Pull KVM updates from Paolo Bonzini:
"For x86, there is a new alternative and (in the future) more scalable
implementation of extended page tables that does not need a reverse
map from guest physical addresses to host physical addresses.
For now it is disabled by default because it is still lacking a few of
the existing MMU's bells and whistles. However it is a very solid
piece of work and it is already available for people to hammer on it.
Other updates:
ARM:
- New page table code for both hypervisor and guest stage-2
- Introduction of a new EL2-private host context
- Allow EL2 to have its own private per-CPU variables
- Support of PMU event filtering
- Complete rework of the Spectre mitigation
PPC:
- Fix for running nested guests with in-kernel IRQ chip
- Fix race condition causing occasional host hard lockup
- Minor cleanups and bugfixes
x86:
- allow trapping unknown MSRs to userspace
- allow userspace to force #GP on specific MSRs
- INVPCID support on AMD
- nested AMD cleanup, on demand allocation of nested SVM state
- hide PV MSRs and hypercalls for features not enabled in CPUID
- new test for MSR_IA32_TSC writes from host and guest
- cleanups: MMU, CPUID, shared MSRs
- LAPIC latency optimizations ad bugfixes"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (232 commits)
kvm: x86/mmu: NX largepage recovery for TDP MMU
kvm: x86/mmu: Don't clear write flooding count for direct roots
kvm: x86/mmu: Support MMIO in the TDP MMU
kvm: x86/mmu: Support write protection for nesting in tdp MMU
kvm: x86/mmu: Support disabling dirty logging for the tdp MMU
kvm: x86/mmu: Support dirty logging for the TDP MMU
kvm: x86/mmu: Support changed pte notifier in tdp MMU
kvm: x86/mmu: Add access tracking for tdp_mmu
kvm: x86/mmu: Support invalidate range MMU notifier for TDP MMU
kvm: x86/mmu: Allocate struct kvm_mmu_pages for all pages in TDP MMU
kvm: x86/mmu: Add TDP MMU PF handler
kvm: x86/mmu: Remove disallowed_hugepage_adjust shadow_walk_iterator arg
kvm: x86/mmu: Support zapping SPTEs in the TDP MMU
KVM: Cache as_id in kvm_memory_slot
kvm: x86/mmu: Add functions to handle changed TDP SPTEs
kvm: x86/mmu: Allocate and free TDP MMU roots
kvm: x86/mmu: Init / Uninit the TDP MMU
kvm: x86/mmu: Introduce tdp_iter
KVM: mmu: extract spte.h and spte.c
KVM: mmu: Separate updating a PTE from kvm_set_pte_rmapp
...
KVM was switched to interrupt-based mechanism for 'page ready' event
delivery in Linux-5.8 (see commit 2635b5c4a0 ("KVM: x86: interrupt based
APF 'page ready' event delivery")) and #PF (ab)use for 'page ready' event
delivery was removed. Linux guest switched to this new mechanism
exclusively in 5.9 (see commit b1d405751c ("KVM: x86: Switch KVM guest to
using interrupts for page ready APF delivery")) so it is not possible to
get #PF for a 'page ready' event even when the guest is running on top
of an older KVM (APF mechanism won't be enabled). Update the comment in
exc_page_fault() to reflect the new reality.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20201002154313.1505327-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pull ACPI updates from Rafael Wysocki:
"These add support for generic initiator-only proximity domains to the
ACPI NUMA code and the architectures using it, clean up some
non-ACPICA code referring to debug facilities from ACPICA, reduce the
overhead related to accessing GPE registers, add a new DPTF (Dynamic
Power and Thermal Framework) participant driver, update the ACPICA
code in the kernel to upstream revision 20200925, add a new ACPI
backlight whitelist entry, fix a few assorted issues and clean up some
code.
Specifics:
- Add support for generic initiator-only proximity domains to the
ACPI NUMA code and the architectures using it (Jonathan Cameron)
- Clean up some non-ACPICA code referring to debug facilities from
ACPICA that are not actually used in there (Hanjun Guo)
- Add new DPTF driver for the PCH FIVR participant (Srinivas
Pandruvada)
- Reduce overhead related to accessing GPE registers in ACPICA and
the OS interface layer and make it possible to access GPE registers
using logical addresses if they are memory-mapped (Rafael Wysocki)
- Update the ACPICA code in the kernel to upstream revision 20200925
including changes as follows:
+ Add predefined names from the SMBus sepcification (Bob Moore)
+ Update acpi_help UUID list (Bob Moore)
+ Return exceptions for string-to-integer conversions in iASL (Bob
Moore)
+ Add a new "ALL <NameSeg>" debugger command (Bob Moore)
+ Add support for 64 bit risc-v compilation (Colin Ian King)
+ Do assorted cleanups (Bob Moore, Colin Ian King, Randy Dunlap)
- Add new ACPI backlight whitelist entry for HP 635 Notebook (Alex
Hung)
- Move TPS68470 OpRegion driver to drivers/acpi/pmic/ and split out
Kconfig and Makefile specific for ACPI PMIC (Andy Shevchenko)
- Clean up the ACPI SoC driver for AMD SoCs (Hanjun Guo)
- Add missing config_item_put() to fix refcount leak (Hanjun Guo)
- Drop lefrover field from struct acpi_memory_device (Hanjun Guo)
- Make the ACPI extlog driver check for RDMSR failures (Ben
Hutchings)
- Fix handling of lid state changes in the ACPI button driver when
input device is closed (Dmitry Torokhov)
- Fix several assorted build issues (Barnabás Pőcze, John Garry,
Nathan Chancellor, Tian Tao)
- Drop unused inline functions and reduce code duplication by using
kobj_to_dev() in the NFIT parsing code (YueHaibing, Wang Qing)
- Serialize tools/power/acpi Makefile (Thomas Renninger)"
* tag 'acpi-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (64 commits)
ACPICA: Update version to 20200925 Version 20200925
ACPICA: Remove unnecessary semicolon
ACPICA: Debugger: Add a new command: "ALL <NameSeg>"
ACPICA: iASL: Return exceptions for string-to-integer conversions
ACPICA: acpi_help: Update UUID list
ACPICA: Add predefined names found in the SMBus sepcification
ACPICA: Tree-wide: fix various typos and spelling mistakes
ACPICA: Drop the repeated word "an" in a comment
ACPICA: Add support for 64 bit risc-v compilation
ACPI: button: fix handling lid state changes when input device closed
tools/power/acpi: Serialize Makefile
ACPI: scan: Replace ACPI_DEBUG_PRINT() with pr_debug()
ACPI: memhotplug: Remove 'state' from struct acpi_memory_device
ACPI / extlog: Check for RDMSR failure
ACPI: Make acpi_evaluate_dsm() prototype consistent
docs: mm: numaperf.rst Add brief description for access class 1.
node: Add access1 class to represent CPU to memory characteristics
ACPI: HMAT: Fix handling of changes from ACPI 6.2 to ACPI 6.3
ACPI: Let ACPI know we support Generic Initiator Affinity Structures
x86: Support Generic Initiator only proximity domains
...
Pull x86 SEV-ES support from Borislav Petkov:
"SEV-ES enhances the current guest memory encryption support called SEV
by also encrypting the guest register state, making the registers
inaccessible to the hypervisor by en-/decrypting them on world
switches. Thus, it adds additional protection to Linux guests against
exfiltration, control flow and rollback attacks.
With SEV-ES, the guest is in full control of what registers the
hypervisor can access. This is provided by a guest-host exchange
mechanism based on a new exception vector called VMM Communication
Exception (#VC), a new instruction called VMGEXIT and a shared
Guest-Host Communication Block which is a decrypted page shared
between the guest and the hypervisor.
Intercepts to the hypervisor become #VC exceptions in an SEV-ES guest
so in order for that exception mechanism to work, the early x86 init
code needed to be made able to handle exceptions, which, in itself,
brings a bunch of very nice cleanups and improvements to the early
boot code like an early page fault handler, allowing for on-demand
building of the identity mapping. With that, !KASLR configurations do
not use the EFI page table anymore but switch to a kernel-controlled
one.
The main part of this series adds the support for that new exchange
mechanism. The goal has been to keep this as much as possibly separate
from the core x86 code by concentrating the machinery in two
SEV-ES-specific files:
arch/x86/kernel/sev-es-shared.c
arch/x86/kernel/sev-es.c
Other interaction with core x86 code has been kept at minimum and
behind static keys to minimize the performance impact on !SEV-ES
setups.
Work by Joerg Roedel and Thomas Lendacky and others"
* tag 'x86_seves_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (73 commits)
x86/sev-es: Use GHCB accessor for setting the MMIO scratch buffer
x86/sev-es: Check required CPU features for SEV-ES
x86/efi: Add GHCB mappings when SEV-ES is active
x86/sev-es: Handle NMI State
x86/sev-es: Support CPU offline/online
x86/head/64: Don't call verify_cpu() on starting APs
x86/smpboot: Load TSS and getcpu GDT entry before loading IDT
x86/realmode: Setup AP jump table
x86/realmode: Add SEV-ES specific trampoline entry point
x86/vmware: Add VMware-specific handling for VMMCALL under SEV-ES
x86/kvm: Add KVM-specific VMMCALL handling under SEV-ES
x86/paravirt: Allow hypervisor-specific VMMCALL handling under SEV-ES
x86/sev-es: Handle #DB Events
x86/sev-es: Handle #AC Events
x86/sev-es: Handle VMMCALL Events
x86/sev-es: Handle MWAIT/MWAITX Events
x86/sev-es: Handle MONITOR/MONITORX Events
x86/sev-es: Handle INVD Events
x86/sev-es: Handle RDPMC Events
x86/sev-es: Handle RDTSC(P) Events
...
Pull x86 mm updates from Ingo Molnar:
"Do not sync vmalloc/ioremap mappings on x86-64 kernels.
Hopefully now without the bugs!"
* tag 'x86-mm-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm/64: Update comment in preallocate_vmalloc_pages()
x86/mm/64: Do not sync vmalloc/ioremap mappings
Pull x86 platform updates from Borislav Petkov:
- Cleanup different aspects of the UV code and start adding support for
the new UV5 class of systems (Mike Travis)
- Use a flexible array for a dynamically sized struct uv_rtc_timer_head
(Gustavo A. R. Silva)
* tag 'x86_platform_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/platform/uv: Update Copyrights to conform to HPE standards
x86/platform/uv: Update for UV5 NMI MMR changes
x86/platform/uv: Update UV5 TSC checking
x86/platform/uv: Update node present counting
x86/platform/uv: Update UV5 MMR references in UV GRU
x86/platform/uv: Adjust GAM MMR references affected by UV5 updates
x86/platform/uv: Update MMIOH references based on new UV5 MMRs
x86/platform/uv: Add and decode Arch Type in UVsystab
x86/platform/uv: Add UV5 direct references
x86/platform/uv: Update UV MMRs for UV5
drivers/misc/sgi-xp: Adjust references in UV kernel modules
x86/platform/uv: Remove SCIR MMR references for UV systems
x86/platform/uv: Remove UV BAU TLB Shootdown Handler
x86/uv/time: Use a flexible array in struct uv_rtc_timer_head
Pull x86 cpu updates from Borislav Petkov:
- Add support for hardware-enforced cache coherency on AMD which
obviates the need to flush cachelines before changing the PTE
encryption bit (Krish Sadhukhan)
- Add Centaur initialization support for families >= 7 (Tony W Wang-oc)
- Add a feature flag for, and expose TSX suspend load tracking feature
to KVM (Cathy Zhang)
- Emulate SLDT and STR so that windows programs don't crash on UMIP
machines (Brendan Shanks and Ricardo Neri)
- Use the new SERIALIZE insn on Intel hardware which supports it
(Ricardo Neri)
- Misc cleanups and fixes
* tag 'x86_cpu_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
KVM: SVM: Don't flush cache if hardware enforces cache coherency across encryption domains
x86/mm/pat: Don't flush cache if hardware enforces cache coherency across encryption domnains
x86/cpu: Add hardware-enforced cache coherency as a CPUID feature
x86/cpu/centaur: Add Centaur family >=7 CPUs initialization support
x86/cpu/centaur: Replace two-condition switch-case with an if statement
x86/kvm: Expose TSX Suspend Load Tracking feature
x86/cpufeatures: Enumerate TSX suspend load address tracking instructions
x86/umip: Add emulation/spoofing for SLDT and STR instructions
x86/cpu: Fix typos and improve the comments in sync_core()
x86/cpu: Use XGETBV and XSETBV mnemonics in fpu/internal.h
x86/cpu: Use SERIALIZE in sync_core() when available
Pull RAS updates from Borislav Petkov:
- Extend the recovery from MCE in kernel space also to processes which
encounter an MCE in kernel space but while copying from user memory
by sending them a SIGBUS on return to user space and umapping the
faulty memory, by Tony Luck and Youquan Song.
- memcpy_mcsafe() rework by splitting the functionality into
copy_mc_to_user() and copy_mc_to_kernel(). This, as a result, enables
support for new hardware which can recover from a machine check
encountered during a fast string copy and makes that the default and
lets the older hardware which does not support that advance recovery,
opt in to use the old, fragile, slow variant, by Dan Williams.
- New AMD hw enablement, by Yazen Ghannam and Akshay Gupta.
- Do not use MSR-tracing accessors in #MC context and flag any fault
while accessing MCA architectural MSRs as an architectural violation
with the hope that such hw/fw misdesigns are caught early during the
hw eval phase and they don't make it into production.
- Misc fixes, improvements and cleanups, as always.
* tag 'ras_updates_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mce: Allow for copy_mc_fragile symbol checksum to be generated
x86/mce: Decode a kernel instruction to determine if it is copying from user
x86/mce: Recover from poison found while copying from user space
x86/mce: Avoid tail copy when machine check terminated a copy from user
x86/mce: Add _ASM_EXTABLE_CPY for copy user access
x86/mce: Provide method to find out the type of an exception handler
x86/mce: Pass pointer to saved pt_regs to severity calculation routines
x86/copy_mc: Introduce copy_mc_enhanced_fast_string()
x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}()
x86/mce: Drop AMD-specific "DEFERRED" case from Intel severity rule list
x86/mce: Add Skylake quirk for patrol scrub reported errors
RAS/CEC: Convert to DEFINE_SHOW_ATTRIBUTE()
x86/mce: Annotate mce_rd/wrmsrl() with noinstr
x86/mce/dev-mcelog: Do not update kflags on AMD systems
x86/mce: Stop mce_reign() from re-computing severity for every CPU
x86/mce: Make mce_rdmsrl() panic on an inaccessible MSR
x86/mce: Increase maximum number of banks to 64
x86/mce: Delay clearing IA32_MCG_STATUS to the end of do_machine_check()
x86/MCE/AMD, EDAC/mce_amd: Remove struct smca_hwid.xec_bitmap
RAS/CEC: Fix cec_init() prototype
All instructions copying data between kernel and user memory
are tagged with either _ASM_EXTABLE_UA or _ASM_EXTABLE_CPY
entries in the exception table. ex_fault_handler_type() returns
EX_HANDLER_UACCESS for both of these.
Recovery is only possible when the machine check was triggered
on a read from user memory. In this case the same strategy for
recovery applies as if the user had made the access in ring3. If
the fault was in kernel memory while copying to user there is no
current recovery plan.
For MOV and MOVZ instructions a full decode of the instruction
is done to find the source address. For MOVS instructions
the source address is in the %rsi register. The function
fault_in_kernel_space() determines whether the source address is
kernel or user, upgrade it from "static" so it can be used here.
Co-developed-by: Youquan Song <youquan.song@intel.com>
Signed-off-by: Youquan Song <youquan.song@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201006210910.21062-7-tony.luck@intel.com
_ASM_EXTABLE_UA is a general exception entry to record the exception fixup
for all exception spots between kernel and user space access.
To enable recovery from machine checks while coping data from user
addresses it is necessary to be able to distinguish the places that are
looping copying data from those that copy a single byte/word/etc.
Add a new macro _ASM_EXTABLE_CPY and use it in place of _ASM_EXTABLE_UA
in the copy functions.
Record the exception reason number to regs->ax at
ex_handler_uaccess which is used to check MCE triggered.
The new fixup routine ex_handler_copy() is almost an exact copy of
ex_handler_uaccess() The difference is that it sets regs->ax to the trap
number. Following patches use this to avoid trying to copy remaining
bytes from the tail of the copy and possibly hitting the poison again.
New mce.kflags bit MCE_IN_KERNEL_COPYIN will be used by mce_severity()
calculation to indicate that a machine check is recoverable because the
kernel was copying from user space.
Signed-off-by: Youquan Song <youquan.song@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201006210910.21062-4-tony.luck@intel.com
Avoid a proliferation of ex_has_*_handler() functions by having just
one function that returns the type of the handler (if any).
Drop the __visible attribute for this function. It is not called
from assembler so the attribute is not necessary.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201006210910.21062-3-tony.luck@intel.com
The Broadcast Assist Unit (BAU) TLB shootdown handler is being rewritten
to become the UV BAU APIC driver. It is designed to speed up sending
IPIs to selective CPUs within the system. Remove the current TLB
shutdown handler (tlb_uv.c) file and a couple of kernel hooks in the
interim.
Signed-off-by: Mike Travis <mike.travis@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Link: https://lkml.kernel.org/r/20201005203929.148656-2-mike.travis@hpe.com
In common with memoryless domains only register GI domains
if the proximity node is not online. If a domain is already
a memory containing domain, or a memoryless domain there is
nothing to do just because it also contains a Generic Initiator.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In some hardware implementations, coherency between the encrypted and
unencrypted mappings of the same physical page is enforced. In such a
system, it is not required for software to flush the page from all CPU
caches in the system prior to changing the value of the C-bit for the
page. So check that bit before flushing the cache.
[ bp: Massage commit message. ]
Suggested-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200917212038.5090-3-krish.sadhukhan@oracle.com
Add the infrastructure to handle #VC exceptions when the kernel runs on
virtual addresses and has mapped a GHCB. This handler will be used until
the runtime #VC handler takes over.
Since the handler runs very early, disable instrumentation for sev-es.c.
[ bp: Make vc_ghcb_invalidate() __always_inline so that it can be
inlined in noinstr functions like __sev_es_nmi_complete(). ]
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200908123816.GB3764@8bytes.org
Refactor the message printed to the kernel log which indicates whether
SEV or SME, etc is active. This will scale better in the future when
more memory encryption features might be added. Also add SEV-ES to the
list of features.
[ bp: Massage. ]
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20200907131613.12703-38-joro@8bytes.org
One can not simply remove vmalloc faulting on x86-32. Upstream
commit: 7f0a002b5a ("x86/mm: remove vmalloc faulting")
removed it on x86 alltogether because previously the
arch_sync_kernel_mappings() interface was introduced. This interface
added synchronization of vmalloc/ioremap page-table updates to all
page-tables in the system at creation time and was thought to make
vmalloc faulting obsolete.
But that assumption was incredibly naive.
It turned out that there is a race window between the time the vmalloc
or ioremap code establishes a mapping and the time it synchronizes
this change to other page-tables in the system.
During this race window another CPU or thread can establish a vmalloc
mapping which uses the same intermediate page-table entries (e.g. PMD
or PUD) and does no synchronization in the end, because it found all
necessary mappings already present in the kernel reference page-table.
But when these intermediate page-table entries are not yet
synchronized, the other CPU or thread will continue with a vmalloc
address that is not yet mapped in the page-table it currently uses,
causing an unhandled page fault and oops like below:
BUG: unable to handle page fault for address: fe80c000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
*pde = 33183067 *pte = a8648163
Oops: 0002 [#1] SMP
CPU: 1 PID: 13514 Comm: cve-2017-17053 Tainted: G
...
Call Trace:
ldt_dup_context+0x66/0x80
dup_mm+0x2b3/0x480
copy_process+0x133b/0x15c0
_do_fork+0x94/0x3e0
__ia32_sys_clone+0x67/0x80
__do_fast_syscall_32+0x3f/0x70
do_fast_syscall_32+0x29/0x60
do_SYSENTER_32+0x15/0x20
entry_SYSENTER_32+0x9f/0xf2
EIP: 0xb7eef549
So the arch_sync_kernel_mappings() interface is racy, but removing it
would mean to re-introduce the vmalloc_sync_all() interface, which is
even more awful. Keep arch_sync_kernel_mappings() in place and catch
the race condition in the page-fault handler instead.
Do a partial revert of above commit to get vmalloc faulting on x86-32
back in place.
Fixes: 7f0a002b5a ("x86/mm: remove vmalloc faulting")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200902155904.17544-1-joro@8bytes.org
Pull locking fixes from Thomas Gleixner:
"A set of fixes for lockdep, tracing and RCU:
- Prevent recursion by using raw_cpu_* operations
- Fixup the interrupt state in the cpu idle code to be consistent
- Push rcu_idle_enter/exit() invocations deeper into the idle path so
that the lock operations are inside the RCU watching sections
- Move trace_cpu_idle() into generic code so it's called before RCU
goes idle.
- Handle raw_local_irq* vs. local_irq* operations correctly
- Move the tracepoints out from under the lockdep recursion handling
which turned out to be fragile and inconsistent"
* tag 'locking-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
lockdep,trace: Expose tracepoints
lockdep: Only trace IRQ edges
mips: Implement arch_irqs_disabled()
arm64: Implement arch_irqs_disabled()
nds32: Implement arch_irqs_disabled()
locking/lockdep: Cleanup
x86/entry: Remove unused THUNKs
cpuidle: Move trace_cpu_idle() into generic code
cpuidle: Make CPUIDLE_FLAG_TLB_FLUSHED generic
sched,idle,rcu: Push rcu_idle deeper into the idle path
cpuidle: Fixup IRQ state
lockdep: Use raw_cpu_*() for per-cpu variables
Remove the code to sync the vmalloc and ioremap ranges for x86-64. The
page-table pages are all pre-allocated so that synchronization is
no longer necessary.
This is a patch that already went into the kernel as:
commit 8bb9bf242d ("x86/mm/64: Do not sync vmalloc/ioremap mappings")
But it had to be reverted later because it unveiled a bug from:
commit 6eb82f9940 ("x86/mm: Pre-allocate P4D/PUD pages for vmalloc area")
The bug in that commit causes the P4D/PUD pages not to be correctly
allocated, making the synchronization still necessary. That issue got
fixed meanwhile upstream:
commit 995909a4e2 ("x86/mm/64: Do not dereference non-present PGD entries")
With that fix it is safe again to remove the page-table synchronization
for vmalloc/ioremap ranges on x86-64.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200814151947.26229-2-joro@8bytes.org
Some of our servers spend significant time at kernel boot initializing
memory block sysfs directories and then creating symlinks between them and
the corresponding nodes. The slowness happens because the machines get
stuck with the smallest supported memory block size on x86 (128M), which
results in 16,288 directories to cover the 2T of installed RAM. The
search for each memory block is noticeable even with commit 4fb6eabf10
("drivers/base/memory.c: cache memory blocks in xarray to accelerate
lookup").
Commit 078eb6aa50 ("x86/mm/memory_hotplug: determine block size based on
the end of boot memory") chooses the block size based on alignment with
memory end. That addresses hotplug failures in qemu guests, but for bare
metal systems whose memory end isn't aligned to even the smallest size, it
leaves them at 128M.
Make kernels that aren't running on a hypervisor use the largest supported
size (2G) to minimize overhead on big machines. Kernel boot goes 7%
faster on the aforementioned servers, shaving off half a second.
[daniel.m.jordan@oracle.com: v3]
Link: http://lkml.kernel.org/r/20200714205450.945834-1-daniel.m.jordan@oracle.com
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200609225451.3542648-1-daniel.m.jordan@oracle.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull locking updates from Thomas Gleixner:
"A set of locking fixes and updates:
- Untangle the header spaghetti which causes build failures in
various situations caused by the lockdep additions to seqcount to
validate that the write side critical sections are non-preemptible.
- The seqcount associated lock debug addons which were blocked by the
above fallout.
seqcount writers contrary to seqlock writers must be externally
serialized, which usually happens via locking - except for strict
per CPU seqcounts. As the lock is not part of the seqcount, lockdep
cannot validate that the lock is held.
This new debug mechanism adds the concept of associated locks.
sequence count has now lock type variants and corresponding
initializers which take a pointer to the associated lock used for
writer serialization. If lockdep is enabled the pointer is stored
and write_seqcount_begin() has a lockdep assertion to validate that
the lock is held.
Aside of the type and the initializer no other code changes are
required at the seqcount usage sites. The rest of the seqcount API
is unchanged and determines the type at compile time with the help
of _Generic which is possible now that the minimal GCC version has
been moved up.
Adding this lockdep coverage unearthed a handful of seqcount bugs
which have been addressed already independent of this.
While generally useful this comes with a Trojan Horse twist: On RT
kernels the write side critical section can become preemtible if
the writers are serialized by an associated lock, which leads to
the well known reader preempts writer livelock. RT prevents this by
storing the associated lock pointer independent of lockdep in the
seqcount and changing the reader side to block on the lock when a
reader detects that a writer is in the write side critical section.
- Conversion of seqcount usage sites to associated types and
initializers"
* tag 'locking-urgent-2020-08-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits)
locking/seqlock, headers: Untangle the spaghetti monster
locking, arch/ia64: Reduce <asm/smp.h> header dependencies by moving XTP bits into the new <asm/xtp.h> header
x86/headers: Remove APIC headers from <asm/smp.h>
seqcount: More consistent seqprop names
seqcount: Compress SEQCNT_LOCKNAME_ZERO()
seqlock: Fold seqcount_LOCKNAME_init() definition
seqlock: Fold seqcount_LOCKNAME_t definition
seqlock: s/__SEQ_LOCKDEP/__SEQ_LOCK/g
hrtimer: Use sequence counter with associated raw spinlock
kvm/eventfd: Use sequence counter with associated spinlock
userfaultfd: Use sequence counter with associated spinlock
NFSv4: Use sequence counter with associated spinlock
iocost: Use sequence counter with associated spinlock
raid5: Use sequence counter with associated spinlock
vfs: Use sequence counter with associated spinlock
timekeeping: Use sequence counter with associated raw spinlock
xfrm: policy: Use sequence counters with associated lock
netfilter: nft_set_rbtree: Use sequence counter with associated rwlock
netfilter: conntrack: Use sequence counter with associated spinlock
sched: tasks: Use sequence counter with associated spinlock
...
Pull Kbuild updates from Masahiro Yamada:
- run the checker (e.g. sparse) after the compiler
- remove unneeded cc-option tests for old compiler flags
- fix tar-pkg to install dtbs
- introduce ccflags-remove-y and asflags-remove-y syntax
- allow to trace functions in sub-directories of lib/
- introduce hostprogs-always-y and userprogs-always-y syntax
- various Makefile cleanups
* tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option base
kbuild: include scripts/Makefile.* only when relevant CONFIG is enabled
kbuild: introduce hostprogs-always-y and userprogs-always-y
kbuild: sort hostprogs before passing it to ifneq
kbuild: move host .so build rules to scripts/gcc-plugins/Makefile
kbuild: Replace HTTP links with HTTPS ones
kbuild: trace functions in subdirectories of lib/
kbuild: introduce ccflags-remove-y and asflags-remove-y
kbuild: do not export LDFLAGS_vmlinux
kbuild: always create directories of targets
powerpc/boot: add DTB to 'targets'
kbuild: buildtar: add dtbs support
kbuild: remove cc-option test of -ffreestanding
kbuild: remove cc-option test of -fno-stack-protector
Revert "kbuild: Create directory for target DTB"
kbuild: run the checker after the compiler
Merge misc updates from Andrew Morton:
- a few MM hotfixes
- kthread, tools, scripts, ntfs and ocfs2
- some of MM
Subsystems affected by this patch series: kthread, tools, scripts, ntfs,
ocfs2 and mm (hofixes, pagealloc, slab-generic, slab, slub, kcsan,
debug, pagecache, gup, swap, shmem, memcg, pagemap, mremap, mincore,
sparsemem, vmalloc, kasan, pagealloc, hugetlb and vmscan).
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (162 commits)
mm: vmscan: consistent update to pgrefill
mm/vmscan.c: fix typo
khugepaged: khugepaged_test_exit() check mmget_still_valid()
khugepaged: retract_page_tables() remember to test exit
khugepaged: collapse_pte_mapped_thp() protect the pmd lock
khugepaged: collapse_pte_mapped_thp() flush the right range
mm/hugetlb: fix calculation of adjust_range_if_pmd_sharing_possible
mm: thp: replace HTTP links with HTTPS ones
mm/page_alloc: fix memalloc_nocma_{save/restore} APIs
mm/page_alloc.c: skip setting nodemask when we are in interrupt
mm/page_alloc: fallbacks at most has 3 elements
mm/page_alloc: silence a KASAN false positive
mm/page_alloc.c: remove unnecessary end_bitidx for [set|get]_pfnblock_flags_mask()
mm/page_alloc.c: simplify pageblock bitmap access
mm/page_alloc.c: extract the common part in pfn_to_bitidx()
mm/page_alloc.c: replace the definition of NR_MIGRATETYPE_BITS with PB_migratetype_bits
mm/shuffle: remove dynamic reconfiguration
mm/memory_hotplug: document why shuffle_zone() is relevant
mm/page_alloc: remove nr_free_pagecache_pages()
mm: remove vm_total_pages
...
After removal of CONFIG_HAVE_MEMBLOCK_NODE_MAP we have two equivalent
functions that call memory_present() for each region in memblock.memory:
sparse_memory_present_with_active_regions() and membocks_present().
Moreover, all architectures have a call to either of these functions
preceding the call to sparse_init() and in the most cases they are called
one after the other.
Mark the regions from memblock.memory as present during sparce_init() by
making sparse_init() call memblocks_present(), make memblocks_present()
and memory_present() functions static and remove redundant
sparse_memory_present_with_active_regions() function.
Also remove no longer required HAVE_MEMORY_PRESENT configuration option.
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200712083130.22919-1-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: cleanup usage of <asm/pgalloc.h>"
Most architectures have very similar versions of pXd_alloc_one() and
pXd_free_one() for intermediate levels of page table. These patches add
generic versions of these functions in <asm-generic/pgalloc.h> and enable
use of the generic functions where appropriate.
In addition, functions declared and defined in <asm/pgalloc.h> headers are
used mostly by core mm and early mm initialization in arch and there is no
actual reason to have the <asm/pgalloc.h> included all over the place.
The first patch in this series removes unneeded includes of
<asm/pgalloc.h>
In the end it didn't work out as neatly as I hoped and moving
pXd_alloc_track() definitions to <asm-generic/pgalloc.h> would require
unnecessary changes to arches that have custom page table allocations, so
I've decided to move lib/ioremap.c to mm/ and make pgalloc-track.h local
to mm/.
This patch (of 8):
In most cases <asm/pgalloc.h> header is required only for allocations of
page table memory. Most of the .c files that include that header do not
use symbols declared in <asm/pgalloc.h> and do not require that header.
As for the other header files that used to include <asm/pgalloc.h>, it is
possible to move that include into the .c file that actually uses symbols
from <asm/pgalloc.h> and drop the include from the header file.
The process was somewhat automated using
sed -i -E '/[<"]asm\/pgalloc\.h/d' \
$(grep -L -w -f /tmp/xx \
$(git grep -E -l '[<"]asm/pgalloc\.h'))
where /tmp/xx contains all the symbols defined in
arch/*/include/asm/pgalloc.h.
[rppt@linux.ibm.com: fix powerpc warning]
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Link: http://lkml.kernel.org/r/20200627143453.31835-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200627143453.31835-2-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The code for preallocate_vmalloc_pages() was written under the
assumption that the p4d_offset() and pud_offset() functions will perform
present checks before dereferencing the parent entries.
This assumption is wrong an leads to a bug in the code which causes the
physical address found in the PGD be used as a page-table page, even if
the PGD is not present.
So the code flow currently is:
pgd = pgd_offset_k(addr);
p4d = p4d_offset(pgd, addr);
if (p4d_none(*p4d))
p4d = p4d_alloc(&init_mm, pgd, addr);
This lacks a check for pgd_none() at least, the correct flow would be:
pgd = pgd_offset_k(addr);
if (pgd_none(*pgd))
p4d = p4d_alloc(&init_mm, pgd, addr);
else
p4d = p4d_offset(pgd, addr);
But this is the same flow that the p4d_alloc() and the pud_alloc()
functions use internally, so there is no need to duplicate them.
Remove the p?d_none() checks from the function and just call into
p4d_alloc() and pud_alloc() to correctly pre-allocate the PGD entries.
Reported-and-tested-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Fixes: 6eb82f9940 ("x86/mm: Pre-allocate P4D/PUD pages for vmalloc area")
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 8bb9bf242d.
It seems the vmalloc page tables aren't always preallocated in all
situations, because Jason Donenfeld reports an oops with this commit:
BUG: unable to handle page fault for address: ffffe8ffffd00608
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP
CPU: 2 PID: 22 Comm: kworker/2:0 Not tainted 5.8.0+ #154
RIP: process_one_work+0x2c/0x2d0
Code: 41 56 41 55 41 54 55 48 89 f5 53 48 89 fb 48 83 ec 08 48 8b 06 4c 8b 67 40 49 89 c6 45 30 f6 a8 04 b8 00 00 00 00 4c 0f 44 f0 <49> 8b 46 08 44 8b a8 00 01 05
Call Trace:
worker_thread+0x4b/0x3b0
? rescuer_thread+0x360/0x360
kthread+0x116/0x140
? __kthread_create_worker+0x110/0x110
ret_from_fork+0x1f/0x30
CR2: ffffe8ffffd00608
and that page fault address is right in that vmalloc space, and we
clearly don't have a PGD/P4D entry for it.
Looking at the "Code:" line, the actual fault seems to come from the
'pwq->wq' dereference at the top of the process_one_work() function:
struct pool_workqueue *pwq = get_work_pwq(work);
struct worker_pool *pool = worker->pool;
bool cpu_intensive = pwq->wq->flags & WQ_CPU_INTENSIVE;
so 'struct pool_workqueue *pwq' is the allocation that hasn't been
synchronized across CPUs.
Just revert for now, while Joerg figures out the cause.
Reported-and-bisected-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86 conversion to generic entry code from Thomas Gleixner:
"The conversion of X86 syscall, interrupt and exception entry/exit
handling to the generic code.
Pretty much a straight-forward 1:1 conversion plus the consolidation
of the KVM handling of pending work before entering guest mode"
* tag 'x86-entry-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/kvm: Use __xfer_to_guest_mode_work_pending() in kvm_run_vcpu()
x86/kvm: Use generic xfer to guest work function
x86/entry: Cleanup idtentry_enter/exit
x86/entry: Use generic interrupt entry/exit code
x86/entry: Cleanup idtentry_entry/exit_user
x86/entry: Use generic syscall exit functionality
x86/entry: Use generic syscall entry function
x86/ptrace: Provide pt_regs helper for entry/exit
x86/entry: Move user return notifier out of loop
x86/entry: Consolidate 32/64 bit syscall entry
x86/entry: Consolidate check_user_regs()
x86: Correct noinstr qualifiers
x86/idtentry: Remove stale comment
Pull x86 mmm update from Ingo Molnar:
"The biggest change is to not sync the vmalloc and ioremap ranges for
x86-64 anymore"
* tag 'x86-mm-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm/64: Make sync_global_pgds() static
x86/mm/64: Do not sync vmalloc/ioremap mappings
x86/mm: Pre-allocate P4D/PUD pages for vmalloc area
Pull x86 cleanups from Ingo Molnar:
"Misc cleanups all around the place"
* tag 'x86-cleanups-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/ioperm: Initialize pointer bitmap with NULL rather than 0
x86: uv: uv_hub.h: Delete duplicated word
x86: cmpxchg_32.h: Delete duplicated word
x86: bootparam.h: Delete duplicated word
x86/mm: Remove the unused mk_kernel_pgd() #define
x86/tsc: Remove unused "US_SCALE" and "NS_SCALE" leftover macros
x86/ioapic: Remove unused "IOAPIC_AUTO" define
x86/mm: Drop unused MAX_PHYSADDR_BITS
x86/msr: Move the F15h MSRs where they belong
x86/idt: Make idt_descr static
initrd: Remove erroneous comment
x86/mm/32: Fix -Wmissing prototypes warnings for init.c
cpu/speculation: Add prototype for cpu_show_srbds()
x86/mm: Fix -Wmissing-prototypes warnings for arch/x86/mm/init.c
x86/asm: Unify __ASSEMBLY__ blocks
x86/cpufeatures: Mark two free bits in word 3
x86/msr: Lift AMD family 0x15 power-specific MSRs
Pull v5.9 KCSAN bits from Paul E. McKenney.
Perhaps the most important change is that GCC 11 now has all fixes in place
to support KCSAN, so GCC support can be enabled again.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
