linux.git/arch/arm/kvm, branch v5.4.272

KVM: arm64: Ensure I-cache isolation between vcpus of a same VM

2021-03-17T16:03:57+00:00

Commit 01dc9262ff5797b675c32c0c6bc682777d23de05 upstream.

It recently became apparent that the ARMv8 architecture has interesting
rules regarding attributes being used when fetching instructions
if the MMU is off at Stage-1.

In this situation, the CPU is allowed to fetch from the PoC and
allocate into the I-cache (unless the memory is mapped with
the XN attribute at Stage-2).

If we transpose this to vcpus sharing a single physical CPU,
it is possible for a vcpu running with its MMU off to influence
another vcpu running with its MMU on, as the latter is expected to
fetch from the PoU (and self-patching code doesn't flush below that
level).

In order to solve this, reuse the vcpu-private TLB invalidation
code to apply the same policy to the I-cache, nuking it every time
the vcpu runs on a physical CPU that ran another vcpu of the same
VM in the past.

This involve renaming __kvm_tlb_flush_local_vmid() to
__kvm_flush_cpu_context(), and inserting a local i-cache invalidation
there.

Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier 
Acked-by: Will Deacon 
Acked-by: Catalin Marinas 
Link: https://lore.kernel.org/r/20210303164505.68492-1-maz@kernel.org
[maz: added 32bit ARM support]
Signed-off-by: Marc Zyngier 
Signed-off-by: Greg Kroah-Hartman

kbuild: change *FLAGS_.o to take the path relative to $(obj)

2019-09-04T14:12:50+00:00

Kbuild provides per-file compiler flag addition/removal:

  CFLAGS_.o
  CFLAGS_REMOVE_.o
  AFLAGS_.o
  AFLAGS_REMOVE_.o
  CPPFLAGS_.lds
  HOSTCFLAGS_.o
  HOSTCXXFLAGS_.o

The  is the filename of the target with its directory and
suffix stripped.

This syntax comes into a trouble when two files with the same basename
appear in one Makefile, for example:

  obj-y += foo.o
  obj-y += dir/foo.o
  CFLAGS_foo.o := 

Here, the  applies to both foo.o and dir/foo.o

The real world problem is:

  scripts/kconfig/util.c
  scripts/kconfig/lxdialog/util.c

Both files are compiled into scripts/kconfig/mconf, but only the
latter should be given with the ncurses flags.

It is more sensible to use the relative path to the Makefile, like this:

  obj-y += foo.o
  CFLAGS_foo.o := 
  obj-y += dir/foo.o
  CFLAGS_dir/foo.o := 

At first, I attempted to replace $(basetarget) with $*. The $* variable
is replaced with the stem ('%') part in a pattern rule. This works with
most of cases, but does not for explicit rules.

For example, arch/ia64/lib/Makefile reuses rule_as_o_S in its own
explicit rules, so $* will be empty, resulting in ignoring the per-file
AFLAGS.

I introduced a new variable, target-stem, which can be used also from
explicit rules.

Signed-off-by: Masahiro Yamada 
Acked-by: Marc Zyngier

KVM: arm: Don't write junk to CP15 registers on reset

2019-08-09T07:07:24+00:00

At the moment, the way we reset CP15 registers is mildly insane:
We write junk to them, call the reset functions, and then check that
we have something else in them.

The "fun" thing is that this can happen while the guest is running
(PSCI, for example). If anything in KVM has to evaluate the state
of a CP15 register while junk is in there, bad thing may happen.

Let's stop doing that. Instead, we track that we have called a
reset function for that register, and assume that the reset
function has done something.

In the end, the very need of this reset check is pretty dubious,
as it doesn't check everything (a lot of the CP15 reg leave outside
of the cp15_regs[] array). It may well be axed in the near future.

Signed-off-by: Marc Zyngier

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234

2019-06-19T15:09:07+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not see http www gnu org
  licenses

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 503 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Alexios Zavras 
Reviewed-by: Allison Randal 
Reviewed-by: Enrico Weigelt 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de
Signed-off-by: Greg Kroah-Hartman

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 422

2019-06-05T15:37:15+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms and conditions of the gnu general public license
  version 2 as published by the free software foundation

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 101 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190113.822954939@linutronix.de
Signed-off-by: Greg Kroah-Hartman

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266

2019-06-05T15:30:28+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not write to the free
  software foundation 51 franklin street fifth floor boston ma 02110
  1301 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 67 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Richard Fontana 
Reviewed-by: Alexios Zavras 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141333.953658117@linutronix.de
Signed-off-by: Greg Kroah-Hartman

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174

2019-05-30T18:26:41+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 655 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Kate Stewart 
Reviewed-by: Richard Fontana 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman

KVM: arm/arm64: Move cc/it checks under hyp's Makefile to avoid instrumentation

2019-05-24T13:53:20+00:00

KVM has helpers to handle the condition codes of trapped aarch32
instructions. These are marked __hyp_text and used from HYP, but they
aren't built by the 'hyp' Makefile, which has all the runes to avoid ASAN
and KCOV instrumentation.

Move this code to a new hyp/aarch32.c to avoid a hyp-panic when starting
an aarch32 guest on a host built with the ASAN/KCOV debug options.

Fixes: 021234ef3752f ("KVM: arm64: Make kvm_condition_valid32() accessible from EL2")
Fixes: 8cebe750c4d9a ("arm64: KVM: Make kvm_skip_instr32 available to HYP")
Signed-off-by: James Morse 
Signed-off-by: Marc Zyngier

Make anon_inodes unconditional

2019-04-19T12:03:11+00:00

Make the anon_inodes facility unconditional so that it can be used by core
VFS code and pidfd code.

Signed-off-by: David Howells 
Signed-off-by: Al Viro 
[christian@brauner.io: adapt commit message to mention pidfds]
Signed-off-by: Christian Brauner

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2019-03-15T22:00:28+00:00

Pull KVM updates from Paolo Bonzini:
 "ARM:
   - some cleanups
   - direct physical timer assignment
   - cache sanitization for 32-bit guests

  s390:
   - interrupt cleanup
   - introduction of the Guest Information Block
   - preparation for processor subfunctions in cpu models

  PPC:
   - bug fixes and improvements, especially related to machine checks
     and protection keys

  x86:
   - many, many cleanups, including removing a bunch of MMU code for
     unnecessary optimizations
   - AVIC fixes

  Generic:
   - memcg accounting"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (147 commits)
  kvm: vmx: fix formatting of a comment
  KVM: doc: Document the life cycle of a VM and its resources
  MAINTAINERS: Add KVM selftests to existing KVM entry
  Revert "KVM/MMU: Flush tlb directly in the kvm_zap_gfn_range()"
  KVM: PPC: Book3S: Add count cache flush parameters to kvmppc_get_cpu_char()
  KVM: PPC: Fix compilation when KVM is not enabled
  KVM: Minor cleanups for kvm_main.c
  KVM: s390: add debug logging for cpu model subfunctions
  KVM: s390: implement subfunction processor calls
  arm64: KVM: Fix architecturally invalid reset value for FPEXC32_EL2
  KVM: arm/arm64: Remove unused timer variable
  KVM: PPC: Book3S: Improve KVM reference counting
  KVM: PPC: Book3S HV: Fix build failure without IOMMU support
  Revert "KVM: Eliminate extra function calls in kvm_get_dirty_log_protect()"
  x86: kvmguest: use TSC clocksource if invariant TSC is exposed
  KVM: Never start grow vCPU halt_poll_ns from value below halt_poll_ns_grow_start
  KVM: Expose the initial start value in grow_halt_poll_ns() as a module parameter
  KVM: grow_halt_poll_ns() should never shrink vCPU halt_poll_ns
  KVM: x86/mmu: Consolidate kvm_mmu_zap_all() and kvm_mmu_zap_mmio_sptes()
  KVM: x86/mmu: WARN if zapping a MMIO spte results in zapping children
  ...