linux_dsm_epyc7002/arch/arm/include/asm
Dave Martin e6b673b741 KVM: arm64: Optimise FPSIMD handling to reduce guest/host thrashing
This patch refactors KVM to align the host and guest FPSIMD
save/restore logic with each other for arm64.  This reduces the
number of redundant save/restore operations that must occur, and
reduces the common-case IRQ blackout time during guest exit storms
by saving the host state lazily and optimising away the need to
restore the host state before returning to the run loop.

Four hooks are defined in order to enable this:

 * kvm_arch_vcpu_run_map_fp():
   Called on PID change to map necessary bits of current to Hyp.

 * kvm_arch_vcpu_load_fp():
   Set up FP/SIMD for entering the KVM run loop (parse as
   "vcpu_load fp").

 * kvm_arch_vcpu_ctxsync_fp():
   Get FP/SIMD into a safe state for re-enabling interrupts after a
   guest exit back to the run loop.

   For arm64 specifically, this involves updating the host kernel's
   FPSIMD context tracking metadata so that kernel-mode NEON use
   will cause the vcpu's FPSIMD state to be saved back correctly
   into the vcpu struct.  This must be done before re-enabling
   interrupts because kernel-mode NEON may be used by softirqs.

 * kvm_arch_vcpu_put_fp():
   Save guest FP/SIMD state back to memory and dissociate from the
   CPU ("vcpu_put fp").

Also, the arm64 FPSIMD context switch code is updated to enable it
to save back FPSIMD state for a vcpu, not just current.  A few
helpers drive this:

 * fpsimd_bind_state_to_cpu(struct user_fpsimd_state *fp):
   mark this CPU as having context fp (which may belong to a vcpu)
   currently loaded in its registers.  This is the non-task
   equivalent of the static function fpsimd_bind_to_cpu() in
   fpsimd.c.

 * task_fpsimd_save():
   exported to allow KVM to save the guest's FPSIMD state back to
   memory on exit from the run loop.

 * fpsimd_flush_state():
   invalidate any context's FPSIMD state that is currently loaded.
   Used to disassociate the vcpu from the CPU regs on run loop exit.

These changes allow the run loop to enable interrupts (and thus
softirqs that may use kernel-mode NEON) without having to save the
guest's FPSIMD state eagerly.

Some new vcpu_arch fields are added to make all this work.  Because
host FPSIMD state can now be saved back directly into current's
thread_struct as appropriate, host_cpu_context is no longer used
for preserving the FPSIMD state.  However, it is still needed for
preserving other things such as the host's system registers.  To
avoid ABI churn, the redundant storage space in host_cpu_context is
not removed for now.

arch/arm is not addressed by this patch and continues to use its
current save/restore logic.  It could provide implementations of
the helpers later if desired.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-25 12:28:28 +01:00
..
hardware Merge branches 'fixes', 'misc', 'sa1111' and 'sa1100-for-next' into for-next 2018-01-21 15:38:10 +00:00
mach ARM/PCI: Convert PCI scan API to pci_scan_root_bus_bridge() 2017-06-28 15:13:55 -05:00
xen License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
arch_gicv3.h irqchip/gic-v3: Probe for SCR_EL3 being clear before resetting AP0Rn 2018-03-22 13:46:18 +00:00
arch_timer.h arm64 updates for 4.15 2017-11-15 10:56:56 -08:00
arm-cci.h
asm-offsets.h
assembler.h ARM: BUG if jumping to usermode address in kernel mode 2017-11-26 15:41:39 +00:00
atomic.h locking/atomic: Remove linux/atomic.h:atomic_fetch_or() 2016-06-16 10:48:32 +02:00
auxvec.h
barrier.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
bitops.h lib: optimize cpumask_next_and() 2018-02-06 18:32:44 -08:00
bitrev.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
bL_switcher.h
bug.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
bugs.h
cache.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
cacheflush.h page cache: use xa_lock 2018-04-11 10:28:39 -07:00
cachetype.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
checksum.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
clocksource.h arm/arm64: arch_timer: Use archdata to indicate vdso suitability 2016-09-23 17:19:25 +01:00
cmpxchg.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compiler.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
cp15.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
cpu.h
cpufeature.h ARM: 8663/1: wire up HWCAP/HWCAP2 feature bits to the CPU modalias 2017-03-30 19:45:52 +01:00
cpuidle.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
cputype.h Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm 2017-11-16 12:50:35 -08:00
cti.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dcc.h
delay.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
device.h ARM: dma-mapping: Don't tear down third-party mappings 2017-05-30 11:31:33 +02:00
div64.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dma-contiguous.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dma-direct.h dma/direct: Handle the memory encryption bit in common code 2018-03-20 10:01:59 +01:00
dma-iommu.h kmemcheck: remove annotations 2017-11-15 18:21:04 -08:00
dma-mapping.h dma-direct: rename dma_noop to dma_direct 2018-01-15 09:35:06 +01:00
dma.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dmi.h efi/arm: Enable DMI/SMBIOS 2017-06-05 17:50:44 +02:00
domain.h ARM: 8573/1: domain: move {set,get}_domain under config guard 2016-05-05 19:03:02 +01:00
ecard.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
edac.h
efi.h efi/arm-stub: Correct FDT and initrd allocation rules for arm64 2017-04-05 12:27:23 +02:00
elf.h Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm 2017-11-16 12:50:35 -08:00
entry-macro-multi.S License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
exception.h ARM: probes: avoid adding kprobes to sensitive kernel-entry/exit code 2017-12-17 22:14:21 +00:00
fb.h
fiq.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
firmware.h
fixmap.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
flat.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
floppy.h ARM: 8584/1: floppy: avoid gcc-6 warning 2016-07-02 11:02:13 +01:00
fncpy.h
fpstate.h
ftrace.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
futex.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
glue-cache.h ARM: 8725/1: Add Broadcom Brahma-B15 readahead cache support 2017-12-17 22:15:35 +00:00
glue-df.h
glue-pf.h
glue-proc.h
glue.h
gpio.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hardirq.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
highmem.h Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm 2017-11-16 12:50:35 -08:00
hugetlb-3level.h
hugetlb.h
hw_breakpoint.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hw_irq.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hwcap.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hypervisor.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ide.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
idmap.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
insn.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
io.h ARM: Implement pci_remap_cfgspace() interface 2017-04-24 13:53:13 -05:00
irq_work.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
irq.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
irqflags.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
jump_label.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kbuild arch: Remove clkdev.h asm-generic from Kbuild 2018-01-03 09:02:11 -08:00
kexec.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
kgdb.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
kmap_types.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
kprobes.h kprobes: move kprobe declarations to asm-generic/kprobes.h 2017-02-27 18:43:45 -08:00
kvm_arm.h arm: KVM: Fix VTTBR_BADDR_MASK BUG_ON off-by-one 2017-11-29 16:46:18 +01:00
kvm_asm.h KVM: arm64: Introduce VHE-specific kvm_vcpu_run 2018-03-19 10:53:13 +00:00
kvm_coproc.h KVM: arm: plug potential guest hardware debug leakage 2017-05-15 14:29:19 +02:00
kvm_emulate.h KVM: arm/arm64: Prepare to handle deferred save/restore of SPSR_EL1 2018-03-19 10:53:17 +00:00
kvm_host.h KVM: arm64: Optimise FPSIMD handling to reduce guest/host thrashing 2018-05-25 12:28:28 +01:00
kvm_hyp.h KVM: arm/arm64: Avoid VGICv3 save/restore on VHE with no IRQs 2018-03-19 10:53:21 +00:00
kvm_mmio.h KVM: arm/arm64: Export mmio_read/write_bus 2016-05-20 15:39:42 +02:00
kvm_mmu.h arm/arm64: KVM: Introduce EL2-specific executable mappings 2018-03-19 13:06:05 +00:00
limits.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
linkage.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mc146818rtc.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mcpm.h
mcs_spinlock.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
memblock.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
memory.h linux/const.h: move UL() macro to include/linux/const.h 2018-04-11 10:28:38 -07:00
mmu_context.h sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h> 2017-03-02 08:42:37 +01:00
mmu.h Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm 2017-11-16 12:50:35 -08:00
module.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mpu.h Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm 2017-11-16 12:50:35 -08:00
mtd-xip.h
neon.h
nwflash.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
opcodes-sec.h
opcodes-virt.h
opcodes.h
outercache.h
page-nommu.h ARM: 8684/1: NOMMU: Remove unused KTHREAD_SIZE definition 2017-06-27 14:58:10 +01:00
page.h
paravirt.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
patch.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pci.h PCI: Remove PCI_REASSIGN_ALL_RSRC use on arm and arm64 2017-12-18 23:07:43 -06:00
percpu.h
perf_event.h
pgalloc.h kmemcheck: stop using GFP_NOTRACK and SLAB_NOTRACK 2017-11-15 18:21:04 -08:00
pgtable-2level-hwdef.h ARM: 8612/1: LPAE: initialize cache policy correctly 2016-09-12 12:12:30 +01:00
pgtable-2level-types.h
pgtable-2level.h ARM: 8578/1: mm: ensure pmd_present only checks the valid bit 2016-06-09 17:51:47 +01:00
pgtable-3level-hwdef.h ARM: 8612/1: LPAE: initialize cache policy correctly 2016-09-12 12:12:30 +01:00
pgtable-3level-types.h
pgtable-3level.h arm/mm: provide pmdp_establish() helper 2018-01-31 17:18:37 -08:00
pgtable-hwdef.h
pgtable-nommu.h ARM: 8676/1: NOMMU: provide pgprot_device() macro 2017-06-05 10:29:40 +01:00
pgtable.h KVM: arm/arm64: Limit icache invalidation to prefetch aborts 2018-01-08 15:20:45 +01:00
probes.h
proc-fns.h ARM: soft-reboot into same mode that we entered the kernel 2017-04-09 07:49:24 -07:00
processor.h arm: Implement thread_struct whitelist for hardened usercopy 2018-01-15 12:08:06 -08:00
procinfo.h
prom.h
psci.h ARM: SoC cleanups for v4.5 2016-01-20 17:55:20 -08:00
ptdump.h ARM: 8737/1: mm: dump: add checking for writable and executable 2018-01-21 15:32:20 +00:00
ptrace.h linux/compiler.h: Split into compiler.h and compiler_types.h 2017-10-24 13:17:32 +02:00
sections.h ARM: probes: avoid adding kprobes to sensitive kernel-entry/exit code 2017-12-17 22:14:21 +00:00
set_memory.h treewide: move set_memory_* functions away from cacheflush.h 2017-05-08 17:15:13 -07:00
setup.h ARM: 8495/1: ATAGS: move save_atags() to arch/arm/include/asm/setup.h 2016-01-04 11:26:00 +00:00
shmparam.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
signal.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
smp_plat.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
smp_scu.h ARM: SoC platform updates for 4.15 2017-11-16 14:05:12 -08:00
smp_twd.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
smp.h ARM: 8708/1: NOMMU: Rework MPU to be mostly done in C 2017-10-23 16:58:59 +01:00
sparsemem.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
spinlock_types.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
spinlock.h Merge branch 'linus' into locking/core, to resolve conflicts 2017-11-07 10:32:44 +01:00
stackprotector.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
stacktrace.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
stage2_pgtable.h kvm-arm: arm32: Introduce stage2 page table helpers 2016-04-21 14:57:26 +02:00
string.h ARM: 8745/1: get rid of __memzero() 2018-01-21 15:37:56 +00:00
suspend.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
swab.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
switch_to.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sync_bitops.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
syscall.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
system_info.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
system_misc.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tcm.h
therm.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
thread_info.h Construct init thread stack in the linker script rather than by union 2018-01-09 23:21:02 +00:00
thread_notify.h
timex.h
tlb.h mm: fix MADV_[FREE|DONTNEED] TLB flush miss problem 2017-08-10 15:54:07 -07:00
tlbflush.h sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h> 2017-03-02 08:42:37 +01:00
tls.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
topology.h Merge branch 'pm-cpufreq' 2017-11-13 01:34:49 +01:00
traps.h ARM: probes: avoid adding kprobes to sensitive kernel-entry/exit code 2017-12-17 22:14:21 +00:00
trusted_foundations.h treewide: remove redundant #include <linux/kconfig.h> 2016-10-11 15:06:33 -07:00
uaccess.h Revert "arm/syscalls: Check address limit on user-mode return" 2017-09-17 19:45:33 +02:00
ucontext.h Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm 2017-11-16 12:50:35 -08:00
unaligned.h ARM: 8715/1: add a private asm/unaligned.h 2017-10-24 10:33:23 +01:00
unified.h ARM: 8723/2: always assume the "unified" syntax for assembly code 2017-12-17 22:14:21 +00:00
unistd.h ARM: wire up new pkey syscalls 2016-10-19 10:18:47 +01:00
unwind.h
uprobes.h
user.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
v7m.h Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm 2017-11-16 12:50:35 -08:00
vdso_datapage.h
vdso.h ARM: 8748/1: mm: Define vdso_start, vdso_end as array 2018-03-24 14:27:49 +00:00
vfp.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
vfpmacros.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
vga.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
virt.h ARM: hyp-stub/KVM: Kill __hyp_get_vectors 2017-04-09 07:49:34 -07:00
word-at-a-time.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xor.h