86/apic: Fake primary thread mask for XEN/PV
[ Upstream commit 965e05ff8af98c44f9937366715c512000373164 ]

The SMT control mechanism got added as speculation attack vector
mitigation. The implemented logic relies on the primary thread mask to
be set up properly.

This turns out to be an issue with XEN/PV guests because their CPU hotplug
mechanics do not enumerate APICs and therefore the mask is never correctly
populated.

This went unnoticed so far because by chance XEN/PV ends up with
smp_num_siblings == 2. So cpu_smt_control stays at its default value
CPU_SMT_ENABLED and the primary thread mask is never evaluated in the
context of CPU hotplug.

This stopped "working" with the upcoming overhaul of the topology
evaluation which legitimately provides a fake topology for XEN/PV. That
sets smp_num_siblings to 1, which causes the core CPU hot-plug core to
refuse to bring up the APs.

This happens because cpu_smt_control is set to CPU_SMT_NOT_SUPPORTED which
causes cpu_bootable() to evaluate the unpopulated primary thread mask with
the conclusion that all non-boot CPUs are not valid to be plugged.

The core code has already been made more robust against this kind of fail,
but the primary thread mask really wants to be populated to avoid other
issues all over the place.

Just fake the mask by pretending that all XEN/PV vCPUs are primary threads,
which is consistent because all of XEN/PVs topology is fake or non-existent.

Fixes: 6a4d2657e0 ("x86/smp: Provide topology_is_primary_thread()")
Fixes: f54d4434c2 ("x86/apic: Provide cpu_primary_thread mask")
Reported-by: Juergen Gross <jgross@suse.com>
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>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230814085112.210011520@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:58:53 +01:00
Yuntao Wang 8d75ebf26a x86/boot: Fix incorrect startup_gdt_descr.size
[ Upstream commit 001470fed5959d01faecbd57fcf2f60294da0de1 ]

Since the size value is added to the base address to yield the last valid
byte address of the GDT, the current size value of startup_gdt_descr is
incorrect (too large by one), fix it.

[ mingo: This probably never mattered, because startup_gdt[] is only used
         in a very controlled fashion - but make it consistent nevertheless. ]

Fixes: 866b556efa ("x86/head/64: Install startup GDT")
Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20230807084547.217390-1-ytcoode@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:58:53 +01:00
Adam Dunlap 95846cd88c x86/sev-es: Allow copy_from_kernel_nofault() in earlier boot
[ Upstream commit f79936545fb122856bd78b189d3c7ee59928c751 ]

Previously, if copy_from_kernel_nofault() was called before
boot_cpu_data.x86_virt_bits was set up, then it would trigger undefined
behavior due to a shift by 64.

This ended up causing boot failures in the latest version of ubuntu2204
in the gcp project when using SEV-SNP.

Specifically, this function is called during an early #VC handler which
is triggered by a CPUID to check if NX is implemented.

Fixes: 1aa9aa8ee5 ("x86/sev-es: Setup GHCB-based boot #VC handler")
Suggested-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Adam Dunlap <acdunlap@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Jacob Xu <jacobhxu@google.com>
Link: https://lore.kernel.org/r/20230912002703.3924521-2-acdunlap@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:58:53 +01:00
Alison Schofield eb38c5edf2 x86/numa: Introduce numa_fill_memblks()
[ Upstream commit 8f012db27c9516be1a7aca93ea4a6ca9c75056c9 ]

numa_fill_memblks() fills in the gaps in numa_meminfo memblks
over an physical address range.

The ACPI driver will use numa_fill_memblks() to implement a new Linux
policy that prescribes extending proximity domains in a portion of a
CFMWS window to the entire window.

Dan Williams offered this explanation of the policy:
A CFWMS is an ACPI data structure that indicates *potential* locations
where CXL memory can be placed. It is the playground where the CXL
driver has free reign to establish regions. That space can be populated
by BIOS created regions, or driver created regions, after hotplug or
other reconfiguration.

When BIOS creates a region in a CXL Window it additionally describes
that subset of the Window range in the other typical ACPI tables SRAT,
SLIT, and HMAT. The rationale for BIOS not pre-describing the entire
CXL Window in SRAT, SLIT, and HMAT is that it can not predict the
future. I.e. there is nothing stopping higher or lower performance
devices being placed in the same Window. Compare that to ACPI memory
hotplug that just onlines additional capacity in the proximity domain
with little freedom for dynamic performance differentiation.

That leaves the OS with a choice, should unpopulated window capacity
match the proximity domain of an existing region, or should it allocate
a new one? This patch takes the simple position of minimizing proximity
domain proliferation by reusing any proximity domain intersection for
the entire Window. If the Window has no intersections then allocate a
new proximity domain. Note that SRAT, SLIT and HMAT information can be
enumerated dynamically in a standard way from device provided data.
Think of CXL as the end of ACPI needing to describe memory attributes,
CXL offers a standard discovery model for performance attributes, but
Linux still needs to interoperate with the old regime.

Reported-by: Derick Marks <derick.w.marks@intel.com>
Suggested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Derick Marks <derick.w.marks@intel.com>
Link: https://lore.kernel.org/all/ef078a6f056ca974e5af85997013c0fda9e3326d.1689018477.git.alison.schofield%40intel.com
Stable-dep-of: 8f1004679987 ("ACPI/NUMA: Apply SRAT proximity domain to entire CFMWS window")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:58:53 +01:00
Josh Poimboeuf 626ea25e6d x86/srso: Fix unret validation dependencies
[ Upstream commit eeb9f34df065f42f0c9195b322ba6df420c9fc92 ]

CONFIG_CPU_SRSO isn't dependent on CONFIG_CPU_UNRET_ENTRY (AMD
Retbleed), so the two features are independently configurable.  Fix
several issues for the (presumably rare) case where CONFIG_CPU_SRSO is
enabled but CONFIG_CPU_UNRET_ENTRY isn't.

Fixes: fb3bd914b3 ("x86/srso: Add a Speculative RAS Overflow mitigation")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/299fb7740174d0f2335e91c58af0e9c242b4bac1.1693889988.git.jpoimboe@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:58:52 +01:00
Josh Poimboeuf 0a958abffa x86/srso: Fix vulnerability reporting for missing microcode
[ Upstream commit dc6306ad5b0dda040baf1fde3cfd458e6abfc4da ]

The SRSO default safe-ret mitigation is reported as "mitigated" even if
microcode hasn't been updated.  That's wrong because userspace may still
be vulnerable to SRSO attacks due to IBPB not flushing branch type
predictions.

Report the safe-ret + !microcode case as vulnerable.

Also report the microcode-only case as vulnerable as it leaves the
kernel open to attacks.

Fixes: fb3bd914b3 ("x86/srso: Add a Speculative RAS Overflow mitigation")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/a8a14f97d1b0e03ec255c81637afdf4cf0ae9c99.1693889988.git.jpoimboe@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:58:52 +01:00
Josh Poimboeuf 5b66cf0762 x86/srso: Print mitigation for retbleed IBPB case
[ Upstream commit de9f5f7b06a5b7adbfdd8016f011120a4e928add ]

When overriding the requested mitigation with IBPB due to retbleed=ibpb,
print the mitigation in the usual format instead of a custom error
message.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/ec3af919e267773d896c240faf30bfc6a1fd6304.1693889988.git.jpoimboe@kernel.org
Stable-dep-of: dc6306ad5b0d ("x86/srso: Fix vulnerability reporting for missing microcode")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:58:52 +01:00
Josh Poimboeuf 1be339b0dc x86/srso: Fix SBPB enablement for (possible) future fixed HW
[ Upstream commit 1d1142ac51307145dbb256ac3535a1d43a1c9800 ]

Make the SBPB check more robust against the (possible) case where future
HW has SRSO fixed but doesn't have the SRSO_NO bit set.

Fixes: 1b5277c0ea ("x86/srso: Add SRSO_NO support")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/cee5050db750b391c9f35f5334f8ff40e66c01b9.1693889988.git.jpoimboe@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:58:52 +01:00
David Howells d73de8157f iov_iter, x86: Be consistent about the __user tag on copy_mc_to_user()
[ Upstream commit 066baf92bed934c9fb4bcee97a193f47aa63431c ]

copy_mc_to_user() has the destination marked __user on powerpc, but not on
x86; the latter results in a sparse warning in lib/iov_iter.c.

Fix this by applying the tag on x86 too.

Fixes: ec6347bb43 ("x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}()")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20230925120309.1731676-3-dhowells@redhat.com
cc: Dan Williams <dan.j.williams@intel.com>
cc: Thomas Gleixner <tglx@linutronix.de>
cc: Ingo Molnar <mingo@redhat.com>
cc: Borislav Petkov <bp@alien8.de>
cc: Dave Hansen <dave.hansen@linux.intel.com>
cc: "H. Peter Anvin" <hpa@zytor.com>
cc: Alexander Viro <viro@zeniv.linux.org.uk>
cc: Jens Axboe <axboe@kernel.dk>
cc: Christoph Hellwig <hch@lst.de>
cc: Christian Brauner <christian@brauner.io>
cc: Matthew Wilcox <willy@infradead.org>
cc: Linus Torvalds <torvalds@linux-foundation.org>
cc: David Laight <David.Laight@ACULAB.COM>
cc: x86@kernel.org
cc: linux-block@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:58:52 +01:00
Linus Torvalds 2af9b20dbb Misc fixes:
- Fix a possible CPU hotplug deadlock bug caused by the new
    TSC synchronization code.
 
  - Fix a legacy PIC discovery bug that results in device troubles on
    affected systems, such as non-working keybards, etc.
 
  - Add a new Intel CPU model number to <asm/intel-family.h>.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-urgent-2023-10-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull misc x86 fixes from Ingo Molnar:

 - Fix a possible CPU hotplug deadlock bug caused by the new TSC
   synchronization code

 - Fix a legacy PIC discovery bug that results in device troubles on
   affected systems, such as non-working keybards, etc

 - Add a new Intel CPU model number to <asm/intel-family.h>

* tag 'x86-urgent-2023-10-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/tsc: Defer marking TSC unstable to a worker
  x86/i8259: Skip probing when ACPI/MADT advertises PCAT compatibility
  x86/cpu: Add model number for Intel Arrow Lake mobile processor
2023-10-28 08:15:07 -10:00
Thomas Gleixner bd94d86f49 x86/tsc: Defer marking TSC unstable to a worker
Tetsuo reported the following lockdep splat when the TSC synchronization
fails during CPU hotplug:

   tsc: Marking TSC unstable due to check_tsc_sync_source failed
  
   WARNING: inconsistent lock state
   inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
   ffffffff8cfa1c78 (watchdog_lock){?.-.}-{2:2}, at: clocksource_watchdog+0x23/0x5a0
   {IN-HARDIRQ-W} state was registered at:
     _raw_spin_lock_irqsave+0x3f/0x60
     clocksource_mark_unstable+0x1b/0x90
     mark_tsc_unstable+0x41/0x50
     check_tsc_sync_source+0x14f/0x180
     sysvec_call_function_single+0x69/0x90

   Possible unsafe locking scenario:
     lock(watchdog_lock);
     <Interrupt>
       lock(watchdog_lock);

   stack backtrace:
    _raw_spin_lock+0x30/0x40
    clocksource_watchdog+0x23/0x5a0
    run_timer_softirq+0x2a/0x50
    sysvec_apic_timer_interrupt+0x6e/0x90

The reason is the recent conversion of the TSC synchronization function
during CPU hotplug on the control CPU to a SMP function call. In case
that the synchronization with the upcoming CPU fails, the TSC has to be
marked unstable via clocksource_mark_unstable().

clocksource_mark_unstable() acquires 'watchdog_lock', but that lock is
taken with interrupts enabled in the watchdog timer callback to minimize
interrupt disabled time. That's obviously a possible deadlock scenario,

Before that change the synchronization function was invoked in thread
context so this could not happen.

As it is not crucical whether the unstable marking happens slightly
delayed, defer the call to a worker thread which avoids the lock context
problem.

Fixes: 9d349d47f0 ("x86/smpboot: Make TSC synchronization function call based")
Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87zg064ceg.ffs@tglx
2023-10-27 20:36:57 +02:00
Thomas Gleixner 128b0c9781 x86/i8259: Skip probing when ACPI/MADT advertises PCAT compatibility
David and a few others reported that on certain newer systems some legacy
interrupts fail to work correctly.

Debugging revealed that the BIOS of these systems leaves the legacy PIC in
uninitialized state which makes the PIC detection fail and the kernel
switches to a dummy implementation.

Unfortunately this fallback causes quite some code to fail as it depends on
checks for the number of legacy PIC interrupts or the availability of the
real PIC.

In theory there is no reason to use the PIC on any modern system when
IO/APIC is available, but the dependencies on the related checks cannot be
resolved trivially and on short notice. This needs lots of analysis and
rework.

The PIC detection has been added to avoid quirky checks and force selection
of the dummy implementation all over the place, especially in VM guest
scenarios. So it's not an option to revert the relevant commit as that
would break a lot of other scenarios.

One solution would be to try to initialize the PIC on detection fail and
retry the detection, but that puts the burden on everything which does not
have a PIC.

Fortunately the ACPI/MADT table header has a flag field, which advertises
in bit 0 that the system is PCAT compatible, which means it has a legacy
8259 PIC.

Evaluate that bit and if set avoid the detection routine and keep the real
PIC installed, which then gets initialized (for nothing) and makes the rest
of the code with all the dependencies work again.

Fixes: e179f69141 ("x86, irq, pic: Probe for legacy PIC and set legacy_pic appropriately")
Reported-by: David Lazar <dlazar@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: David Lazar <dlazar@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Cc: stable@vger.kernel.org
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218003
Link: https://lore.kernel.org/r/875y2u5s8g.ffs@tglx
2023-10-27 20:36:49 +02:00
Tony Luck b99d70c0d1 x86/cpu: Add model number for Intel Arrow Lake mobile processor
For "reasons" Intel has code-named this CPU with a "_H" suffix.

[ dhansen: As usual, apply this and send it upstream quickly to
	   make it easier for anyone who is doing work that
	   consumes this. ]

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/20231025202513.12358-1-tony.luck%40intel.com
2023-10-27 10:19:26 -07:00
Linus Torvalds 0df072ab65 Take care of a race between when the #VC exception is raised and when
the guest kernel gets to emulate certain instructions in SEV-{ES,SNP}
 guests by:
 
 - disabling emulation of MMIO instructions when coming from user mode
 
 - checking the IO permission bitmap before emulating IO instructions and
   verifying the memory operands of INS/OUTS insns.
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Merge tag 'sev_fixes_for_v6.6' of //git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Borislav Petkov:
 "Take care of a race between when the #VC exception is raised and when
  the guest kernel gets to emulate certain instructions in SEV-{ES,SNP}
  guests by:

   - disabling emulation of MMIO instructions when coming from user mode

   - checking the IO permission bitmap before emulating IO instructions
     and verifying the memory operands of INS/OUTS insns"

* tag 'sev_fixes_for_v6.6' of //git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sev: Check for user-space IOIO pointing to kernel space
  x86/sev: Check IOBM for IOIO exceptions from user-space
  x86/sev: Disable MMIO emulation from user mode
2023-10-19 18:12:08 -07:00
Joerg Roedel 63e44bc520 x86/sev: Check for user-space IOIO pointing to kernel space
Check the memory operand of INS/OUTS before emulating the instruction.
The #VC exception can get raised from user-space, but the memory operand
can be manipulated to access kernel memory before the emulation actually
begins and after the exception handler has run.

  [ bp: Massage commit message. ]

Fixes: 597cfe4821 ("x86/boot/compressed/64: Setup a GHCB-based VC Exception handler")
Reported-by: Tom Dohrmann <erbse.13@gmx.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
2023-10-17 10:58:16 +02:00
Linus Torvalds 86d6a628a2 ARM:
- Fix the handling of the phycal timer offset when FEAT_ECV
   and CNTPOFF_EL2 are implemented.
 
 - Restore the functionnality of Permission Indirection that
   was broken by the Fine Grained Trapping rework
 
 - Cleanup some PMU event sharing code
 
 MIPS:
 
 - Fix W=1 build.
 
 s390:
 
 - One small fix for gisa to avoid stalls.
 
 x86:
 
 - Truncate writes to PMU counters to the counter's width to avoid spurious
   overflows when emulating counter events in software.
 
 - Set the LVTPC entry mask bit when handling a PMI (to match Intel-defined
   architectural behavior).
 
 - Treat KVM_REQ_PMI as a wake event instead of queueing host IRQ work to
   kick the guest out of emulated halt.
 
 - Fix for loading XSAVE state from an old kernel into a new one.
 
 - Fixes for AMD AVIC
 
 selftests:
 
 - Play nice with %llx when formatting guest printf and assert statements.
 
 - Clean up stale test metadata.
 
 - Zero-initialize structures in memslot perf test to workaround a suspected
   "may be used uninitialized" false positives from GCC.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "ARM:

   - Fix the handling of the phycal timer offset when FEAT_ECV and
     CNTPOFF_EL2 are implemented

   - Restore the functionnality of Permission Indirection that was
     broken by the Fine Grained Trapping rework

   - Cleanup some PMU event sharing code

  MIPS:

   - Fix W=1 build

  s390:

   - One small fix for gisa to avoid stalls

  x86:

   - Truncate writes to PMU counters to the counter's width to avoid
     spurious overflows when emulating counter events in software

   - Set the LVTPC entry mask bit when handling a PMI (to match
     Intel-defined architectural behavior)

   - Treat KVM_REQ_PMI as a wake event instead of queueing host IRQ work
     to kick the guest out of emulated halt

   - Fix for loading XSAVE state from an old kernel into a new one

   - Fixes for AMD AVIC

  selftests:

   - Play nice with %llx when formatting guest printf and assert
     statements

   - Clean up stale test metadata

   - Zero-initialize structures in memslot perf test to workaround a
     suspected 'may be used uninitialized' false positives from GCC"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (21 commits)
  KVM: arm64: timers: Correctly handle TGE flip with CNTPOFF_EL2
  KVM: arm64: POR{E0}_EL1 do not need trap handlers
  KVM: arm64: Add nPIR{E0}_EL1 to HFG traps
  KVM: MIPS: fix -Wunused-but-set-variable warning
  KVM: arm64: pmu: Drop redundant check for non-NULL kvm_pmu_events
  KVM: SVM: Fix build error when using -Werror=unused-but-set-variable
  x86: KVM: SVM: refresh AVIC inhibition in svm_leave_nested()
  x86: KVM: SVM: add support for Invalid IPI Vector interception
  x86: KVM: SVM: always update the x2avic msr interception
  KVM: selftests: Force load all supported XSAVE state in state test
  KVM: selftests: Load XSAVE state into untouched vCPU during state test
  KVM: selftests: Touch relevant XSAVE state in guest for state test
  KVM: x86: Constrain guest-supported xfeatures only at KVM_GET_XSAVE{2}
  x86/fpu: Allow caller to constrain xfeatures when copying to uabi buffer
  KVM: selftests: Zero-initialize entire test_result in memslot perf test
  KVM: selftests: Remove obsolete and incorrect test case metadata
  KVM: selftests: Treat %llx like %lx when formatting guest printf
  KVM: x86/pmu: Synthesize at most one PMI per VM-exit
  KVM: x86: Mask LVTPC when handling a PMI
  KVM: x86/pmu: Truncate counter value to allowed width on write
  ...
2023-10-16 18:34:17 -07:00
Linus Torvalds fbe1bf1e5f Revert "x86/smp: Put CPUs into INIT on shutdown if possible"
This reverts commit 45e34c8af5, and the
two subsequent fixes to it:

  3f874c9b2a ("x86/smp: Don't send INIT to non-present and non-booted CPUs")
  b1472a60a5 ("x86/smp: Don't send INIT to boot CPU")

because it seems to result in hung machines at shutdown.  Particularly
some Dell machines, but Thomas says

 "The rest seems to be Lenovo and Sony with Alderlake/Raptorlake CPUs -
  at least that's what I could figure out from the various bug reports.

  I don't know which CPUs the DELL machines have, so I can't say it's a
  pattern.

  I agree with the revert for now"

Ashok Raj chimes in:

 "There was a report (probably this same one), and it turns out it was a
  bug in the BIOS SMI handler.

  The client BIOS's were waiting for the lowest APICID to be the SMI
  rendevous master. If this is MeteorLake, the BSP wasn't the one with
  the lowest APIC and it triped here.

  The BIOS change is also being pushed to others for assimilation :)

  Server BIOS's had this correctly for a while now"

and it does look likely to be some bad interaction between SMI and the
non-BSP cores having put into INIT (and thus unresponsive until reset).

Link: https://bbs.archlinux.org/viewtopic.php?pid=2124429
Link: https://www.reddit.com/r/openSUSE/comments/16qq99b/tumbleweed_shutdown_did_not_finish_completely/
Link: https://forum.artixlinux.org/index.php/topic,5997.0.html
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2241279
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-10-15 12:02:02 -07:00
Linus Torvalds ddf2085598 Fix a Longsoon build warning by harmonizing the arch_[un]register_cpu()
prototypes between architectures.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'smp-urgent-2023-10-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull CPU hotplug fix from Ingo Molnar:
 "Fix a Longsoon build warning by harmonizing the
  arch_[un]register_cpu() prototypes between architectures"

* tag 'smp-urgent-2023-10-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu-hotplug: Provide prototypes for arch CPU registration
2023-10-15 08:44:56 -07:00
Paolo Bonzini 88e4cd893f KVM x86/pmu fixes for 6.6:
- Truncate writes to PMU counters to the counter's width to avoid spurious
    overflows when emulating counter events in software.
 
  - Set the LVTPC entry mask bit when handling a PMI (to match Intel-defined
    architectural behavior).
 
  - Treat KVM_REQ_PMI as a wake event instead of queueing host IRQ work to
    kick the guest out of emulated halt.
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Merge tag 'kvm-x86-pmu-6.6-fixes' of https://github.com/kvm-x86/linux into HEAD

KVM x86/pmu fixes for 6.6:

 - Truncate writes to PMU counters to the counter's width to avoid spurious
   overflows when emulating counter events in software.

 - Set the LVTPC entry mask bit when handling a PMI (to match Intel-defined
   architectural behavior).

 - Treat KVM_REQ_PMI as a wake event instead of queueing host IRQ work to
   kick the guest out of emulated halt.
2023-10-15 08:24:18 -04:00
Linus Torvalds dc9b2e683b Fix a false-positive KASAN warning, fix an AMD erratum on Zen4 CPUs,
and fix kernel-doc build warnings.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-urgent-2023-10-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:
 "Fix a false-positive KASAN warning, fix an AMD erratum on Zen4 CPUs,
  and fix kernel-doc build warnings"

* tag 'x86-urgent-2023-10-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/alternatives: Disable KASAN in apply_alternatives()
  x86/cpu: Fix AMD erratum #1485 on Zen4-based CPUs
  x86/resctrl: Fix kernel-doc warnings
2023-10-14 15:32:20 -07:00
Linus Torvalds 23931d9353 Fix an LBR sampling bug.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-urgent-2023-10-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 perf event fix from Ingo Molnar:
 "Fix an LBR sampling bug"

* tag 'perf-urgent-2023-10-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/lbr: Filter vsyscall addresses
2023-10-14 15:09:55 -07:00
Kirill A. Shutemov d35652a5fc x86/alternatives: Disable KASAN in apply_alternatives()
Fei has reported that KASAN triggers during apply_alternatives() on
a 5-level paging machine:

	BUG: KASAN: out-of-bounds in rcu_is_watching()
	Read of size 4 at addr ff110003ee6419a0 by task swapper/0/0
	...
	__asan_load4()
	rcu_is_watching()
	trace_hardirqs_on()
	text_poke_early()
	apply_alternatives()
	...

On machines with 5-level paging, cpu_feature_enabled(X86_FEATURE_LA57)
gets patched. It includes KASAN code, where KASAN_SHADOW_START depends on
__VIRTUAL_MASK_SHIFT, which is defined with cpu_feature_enabled().

KASAN gets confused when apply_alternatives() patches the
KASAN_SHADOW_START users. A test patch that makes KASAN_SHADOW_START
static, by replacing __VIRTUAL_MASK_SHIFT with 56, works around the issue.

Fix it for real by disabling KASAN while the kernel is patching alternatives.

[ mingo: updated the changelog ]

Fixes: 6657fca06e ("x86/mm: Allow to boot without LA57 if CONFIG_X86_5LEVEL=y")
Reported-by: Fei Yang <fei.yang@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20231012100424.1456-1-kirill.shutemov@linux.intel.com
2023-10-12 20:27:16 +02:00