| Age | Commit message (Collapse) | Author | Files | Lines |
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To facilitate additional options to get_user_pages_fast() change the
singular write parameter to be gup_flags.
This patch does not change any functionality. New functionality will
follow in subsequent patches.
Some of the get_user_pages_fast() call sites were unchanged because they
already passed FOLL_WRITE or 0 for the write parameter.
NOTE: It was suggested to change the ordering of the get_user_pages_fast()
arguments to ensure that callers were converted. This breaks the current
GUP call site convention of having the returned pages be the final
parameter. So the suggestion was rejected.
Link: http://lkml.kernel.org/r/20190328084422.29911-4-ira.weiny@intel.com
Link: http://lkml.kernel.org/r/20190317183438.2057-4-ira.weiny@intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Mike Marshall <hubcap@omnibond.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Pull powerpc updates from Michael Ellerman:
"Slightly delayed due to the issue with printk() calling
probe_kernel_read() interacting with our new user access prevention
stuff, but all fixed now.
The only out-of-area changes are the addition of a cpuhp_state, small
additions to Documentation and MAINTAINERS updates.
Highlights:
- Support for Kernel Userspace Access/Execution Prevention (like
SMAP/SMEP/PAN/PXN) on some 64-bit and 32-bit CPUs. This prevents
the kernel from accidentally accessing userspace outside
copy_to/from_user(), or ever executing userspace.
- KASAN support on 32-bit.
- Rework of where we map the kernel, vmalloc, etc. on 64-bit hash to
use the same address ranges we use with the Radix MMU.
- A rewrite into C of large parts of our idle handling code for
64-bit Book3S (ie. power8 & power9).
- A fast path entry for syscalls on 32-bit CPUs, for a 12-17% speedup
in the null_syscall benchmark.
- On 64-bit bare metal we have support for recovering from errors
with the time base (our clocksource), however if that fails
currently we hang in __delay() and never crash. We now have support
for detecting that case and short circuiting __delay() so we at
least panic() and reboot.
- Add support for optionally enabling the DAWR on Power9, which had
to be disabled by default due to a hardware erratum. This has the
effect of enabling hardware breakpoints for GDB, the downside is a
badly behaved program could crash the machine by pointing the DAWR
at cache inhibited memory. This is opt-in obviously.
- xmon, our crash handler, gets support for a read only mode where
operations that could change memory or otherwise disturb the system
are disabled.
Plus many clean-ups, reworks and minor fixes etc.
Thanks to: Christophe Leroy, Akshay Adiga, Alastair D'Silva, Alexey
Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar,
Anton Blanchard, Ben Hutchings, Bo YU, Breno Leitao, Cédric Le Goater,
Christopher M. Riedl, Christoph Hellwig, Colin Ian King, David Gibson,
Ganesh Goudar, Gautham R. Shenoy, George Spelvin, Greg Kroah-Hartman,
Greg Kurz, Horia Geantă, Jagadeesh Pagadala, Joel Stanley, Joe
Perches, Julia Lawall, Laurentiu Tudor, Laurent Vivier, Lukas Bulwahn,
Madhavan Srinivasan, Mahesh Salgaonkar, Mathieu Malaterre, Michael
Neuling, Mukesh Ojha, Nathan Fontenot, Nathan Lynch, Nicholas Piggin,
Nick Desaulniers, Oliver O'Halloran, Peng Hao, Qian Cai, Ravi
Bangoria, Rick Lindsley, Russell Currey, Sachin Sant, Stewart Smith,
Sukadev Bhattiprolu, Thomas Huth, Tobin C. Harding, Tyrel Datwyler,
Valentin Schneider, Wei Yongjun, Wen Yang, YueHaibing"
* tag 'powerpc-5.2-1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (205 commits)
powerpc/64s: Use early_mmu_has_feature() in set_kuap()
powerpc/book3s/64: check for NULL pointer in pgd_alloc()
powerpc/mm: Fix hugetlb page initialization
ocxl: Fix return value check in afu_ioctl()
powerpc/mm: fix section mismatch for setup_kup()
powerpc/mm: fix redundant inclusion of pgtable-frag.o in Makefile
powerpc/mm: Fix makefile for KASAN
powerpc/kasan: add missing/lost Makefile
selftests/powerpc: Add a signal fuzzer selftest
powerpc/booke64: set RI in default MSR
ocxl: Provide global MMIO accessors for external drivers
ocxl: move event_fd handling to frontend
ocxl: afu_irq only deals with IRQ IDs, not offsets
ocxl: Allow external drivers to use OpenCAPI contexts
ocxl: Create a clear delineation between ocxl backend & frontend
ocxl: Don't pass pci_dev around
ocxl: Split pci.c
ocxl: Remove some unused exported symbols
ocxl: Remove superfluous 'extern' from headers
ocxl: read_pasid never returns an error, so make it void
...
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Pull pidfd updates from Christian Brauner:
"This patchset makes it possible to retrieve pidfds at process creation
time by introducing the new flag CLONE_PIDFD to the clone() system
call. Linus originally suggested to implement this as a new flag to
clone() instead of making it a separate system call.
After a thorough review from Oleg CLONE_PIDFD returns pidfds in the
parent_tidptr argument. This means we can give back the associated pid
and the pidfd at the same time. Access to process metadata information
thus becomes rather trivial.
As has been agreed, CLONE_PIDFD creates file descriptors based on
anonymous inodes similar to the new mount api. They are made
unconditional by this patchset as they are now needed by core kernel
code (vfs, pidfd) even more than they already were before (timerfd,
signalfd, io_uring, epoll etc.). The core patchset is rather small.
The bulky looking changelist is caused by David's very simple changes
to Kconfig to make anon inodes unconditional.
A pidfd comes with additional information in fdinfo if the kernel
supports procfs. The fdinfo file contains the pid of the process in
the callers pid namespace in the same format as the procfs status
file, i.e. "Pid:\t%d".
To remove worries about missing metadata access this patchset comes
with a sample/test program that illustrates how a combination of
CLONE_PIDFD and pidfd_send_signal() can be used to gain race-free
access to process metadata through /proc/<pid>.
Further work based on this patchset has been done by Joel. His work
makes pidfds pollable. It finished too late for this merge window. I
would prefer to have it sitting in linux-next for a while and send it
for inclusion during the 5.3 merge window"
* tag 'pidfd-v5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
samples: show race-free pidfd metadata access
signal: support CLONE_PIDFD with pidfd_send_signal
clone: add CLONE_PIDFD
Make anon_inodes unconditional
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Merge our topic branch shared with KVM. In particular this includes the
rewrite of the idle code into C.
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Reimplement Book3S idle code in C, moving POWER7/8/9 implementation
speific HV idle code to the powernv platform code.
Book3S assembly stubs are kept in common code and used only to save
the stack frame and non-volatile GPRs before executing architected
idle instructions, and restoring the stack and reloading GPRs then
returning to C after waking from idle.
The complex logic dealing with threads and subcores, locking, SPRs,
HMIs, timebase resync, etc., is all done in C which makes it more
maintainable.
This is not a strict translation to C code, there are some
significant differences:
- Idle wakeup no longer uses the ->cpu_restore call to reinit SPRs,
but saves and restores them itself.
- The optimisation where EC=ESL=0 idle modes did not have to save GPRs
or change MSR is restored, because it's now simple to do. ESL=1
sleeps that do not lose GPRs can use this optimization too.
- KVM secondary entry and cede is now more of a call/return style
rather than branchy. nap_state_lost is not required because KVM
always returns via NVGPR restoring path.
- KVM secondary wakeup from offline sequence is moved entirely into
the offline wakeup, which avoids a hwsync in the normal idle wakeup
path.
Performance measured with context switch ping-pong on different
threads or cores, is possibly improved a small amount, 1-3% depending
on stop state and core vs thread test for shallow states. Deep states
it's in the noise compared with other latencies.
KVM improvements:
- Idle sleepers now always return to caller rather than branch out
to KVM first.
- This allows optimisations like very fast return to caller when no
state has been lost.
- KVM no longer requires nap_state_lost because it controls NVGPR
save/restore itself on the way in and out.
- The heavy idle wakeup KVM request check can be moved out of the
normal host idle code and into the not-performance-critical offline
code.
- KVM nap code now returns from where it is called, which makes the
flow a bit easier to follow.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Squash the KVM changes in]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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This patch maps vmalloc, IO and vmemap regions in the 0xc address range
instead of the current 0xd and 0xf range. This brings the mapping closer
to radix translation mode.
With hash 64K page size each of this region is 512TB whereas with 4K config
we are limited by the max page table range of 64TB and hence there regions
are of 16TB size.
The kernel mapping is now:
On 4K hash
kernel_region_map_size = 16TB
kernel vmalloc start = 0xc000100000000000
kernel IO start = 0xc000200000000000
kernel vmemmap start = 0xc000300000000000
64K hash, 64K radix and 4k radix:
kernel_region_map_size = 512TB
kernel vmalloc start = 0xc008000000000000
kernel IO start = 0xc00a000000000000
kernel vmemmap start = 0xc00c000000000000
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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This adds a flag so that the DAWR can be enabled on P9 via:
echo Y > /sys/kernel/debug/powerpc/dawr_enable_dangerous
The DAWR was previously force disabled on POWER9 in:
9654153158 powerpc: Disable DAWR in the base POWER9 CPU features
Also see Documentation/powerpc/DAWR-POWER9.txt
This is a dangerous setting, USE AT YOUR OWN RISK.
Some users may not care about a bad user crashing their box
(ie. single user/desktop systems) and really want the DAWR. This
allows them to force enable DAWR.
This flag can also be used to disable DAWR access. Once this is
cleared, all DAWR access should be cleared immediately and your
machine once again safe from crashing.
Userspace may get confused by toggling this. If DAWR is force
enabled/disabled between getting the number of breakpoints (via
PTRACE_GETHWDBGINFO) and setting the breakpoint, userspace will get an
inconsistent view of what's available. Similarly for guests.
For the DAWR to be enabled in a KVM guest, the DAWR needs to be force
enabled in the host AND the guest. For this reason, this won't work on
POWERVM as it doesn't allow the HCALL to work. Writes of 'Y' to the
dawr_enable_dangerous file will fail if the hypervisor doesn't support
writing the DAWR.
To double check the DAWR is working, run this kernel selftest:
tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak.c
Any errors/failures/skips mean something is wrong.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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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>
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Guest physical to user address translation uses KVM memslots and reading
these requires holding the kvm->srcu lock. However recently introduced
kvmppc_tce_validate() broke the rule (see the lockdep warning below).
This moves srcu_read_lock(&vcpu->kvm->srcu) earlier to protect
kvmppc_tce_validate() as well.
=============================
WARNING: suspicious RCU usage
5.1.0-rc2-le_nv2_aikATfstn1-p1 #380 Not tainted
-----------------------------
include/linux/kvm_host.h:605 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by qemu-system-ppc/8020:
#0: 0000000094972fe9 (&vcpu->mutex){+.+.}, at: kvm_vcpu_ioctl+0xdc/0x850 [kvm]
stack backtrace:
CPU: 44 PID: 8020 Comm: qemu-system-ppc Not tainted 5.1.0-rc2-le_nv2_aikATfstn1-p1 #380
Call Trace:
[c000003fece8f740] [c000000000bcc134] dump_stack+0xe8/0x164 (unreliable)
[c000003fece8f790] [c000000000181be0] lockdep_rcu_suspicious+0x130/0x170
[c000003fece8f810] [c0000000000d5f50] kvmppc_tce_to_ua+0x280/0x290
[c000003fece8f870] [c00800001a7e2c78] kvmppc_tce_validate+0x80/0x1b0 [kvm]
[c000003fece8f8e0] [c00800001a7e3fac] kvmppc_h_put_tce+0x94/0x3e4 [kvm]
[c000003fece8f9a0] [c00800001a8baac4] kvmppc_pseries_do_hcall+0x30c/0xce0 [kvm_hv]
[c000003fece8fa10] [c00800001a8bd89c] kvmppc_vcpu_run_hv+0x694/0xec0 [kvm_hv]
[c000003fece8fae0] [c00800001a7d95dc] kvmppc_vcpu_run+0x34/0x48 [kvm]
[c000003fece8fb00] [c00800001a7d56bc] kvm_arch_vcpu_ioctl_run+0x2f4/0x400 [kvm]
[c000003fece8fb90] [c00800001a7c3618] kvm_vcpu_ioctl+0x460/0x850 [kvm]
[c000003fece8fd00] [c00000000041c4f4] do_vfs_ioctl+0xe4/0x930
[c000003fece8fdb0] [c00000000041ce04] ksys_ioctl+0xc4/0x110
[c000003fece8fe00] [c00000000041ce78] sys_ioctl+0x28/0x80
[c000003fece8fe20] [c00000000000b5a4] system_call+0x5c/0x70
Fixes: 42de7b9e2167 ("KVM: PPC: Validate TCEs against preregistered memory page sizes", 2018-09-10)
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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There is a hardware bug in some POWER9 processors where a treclaim in
fake suspend mode can cause an inconsistency in the XER[SO] bit across
the threads of a core, the workaround being to force the core into SMT4
when doing the treclaim.
The FAKE_SUSPEND bit (bit 10) in the PSSCR is used to control whether a
thread is in fake suspend or real suspend. The important difference here
being that thread reconfiguration is blocked in real suspend but not
fake suspend mode.
When we exit a guest which was in fake suspend mode, we force the core
into SMT4 while we do the treclaim in kvmppc_save_tm_hv().
However on the new exit path introduced with the function
kvmhv_run_single_vcpu() we restore the host PSSCR before calling
kvmppc_save_tm_hv() which means that if we were in fake suspend mode we
put the thread into real suspend mode when we clear the
PSSCR[FAKE_SUSPEND] bit. This means that we block thread reconfiguration
and the thread which is trying to get the core into SMT4 before it can
do the treclaim spins forever since it itself is blocking thread
reconfiguration. The result is that that core is essentially lost.
This results in a trace such as:
[ 93.512904] CPU: 7 PID: 13352 Comm: qemu-system-ppc Not tainted 5.0.0 #4
[ 93.512905] NIP: c000000000098a04 LR: c0000000000cc59c CTR: 0000000000000000
[ 93.512908] REGS: c000003fffd2bd70 TRAP: 0100 Not tainted (5.0.0)
[ 93.512908] MSR: 9000000302883033 <SF,HV,VEC,VSX,FP,ME,IR,DR,RI,LE,TM[SE]> CR: 22222444 XER: 00000000
[ 93.512914] CFAR: c000000000098a5c IRQMASK: 3
[ 93.512915] PACATMSCRATCH: 0000000000000001
[ 93.512916] GPR00: 0000000000000001 c000003f6cc1b830 c000000001033100 0000000000000004
[ 93.512928] GPR04: 0000000000000004 0000000000000002 0000000000000004 0000000000000007
[ 93.512930] GPR08: 0000000000000000 0000000000000004 0000000000000000 0000000000000004
[ 93.512932] GPR12: c000203fff7fc000 c000003fffff9500 0000000000000000 0000000000000000
[ 93.512935] GPR16: 2000000000300375 000000000000059f 0000000000000000 0000000000000000
[ 93.512951] GPR20: 0000000000000000 0000000000080053 004000000256f41f c000003f6aa88ef0
[ 93.512953] GPR24: c000003f6aa89100 0000000000000010 0000000000000000 0000000000000000
[ 93.512956] GPR28: c000003f9e9a0800 0000000000000000 0000000000000001 c000203fff7fc000
[ 93.512959] NIP [c000000000098a04] pnv_power9_force_smt4_catch+0x1b4/0x2c0
[ 93.512960] LR [c0000000000cc59c] kvmppc_save_tm_hv+0x40/0x88
[ 93.512960] Call Trace:
[ 93.512961] [c000003f6cc1b830] [0000000000080053] 0x80053 (unreliable)
[ 93.512965] [c000003f6cc1b8a0] [c00800001e9cb030] kvmhv_p9_guest_entry+0x508/0x6b0 [kvm_hv]
[ 93.512967] [c000003f6cc1b940] [c00800001e9cba44] kvmhv_run_single_vcpu+0x2dc/0xb90 [kvm_hv]
[ 93.512968] [c000003f6cc1ba10] [c00800001e9cc948] kvmppc_vcpu_run_hv+0x650/0xb90 [kvm_hv]
[ 93.512969] [c000003f6cc1bae0] [c00800001e8f620c] kvmppc_vcpu_run+0x34/0x48 [kvm]
[ 93.512971] [c000003f6cc1bb00] [c00800001e8f2d4c] kvm_arch_vcpu_ioctl_run+0x2f4/0x400 [kvm]
[ 93.512972] [c000003f6cc1bb90] [c00800001e8e3918] kvm_vcpu_ioctl+0x460/0x7d0 [kvm]
[ 93.512974] [c000003f6cc1bd00] [c0000000003ae2c0] do_vfs_ioctl+0xe0/0x8e0
[ 93.512975] [c000003f6cc1bdb0] [c0000000003aeb24] ksys_ioctl+0x64/0xe0
[ 93.512978] [c000003f6cc1be00] [c0000000003aebc8] sys_ioctl+0x28/0x80
[ 93.512981] [c000003f6cc1be20] [c00000000000b3a4] system_call+0x5c/0x70
[ 93.512983] Instruction dump:
[ 93.512986] 419dffbc e98c0000 2e8b0000 38000001 60000000 60000000 60000000 40950068
[ 93.512993] 392bffff 39400000 79290020 39290001 <7d2903a6> 60000000 60000000 7d235214
To fix this we preserve the PSSCR[FAKE_SUSPEND] bit until we call
kvmppc_save_tm_hv() which will mean the core can get into SMT4 and
perform the treclaim. Note kvmppc_save_tm_hv() clears the
PSSCR[FAKE_SUSPEND] bit again so there is no need to explicitly do that.
Fixes: 95a6432ce9038 ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests")
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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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
...
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Merge another commit in the topic/ppc-kvm branch we're sharing with
kvm-ppc.
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Add KVM_PPC_CPU_CHAR_BCCTR_FLUSH_ASSIST &
KVM_PPC_CPU_BEHAV_FLUSH_COUNT_CACHE to the characteristics returned
from the H_GET_CPU_CHARACTERISTICS H-CALL, as queried from either the
hypervisor or the device tree.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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When activating CONFIG_THREAD_INFO_IN_TASK, linux/sched.h includes
asm/current.h. This generates a circular dependency. To avoid that,
asm/processor.h shall not be included in mmu-hash.h.
In order to do that, this patch moves into a new header called
asm/task_size_64/32.h all the TASK_SIZE related constants, which can
then be included in mmu-hash.h directly.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Split out all the TASK_SIZE constants not just 64-bit ones]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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PPC KVM update for 5.1
There are no major new features this time, just a collection of bug
fixes and improvements in various areas, including machine check
handling and context switching of protection-key-related registers.
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This merges in the "ppc-kvm" topic branch of the powerpc tree to get a
series of commits that touch both general arch/powerpc code and KVM
code. These commits will be merged both via the KVM tree and the
powerpc tree.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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When the hash MMU is active the AMR, IAMR and UAMOR are used for
pkeys. The AMR is directly writable by user space, and the UAMOR masks
those writes, meaning both registers are effectively user register
state. The IAMR is used to create an execute only key.
Also we must maintain the value of at least the AMR when running in
process context, so that any memory accesses done by the kernel on
behalf of the process are correctly controlled by the AMR.
Although we are correctly switching all registers when going into a
guest, on returning to the host we just write 0 into all regs, except
on Power9 where we restore the IAMR correctly.
This could be observed by a user process if it writes the AMR, then
runs a guest and we then return immediately to it without
rescheduling. Because we have written 0 to the AMR that would have the
effect of granting read/write permission to pages that the process was
trying to protect.
In addition, when using the Radix MMU, the AMR can prevent inadvertent
kernel access to userspace data, writing 0 to the AMR disables that
protection.
So save and restore AMR, IAMR and UAMOR.
Fixes: cf43d3b26452 ("powerpc: Enable pkey subsystem")
Cc: stable@vger.kernel.org # v4.16+
Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Paul Mackerras <paulus@ozlabs.org>
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The anon fd's ops releases the KVM reference in the release hook.
However we reference the KVM object after we create the fd so there is
small window when the release function can be called and
dereferenced the KVM object which potentially may free it.
It is not a problem at the moment as the file is created and KVM is
referenced under the KVM lock and the release function obtains the same
lock before dereferencing the KVM (although the lock is not held when
calling kvm_put_kvm()) but it is potentially fragile against future changes.
This references the KVM object before creating a file.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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Currently trying to build without IOMMU support will fail:
(.text+0x1380): undefined reference to `kvmppc_h_get_tce'
(.text+0x1384): undefined reference to `kvmppc_rm_h_put_tce'
(.text+0x149c): undefined reference to `kvmppc_rm_h_stuff_tce'
(.text+0x14a0): undefined reference to `kvmppc_rm_h_put_tce_indirect'
This happens because turning off IOMMU support will prevent
book3s_64_vio_hv.c from being built because it is only built when
SPAPR_TCE_IOMMU is set, which depends on IOMMU support.
Fix it using ifdefs for the undefined references.
Fixes: 76d837a4c0f9 ("KVM: PPC: Book3S PR: Don't include SPAPR TCE code on non-pseries platforms")
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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Merge commits we're sharing with kvm-ppc tree.
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This adds an "in_guest" parameter to machine_check_print_event_info()
so that we can avoid trying to translate guest NIP values into
symbolic form using the host kernel's symbol table.
Reviewed-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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This makes the handling of machine check interrupts that occur inside
a guest simpler and more robust, with less done in assembler code and
in real mode.
Now, when a machine check occurs inside a guest, we always get the
machine check event struct and put a copy in the vcpu struct for the
vcpu where the machine check occurred. We no longer call
machine_check_queue_event() from kvmppc_realmode_mc_power7(), because
on POWER8, when a vcpu is running on an offline secondary thread and
we call machine_check_queue_event(), that calls irq_work_queue(),
which doesn't work because the CPU is offline, but instead triggers
the WARN_ON(lazy_irq_pending()) in pnv_smp_cpu_kill_self() (which
fires again and again because nothing clears the condition).
All that machine_check_queue_event() actually does is to cause the
event to be printed to the console. For a machine check occurring in
the guest, we now print the event in kvmppc_handle_exit_hv()
instead.
The assembly code at label machine_check_realmode now just calls C
code and then continues exiting the guest. We no longer either
synthesize a machine check for the guest in assembly code or return
to the guest without a machine check.
The code in kvmppc_handle_exit_hv() is extended to handle the case
where the guest is not FWNMI-capable. In that case we now always
synthesize a machine check interrupt for the guest. Previously, if
the host thinks it has recovered the machine check fully, it would
return to the guest without any notification that the machine check
had occurred. If the machine check was caused by some action of the
guest (such as creating duplicate SLB entries), it is much better to
tell the guest that it has caused a problem. Therefore we now always
generate a machine check interrupt for guests that are not
FWNMI-capable.
Reviewed-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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kvmhv_p9_guest_entry() implements a fast-path guest entry for Power9
when guest and host are both running with the Radix MMU.
Currently in that path we don't save the host AMR (Authority Mask
Register) value, and we always restore 0 on return to the host. That
is OK at the moment because the AMR is not used for storage keys with
the Radix MMU.
However we plan to start using the AMR on Radix to prevent the kernel
from reading/writing to userspace outside of copy_to/from_user(). In
order to make that work we need to save/restore the AMR value.
We only restore the value if it is different from the guest value,
which is already in the register when we exit to the host. This should
mean we rarely need to actually restore the value when running a
modern Linux as a guest, because it will be using the same value as
us.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Russell Currey <ruscur@russell.cc>
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grow_halt_poll_ns() have a strange behaviour in case
(vcpu->halt_poll_ns != 0) &&
(vcpu->halt_poll_ns < halt_poll_ns_grow_start).
In this case, vcpu->halt_poll_ns will be multiplied by grow factor
(halt_poll_ns_grow) which will require several grow iteration in order
to reach a value bigger than halt_poll_ns_grow_start.
This means that growing vcpu->halt_poll_ns from value of 0 is slower
than growing it from a positive value less than halt_poll_ns_grow_start.
Which is misleading and inaccurate.
Fix issue by changing grow_halt_poll_ns() to set vcpu->halt_poll_ns
to halt_poll_ns_grow_start in any case that
(vcpu->halt_poll_ns < halt_poll_ns_grow_start).
Regardless if vcpu->halt_poll_ns is 0.
use READ_ONCE to get a consistent number for all cases.
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Nir Weiner <nir.weiner@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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The hard-coded value 10000 in grow_halt_poll_ns() stands for the initial
start value when raising up vcpu->halt_poll_ns.
It actually sets the first timeout to the first polling session.
This value has significant effect on how tolerant we are to outliers.
On the standard case, higher value is better - we will spend more time
in the polling busyloop, handle events/interrupts faster and result
in better performance.
But on outliers it puts us in a busy loop that does nothing.
Even if the shrink factor is zero, we will still waste time on the first
iteration.
The optimal value changes between different workloads. It depends on
outliers rate and polling sessions length.
As this value has significant effect on the dynamic halt-polling
algorithm, it should be configurable and exposed.
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Nir Weiner <nir.weiner@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
grow_halt_poll_ns() have a strange behavior in case
(halt_poll_ns_grow == 0) && (vcpu->halt_poll_ns != 0).
In this case, vcpu->halt_pol_ns will be set to zero.
That results in shrinking instead of growing.
Fix issue by changing grow_halt_poll_ns() to not modify
vcpu->halt_poll_ns in case halt_poll_ns_grow is zero
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Nir Weiner <nir.weiner@oracle.com>
Suggested-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
This adds an entry to the kvm_stats_debugfs directory which provides the
number of large (2M or 1G) pages which have been used to setup the guest
mappings, for radix guests.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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|
The SPAPR TCE KVM device references all hardware IOMMU tables assigned to
some IOMMU group to ensure that in-kernel KVM acceleration of H_PUT_TCE
can work. The tables are references when an IOMMU group gets registered
with the VFIO KVM device by the KVM_DEV_VFIO_GROUP_ADD ioctl;
KVM_DEV_VFIO_GROUP_DEL calls into the dereferencing code
in kvm_spapr_tce_release_iommu_group() which walks through the list of
LIOBNs, finds a matching IOMMU table and calls kref_put() when found.
However that code stops after the very first successful derefencing
leaving other tables referenced till the SPAPR TCE KVM device is destroyed
which normally happens on guest reboot or termination so if we do hotplug
and unplug in a loop, we are leaking IOMMU tables here.
This removes a premature return to let kvm_spapr_tce_release_iommu_group()
find and dereference all attached tables.
Fixes: 121f80ba68f ("KVM: PPC: VFIO: Add in-kernel acceleration for VFIO")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
|
|
Devices on the KVM_FAST_MMIO_BUS by definition have length zero and are
thus used for notification purposes rather than data transfer. For
example eventfd for virtio devices.
This means that when emulating mmio instructions which target devices on
this bus we can immediately handle them and return without needing to load
the instruction from guest memory.
For now we restrict this to stores as this is the only use case at
present.
For a normal guest the effect is negligible, however for a nested guest
we save on the order of 5us per access.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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|
Currently, the KVM code assumes that if the host kernel is using the
XIVE interrupt controller (the new interrupt controller that first
appeared in POWER9 systems), then the in-kernel XICS emulation will
use the XIVE hardware to deliver interrupts to the guest. However,
this only works when the host is running in hypervisor mode and has
full access to all of the XIVE functionality. It doesn't work in any
nested virtualization scenario, either with PR KVM or nested-HV KVM,
because the XICS-on-XIVE code calls directly into the native-XIVE
routines, which are not initialized and cannot function correctly
because they use OPAL calls, and OPAL is not available in a guest.
This means that using the in-kernel XICS emulation in a nested
hypervisor that is using XIVE as its interrupt controller will cause a
(nested) host kernel crash. To fix this, we change most of the places
where the current code calls xive_enabled() to select between the
XICS-on-XIVE emulation and the plain XICS emulation to call a new
function, xics_on_xive(), which returns false in a guest.
However, there is a further twist. The plain XICS emulation has some
functions which are used in real mode and access the underlying XICS
controller (the interrupt controller of the host) directly. In the
case of a nested hypervisor, this means doing XICS hypercalls
directly. When the nested host is using XIVE as its interrupt
controller, these hypercalls will fail. Therefore this also adds
checks in the places where the XICS emulation wants to access the
underlying interrupt controller directly, and if that is XIVE, makes
the code use the virtual mode fallback paths, which call generic
kernel infrastructure rather than doing direct XICS access.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
|
|
The header search path -I. in kernel Makefiles is very suspicious;
it allows the compiler to search for headers in the top of $(srctree),
where obviously no header file exists.
Commit 46f43c6ee022 ("KVM: powerpc: convert marker probes to event
trace") first added these options, but they are completely useless.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
|
|
Replace kmalloc_node and memset with kzalloc_node
Signed-off-by: wangbo <wang.bo116@zte.com.cn>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
|
|
Recent kernels, since commit e15a4fea4dee ("powerpc/64s/hash: Add
some SLB debugging tests", 2018-10-03) use the slbfee. instruction,
which PR KVM currently does not have code to emulate. Consequently
recent kernels fail to boot under PR KVM. This adds emulation of
slbfee., enabling these kernels to boot successfully.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
|
|
The header search path -I. in kernel Makefiles is very suspicious;
it allows the compiler to search for headers in the top of $(srctree),
where obviously no header file exists.
Commit 46f43c6ee022 ("KVM: powerpc: convert marker probes to event
trace") first added these options, but they are completely useless.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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We have a fix to apply on top of commit 96d4f267e40f ("Remove 'type'
argument from access_ok() function"), so merge master to get it.
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Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.
It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access. But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.
A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model. And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.
This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.
There were a couple of notable cases:
- csky still had the old "verify_area()" name as an alias.
- the iter_iov code had magical hardcoded knowledge of the actual
values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
really used it)
- microblaze used the type argument for a debug printout
but other than those oddities this should be a total no-op patch.
I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something. Any missed conversion should be trivially fixable, though.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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|
Old GCCs (4.6.3 at least), aren't able to follow the logic in
__kvmhv_copy_tofrom_guest_radix() and warn that old_pid is used
uninitialized:
arch/powerpc/kvm/book3s_64_mmu_radix.c:75:3: error: 'old_pid' may be
used uninitialized in this function
The logic is OK, we only use old_pid if quadrant == 1, and in that
case it has definitely be initialised, eg:
if (quadrant == 1) {
old_pid = mfspr(SPRN_PID);
...
if (quadrant == 1 && pid != old_pid)
mtspr(SPRN_PID, old_pid);
Annotate it to fix the error.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Pull Kconfig updates from Masahiro Yamada:
- support -y option for merge_config.sh to avoid downgrading =y to =m
- remove S_OTHER symbol type, and touch include/config/*.h files correctly
- fix file name and line number in lexer warnings
- fix memory leak when EOF is encountered in quotation
- resolve all shift/reduce conflicts of the parser
- warn no new line at end of file
- make 'source' statement more strict to take only string literal
- rewrite the lexer and remove the keyword lookup table
- convert to SPDX License Identifier
- compile C files independently instead of including them from zconf.y
- fix various warnings of gconfig
- misc cleanups
* tag 'kconfig-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (39 commits)
kconfig: surround dbg_sym_flags with #ifdef DEBUG to fix gconf warning
kconfig: split images.c out of qconf.cc/gconf.c to fix gconf warnings
kconfig: add static qualifiers to fix gconf warnings
kconfig: split the lexer out of zconf.y
kconfig: split some C files out of zconf.y
kconfig: convert to SPDX License Identifier
kconfig: remove keyword lookup table entirely
kconfig: update current_pos in the second lexer
kconfig: switch to ASSIGN_VAL state in the second lexer
kconfig: stop associating kconf_id with yylval
kconfig: refactor end token rules
kconfig: stop supporting '.' and '/' in unquoted words
treewide: surround Kconfig file paths with double quotes
microblaze: surround string default in Kconfig with double quotes
kconfig: use T_WORD instead of T_VARIABLE for variables
kconfig: use specific tokens instead of T_ASSIGN for assignments
kconfig: refactor scanning and parsing "option" properties
kconfig: use distinct tokens for type and default properties
kconfig: remove redundant token defines
kconfig: rename depends_list to comment_option_list
...
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Pull powerpc updates from Michael Ellerman:
"Notable changes:
- Mitigations for Spectre v2 on some Freescale (NXP) CPUs.
- A large series adding support for pass-through of Nvidia V100 GPUs
to guests on Power9.
- Another large series to enable hardware assistance for TLB table
walk on MPC8xx CPUs.
- Some preparatory changes to our DMA code, to make way for further
cleanups from Christoph.
- Several fixes for our Transactional Memory handling discovered by
fuzzing the signal return path.
- Support for generating our system call table(s) from a text file
like other architectures.
- A fix to our page fault handler so that instead of generating a
WARN_ON_ONCE, user accesses of kernel addresses instead print a
ratelimited and appropriately scary warning.
- A cosmetic change to make our unhandled page fault messages more
similar to other arches and also more compact and informative.
- Freescale updates from Scott:
"Highlights include elimination of legacy clock bindings use from
dts files, an 83xx watchdog handler, fixes to old dts interrupt
errors, and some minor cleanup."
And many clean-ups, reworks and minor fixes etc.
Thanks to: Alexandre Belloni, Alexey Kardashevskiy, Andrew Donnellan,
Aneesh Kumar K.V, Arnd Bergmann, Benjamin Herrenschmidt, Breno Leitao,
Christian Lamparter, Christophe Leroy, Christoph Hellwig, Daniel
Axtens, Darren Stevens, David Gibson, Diana Craciun, Dmitry V. Levin,
Firoz Khan, Geert Uytterhoeven, Greg Kurz, Gustavo Romero, Hari
Bathini, Joel Stanley, Kees Cook, Madhavan Srinivasan, Mahesh
Salgaonkar, Markus Elfring, Mathieu Malaterre, Michal Suchánek, Naveen
N. Rao, Nick Desaulniers, Oliver O'Halloran, Paul Mackerras, Ram Pai,
Ravi Bangoria, Rob Herring, Russell Currey, Sabyasachi Gupta, Sam
Bobroff, Satheesh Rajendran, Scott Wood, Segher Boessenkool, Stephen
Rothwell, Tang Yuantian, Thiago Jung Bauermann, Yangtao Li, Yuantian
Tang, Yue Haibing"
* tag 'powerpc-4.21-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (201 commits)
Revert "powerpc/fsl_pci: simplify fsl_pci_dma_set_mask"
powerpc/zImage: Also check for stdout-path
powerpc: Fix HMIs on big-endian with CONFIG_RELOCATABLE=y
macintosh: Use of_node_name_{eq, prefix} for node name comparisons
ide: Use of_node_name_eq for node name comparisons
powerpc: Use of_node_name_eq for node name comparisons
powerpc/pseries/pmem: Convert to %pOFn instead of device_node.name
powerpc/mm: Remove very old comment in hash-4k.h
powerpc/pseries: Fix node leak in update_lmb_associativity_index()
powerpc/configs/85xx: Enable CONFIG_DEBUG_KERNEL
powerpc/dts/fsl: Fix dtc-flagged interrupt errors
clk: qoriq: add more compatibles strings
powerpc/fsl: Use new clockgen binding
powerpc/83xx: handle machine check caused by watchdog timer
powerpc/fsl-rio: fix spelling mistake "reserverd" -> "reserved"
powerpc/fsl_pci: simplify fsl_pci_dma_set_mask
arch/powerpc/fsl_rmu: Use dma_zalloc_coherent
vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriver
vfio_pci: Allow regions to add own capabilities
vfio_pci: Allow mapping extra regions
...
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The Kconfig lexer supports special characters such as '.' and '/' in
the parameter context. In my understanding, the reason is just to
support bare file paths in the source statement.
I do not see a good reason to complicate Kconfig for the room of
ambiguity.
The majority of code already surrounds file paths with double quotes,
and it makes sense since file paths are constant string literals.
Make it treewide consistent now.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
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Second PPC KVM update for 4.21
This has 5 commits that fix page dirty tracking when running nested
HV KVM guests, from Suraj Jitindar Singh.
|
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The patch is to make kvm_set_spte_hva() return int and caller can
check return value to determine flush tlb or not.
Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com>
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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This new memory does not have page structs as it is not plugged to
the host so gup() will fail anyway.
This adds 2 helpers:
- mm_iommu_newdev() to preregister the "memory device" memory so
the rest of API can still be used;
- mm_iommu_is_devmem() to know if the physical address is one of thise
new regions which we must avoid unpinning of.
This adds @mm to tce_page_is_contained() and iommu_tce_xchg() to test
if the memory is device memory to avoid pfn_to_page().
This adds a check for device memory in mm_iommu_ua_mark_dirty_rm() which
does delayed pages dirtying.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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The rc bits contained in ptes are used to track whether a page has been
accessed and whether it is dirty. The accessed bit is used to age a page
and the dirty bit to track whether a page is dirty or not.
Now that we support nested guests there are three ptes which track the
state of the same page:
- The partition-scoped page table in the L1 guest, mapping L2->L1 address
- The partition-scoped page table in the host for the L1 guest, mapping
L1->L0 address
- The shadow partition-scoped page table for the nested guest in the host,
mapping L2->L0 address
The idea is to attempt to keep the rc state of these three ptes in sync,
both when setting and when clearing rc bits.
When setting the bits we achieve consistency by:
- Initially setting the bits in the shadow page table as the 'and' of the
other two.
- When updating in software the rc bits in the shadow page table we
ensure the state is consistent with the other two locations first, and
update these before reflecting the change into the shadow page table.
i.e. only set the bits in the L2->L0 pte if also set in both the
L2->L1 and the L1->L0 pte.
When clearing the bits we achieve consistency by:
- The rc bits in the shadow page table are only cleared when discarding
a pte, and we don't need to record this as if either bit is set then
it must also be set in the pte mapping L1->L0.
- When L1 clears an rc bit in the L2->L1 mapping it __should__ issue a
tlbie instruction
- This means we will discard the pte from the shadow page table
meaning the mapping will have to be setup again.
- When setup the pte again in the shadow page table we will ensure
consistency with the L2->L1 pte.
- When the host clears an rc bit in the L1->L0 mapping we need to also
clear the bit in any ptes in the shadow page table which map the same
gfn so we will be notified if a nested guest accesses the page.
This case is what this patch specifically concerns.
- We can search the nest_rmap list for that given gfn and clear the
same bit from all corresponding ptes in shadow page tables.
- If a nested guest causes either of the rc bits to be set by software
in future then we will update the L1->L0 pte and maintain consistency.
With the process outlined above we aim to maintain consistency of the 3
pte locations where we track rc for a given guest page.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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Introduce a function kvmhv_update_nest_rmap_rc_list() which for a given
nest_rmap list will traverse it, find the corresponding pte in the shadow
page tables, and if it still maps the same host page update the rc bits
accordingly.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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The shadow page table contains ptes for translations from nested guest
address to host address. Currently when creating these ptes we take the
rc bits from the pte for the L1 guest address to host address
translation. This is incorrect as we must also factor in the rc bits
from the pte for the nested guest address to L1 guest address
translation (as contained in the L1 guest partition table for the nested
guest).
By not calculating these bits correctly L1 may not have been correctly
notified when it needed to update its rc bits in the partition table it
maintains for its nested guest.
Modify the code so that the rc bits in the resultant pte for the L2->L0
translation are the 'and' of the rc bits in the L2->L1 pte and the L1->L0
pte, also accounting for whether this was a write access when setting
the dirty bit.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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Nested rmap entries are used to store the translation from L1 gpa to L2
gpa when entries are inserted into the shadow (nested) page tables. This
rmap list is located by indexing the rmap array in the memslot by L1
gfn. When we come to search for these entries we only know the L1 page size
(which could be PAGE_SIZE, 2M or a 1G page) and so can only select a gfn
aligned to that size. This means that when we insert the entry, so we can
find it later, we need to align the gfn we use to select the rmap list
in which to insert the entry to L1 page size as well.
By not doing this we were missing nested rmap entries when modifying L1
ptes which were for a page also passed through to an L2 guest.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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We already hold the kvm->mmu_lock spin lock across updating the rc bits
in the pte for the L1 guest. Continue to hold the lock across updating
the rc bits in the pte for the nested guest as well to prevent
invalidations from occurring.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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PPC KVM update for 4.21 from Paul Mackerras
The main new feature this time is support in HV nested KVM for passing
a device that is emulated by a level 0 hypervisor and presented to
level 1 as a PCI device through to a level 2 guest using VFIO.
Apart from that there are improvements for migration of radix guests
under HV KVM and some other fixes and cleanups.
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Switching from the guest to host is another place
where the speculative accesses can be exploited.
Flush the branch predictor when entering KVM.
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Ira Weiny
Linus Torvalds
Michael Ellerman
Nicholas Piggin
Aneesh Kumar K.V
Michael Neuling
David Howells
Alexey Kardashevskiy
Suraj Jitindar Singh
Christophe Leroy
Paolo Bonzini
Paul Mackerras
Jordan Niethe
Nir Weiner
Masahiro Yamada
wangbo
Lan Tianyu
Radim Krčmář
Diana Craciun