Commit Graph

776 Commits

Author SHA1 Message Date
Miaohe Lin faf0be2216 KVM: Fix jump label out_free_* in kvm_init()
The jump label out_free_1 and out_free_2 deal with
the same stuff, so git rid of one and rename the
label out_free_0a to retain the label name order.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-23 11:29:17 +01:00
Paolo Bonzini 46f4f0aabc Merge branch 'kvm-tsx-ctrl' into HEAD
Conflicts:
	arch/x86/kvm/vmx/vmx.c
2019-11-21 12:03:40 +01:00
Paolo Bonzini 14edff8831 KVM/arm updates for Linux 5.5:
- Allow non-ISV data aborts to be reported to userspace
 - Allow injection of data aborts from userspace
 - Expose stolen time to guests
 - GICv4 performance improvements
 - vgic ITS emulation fixes
 - Simplify FWB handling
 - Enable halt pool counters
 - Make the emulated timer PREEMPT_RT compliant
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Merge tag 'kvmarm-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm updates for Linux 5.5:

- Allow non-ISV data aborts to be reported to userspace
- Allow injection of data aborts from userspace
- Expose stolen time to guests
- GICv4 performance improvements
- vgic ITS emulation fixes
- Simplify FWB handling
- Enable halt pool counters
- Make the emulated timer PREEMPT_RT compliant

Conflicts:
	include/uapi/linux/kvm.h
2019-11-21 09:58:35 +01:00
Radim Krčmář 8750e72a79 KVM: remember position in kvm->vcpus array
Fetching an index for any vcpu in kvm->vcpus array by traversing
the entire array everytime is costly.
This patch remembers the position of each vcpu in kvm->vcpus array
by storing it in vcpus_idx under kvm_vcpu structure.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-15 11:44:21 +01:00
Marc Zyngier 9cb09e7c1c KVM: Add a comment describing the /dev/kvm no_compat handling
Add a comment explaining the rational behind having both
no_compat open and ioctl callbacks to fend off compat tasks.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-15 10:14:04 +01:00
Marc Zyngier b9876e6de1 KVM: Forbid /dev/kvm being opened by a compat task when CONFIG_KVM_COMPAT=n
On a system without KVM_COMPAT, we prevent IOCTLs from being issued
by a compat task. Although this prevents most silly things from
happening, it can still confuse a 32bit userspace that is able
to open the kvm device (the qemu test suite seems to be pretty
mad with this behaviour).

Take a more radical approach and return a -ENODEV to the compat
task.

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-13 17:13:12 +01:00
Linus Torvalds 8c5bd25bf4 Bugfixes: unwinding of KVM_CREATE_VM failure,
VT-d posted interrupts, DAX/ZONE_DEVICE,
 module unload/reload.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "Fix unwinding of KVM_CREATE_VM failure, VT-d posted interrupts,
  DAX/ZONE_DEVICE, and module unload/reload"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: MMU: Do not treat ZONE_DEVICE pages as being reserved
  KVM: VMX: Introduce pi_is_pir_empty() helper
  KVM: VMX: Do not change PID.NDST when loading a blocked vCPU
  KVM: VMX: Consider PID.PIR to determine if vCPU has pending interrupts
  KVM: VMX: Fix comment to specify PID.ON instead of PIR.ON
  KVM: X86: Fix initialization of MSR lists
  KVM: fix placement of refcount initialization
  KVM: Fix NULL-ptr deref after kvm_create_vm fails
2019-11-12 13:19:15 -08:00
Sean Christopherson a78986aae9 KVM: MMU: Do not treat ZONE_DEVICE pages as being reserved
Explicitly exempt ZONE_DEVICE pages from kvm_is_reserved_pfn() and
instead manually handle ZONE_DEVICE on a case-by-case basis.  For things
like page refcounts, KVM needs to treat ZONE_DEVICE pages like normal
pages, e.g. put pages grabbed via gup().  But for flows such as setting
A/D bits or shifting refcounts for transparent huge pages, KVM needs to
to avoid processing ZONE_DEVICE pages as the flows in question lack the
underlying machinery for proper handling of ZONE_DEVICE pages.

This fixes a hang reported by Adam Borowski[*] in dev_pagemap_cleanup()
when running a KVM guest backed with /dev/dax memory, as KVM straight up
doesn't put any references to ZONE_DEVICE pages acquired by gup().

Note, Dan Williams proposed an alternative solution of doing put_page()
on ZONE_DEVICE pages immediately after gup() in order to simplify the
auditing needed to ensure is_zone_device_page() is called if and only if
the backing device is pinned (via gup()).  But that approach would break
kvm_vcpu_{un}map() as KVM requires the page to be pinned from map() 'til
unmap() when accessing guest memory, unlike KVM's secondary MMU, which
coordinates with mmu_notifier invalidations to avoid creating stale
page references, i.e. doesn't rely on pages being pinned.

[*] http://lkml.kernel.org/r/20190919115547.GA17963@angband.pl

Reported-by: Adam Borowski <kilobyte@angband.pl>
Analyzed-by: David Hildenbrand <david@redhat.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: stable@vger.kernel.org
Fixes: 3565fce3a6 ("mm, x86: get_user_pages() for dax mappings")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-12 10:17:42 +01:00
Paolo Bonzini e2d3fcaf93 KVM: fix placement of refcount initialization
Reported by syzkaller:

   =============================
   WARNING: suspicious RCU usage
   -----------------------------
   ./include/linux/kvm_host.h:536 suspicious rcu_dereference_check() usage!

   other info that might help us debug this:

   rcu_scheduler_active = 2, debug_locks = 1
   no locks held by repro_11/12688.

   stack backtrace:
   Call Trace:
    dump_stack+0x7d/0xc5
    lockdep_rcu_suspicious+0x123/0x170
    kvm_dev_ioctl+0x9a9/0x1260 [kvm]
    do_vfs_ioctl+0x1a1/0xfb0
    ksys_ioctl+0x6d/0x80
    __x64_sys_ioctl+0x73/0xb0
    do_syscall_64+0x108/0xaa0
    entry_SYSCALL_64_after_hwframe+0x49/0xbe

Commit a97b0e773e (kvm: call kvm_arch_destroy_vm if vm creation fails)
sets users_count to 1 before kvm_arch_init_vm(), however, if kvm_arch_init_vm()
fails, we need to decrease this count.  By moving it earlier, we can push
the decrease to out_err_no_arch_destroy_vm without introducing yet another
error label.

syzkaller source: https://syzkaller.appspot.com/x/repro.c?x=15209b84e00000

Reported-by: syzbot+75475908cd0910f141ee@syzkaller.appspotmail.com
Fixes: a97b0e773e ("kvm: call kvm_arch_destroy_vm if vm creation fails")
Cc: Jim Mattson <jmattson@google.com>
Analyzed-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-11 15:48:03 +01:00
Paolo Bonzini 8a44119a98 KVM: Fix NULL-ptr deref after kvm_create_vm fails
Reported by syzkaller:

    kasan: CONFIG_KASAN_INLINE enabled
    kasan: GPF could be caused by NULL-ptr deref or user memory access
    general protection fault: 0000 [#1] PREEMPT SMP KASAN
    CPU: 0 PID: 14727 Comm: syz-executor.3 Not tainted 5.4.0-rc4+ #0
    RIP: 0010:kvm_coalesced_mmio_init+0x5d/0x110 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:121
    Call Trace:
     kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:3446 [inline]
     kvm_dev_ioctl+0x781/0x1490 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3494
     vfs_ioctl fs/ioctl.c:46 [inline]
     file_ioctl fs/ioctl.c:509 [inline]
     do_vfs_ioctl+0x196/0x1150 fs/ioctl.c:696
     ksys_ioctl+0x62/0x90 fs/ioctl.c:713
     __do_sys_ioctl fs/ioctl.c:720 [inline]
     __se_sys_ioctl fs/ioctl.c:718 [inline]
     __x64_sys_ioctl+0x6e/0xb0 fs/ioctl.c:718
     do_syscall_64+0xca/0x5d0 arch/x86/entry/common.c:290
     entry_SYSCALL_64_after_hwframe+0x49/0xbe

Commit 9121923c45 ("kvm: Allocate memslots and buses before calling kvm_arch_init_vm")
moves memslots and buses allocations around, however, if kvm->srcu/irq_srcu fails
initialization, NULL will be returned instead of error code, NULL will not be intercepted
in kvm_dev_ioctl_create_vm() and be dereferenced by kvm_coalesced_mmio_init(), this patch
fixes it.

Moving the initialization is required anyway to avoid an incorrect synchronize_srcu that
was also reported by syzkaller:

 wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136
 __synchronize_srcu+0x197/0x250 kernel/rcu/srcutree.c:921
 synchronize_srcu_expedited kernel/rcu/srcutree.c:946 [inline]
 synchronize_srcu+0x239/0x3e8 kernel/rcu/srcutree.c:997
 kvm_page_track_unregister_notifier+0xe7/0x130 arch/x86/kvm/page_track.c:212
 kvm_mmu_uninit_vm+0x1e/0x30 arch/x86/kvm/mmu.c:5828
 kvm_arch_destroy_vm+0x4a2/0x5f0 arch/x86/kvm/x86.c:9579
 kvm_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:702 [inline]

so do it.

Reported-by: syzbot+89a8060879fa0bd2db4f@syzkaller.appspotmail.com
Reported-by: syzbot+e27e7027eb2b80e44225@syzkaller.appspotmail.com
Fixes: 9121923c45 ("kvm: Allocate memslots and buses before calling kvm_arch_init_vm")
Cc: Jim Mattson <jmattson@google.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-11 15:48:02 +01:00
Junaid Shahid 1aa9b9572b kvm: x86: mmu: Recovery of shattered NX large pages
The page table pages corresponding to broken down large pages are zapped in
FIFO order, so that the large page can potentially be recovered, if it is
not longer being used for execution.  This removes the performance penalty
for walking deeper EPT page tables.

By default, one large page will last about one hour once the guest
reaches a steady state.

Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2019-11-04 20:26:00 +01:00
Junaid Shahid c57c80467f kvm: Add helper function for creating VM worker threads
Add a function to create a kernel thread associated with a given VM. In
particular, it ensures that the worker thread inherits the priority and
cgroups of the calling thread.

Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2019-11-04 12:22:02 +01:00
Jim Mattson a97b0e773e kvm: call kvm_arch_destroy_vm if vm creation fails
In kvm_create_vm(), if we've successfully called kvm_arch_init_vm(), but
then fail later in the function, we need to call kvm_arch_destroy_vm()
so that it can do any necessary cleanup (like freeing memory).

Fixes: 44a95dae1d ("KVM: x86: Detect and Initialize AVIC support")

Signed-off-by: John Sperbeck <jsperbeck@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Junaid Shahid <junaids@google.com>
[Remove dependency on "kvm: Don't clear reference count on
 kvm_create_vm() error path" which was not committed. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-31 12:13:16 +01:00
Jim Mattson 9121923c45 kvm: Allocate memslots and buses before calling kvm_arch_init_vm
This reorganization will allow us to call kvm_arch_destroy_vm in the
event that kvm_create_vm fails after calling kvm_arch_init_vm.

Suggested-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-25 13:32:33 +02:00
Sean Christopherson 149487bdac KVM: Add separate helper for putting borrowed reference to kvm
Add a new helper, kvm_put_kvm_no_destroy(), to handle putting a borrowed
reference[*] to the VM when installing a new file descriptor fails.  KVM
expects the refcount to remain valid in this case, as the in-progress
ioctl() has an explicit reference to the VM.  The primary motiviation
for the helper is to document that the 'kvm' pointer is still valid
after putting the borrowed reference, e.g. to document that doing
mutex(&kvm->lock) immediately after putting a ref to kvm isn't broken.

[*] When exposing a new object to userspace via a file descriptor, e.g.
    a new vcpu, KVM grabs a reference to itself (the VM) prior to making
    the object visible to userspace to avoid prematurely freeing the VM
    in the scenario where userspace immediately closes file descriptor.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-22 15:48:30 +02:00
Wanpeng Li 44551b2f69 KVM: Don't shrink/grow vCPU halt_poll_ns if host side polling is disabled
Don't waste cycles to shrink/grow vCPU halt_poll_ns if host
side polling is disabled.

Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-22 13:31:14 +02:00
Steven Price 8538cb22bb KVM: Allow kvm_device_ops to be const
Currently a kvm_device_ops structure cannot be const without triggering
compiler warnings. However the structure doesn't need to be written to
and, by marking it const, it can be read-only in memory. Add some more
const keywords to allow this.

Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-21 19:20:28 +01:00
Paolo Bonzini 833b45de69 kvm: x86, powerpc: do not allow clearing largepages debugfs entry
The largepages debugfs entry is incremented/decremented as shadow
pages are created or destroyed.  Clearing it will result in an
underflow, which is harmless to KVM but ugly (and could be
misinterpreted by tools that use debugfs information), so make
this particular statistic read-only.

Cc: kvm-ppc@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-30 18:52:00 +02:00
Marc Zyngier 07ab0f8d9a KVM: Call kvm_arch_vcpu_blocking early into the blocking sequence
When a vpcu is about to block by calling kvm_vcpu_block, we call
back into the arch code to allow any form of synchronization that
may be required at this point (SVN stops the AVIC, ARM synchronises
the VMCR and enables GICv4 doorbells). But this synchronization
comes in quite late, as we've potentially waited for halt_poll_ns
to expire.

Instead, let's move kvm_arch_vcpu_blocking() to the beginning of
kvm_vcpu_block(), which on ARM has several benefits:

- VMCR gets synchronised early, meaning that any interrupt delivered
  during the polling window will be evaluated with the correct guest
  PMR
- GICv4 doorbells are enabled, which means that any guest interrupt
  directly injected during that window will be immediately recognised

Tang Nianyao ran some tests on a GICv4 machine to evaluate such
change, and reported up to a 10% improvement for netperf:

<quote>
	netperf result:
	D06 as server, intel 8180 server as client
	with change:
	package 512 bytes - 5500 Mbits/s
	package 64 bytes - 760 Mbits/s
	without change:
	package 512 bytes - 5000 Mbits/s
	package 64 bytes - 710 Mbits/s
</quote>

Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-08-18 18:50:44 +01:00
Paolo Bonzini 8f946da73a kvm: remove unnecessary PageReserved check
The same check is already done in kvm_is_reserved_pfn.

Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-08-09 16:49:58 +02:00
Greg KH 3e7093d045 KVM: no need to check return value of debugfs_create functions
When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Also, when doing this, change kvm_arch_create_vcpu_debugfs() to return
void instead of an integer, as we should not care at all about if this
function actually does anything or not.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <x86@kernel.org>
Cc: <kvm@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-08-05 12:55:49 +02:00
Paolo Bonzini 741cbbae07 KVM: remove kvm_arch_has_vcpu_debugfs()
There is no need for this function as all arches have to implement
kvm_arch_create_vcpu_debugfs() no matter what.  A #define symbol
let us actually simplify the code.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-08-05 12:55:48 +02:00
Wanpeng Li 17e433b543 KVM: Fix leak vCPU's VMCS value into other pCPU
After commit d73eb57b80 (KVM: Boost vCPUs that are delivering interrupts), a
five years old bug is exposed. Running ebizzy benchmark in three 80 vCPUs VMs
on one 80 pCPUs Skylake server, a lot of rcu_sched stall warning splatting
in the VMs after stress testing:

 INFO: rcu_sched detected stalls on CPUs/tasks: { 4 41 57 62 77} (detected by 15, t=60004 jiffies, g=899, c=898, q=15073)
 Call Trace:
   flush_tlb_mm_range+0x68/0x140
   tlb_flush_mmu.part.75+0x37/0xe0
   tlb_finish_mmu+0x55/0x60
   zap_page_range+0x142/0x190
   SyS_madvise+0x3cd/0x9c0
   system_call_fastpath+0x1c/0x21

swait_active() sustains to be true before finish_swait() is called in
kvm_vcpu_block(), voluntarily preempted vCPUs are taken into account
by kvm_vcpu_on_spin() loop greatly increases the probability condition
kvm_arch_vcpu_runnable(vcpu) is checked and can be true, when APICv
is enabled the yield-candidate vCPU's VMCS RVI field leaks(by
vmx_sync_pir_to_irr()) into spinning-on-a-taken-lock vCPU's current
VMCS.

This patch fixes it by checking conservatively a subset of events.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Marc Zyngier <Marc.Zyngier@arm.com>
Cc: stable@vger.kernel.org
Fixes: 98f4a1467 (KVM: add kvm_arch_vcpu_runnable() test to kvm_vcpu_on_spin() loop)
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-08-05 12:55:47 +02:00
Wanpeng Li 046ddeed04 KVM: Check preempted_in_kernel for involuntary preemption
preempted_in_kernel is updated in preempt_notifier when involuntary preemption
ocurrs, it can be stale when the voluntarily preempted vCPUs are taken into
account by kvm_vcpu_on_spin() loop. This patch lets it just check preempted_in_kernel
for involuntary preemption.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-08-05 12:55:46 +02:00
Wanpeng Li d73eb57b80 KVM: Boost vCPUs that are delivering interrupts
Inspired by commit 9cac38dd5d (KVM/s390: Set preempted flag during
vcpu wakeup and interrupt delivery), we want to also boost not just
lock holders but also vCPUs that are delivering interrupts. Most
smp_call_function_many calls are synchronous, so the IPI target vCPUs
are also good yield candidates.  This patch introduces vcpu->ready to
boost vCPUs during wakeup and interrupt delivery time; unlike s390 we do
not reuse vcpu->preempted so that voluntarily preempted vCPUs are taken
into account by kvm_vcpu_on_spin, but vmx_vcpu_pi_put is not affected
(VT-d PI handles voluntary preemption separately, in pi_pre_block).

Testing on 80 HT 2 socket Xeon Skylake server, with 80 vCPUs VM 80GB RAM:
ebizzy -M

            vanilla     boosting    improved
1VM          21443       23520         9%
2VM           2800        8000       180%
3VM           1800        3100        72%

Testing on my Haswell desktop 8 HT, with 8 vCPUs VM 8GB RAM, two VMs,
one running ebizzy -M, the other running 'stress --cpu 2':

w/ boosting + w/o pv sched yield(vanilla)

            vanilla     boosting   improved
              1570         4000      155%

w/ boosting + w/ pv sched yield(vanilla)

            vanilla     boosting   improved
              1844         5157      179%

w/o boosting, perf top in VM:

 72.33%  [kernel]       [k] smp_call_function_many
  4.22%  [kernel]       [k] call_function_i
  3.71%  [kernel]       [k] async_page_fault

w/ boosting, perf top in VM:

 38.43%  [kernel]       [k] smp_call_function_many
  6.31%  [kernel]       [k] async_page_fault
  6.13%  libc-2.23.so   [.] __memcpy_avx_unaligned
  4.88%  [kernel]       [k] call_function_interrupt

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Marc Zyngier <maz@kernel.org>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-07-20 09:00:45 +02:00
Paolo Bonzini a45ff5994c KVM/arm updates for 5.3
- Add support for chained PMU counters in guests
 - Improve 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
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Merge tag 'kvm-arm-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm updates for 5.3

- Add support for chained PMU counters in guests
- Improve 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
2019-07-11 15:14:16 +02:00
KarimAllah Ahmed b614c60278 KVM: Properly check if "page" is valid in kvm_vcpu_unmap
The field "page" is initialized to KVM_UNMAPPED_PAGE when it is not used
(i.e. when the memory lives outside kernel control). So this check will
always end up using kunmap even for memremap regions.

Fixes: e45adf665a ("KVM: Introduce a new guest mapping API")
Cc: stable@vger.kernel.org
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-07-10 16:25:39 +02:00
Thomas Gleixner 20c8ccb197 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499
Based on 1 normalized pattern(s):

  this work is licensed under the terms of the gnu gpl version 2 see
  the copying file in the top level directory

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 35 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.797835076@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:53 +02:00
Junaid Shahid 0d9ce162cf kvm: Convert kvm_lock to a mutex
It doesn't seem as if there is any particular need for kvm_lock to be a
spinlock, so convert the lock to a mutex so that sleepable functions (in
particular cond_resched()) can be called while holding it.

Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-06-05 14:14:50 +02:00
Sean Christopherson f257d6dcda KVM: Directly return result from kvm_arch_check_processor_compat()
Add a wrapper to invoke kvm_arch_check_processor_compat() so that the
boilerplate ugliness of checking virtualization support on all CPUs is
hidden from the arch specific code.  x86's implementation in particular
is quite heinous, as it unnecessarily propagates the out-param pattern
into kvm_x86_ops.

While the x86 specific issue could be resolved solely by changing
kvm_x86_ops, make the change for all architectures as returning a value
directly is prettier and technically more robust, e.g. s390 doesn't set
the out param, which could lead to subtle breakage in the (highly
unlikely) scenario where the out-param was not pre-initialized by the
caller.

Opportunistically annotate svm_check_processor_compat() with __init.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-06-04 19:27:32 +02:00
Thomas Huth a86cb413f4 KVM: s390: Do not report unusabled IDs via KVM_CAP_MAX_VCPU_ID
KVM_CAP_MAX_VCPU_ID is currently always reporting KVM_MAX_VCPU_ID on all
architectures. However, on s390x, the amount of usable CPUs is determined
during runtime - it is depending on the features of the machine the code
is running on. Since we are using the vcpu_id as an index into the SCA
structures that are defined by the hardware (see e.g. the sca_add_vcpu()
function), it is not only the amount of CPUs that is limited by the hard-
ware, but also the range of IDs that we can use.
Thus KVM_CAP_MAX_VCPU_ID must be determined during runtime on s390x, too.
So the handling of KVM_CAP_MAX_VCPU_ID has to be moved from the common
code into the architecture specific code, and on s390x we have to return
the same value here as for KVM_CAP_MAX_VCPUS.
This problem has been discovered with the kvm_create_max_vcpus selftest.
With this change applied, the selftest now passes on s390x, too.

Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20190523164309.13345-9-thuth@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2019-05-28 15:52:19 +02:00
Christian Borntraeger eb1f2f387d kvm: fix compile on s390 part 2
We also need to fence the memunmap part.

Fixes: e45adf665a ("KVM: Introduce a new guest mapping API")
Fixes: d30b214d1d (kvm: fix compilation on s390)
Cc: Michal Kubecek <mkubecek@suse.cz>
Cc: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2019-05-28 15:51:52 +02:00
Paolo Bonzini d30b214d1d kvm: fix compilation on s390
s390 does not have memremap, even though in this particular case it
would be useful.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-05-24 21:27:07 +02:00
Wanpeng Li 2eb06c306a KVM: Fix spinlock taken warning during host resume
WARNING: CPU: 0 PID: 13554 at kvm/arch/x86/kvm//../../../virt/kvm/kvm_main.c:4183 kvm_resume+0x3c/0x40 [kvm]
  CPU: 0 PID: 13554 Comm: step_after_susp Tainted: G           OE     5.1.0-rc4+ #1
  RIP: 0010:kvm_resume+0x3c/0x40 [kvm]
  Call Trace:
   syscore_resume+0x63/0x2d0
   suspend_devices_and_enter+0x9d1/0xa40
   pm_suspend+0x33a/0x3b0
   state_store+0x82/0xf0
   kobj_attr_store+0x12/0x20
   sysfs_kf_write+0x4b/0x60
   kernfs_fop_write+0x120/0x1a0
   __vfs_write+0x1b/0x40
   vfs_write+0xcd/0x1d0
   ksys_write+0x5f/0xe0
   __x64_sys_write+0x1a/0x20
   do_syscall_64+0x6f/0x6c0
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

Commit ca84d1a24 (KVM: x86: Add clock sync request to hardware enable) mentioned
that "we always hold kvm_lock when hardware_enable is called.  The one place that
doesn't need to worry about it is resume, as resuming a frozen CPU, the spinlock
won't be taken." However, commit 6706dae9 (virt/kvm: Replace spin_is_locked() with
lockdep) introduces a bug, it asserts when the lock is not held which is contrary
to the original goal.

This patch fixes it by WARN_ON when the lock is held.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Fixes: 6706dae9 ("virt/kvm: Replace spin_is_locked() with lockdep")
[Wrap with #ifdef CONFIG_LOCKDEP - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-05-24 21:27:03 +02:00
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 c011d23ba0 kvm: fix compilation on aarch64
Commit e45adf665a ("KVM: Introduce a new guest mapping API", 2019-01-31)
introduced a build failure on aarch64 defconfig:

$ make -j$(nproc) ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- O=out defconfig \
                Image.gz
...
../arch/arm64/kvm/../../../virt/kvm/kvm_main.c:
    In function '__kvm_map_gfn':
../arch/arm64/kvm/../../../virt/kvm/kvm_main.c:1763:9: error:
    implicit declaration of function 'memremap'; did you mean 'memset_p'?
../arch/arm64/kvm/../../../virt/kvm/kvm_main.c:1763:46: error:
    'MEMREMAP_WB' undeclared (first use in this function)
../arch/arm64/kvm/../../../virt/kvm/kvm_main.c:
    In function 'kvm_vcpu_unmap':
../arch/arm64/kvm/../../../virt/kvm/kvm_main.c:1795:3: error:
    implicit declaration of function 'memunmap'; did you mean 'vm_munmap'?

because these functions are declared in <linux/io.h> rather than <asm/io.h>,
and the former was being pulled in already on x86 but not on aarch64.

Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-05-17 14:08:53 +02:00
Paolo Bonzini 59c5c58c5b Second PPC KVM update for 5.2
- Fix a bug, fix a spelling mistake, remove some useless code.
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Merge tag 'kvm-ppc-next-5.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD

PPC KVM update for 5.2

* Support for guests to access the new POWER9 XIVE interrupt controller
  hardware directly, reducing interrupt latency and overhead for guests.

* In-kernel implementation of the H_PAGE_INIT hypercall.

* Reduce memory usage of sparsely-populated IOMMU tables.

* Several bug fixes.

Second PPC KVM update for 5.2

* Fix a bug, fix a spelling mistake, remove some useless code.
2019-05-15 23:39:38 +02:00
Jérôme Glisse dfcd66604c mm/mmu_notifier: convert user range->blockable to helper function
Use the mmu_notifier_range_blockable() helper function instead of directly
dereferencing the range->blockable field.  This is done to make it easier
to change the mmu_notifier range field.

This patch is the outcome of the following coccinelle patch:

%<-------------------------------------------------------------------
@@
identifier I1, FN;
@@
FN(..., struct mmu_notifier_range *I1, ...) {
<...
-I1->blockable
+mmu_notifier_range_blockable(I1)
...>
}
------------------------------------------------------------------->%

spatch --in-place --sp-file blockable.spatch --dir .

Link: http://lkml.kernel.org/r/20190326164747.24405-3-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Ross Zwisler <zwisler@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Christian Koenig <christian.koenig@amd.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 09:47:49 -07:00
Cédric Le Goater 4894fbcce8 KVM: PPC: Book3S: Remove useless checks in 'release' method of KVM device
There is no need to test for the device pointer validity when releasing
a KVM device. The file descriptor should identify it safely.

Fixes: 2bde9b3ec8 ("KVM: Introduce a 'release' method for KVM devices")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-05-14 12:06:03 +10:00
Peter Xu d7547c55cb KVM: Introduce KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2
The previous KVM_CAP_MANUAL_DIRTY_LOG_PROTECT has some problem which
blocks the correct usage from userspace.  Obsolete the old one and
introduce a new capability bit for it.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-05-08 13:48:24 +02:00
Peter Xu 53eac7a8f8 KVM: Fix kvm_clear_dirty_log_protect off-by-(minus-)one
Just imaging the case where num_pages < BITS_PER_LONG, then the loop
will be skipped while it shouldn't.

Signed-off-by: Peter Xu <peterx@redhat.com>
Fixes: 2a31b9db15
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-05-08 13:43:28 +02:00
Peter Xu 4ddc920457 KVM: Fix the bitmap range to copy during clear dirty
kvm_dirty_bitmap_bytes() will return the size of the dirty bitmap of
the memslot rather than the size of bitmap passed over from the ioctl.
Here for KVM_CLEAR_DIRTY_LOG we should only copy exactly the size of
bitmap that covers kvm_clear_dirty_log.num_pages.

Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 2a31b9db15
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-05-08 13:42:53 +02:00
KarimAllah Ahmed e45adf665a KVM: Introduce a new guest mapping API
In KVM, specially for nested guests, there is a dominant pattern of:

	=> map guest memory -> do_something -> unmap guest memory

In addition to all this unnecessarily noise in the code due to boiler plate
code, most of the time the mapping function does not properly handle memory
that is not backed by "struct page". This new guest mapping API encapsulate
most of this boiler plate code and also handles guest memory that is not
backed by "struct page".

The current implementation of this API is using memremap for memory that is
not backed by a "struct page" which would lead to a huge slow-down if it
was used for high-frequency mapping operations. The API does not have any
effect on current setups where guest memory is backed by a "struct page".
Further patches are going to also introduce a pfn-cache which would
significantly improve the performance of the memremap case.

Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-04-30 21:32:51 +02:00
Jiang Biao b8b002209c kvm_main: fix some comments
is_dirty has been renamed to flush, but the comment for it is
outdated. And the description about @flush parameter for
kvm_clear_dirty_log_protect() is missing, add it in this patch
as well.

Signed-off-by: Jiang Biao <benbjiang@tencent.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-04-30 21:32:19 +02:00
Paolo Bonzini 65c4189de8 KVM: fix KVM_CLEAR_DIRTY_LOG for memory slots of unaligned size
If a memory slot's size is not a multiple of 64 pages (256K), then
the KVM_CLEAR_DIRTY_LOG API is unusable: clearing the final 64 pages
either requires the requested page range to go beyond memslot->npages,
or requires log->num_pages to be unaligned, and kvm_clear_dirty_log_protect
requires log->num_pages to be both in range and aligned.

To allow this case, allow log->num_pages not to be a multiple of 64 if
it ends exactly on the last page of the slot.

Reported-by: Peter Xu <peterx@redhat.com>
Fixes: 98938aa8ed ("KVM: validate userspace input in kvm_clear_dirty_log_protect()", 2019-01-02)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-04-30 21:32:19 +02:00
Paolo Bonzini da8f0d97b2 KVM: s390: Features and fixes for 5.2
- VSIE crypto fixes
 - new guest features for gen15
 - disable halt polling for nested virtualization with overcommit
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Merge tag 'kvm-s390-next-5.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

KVM: s390: Features and fixes for 5.2

- VSIE crypto fixes
- new guest features for gen15
- disable halt polling for nested virtualization with overcommit
2019-04-30 21:29:14 +02:00
Paolo Bonzini 76d58e0f07 KVM: fix KVM_CLEAR_DIRTY_LOG for memory slots of unaligned size
If a memory slot's size is not a multiple of 64 pages (256K), then
the KVM_CLEAR_DIRTY_LOG API is unusable: clearing the final 64 pages
either requires the requested page range to go beyond memslot->npages,
or requires log->num_pages to be unaligned, and kvm_clear_dirty_log_protect
requires log->num_pages to be both in range and aligned.

To allow this case, allow log->num_pages not to be a multiple of 64 if
it ends exactly on the last page of the slot.

Reported-by: Peter Xu <peterx@redhat.com>
Fixes: 98938aa8ed ("KVM: validate userspace input in kvm_clear_dirty_log_protect()", 2019-01-02)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-04-30 21:22:15 +02:00
Cédric Le Goater 2bde9b3ec8 KVM: Introduce a 'release' method for KVM devices
When a P9 sPAPR VM boots, the CAS negotiation process determines which
interrupt mode to use (XICS legacy or XIVE native) and invokes a
machine reset to activate the chosen mode.

To be able to switch from one interrupt mode to another, we introduce
the capability to release a KVM device without destroying the VM. The
KVM device interface is extended with a new 'release' method which is
called when the file descriptor of the device is closed.

Once 'release' is called, the 'destroy' method will not be called
anymore as the device is removed from the device list of the VM.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30 19:35:16 +10:00
Cédric Le Goater a1cd3f0883 KVM: Introduce a 'mmap' method for KVM devices
Some KVM devices will want to handle special mappings related to the
underlying HW. For instance, the XIVE interrupt controller of the
POWER9 processor has MMIO pages for thread interrupt management and
for interrupt source control that need to be exposed to the guest when
the OS has the required support.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30 19:35:16 +10:00
Christian Borntraeger cdd6ad3ac6 KVM: polling: add architecture backend to disable polling
There are cases where halt polling is unwanted. For example when running
KVM on an over committed LPAR we rather want to give back the CPU to
neighbour LPARs instead of polling. Let us provide a callback that
allows architectures to disable polling.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2019-04-26 09:08:17 +02:00