Commit Graph

608 Commits

Author SHA1 Message Date
Marc Zyngier
03fdfb2690 KVM: arm64: Don't write junk to sysregs on reset
At the moment, the way we reset system 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 system 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. This requires fixing a couple of
sysreg refinition in the trap table.

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

Tested-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-08-09 08:07:07 +01:00
Anders Roxell
cdb2d3ee04 arm64: KVM: hyp: debug-sr: Mark expected switch fall-through
When fall-through warnings was enabled by default the following warnings
was starting to show up:

../arch/arm64/kvm/hyp/debug-sr.c: In function ‘__debug_save_state’:
../arch/arm64/kvm/hyp/debug-sr.c:20:19: warning: this statement may fall
 through [-Wimplicit-fallthrough=]
  case 15: ptr[15] = read_debug(reg, 15);   \
../arch/arm64/kvm/hyp/debug-sr.c:113:2: note: in expansion of macro ‘save_debug’
  save_debug(dbg->dbg_bcr, dbgbcr, brps);
  ^~~~~~~~~~
../arch/arm64/kvm/hyp/debug-sr.c:21:2: note: here
  case 14: ptr[14] = read_debug(reg, 14);   \
  ^~~~
../arch/arm64/kvm/hyp/debug-sr.c:113:2: note: in expansion of macro ‘save_debug’
  save_debug(dbg->dbg_bcr, dbgbcr, brps);
  ^~~~~~~~~~
../arch/arm64/kvm/hyp/debug-sr.c:21:19: warning: this statement may fall
 through [-Wimplicit-fallthrough=]
  case 14: ptr[14] = read_debug(reg, 14);   \
../arch/arm64/kvm/hyp/debug-sr.c:113:2: note: in expansion of macro ‘save_debug’
  save_debug(dbg->dbg_bcr, dbgbcr, brps);
  ^~~~~~~~~~
../arch/arm64/kvm/hyp/debug-sr.c:22:2: note: here
  case 13: ptr[13] = read_debug(reg, 13);   \
  ^~~~
../arch/arm64/kvm/hyp/debug-sr.c:113:2: note: in expansion of macro ‘save_debug’
  save_debug(dbg->dbg_bcr, dbgbcr, brps);
  ^~~~~~~~~~

Rework to add a 'Fall through' comment where the compiler warned
about fall-through, hence silencing the warning.

Fixes: d93512ef0f0e ("Makefile: Globally enable fall-through warning")
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
[maz: fixed commit message]
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-07-29 11:01:37 +01:00
Anders Roxell
3d584a3c85 arm64: KVM: regmap: Fix unexpected switch fall-through
When fall-through warnings was enabled by default, commit d93512ef0f0e
("Makefile: Globally enable fall-through warning"), the following
warnings was starting to show up:

In file included from ../arch/arm64/include/asm/kvm_emulate.h:19,
                 from ../arch/arm64/kvm/regmap.c:13:
../arch/arm64/kvm/regmap.c: In function ‘vcpu_write_spsr32’:
../arch/arm64/include/asm/kvm_hyp.h:31:3: warning: this statement may fall
 through [-Wimplicit-fallthrough=]
   asm volatile(ALTERNATIVE(__msr_s(r##nvh, "%x0"), \
   ^~~
../arch/arm64/include/asm/kvm_hyp.h:46:31: note: in expansion of macro ‘write_sysreg_elx’
 #define write_sysreg_el1(v,r) write_sysreg_elx(v, r, _EL1, _EL12)
                               ^~~~~~~~~~~~~~~~
../arch/arm64/kvm/regmap.c:180:3: note: in expansion of macro ‘write_sysreg_el1’
   write_sysreg_el1(v, SYS_SPSR);
   ^~~~~~~~~~~~~~~~
../arch/arm64/kvm/regmap.c:181:2: note: here
  case KVM_SPSR_ABT:
  ^~~~
In file included from ../arch/arm64/include/asm/cputype.h:132,
                 from ../arch/arm64/include/asm/cache.h:8,
                 from ../include/linux/cache.h:6,
                 from ../include/linux/printk.h:9,
                 from ../include/linux/kernel.h:15,
                 from ../include/asm-generic/bug.h:18,
                 from ../arch/arm64/include/asm/bug.h:26,
                 from ../include/linux/bug.h:5,
                 from ../include/linux/mmdebug.h:5,
                 from ../include/linux/mm.h:9,
                 from ../arch/arm64/kvm/regmap.c:11:
../arch/arm64/include/asm/sysreg.h:837:2: warning: this statement may fall
 through [-Wimplicit-fallthrough=]
  asm volatile("msr " __stringify(r) ", %x0"  \
  ^~~
../arch/arm64/kvm/regmap.c:182:3: note: in expansion of macro ‘write_sysreg’
   write_sysreg(v, spsr_abt);
   ^~~~~~~~~~~~
../arch/arm64/kvm/regmap.c:183:2: note: here
  case KVM_SPSR_UND:
  ^~~~

Rework to add a 'break;' in the swich-case since it didn't have that,
leading to an interresting set of bugs.

Cc: stable@vger.kernel.org # v4.17+
Fixes: a892819560 ("KVM: arm64: Prepare to handle deferred save/restore of 32-bit registers")
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
[maz: reworked commit message, fixed stable range]
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-07-26 15:33:41 +01:00
Linus Torvalds
39d7530d74 ARM:
* support for chained PMU counters in guests
 * improved SError handling
 * handle Neoverse N1 erratum #1349291
 * allow side-channel mitigation status to be migrated
 * standardise most AArch64 system register accesses to msr_s/mrs_s
 * fix host MPIDR corruption on 32bit
 * selftests ckleanups
 
 x86:
 * PMU event {white,black}listing
 * ability for the guest to disable host-side interrupt polling
 * fixes for enlightened VMCS (Hyper-V pv nested virtualization),
 * new hypercall to yield to IPI target
 * support for passing cstate MSRs through to the guest
 * lots of cleanups and optimizations
 
 Generic:
 * Some txt->rST conversions for the documentation
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "ARM:
   - support for chained PMU counters in guests
   - improved SError handling
   - handle Neoverse N1 erratum #1349291
   - allow side-channel mitigation status to be migrated
   - standardise most AArch64 system register accesses to msr_s/mrs_s
   - fix host MPIDR corruption on 32bit
   - selftests ckleanups

  x86:
   - PMU event {white,black}listing
   - ability for the guest to disable host-side interrupt polling
   - fixes for enlightened VMCS (Hyper-V pv nested virtualization),
   - new hypercall to yield to IPI target
   - support for passing cstate MSRs through to the guest
   - lots of cleanups and optimizations

  Generic:
   - Some txt->rST conversions for the documentation"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (128 commits)
  Documentation: virtual: Add toctree hooks
  Documentation: kvm: Convert cpuid.txt to .rst
  Documentation: virtual: Convert paravirt_ops.txt to .rst
  KVM: x86: Unconditionally enable irqs in guest context
  KVM: x86: PMU Event Filter
  kvm: x86: Fix -Wmissing-prototypes warnings
  KVM: Properly check if "page" is valid in kvm_vcpu_unmap
  KVM: arm/arm64: Initialise host's MPIDRs by reading the actual register
  KVM: LAPIC: Retry tune per-vCPU timer_advance_ns if adaptive tuning goes insane
  kvm: LAPIC: write down valid APIC registers
  KVM: arm64: Migrate _elx sysreg accessors to msr_s/mrs_s
  KVM: doc: Add API documentation on the KVM_REG_ARM_WORKAROUNDS register
  KVM: arm/arm64: Add save/restore support for firmware workaround state
  arm64: KVM: Propagate full Spectre v2 workaround state to KVM guests
  KVM: arm/arm64: Support chained PMU counters
  KVM: arm/arm64: Remove pmc->bitmask
  KVM: arm/arm64: Re-create event when setting counter value
  KVM: arm/arm64: Extract duplicated code to own function
  KVM: arm/arm64: Rename kvm_pmu_{enable/disable}_counter functions
  KVM: LAPIC: ARBPRI is a reserved register for x2APIC
  ...
2019-07-12 15:35:14 -07:00
Linus Torvalds
dfd437a257 arm64 updates for 5.3:
- arm64 support for syscall emulation via PTRACE_SYSEMU{,_SINGLESTEP}
 
 - Wire up VM_FLUSH_RESET_PERMS for arm64, allowing the core code to
   manage the permissions of executable vmalloc regions more strictly
 
 - Slight performance improvement by keeping softirqs enabled while
   touching the FPSIMD/SVE state (kernel_neon_begin/end)
 
 - Expose a couple of ARMv8.5 features to user (HWCAP): CondM (new XAFLAG
   and AXFLAG instructions for floating point comparison flags
   manipulation) and FRINT (rounding floating point numbers to integers)
 
 - Re-instate ARM64_PSEUDO_NMI support which was previously marked as
   BROKEN due to some bugs (now fixed)
 
 - Improve parking of stopped CPUs and implement an arm64-specific
   panic_smp_self_stop() to avoid warning on not being able to stop
   secondary CPUs during panic
 
 - perf: enable the ARM Statistical Profiling Extensions (SPE) on ACPI
   platforms
 
 - perf: DDR performance monitor support for iMX8QXP
 
 - cache_line_size() can now be set from DT or ACPI/PPTT if provided to
   cope with a system cache info not exposed via the CPUID registers
 
 - Avoid warning on hardware cache line size greater than
   ARCH_DMA_MINALIGN if the system is fully coherent
 
 - arm64 do_page_fault() and hugetlb cleanups
 
 - Refactor set_pte_at() to avoid redundant READ_ONCE(*ptep)
 
 - Ignore ACPI 5.1 FADTs reported as 5.0 (infer from the 'arm_boot_flags'
   introduced in 5.1)
 
 - CONFIG_RANDOMIZE_BASE now enabled in defconfig
 
 - Allow the selection of ARM64_MODULE_PLTS, currently only done via
   RANDOMIZE_BASE (and an erratum workaround), allowing modules to spill
   over into the vmalloc area
 
 - Make ZONE_DMA32 configurable
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:

 - arm64 support for syscall emulation via PTRACE_SYSEMU{,_SINGLESTEP}

 - Wire up VM_FLUSH_RESET_PERMS for arm64, allowing the core code to
   manage the permissions of executable vmalloc regions more strictly

 - Slight performance improvement by keeping softirqs enabled while
   touching the FPSIMD/SVE state (kernel_neon_begin/end)

 - Expose a couple of ARMv8.5 features to user (HWCAP): CondM (new
   XAFLAG and AXFLAG instructions for floating point comparison flags
   manipulation) and FRINT (rounding floating point numbers to integers)

 - Re-instate ARM64_PSEUDO_NMI support which was previously marked as
   BROKEN due to some bugs (now fixed)

 - Improve parking of stopped CPUs and implement an arm64-specific
   panic_smp_self_stop() to avoid warning on not being able to stop
   secondary CPUs during panic

 - perf: enable the ARM Statistical Profiling Extensions (SPE) on ACPI
   platforms

 - perf: DDR performance monitor support for iMX8QXP

 - cache_line_size() can now be set from DT or ACPI/PPTT if provided to
   cope with a system cache info not exposed via the CPUID registers

 - Avoid warning on hardware cache line size greater than
   ARCH_DMA_MINALIGN if the system is fully coherent

 - arm64 do_page_fault() and hugetlb cleanups

 - Refactor set_pte_at() to avoid redundant READ_ONCE(*ptep)

 - Ignore ACPI 5.1 FADTs reported as 5.0 (infer from the
   'arm_boot_flags' introduced in 5.1)

 - CONFIG_RANDOMIZE_BASE now enabled in defconfig

 - Allow the selection of ARM64_MODULE_PLTS, currently only done via
   RANDOMIZE_BASE (and an erratum workaround), allowing modules to spill
   over into the vmalloc area

 - Make ZONE_DMA32 configurable

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (54 commits)
  perf: arm_spe: Enable ACPI/Platform automatic module loading
  arm_pmu: acpi: spe: Add initial MADT/SPE probing
  ACPI/PPTT: Add function to return ACPI 6.3 Identical tokens
  ACPI/PPTT: Modify node flag detection to find last IDENTICAL
  x86/entry: Simplify _TIF_SYSCALL_EMU handling
  arm64: rename dump_instr as dump_kernel_instr
  arm64/mm: Drop [PTE|PMD]_TYPE_FAULT
  arm64: Implement panic_smp_self_stop()
  arm64: Improve parking of stopped CPUs
  arm64: Expose FRINT capabilities to userspace
  arm64: Expose ARMv8.5 CondM capability to userspace
  arm64: defconfig: enable CONFIG_RANDOMIZE_BASE
  arm64: ARM64_MODULES_PLTS must depend on MODULES
  arm64: bpf: do not allocate executable memory
  arm64/kprobes: set VM_FLUSH_RESET_PERMS on kprobe instruction pages
  arm64/mm: wire up CONFIG_ARCH_HAS_SET_DIRECT_MAP
  arm64: module: create module allocations without exec permissions
  arm64: Allow user selection of ARM64_MODULE_PLTS
  acpi/arm64: ignore 5.1 FADTs that are reported as 5.0
  arm64: Allow selecting Pseudo-NMI again
  ...
2019-07-08 09:54:55 -07:00
Dave Martin
fdec2a9ef8 KVM: arm64: Migrate _elx sysreg accessors to msr_s/mrs_s
Currently, the {read,write}_sysreg_el*() accessors for accessing
particular ELs' sysregs in the presence of VHE rely on some local
hacks and define their system register encodings in a way that is
inconsistent with the core definitions in <asm/sysreg.h>.

As a result, it is necessary to add duplicate definitions for any
system register that already needs a definition in sysreg.h for
other reasons.

This is a bit of a maintenance headache, and the reasons for the
_el*() accessors working the way they do is a bit historical.

This patch gets rid of the shadow sysreg definitions in
<asm/kvm_hyp.h>, converts the _el*() accessors to use the core
__msr_s/__mrs_s interface, and converts all call sites to use the
standard sysreg #define names (i.e., upper case, with SYS_ prefix).

This patch will conflict heavily anyway, so the opportunity
to clean up some bad whitespace in the context of the changes is
taken.

The change exposes a few system registers that have no sysreg.h
definition, due to msr_s/mrs_s being used in place of msr/mrs:
additions are made in order to fill in the gaps.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoffer Dall <christoffer.dall@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Link: https://www.spinics.net/lists/kvm-arm/msg31717.html
[Rebased to v4.21-rc1]
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
[Rebased to v5.2-rc5, changelog updates]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-07-05 13:57:25 +01:00
Andrew Murray
418e5ca88c KVM: arm/arm64: Rename kvm_pmu_{enable/disable}_counter functions
The kvm_pmu_{enable/disable}_counter functions can enable/disable
multiple counters at once as they operate on a bitmask. Let's
make this clearer by renaming the function.

Suggested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-07-05 13:56:04 +01:00
James Morse
11b41626bd KVM: arm64: Skip more of the SError vaxorcism
During __guest_exit() we need to consume any SError left pending by the
guest so it doesn't contaminate the host. With v8.2 we use the
ESB-instruction. For systems without v8.2, we use dsb+isb and unmask
SError. We do this on every guest exit.

Use the same dsb+isr_el1 trick, this lets us know if an SError is pending
after the dsb, allowing us to skip the isb and self-synchronising PSTATE
write if its not.

This means SError remains masked during KVM's world-switch, so any SError
that occurs during this time is reported by the host, instead of causing
a hyp-panic.

As we're benchmarking this code lets polish the layout. If you give gcc
likely()/unlikely() hints in an if() condition, it shuffles the generated
assembly so that the likely case is immediately after the branch. Lets
do the same here.

Signed-off-by: James Morse <james.morse@arm.com>

Changes since v2:
 * Added isb after the dsb to prevent an early read

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-07-05 13:03:34 +01:00
James Morse
dad6321ffa KVM: arm64: Re-mask SError after the one instruction window
KVM consumes any SError that were pending during guest exit with a
dsb/isb and unmasking SError. It currently leaves SError unmasked for
the rest of world-switch.

This means any SError that occurs during this part of world-switch
will cause a hyp-panic. We'd much prefer it to remain pending until
we return to the host.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-07-05 13:03:34 +01:00
James Morse
5dcd0fdbb4 KVM: arm64: Defer guest entry when an asynchronous exception is pending
SError that occur during world-switch's entry to the guest will be
accounted to the guest, as the exception is masked until we enter the
guest... but we want to attribute the SError as precisely as possible.

Reading DISR_EL1 before guest entry requires free registers, and using
ESB+DISR_EL1 to consume and read back the ESR would leave KVM holding
a host SError... We would rather leave the SError pending and let the
host take it once we exit world-switch. To do this, we need to defer
guest-entry if an SError is pending.

Read the ISR to see if SError (or an IRQ) is pending. If so fake an
exit. Place this check between __guest_enter()'s save of the host
registers, and restore of the guest's. SError that occur between
here and the eret into the guest must have affected the guest's
registers, which we can naturally attribute to the guest.

The dsb is needed to ensure any previous writes have been done before
we read ISR_EL1. On systems without the v8.2 RAS extensions this
doesn't give us anything as we can't contain errors, and the ESR bits
to describe the severity are all implementation-defined. Replace
this with a nop for these systems.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-07-05 13:03:30 +01:00
James Morse
0e5b9c085d KVM: arm64: Consume pending SError as early as possible
On systems with v8.2 we switch the 'vaxorcism' of guest SError with an
alternative sequence that uses the ESB-instruction, then reads DISR_EL1.
This saves the unmasking and remasking of asynchronous exceptions.

We do this after we've saved the guest registers and restored the
host's. Any SError that becomes pending due to this will be accounted
to the guest, when it actually occurred during host-execution.

Move the ESB-instruction as early as possible. Any guest SError
will become pending due to this ESB-instruction and then consumed to
DISR_EL1 before the host touches anything.

This lets us account for host/guest SError precisely on the guest
exit exception boundary.

Because the ESB-instruction now lands in the preamble section of
the vectors, we need to add it to the unpatched indirect vectors
too, and to any sequence that may be patched in over the top.

The ESB-instruction always lives in the head of the vectors,
to be before any memory write. Whereas the register-store always
lives in the tail.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-07-05 13:03:29 +01:00
James Morse
5d994374e8 KVM: arm64: Make indirect vectors preamble behaviour symmetric
The KVM indirect vectors support is a little complicated. Different CPUs
may use different exception vectors for KVM that are generated at boot.
Adding new instructions involves checking all the possible combinations
do the right thing.

To make changes here easier to review lets state what we expect of the
preamble:
  1. The first vector run, must always run the preamble.
  2. Patching the head or tail of the vector shouldn't remove
     preamble instructions.

Today, this is easy as we only have one instruction in the preamble.
Change the unpatched tail of the indirect vector so that it always
runs this, regardless of patching.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-07-05 13:03:29 +01:00
James Morse
3dbf100b0b KVM: arm64: Abstract the size of the HYP vectors pre-amble
The EL2 vector hardening feature causes KVM to generate vectors for
each type of CPU present in the system. The generated sequences already
do some of the early guest-exit work (i.e. saving registers). To avoid
duplication the generated vectors branch to the original vector just
after the preamble. This size is hard coded.

Adding new instructions to the HYP vector causes strange side effects,
which are difficult to debug as the affected code is patched in at
runtime.

Add KVM_VECTOR_PREAMBLE to tell kvm_patch_vector_branch() how big
the preamble is. The valid_vect macro can then validate this at
build time.

Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-07-05 13:03:29 +01:00
Zhang Lei
e644fa18e2 KVM: arm64/sve: Fix vq_present() macro to yield a bool
The original implementation of vq_present() relied on aggressive
inlining in order for the compiler to know that the code is
correct, due to some const-casting issues.  This was causing sparse
and clang to complain, while GCC compiled cleanly.

Commit 0c529ff789 addressed this problem, but since vq_present()
is no longer a function, there is now no implicit casting of the
returned value to the return type (bool).

In set_sve_vls(), this uncast bit value is compared against a bool,
and so may spuriously compare as unequal when both are nonzero.  As
a result, KVM may reject valid SVE vector length configurations as
invalid, and vice versa.

Fix it by forcing the returned value to a bool.

Signed-off-by: Zhang Lei <zhang.lei@jp.fujitsu.com>
Fixes: 0c529ff789 ("KVM: arm64: Implement vq_present() as a macro")
Signed-off-by: Dave Martin <Dave.Martin@arm.com> [commit message rewrite]
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-07-05 12:07:51 +02:00
Linus Torvalds
c884d8ac7f SPDX update for 5.2-rc6
Another round of SPDX updates for 5.2-rc6
 
 Here is what I am guessing is going to be the last "big" SPDX update for
 5.2.  It contains all of the remaining GPLv2 and GPLv2+ updates that
 were "easy" to determine by pattern matching.  The ones after this are
 going to be a bit more difficult and the people on the spdx list will be
 discussing them on a case-by-case basis now.
 
 Another 5000+ files are fixed up, so our overall totals are:
 	Files checked:            64545
 	Files with SPDX:          45529
 
 Compared to the 5.1 kernel which was:
 	Files checked:            63848
 	Files with SPDX:          22576
 This is a huge improvement.
 
 Also, we deleted another 20000 lines of boilerplate license crud, always
 nice to see in a diffstat.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'spdx-5.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx

Pull still more SPDX updates from Greg KH:
 "Another round of SPDX updates for 5.2-rc6

  Here is what I am guessing is going to be the last "big" SPDX update
  for 5.2. It contains all of the remaining GPLv2 and GPLv2+ updates
  that were "easy" to determine by pattern matching. The ones after this
  are going to be a bit more difficult and the people on the spdx list
  will be discussing them on a case-by-case basis now.

  Another 5000+ files are fixed up, so our overall totals are:
	Files checked:            64545
	Files with SPDX:          45529

  Compared to the 5.1 kernel which was:
	Files checked:            63848
	Files with SPDX:          22576

  This is a huge improvement.

  Also, we deleted another 20000 lines of boilerplate license crud,
  always nice to see in a diffstat"

* tag 'spdx-5.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx: (65 commits)
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 507
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 506
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 505
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 504
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 503
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 502
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 501
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 498
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 497
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 496
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 495
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 491
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 490
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 489
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 488
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 487
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 486
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 485
  ...
2019-06-21 09:58:42 -07:00
Julien Thierry
bd82d4bd21 arm64: Fix incorrect irqflag restore for priority masking
When using IRQ priority masking to disable interrupts, in order to deal
with the PSR.I state, local_irq_save() would convert the I bit into a
PMR value (GIC_PRIO_IRQOFF). This resulted in local_irq_restore()
potentially modifying the value of PMR in undesired location due to the
state of PSR.I upon flag saving [1].

In an attempt to solve this issue in a less hackish manner, introduce
a bit (GIC_PRIO_IGNORE_PMR) for the PMR values that can represent
whether PSR.I is being used to disable interrupts, in which case it
takes precedence of the status of interrupt masking via PMR.

GIC_PRIO_PSR_I_SET is chosen such that (<pmr_value> |
GIC_PRIO_PSR_I_SET) does not mask more interrupts than <pmr_value> as
some sections (e.g. arch_cpu_idle(), interrupt acknowledge path)
requires PMR not to mask interrupts that could be signaled to the
CPU when using only PSR.I.

[1] https://www.spinics.net/lists/arm-kernel/msg716956.html

Fixes: 4a503217ce ("arm64: irqflags: Use ICC_PMR_EL1 for interrupt masking")
Cc: <stable@vger.kernel.org> # 5.1.x-
Reported-by: Zenghui Yu <yuzenghui@huawei.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Wei Li <liwei391@huawei.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Christoffer Dall <christoffer.dall@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Suzuki K Pouloze <suzuki.poulose@arm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-06-21 15:50:10 +01:00
Linus Torvalds
b3e978337b Fixes for ARM and x86, plus selftest patches and nicer structs
for nested state save/restore.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "Fixes for ARM and x86, plus selftest patches and nicer structs for
  nested state save/restore"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: nVMX: reorganize initial steps of vmx_set_nested_state
  KVM: arm/arm64: Fix emulated ptimer irq injection
  tests: kvm: Check for a kernel warning
  kvm: tests: Sort tests in the Makefile alphabetically
  KVM: x86/mmu: Allocate PAE root array when using SVM's 32-bit NPT
  KVM: x86: Modify struct kvm_nested_state to have explicit fields for data
  KVM: fix typo in documentation
  KVM: nVMX: use correct clean fields when copying from eVMCS
  KVM: arm/arm64: vgic: Fix kvm_device leak in vgic_its_destroy
  KVM: arm64: Filter out invalid core register IDs in KVM_GET_REG_LIST
  KVM: arm64: Implement vq_present() as a macro
2019-06-20 13:50:37 -07:00
Thomas Gleixner
caab277b1d treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234
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 <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:07 +02:00
Dave Martin
df205b5c63 KVM: arm64: Filter out invalid core register IDs in KVM_GET_REG_LIST
Since commit d26c25a9d1 ("arm64: KVM: Tighten guest core register
access from userspace"), KVM_{GET,SET}_ONE_REG rejects register IDs
that do not correspond to a single underlying architectural register.

KVM_GET_REG_LIST was not changed to match however: instead, it
simply yields a list of 32-bit register IDs that together cover the
whole kvm_regs struct.  This means that if userspace tries to use
the resulting list of IDs directly to drive calls to KVM_*_ONE_REG,
some of those calls will now fail.

This was not the intention.  Instead, iterating KVM_*_ONE_REG over
the list of IDs returned by KVM_GET_REG_LIST should be guaranteed
to work.

This patch fixes the problem by splitting validate_core_offset()
into a backend core_reg_size_from_offset() which does all of the
work except for checking that the size field in the register ID
matches, and kvm_arm_copy_reg_indices() and num_core_regs() are
converted to use this to enumerate the valid offsets.

kvm_arm_copy_reg_indices() now also sets the register ID size field
appropriately based on the value returned, so the register ID
supplied to userspace is fully qualified for use with the register
access ioctls.

Cc: stable@vger.kernel.org
Fixes: d26c25a9d1 ("arm64: KVM: Tighten guest core register access from userspace")
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Tested-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-06-12 15:53:55 +01:00
Viresh Kumar
0c529ff789 KVM: arm64: Implement vq_present() as a macro
This routine is a one-liner and doesn't really need to be function and
can be implemented as a macro.

Suggested-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-06-12 15:53:33 +01:00
Thomas Gleixner
75a6faf617 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 422
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 <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190113.822954939@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:37:15 +02:00
Julien Grall
54b8c7cbc5 arm64/fpsimd: Introduce fpsimd_save_and_flush_cpu_state() and use it
The only external user of fpsimd_save() and fpsimd_flush_cpu_state() is
the KVM FPSIMD code.

A following patch will introduce a mechanism to acquire owernship of the
FPSIMD/SVE context for performing context management operations. Rather
than having to export the new helpers to get/put the context, we can just
introduce a new function to combine fpsimd_save() and
fpsimd_flush_cpu_state().

This has also the advantage to remove any external call of fpsimd_save()
and fpsimd_flush_cpu_state(), so they can be turned static.

Lastly, the new function can also be used in the PM notifier.

Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-06-04 13:17:30 +01:00
Thomas Gleixner
1802d0beec treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174
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 <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:41 -07:00
James Morse
623e1528d4 KVM: arm/arm64: Move cc/it checks under hyp's Makefile to avoid instrumentation
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: 021234ef37 ("KVM: arm64: Make kvm_condition_valid32() accessible from EL2")
Fixes: 8cebe750c4 ("arm64: KVM: Make kvm_skip_instr32 available to HYP")
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-05-24 14:53:20 +01:00
James Morse
b7c50fab66 KVM: arm64: Move pmu hyp code under hyp's Makefile to avoid instrumentation
KVM's pmu.c contains the __hyp_text needed to switch the pmu registers
between host and guest. Because this isn't covered by the 'hyp' Makefile,
it can be built with kasan and friends when these are enabled in Kconfig.

When starting a guest, this results in:
| Kernel panic - not syncing: HYP panic:
| PS:a00003c9 PC:000083000028ada0 ESR:86000007
| FAR:000083000028ada0 HPFAR:0000000029df5300 PAR:0000000000000000
| VCPU:000000004e10b7d6
| CPU: 0 PID: 3088 Comm: qemu-system-aar Not tainted 5.2.0-rc1 #11026
| Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Plat
| Call trace:
|  dump_backtrace+0x0/0x200
|  show_stack+0x20/0x30
|  dump_stack+0xec/0x158
|  panic+0x1ec/0x420
|  panic+0x0/0x420
| SMP: stopping secondary CPUs
| Kernel Offset: disabled
| CPU features: 0x002,25006082
| Memory Limit: none
| ---[ end Kernel panic - not syncing: HYP panic:

This is caused by functions in pmu.c calling the instrumented
code, which isn't mapped to hyp. From objdump -r:
| RELOCATION RECORDS FOR [.hyp.text]:
| OFFSET           TYPE              VALUE
| 0000000000000010 R_AARCH64_CALL26  __sanitizer_cov_trace_pc
| 0000000000000018 R_AARCH64_CALL26  __asan_load4_noabort
| 0000000000000024 R_AARCH64_CALL26  __asan_load4_noabort

Move the affected code to a new file under 'hyp's Makefile.

Fixes: 3d91befbb3 ("arm64: KVM: Enable !VHE support for :G/:H perf event modifiers")
Cc: Andrew Murray <Andrew.Murray@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-05-24 14:53:20 +01:00
Linus Torvalds
0ef0fd3515 * ARM: support for SVE and Pointer Authentication in guests, PMU improvements
* POWER: support for direct access to the POWER9 XIVE interrupt controller,
 memory and performance optimizations.
 
 * x86: support for accessing memory not backed by struct page, fixes and refactoring
 
 * Generic: dirty page tracking improvements
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "ARM:
   - support for SVE and Pointer Authentication in guests
   - PMU improvements

  POWER:
   - support for direct access to the POWER9 XIVE interrupt controller
   - memory and performance optimizations

  x86:
   - support for accessing memory not backed by struct page
   - fixes and refactoring

  Generic:
   - dirty page tracking improvements"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (155 commits)
  kvm: fix compilation on aarch64
  Revert "KVM: nVMX: Expose RDPMC-exiting only when guest supports PMU"
  kvm: x86: Fix L1TF mitigation for shadow MMU
  KVM: nVMX: Disable intercept for FS/GS base MSRs in vmcs02 when possible
  KVM: PPC: Book3S: Remove useless checks in 'release' method of KVM device
  KVM: PPC: Book3S HV: XIVE: Fix spelling mistake "acessing" -> "accessing"
  KVM: PPC: Book3S HV: Make sure to load LPID for radix VCPUs
  kvm: nVMX: Set nested_run_pending in vmx_set_nested_state after checks complete
  tests: kvm: Add tests for KVM_SET_NESTED_STATE
  KVM: nVMX: KVM_SET_NESTED_STATE - Tear down old EVMCS state before setting new state
  tests: kvm: Add tests for KVM_CAP_MAX_VCPUS and KVM_CAP_MAX_CPU_ID
  tests: kvm: Add tests to .gitignore
  KVM: Introduce KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2
  KVM: Fix kvm_clear_dirty_log_protect off-by-(minus-)one
  KVM: Fix the bitmap range to copy during clear dirty
  KVM: arm64: Fix ptrauth ID register masking logic
  KVM: x86: use direct accessors for RIP and RSP
  KVM: VMX: Use accessors for GPRs outside of dedicated caching logic
  KVM: x86: Omit caching logic for always-available GPRs
  kvm, x86: Properly check whether a pfn is an MMIO or not
  ...
2019-05-17 10:33:30 -07:00
Paolo Bonzini
dd53f6102c KVM/arm updates for 5.2
- guest SVE support
 - guest Pointer Authentication support
 - Better discrimination of perf counters between host and guests
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Merge tag 'kvmarm-for-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm updates for 5.2

- guest SVE support
- guest Pointer Authentication support
- Better discrimination of perf counters between host and guests

Conflicts:
	include/uapi/linux/kvm.h
2019-05-15 23:41:43 +02:00
Kristina Martsenko
9eecfc22e0 KVM: arm64: Fix ptrauth ID register masking logic
When a VCPU doesn't have pointer auth, we want to hide all four pointer
auth ID register fields from the guest, not just one of them.

Fixes: 384b40caa8 ("KVM: arm/arm64: Context-switch ptrauth registers")
Reported-by: Andrew Murray <andrew.murray@arm.com>
Fscked-up-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by: Andrew Murray <andrew.murray@arm.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-05-01 17:21:51 +01:00
Andrew Murray
21137301de arm64: KVM: Fix perf cycle counter support for VHE
The kvm_vcpu_pmu_{read,write}_evtype_direct functions do not handle
the cycle counter use-case, this leads to inaccurate counts and a
WARN message when using perf with the cycle counter (-e cycle).

Let's fix this by adding a use case for pmccfiltr_el0.

Fixes: 39e3406a09 ("arm64: KVM: Avoid isb's by using direct pmxevtyper sysreg")
Reported-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-30 10:11:49 +01:00
Andrew Murray
39e3406a09 arm64: KVM: Avoid isb's by using direct pmxevtyper sysreg
Upon entering or exiting a guest we may modify multiple PMU counters to
enable of disable EL0 filtering. We presently do this via the indirect
PMXEVTYPER_EL0 system register (where the counter we modify is selected
by PMSELR). With this approach it is necessary to order the writes via
isb instructions such that we select the correct counter before modifying
it.

Let's avoid potentially expensive instruction barriers by using the
direct PMEVTYPER<n>_EL0 registers instead.

As the change to counter type relates only to EL0 filtering we can rely
on the implicit instruction barrier which occurs when we transition from
EL2 to EL1 on entering the guest. On returning to userspace we can, at the
latest, rely on the implicit barrier between EL2 and EL0. We can also
depend on the explicit isb in armv8pmu_select_counter to order our write
against any other kernel changes by the PMU driver to the type register as
a result of preemption.

Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-24 15:46:26 +01:00
Andrew Murray
435e53fb5e arm64: KVM: Enable VHE support for :G/:H perf event modifiers
With VHE different exception levels are used between the host (EL2) and
guest (EL1) with a shared exception level for userpace (EL0). We can take
advantage of this and use the PMU's exception level filtering to avoid
enabling/disabling counters in the world-switch code. Instead we just
modify the counter type to include or exclude EL0 at vcpu_{load,put} time.

We also ensure that trapped PMU system register writes do not re-enable
EL0 when reconfiguring the backing perf events.

This approach completely avoids blackout windows seen with !VHE.

Suggested-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-24 15:46:26 +01:00
Andrew Murray
3d91befbb3 arm64: KVM: Enable !VHE support for :G/:H perf event modifiers
Enable/disable event counters as appropriate when entering and exiting
the guest to enable support for guest or host only event counting.

For both VHE and non-VHE we switch the counters between host/guest at
EL2.

The PMU may be on when we change which counters are enabled however
we avoid adding an isb as we instead rely on existing context
synchronisation events: the eret to enter the guest (__guest_enter)
and eret in kvm_call_hyp for __kvm_vcpu_run_nvhe on returning.

Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-24 15:36:22 +01:00
Andrew Murray
eb41238cf1 arm64: KVM: Add accessors to track guest/host only counters
In order to effeciently switch events_{guest,host} perf counters at
guest entry/exit we add bitfields to kvm_cpu_context for guest and host
events as well as accessors for updating them.

A function is also provided which allows the PMU driver to determine
if a counter should start counting when it is enabled. With exclude_host,
we may only start counting when entering the guest.

Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-24 15:35:30 +01:00
Amit Daniel Kachhap
a243c16d18 KVM: arm64: Add capability to advertise ptrauth for guest
This patch advertises the capability of two cpu feature called address
pointer authentication and generic pointer authentication. These
capabilities depend upon system support for pointer authentication and
VHE mode.

The current arm64 KVM partially implements pointer authentication and
support of address/generic authentication are tied together. However,
separate ABI requirements for both of them is added so that any future
isolated implementation will not require any ABI changes.

Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Christoffer Dall <christoffer.dall@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-24 15:30:40 +01:00
Amit Daniel Kachhap
a22fa321d1 KVM: arm64: Add userspace flag to enable pointer authentication
Now that the building blocks of pointer authentication are present, lets
add userspace flags KVM_ARM_VCPU_PTRAUTH_ADDRESS and
KVM_ARM_VCPU_PTRAUTH_GENERIC. These flags will enable pointer
authentication for the KVM guest on a per-vcpu basis through the ioctl
KVM_ARM_VCPU_INIT.

This features will allow the KVM guest to allow the handling of
pointer authentication instructions or to treat them as undefined
if not set.

Necessary documentations are added to reflect the changes done.

Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Christoffer Dall <christoffer.dall@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-24 15:30:40 +01:00
Mark Rutland
384b40caa8 KVM: arm/arm64: Context-switch ptrauth registers
When pointer authentication is supported, a guest may wish to use it.
This patch adds the necessary KVM infrastructure for this to work, with
a semi-lazy context switch of the pointer auth state.

Pointer authentication feature is only enabled when VHE is built
in the kernel and present in the CPU implementation so only VHE code
paths are modified.

When we schedule a vcpu, we disable guest usage of pointer
authentication instructions and accesses to the keys. While these are
disabled, we avoid context-switching the keys. When we trap the guest
trying to use pointer authentication functionality, we change to eagerly
context-switching the keys, and enable the feature. The next time the
vcpu is scheduled out/in, we start again. However the host key save is
optimized and implemented inside ptrauth instruction/register access
trap.

Pointer authentication consists of address authentication and generic
authentication, and CPUs in a system might have varied support for
either. Where support for either feature is not uniform, it is hidden
from guests via ID register emulation, as a result of the cpufeature
framework in the host.

Unfortunately, address authentication and generic authentication cannot
be trapped separately, as the architecture provides a single EL2 trap
covering both. If we wish to expose one without the other, we cannot
prevent a (badly-written) guest from intermittently using a feature
which is not uniformly supported (when scheduled on a physical CPU which
supports the relevant feature). Hence, this patch expects both type of
authentication to be present in a cpu.

This switch of key is done from guest enter/exit assembly as preparation
for the upcoming in-kernel pointer authentication support. Hence, these
key switching routines are not implemented in C code as they may cause
pointer authentication key signing error in some situations.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[Only VHE, key switch in full assembly, vcpu_has_ptrauth checks
, save host key in ptrauth exception trap]
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Cc: Christoffer Dall <christoffer.dall@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
[maz: various fixups]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-24 15:30:40 +01:00
David Howells
5dd50aaeb1
Make anon_inodes unconditional
Make the anon_inodes facility unconditional so that it can be used by core
VFS code and pidfd code.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[christian@brauner.io: adapt commit message to mention pidfds]
Signed-off-by: Christian Brauner <christian@brauner.io>
2019-04-19 14:03:11 +02:00
Dave Martin
92e68b2b1b KVM: arm/arm64: Clean up vcpu finalization function parameter naming
Currently, the internal vcpu finalization functions use a different
name ("what") for the feature parameter than the name ("feature")
used in the documentation.

To avoid future confusion, this patch converts everything to use
the name "feature" consistently.

No functional change.

Suggested-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-18 17:14:02 +01:00
Dave Martin
ecfb6ed4f6 KVM: arm64/sve: Explain validity checks in set_sve_vls()
Correct virtualization of SVE relies for correctness on code in
set_sve_vls() that verifies consistency between the set of vector
lengths requested by userspace and the set of vector lengths
available on the host.

However, the purpose of this code is not obvious, and not likely to
be apparent at all to people who do not have detailed knowledge of
the SVE system-level architecture.

This patch adds a suitable comment to explain what these checks are
for.

No functional change.

Suggested-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-18 17:14:02 +01:00
Dave Martin
4bd774e57b KVM: arm64/sve: Simplify KVM_REG_ARM64_SVE_VLS array sizing
A complicated DIV_ROUND_UP() expression is currently written out
explicitly in multiple places in order to specify the size of the
bitmap exchanged with userspace to represent the value of the
KVM_REG_ARM64_SVE_VLS pseudo-register.

Userspace currently has no direct way to work this out either: for
documentation purposes, the size is just quoted as 8 u64s.

To make this more intuitive, this patch replaces these with a
single define, which is also exported to userspace as
KVM_ARM64_SVE_VLS_WORDS.

Since the number of words in a bitmap is just the index of the last
word used + 1, this patch expresses the bound that way instead.
This should make it clearer what is being expressed.

For userspace convenience, the minimum and maximum possible vector
lengths relevant to the KVM ABI are exposed to UAPI as
KVM_ARM64_SVE_VQ_MIN, KVM_ARM64_SVE_VQ_MAX.  Since the only direct
use for these at present is manipulation of KVM_REG_ARM64_SVE_VLS,
no corresponding _VL_ macros are defined.  They could be added
later if a need arises.

Since use of DIV_ROUND_UP() was the only reason for including
<linux/kernel.h> in guest.c, this patch also removes that #include.

Suggested-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-18 17:14:02 +01:00
Dave Martin
55ffad3b63 KVM: arm64/sve: WARN when avoiding divide-by-zero in sve_reg_to_region()
sve_reg_to_region() currently passes the result of
vcpu_sve_state_size() to array_index_nospec(), effectively
leading to a divide / modulo operation.

Currently the code bails out and returns -EINVAL if
vcpu_sve_state_size() turns out to be zero, in order to avoid going
ahead and attempting to divide by zero.  This is reasonable, but it
should only happen if the kernel contains some other bug that
allowed this code to be reached without the vcpu having been
properly initialised.

To make it clear that this is a defence against bugs rather than
something that the user should be able to trigger, this patch marks
the check with WARN_ON().

Suggested-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-18 17:14:01 +01:00
Dave Martin
52110aa959 KVM: arm64/sve: Make register ioctl access errors more consistent
Currently, the way error codes are generated when processing the
SVE register access ioctls in a bit haphazard.

This patch refactors the code so that the behaviour is more
consistent: now, -EINVAL should be returned only for unrecognised
register IDs or when some other runtime error occurs.  -ENOENT is
returned for register IDs that are recognised, but whose
corresponding register (or slice) does not exist for the vcpu.

To this end, in {get,set}_sve_reg() we now delegate the
vcpu_has_sve() check down into {get,set}_sve_vls() and
sve_reg_to_region().  The KVM_REG_ARM64_SVE_VLS special case is
picked off first, then sve_reg_to_region() plays the role of
exhaustively validating or rejecting the register ID and (where
accepted) computing the applicable register region as before.

sve_reg_to_region() is rearranged so that -ENOENT or -EPERM is not
returned prematurely, before checking whether reg->id is in a
recognised range.

-EPERM is now only returned when an attempt is made to access an
actually existing register slice on an unfinalized vcpu.

Fixes: e1c9c98345 ("KVM: arm64/sve: Add SVE support to register access ioctl interface")
Fixes: 9033bba4b5 ("KVM: arm64/sve: Add pseudo-register for the guest's vector lengths")
Suggested-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-18 17:14:01 +01:00
Dave Martin
f8d4635aff KVM: arm64/sve: Miscellaneous tidyups in guest.c
* Remove a few redundant blank lines that are stylistically
   inconsistent with code already in guest.c and are just taking up
   space.

 * Delete a couple of pointless empty default cases from switch
   statements whose behaviour is otherwise obvious anyway.

 * Fix some typos and consolidate some redundantly duplicated
   comments.

 * Respell the slice index check in sve_reg_to_region() as "> 0"
   to be more consistent with what is logically being checked here
   (i.e., "is the slice index too large"), even though we don't try
   to cope with multiple slices yet.

No functional change.

Suggested-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-18 17:14:01 +01:00
Dave Martin
8ae6efdde4 KVM: arm64/sve: Clean up UAPI register ID definitions
Currently, the SVE register ID macros are not all defined in the
same way, and advertise the fact that FFR maps onto the nonexistent
predicate register P16.  This is really just for kernel
convenience, and may lead userspace into bad habits.

Instead, this patch masks the ID macro arguments so that
architecturally invalid register numbers will not be passed through
any more, and uses a literal KVM_REG_ARM64_SVE_FFR_BASE macro to
define KVM_REG_ARM64_SVE_FFR(), similarly to the way the _ZREG()
and _PREG() macros are defined.

Rather than plugging in magic numbers for the number of Z- and P-
registers and the maximum possible number of register slices, this
patch provides definitions for those too.  Userspace is going to
need them in any case, and it makes sense for them to come from
<uapi/asm/kvm.h>.

sve_reg_to_region() uses convenience constants that are defined in
a different way, and also makes use of the fact that the FFR IDs
are really contiguous with the P15 IDs, so this patch retains the
existing convenience constants in guest.c, supplemented with a
couple of sanity checks to check for consistency with the UAPI
header.

Fixes: e1c9c98345 ("KVM: arm64/sve: Add SVE support to register access ioctl interface")
Suggested-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-18 17:14:01 +01:00
Dave Martin
700698a8a9 KVM: arm64/sve: sys_regs: Demote redundant vcpu_has_sve() checks to WARNs
Because of the logic in kvm_arm_sys_reg_{get,set}_reg() and
sve_id_visibility(), we should never call
{get,set}_id_aa64zfr0_el1() for a vcpu where !vcpu_has_sve(vcpu).

To avoid the code giving the impression that it is valid for these
functions to be called in this situation, and to help the compiler
make the right optimisation decisions, this patch adds WARN_ON()
for these cases.

Given the way the logic is spread out, this seems preferable to
dropping the checks altogether.

Suggested-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-18 17:14:01 +01:00
Dave Martin
a3be836df7 KVM: arm/arm64: Demote kvm_arm_init_arch_resources() to just set up SVE
The introduction of kvm_arm_init_arch_resources() looks like
premature factoring, since nothing else uses this hook yet and it
is not clear what will use it in the future.

For now, let's not pretend that this is a general thing:

This patch simply renames the function to kvm_arm_init_sve(),
retaining the arm stub version under the new name.

Suggested-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-18 17:14:01 +01:00
Marc Zyngier
5d8d4af244 arm64: KVM: Fix system register enumeration
The introduction of the SVE registers to userspace started with a
refactoring of the way we expose any register via the ONE_REG
interface.

Unfortunately, this change doesn't exactly behave as expected
if the number of registers is non-zero and consider everything
to be an error. The visible result is that QEMU barfs very early
when creating vcpus.

Make sure we only exit early in case there is an actual error, rather
than a positive number of registers...

Fixes: be25bbb392 ("KVM: arm64: Factor out core register ID enumeration")
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-02 05:13:40 +01:00
Dave Martin
555f3d03e7 KVM: arm64: Add a capability to advertise SVE support
To provide a uniform way to check for KVM SVE support amongst other
features, this patch adds a suitable capability KVM_CAP_ARM_SVE,
and reports it as present when SVE is available.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-03-29 14:41:54 +00:00
Dave Martin
9a3cdf26e3 KVM: arm64/sve: Allow userspace to enable SVE for vcpus
Now that all the pieces are in place, this patch offers a new flag
KVM_ARM_VCPU_SVE that userspace can pass to KVM_ARM_VCPU_INIT to
turn on SVE for the guest, on a per-vcpu basis.

As part of this, support for initialisation and reset of the SVE
vector length set and registers is added in the appropriate places,
as well as finally setting the KVM_ARM64_GUEST_HAS_SVE vcpu flag,
to turn on the SVE support code.

Allocation of the SVE register storage in vcpu->arch.sve_state is
deferred until the SVE configuration is finalized, by which time
the size of the registers is known.

Setting the vector lengths supported by the vcpu is considered
configuration of the emulated hardware rather than runtime
configuration, so no support is offered for changing the vector
lengths available to an existing vcpu across reset.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-03-29 14:41:54 +00:00
Dave Martin
9033bba4b5 KVM: arm64/sve: Add pseudo-register for the guest's vector lengths
This patch adds a new pseudo-register KVM_REG_ARM64_SVE_VLS to
allow userspace to set and query the set of vector lengths visible
to the guest.

In the future, multiple register slices per SVE register may be
visible through the ioctl interface.  Once the set of slices has
been determined we would not be able to allow the vector length set
to be changed any more, in order to avoid userspace seeing
inconsistent sets of registers.  For this reason, this patch adds
support for explicit finalization of the SVE configuration via the
KVM_ARM_VCPU_FINALIZE ioctl.

Finalization is the proper place to allocate the SVE register state
storage in vcpu->arch.sve_state, so this patch adds that as
appropriate.  The data is freed via kvm_arch_vcpu_uninit(), which
was previously a no-op on arm64.

To simplify the logic for determining what vector lengths can be
supported, some code is added to KVM init to work this out, in the
kvm_arm_init_arch_resources() hook.

The KVM_REG_ARM64_SVE_VLS pseudo-register is not exposed yet.
Subsequent patches will allow SVE to be turned on for guest vcpus,
making it visible.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-03-29 14:41:54 +00:00