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  1. 15 11月, 2020 6 次提交
    • P
      KVM: X86: Implement ring-based dirty memory tracking · fb04a1ed
      由 Peter Xu 提交于 
      This patch is heavily based on previous work from Lei Cao
<lei.cao@stratus.com> and Paolo Bonzini <pbonzini@redhat.com>. [1]

KVM currently uses large bitmaps to track dirty memory.  These bitmaps
are copied to userspace when userspace queries KVM for its dirty page
information.  The use of bitmaps is mostly sufficient for live
migration, as large parts of memory are be dirtied from one log-dirty
pass to another.  However, in a checkpointing system, the number of
dirty pages is small and in fact it is often bounded---the VM is
paused when it has dirtied a pre-defined number of pages. Traversing a
large, sparsely populated bitmap to find set bits is time-consuming,
as is copying the bitmap to user-space.

A similar issue will be there for live migration when the guest memory
is huge while the page dirty procedure is trivial.  In that case for
each dirty sync we need to pull the whole dirty bitmap to userspace
and analyse every bit even if it's mostly zeros.

The preferred data structure for above scenarios is a dense list of
guest frame numbers (GFN).  This patch series stores the dirty list in
kernel memory that can be memory mapped into userspace to allow speedy
harvesting.

This patch enables dirty ring for X86 only.  However it should be
easily extended to other archs as well.

[1] https://patchwork.kernel.org/patch/10471409/Signed-off-by: NLei Cao <lei.cao@stratus.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20201001012222.5767-1-peterx@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      fb04a1ed
    • P
      KVM: Pass in kvm pointer into mark_page_dirty_in_slot() · 28bd726a
      由 Peter Xu 提交于 
      The context will be needed to implement the kvm dirty ring.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20201001012044.5151-5-peterx@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      28bd726a
    • P
      KVM: remove kvm_clear_guest_page · 2f541442
      由 Paolo Bonzini 提交于 
      kvm_clear_guest_page is not used anymore after "KVM: X86: Don't track dirty
for KVM_SET_[TSS_ADDR|IDENTITY_MAP_ADDR]", except from kvm_clear_guest.
We can just inline it in its sole user.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      2f541442
    • V
      KVM: x86: hyper-v: allow KVM_GET_SUPPORTED_HV_CPUID as a system ioctl · c21d54f0
      由 Vitaly Kuznetsov 提交于 
      KVM_GET_SUPPORTED_HV_CPUID is a vCPU ioctl but its output is now
independent from vCPU and in some cases VMMs may want to use it as a system
ioctl instead. In particular, QEMU doesn CPU feature expansion before any
vCPU gets created so KVM_GET_SUPPORTED_HV_CPUID can't be used.

Convert KVM_GET_SUPPORTED_HV_CPUID to 'dual' system/vCPU ioctl with the
same meaning.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200929150944.1235688-2-vkuznets@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      c21d54f0
    • D
      eventfd: Export eventfd_ctx_do_read() · 28f13267
      由 David Woodhouse 提交于 
      Where events are consumed in the kernel, for example by KVM's
irqfd_wakeup() and VFIO's virqfd_wakeup(), they currently lack a
mechanism to drain the eventfd's counter.

Since the wait queue is already locked while the wakeup functions are
invoked, all they really need to do is call eventfd_ctx_do_read().

Add a check for the lock, and export it for them.
Signed-off-by: NDavid Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20201027135523.646811-2-dwmw2@infradead.org>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      28f13267
    • D
      sched/wait: Add add_wait_queue_priority() · c4d51a52
      由 David Woodhouse 提交于 
      This allows an exclusive wait_queue_entry to be added at the head of the
queue, instead of the tail as normal. Thus, it gets to consume events
first without allowing non-exclusive waiters to be woken at all.

The (first) intended use is for KVM IRQFD, which currently has
inconsistent behaviour depending on whether posted interrupts are
available or not. If they are, KVM will bypass the eventfd completely
and deliver interrupts directly to the appropriate vCPU. If not, events
are delivered through the eventfd and userspace will receive them when
polling on the eventfd.

By using add_wait_queue_priority(), KVM will be able to consistently
consume events within the kernel without accidentally exposing them
to userspace when they're supposed to be bypassed. This, in turn, means
that userspace doesn't have to jump through hoops to avoid listening
on the erroneously noisy eventfd and injecting duplicate interrupts.
Signed-off-by: NDavid Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20201027143944.648769-2-dwmw2@infradead.org>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      c4d51a52
  3. 11 11月, 2020 3 次提交
  5. 07 11月, 2020 7 次提交
  7. 06 11月, 2020 1 次提交
  9. 05 11月, 2020 2 次提交
    • J
      io_uring: properly handle SQPOLL request cancelations · fdaf083c
      由 Jens Axboe 提交于 
      Track if a given task io_uring context contains SQPOLL instances, so we
can iterate those for cancelation (and request counts). This ensures that
we properly wait on SQPOLL contexts, and find everything that needs
canceling.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      fdaf083c
    • B
      iomap: support partial page discard on writeback block mapping failure · 763e4cdc
      由 Brian Foster 提交于 
      iomap writeback mapping failure only calls into ->discard_page() if
the current page has not been added to the ioend. Accordingly, the
XFS callback assumes a full page discard and invalidation. This is
problematic for sub-page block size filesystems where some portion
of a page might have been mapped successfully before a failure to
map a delalloc block occurs. ->discard_page() is not called in that
error scenario and the bio is explicitly failed by iomap via the
error return from ->prepare_ioend(). As a result, the filesystem
leaks delalloc blocks and corrupts the filesystem block counters.

Since XFS is the only user of ->discard_page(), tweak the semantics
to invoke the callback unconditionally on mapping errors and provide
the file offset that failed to map. Update xfs_discard_page() to
discard the corresponding portion of the file and pass the range
along to iomap_invalidatepage(). The latter already properly handles
both full and sub-page scenarios by not changing any iomap or page
state on sub-page invalidations.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      763e4cdc
  11. 04 11月, 2020 1 次提交
    • O
      can: can_create_echo_skb(): fix echo skb generation: always use skb_clone() · 286228d3
      由 Oleksij Rempel 提交于 
      All user space generated SKBs are owned by a socket (unless injected into the
key via AF_PACKET). If a socket is closed, all associated skbs will be cleaned
up.

This leads to a problem when a CAN driver calls can_put_echo_skb() on a
unshared SKB. If the socket is closed prior to the TX complete handler,
can_get_echo_skb() and the subsequent delivering of the echo SKB to all
registered callbacks, a SKB with a refcount of 0 is delivered.

To avoid the problem, in can_get_echo_skb() the original SKB is now always
cloned, regardless of shared SKB or not. If the process exists it can now
safely discard its SKBs, without disturbing the delivery of the echo SKB.

The problem shows up in the j1939 stack, when it clones the incoming skb, which
detects the already 0 refcount.

We can easily reproduce this with following example:

testj1939 -B -r can0: &
cansend can0 1823ff40#0123

WARNING: CPU: 0 PID: 293 at lib/refcount.c:25 refcount_warn_saturate+0x108/0x174
refcount_t: addition on 0; use-after-free.
Modules linked in: coda_vpu imx_vdoa videobuf2_vmalloc dw_hdmi_ahb_audio vcan
CPU: 0 PID: 293 Comm: cansend Not tainted 5.5.0-rc6-00376-g9e20dcb7040d #1
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
Backtrace:
[<c010f570>] (dump_backtrace) from [<c010f90c>] (show_stack+0x20/0x24)
[<c010f8ec>] (show_stack) from [<c0c3e1a4>] (dump_stack+0x8c/0xa0)
[<c0c3e118>] (dump_stack) from [<c0127fec>] (__warn+0xe0/0x108)
[<c0127f0c>] (__warn) from [<c01283c8>] (warn_slowpath_fmt+0xa8/0xcc)
[<c0128324>] (warn_slowpath_fmt) from [<c0539c0c>] (refcount_warn_saturate+0x108/0x174)
[<c0539b04>] (refcount_warn_saturate) from [<c0ad2cac>] (j1939_can_recv+0x20c/0x210)
[<c0ad2aa0>] (j1939_can_recv) from [<c0ac9dc8>] (can_rcv_filter+0xb4/0x268)
[<c0ac9d14>] (can_rcv_filter) from [<c0aca2cc>] (can_receive+0xb0/0xe4)
[<c0aca21c>] (can_receive) from [<c0aca348>] (can_rcv+0x48/0x98)
[<c0aca300>] (can_rcv) from [<c09b1fdc>] (__netif_receive_skb_one_core+0x64/0x88)
[<c09b1f78>] (__netif_receive_skb_one_core) from [<c09b2070>] (__netif_receive_skb+0x38/0x94)
[<c09b2038>] (__netif_receive_skb) from [<c09b2130>] (netif_receive_skb_internal+0x64/0xf8)
[<c09b20cc>] (netif_receive_skb_internal) from [<c09b21f8>] (netif_receive_skb+0x34/0x19c)
[<c09b21c4>] (netif_receive_skb) from [<c0791278>] (can_rx_offload_napi_poll+0x58/0xb4)

Fixes: 0ae89beb ("can: add destructor for self generated skbs")
Signed-off-by: NOleksij Rempel <o.rempel@pengutronix.de>
Link: http://lore.kernel.org/r/20200124132656.22156-1-o.rempel@pengutronix.deAcked-by: NOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>
      286228d3
  13. 03 11月, 2020 3 次提交
    • J
      mm: always have io_remap_pfn_range() set pgprot_decrypted() · f8f6ae5d
      由 Jason Gunthorpe 提交于 
      The purpose of io_remap_pfn_range() is to map IO memory, such as a
memory mapped IO exposed through a PCI BAR.  IO devices do not
understand encryption, so this memory must always be decrypted.
Automatically call pgprot_decrypted() as part of the generic
implementation.

This fixes a bug where enabling AMD SME causes subsystems, such as RDMA,
using io_remap_pfn_range() to expose BAR pages to user space to fail.
The CPU will encrypt access to those BAR pages instead of passing
unencrypted IO directly to the device.

Places not mapping IO should use remap_pfn_range().

Fixes: aca20d54 ("x86/mm: Add support to make use of Secure Memory Encryption")
Signed-off-by: NJason Gunthorpe <jgg@nvidia.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Dave Young" <dyoung@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Toshimitsu Kani <toshi.kani@hpe.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/0-v1-025d64bdf6c4+e-amd_sme_fix_jgg@nvidia.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f8f6ae5d
    • R
      PM: runtime: Drop pm_runtime_clean_up_links() · d6e36668
      由 Rafael J. Wysocki 提交于 
      After commit d12544fb ("PM: runtime: Remove link state checks in
rpm_get/put_supplier()") nothing prevents the consumer device's
runtime PM from acquiring additional references to the supplier
device after pm_runtime_clean_up_links() has run (or even while it
is running), so calling this function from __device_release_driver()
may be pointless (or even harmful).

Moreover, it ignores stateless device links, so the runtime PM
handling of managed and stateless device links is inconsistent
because of it, so better get rid of it entirely.

Fixes: d12544fb ("PM: runtime: Remove link state checks in rpm_get/put_supplier()")
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: 5.1+ <stable@vger.kernel.org> # 5.1+
Tested-by: NXiang Chen <chenxiang66@hisilicon.com>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d6e36668
    • R
      PM: runtime: Drop runtime PM references to supplier on link removal · e0e398e2
      由 Rafael J. Wysocki 提交于 
      While removing a device link, drop the supplier device's runtime PM
usage counter as many times as needed to drop all of the runtime PM
references to it from the consumer in addition to dropping the
consumer's link count.

Fixes: baa8809f ("PM / runtime: Optimize the use of device links")
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: 5.1+ <stable@vger.kernel.org> # 5.1+
Tested-by: NXiang Chen <chenxiang66@hisilicon.com>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e0e398e2
  15. 02 11月, 2020 1 次提交
  17. 01 11月, 2020 1 次提交
  19. 31 10月, 2020 1 次提交
  21. 30 10月, 2020 11 次提交
  23. 29 10月, 2020 3 次提交
    • M
      xsk: Fix possible memory leak at socket close · e5e1a4bc
      由 Magnus Karlsson 提交于 
      Fix a possible memory leak at xsk socket close that is caused by the
refcounting of the umem object being wrong. The reference count of the
umem was decremented only after the pool had been freed. Note that if
the buffer pool is destroyed, it is important that the umem is
destroyed after the pool, otherwise the umem would disappear while the
driver is still running. And as the buffer pool needs to be destroyed
in a work queue, the umem is also (if its refcount reaches zero)
destroyed after the buffer pool in that same work queue.

What was missing is that the refcount also needs to be decremented
when the pool is not freed and when the pool has not even been
created. The first case happens when the refcount of the pool is
higher than 1, i.e. it is still being used by some other socket using
the same device and queue id. In this case, it is safe to decrement
the refcount of the umem outside of the work queue as the umem will
never be freed because the refcount of the umem is always greater than
or equal to the refcount of the buffer pool. The second case is if the
buffer pool has not been created yet, i.e. the socket was closed
before it was bound but after the umem was created. In this case, it
is safe to destroy the umem outside of the work queue, since there is
no pool that can use it by definition.

Fixes: 1c1efc2a ("xsk: Create and free buffer pool independently from umem")
Reported-by: syzbot+eb71df123dc2be2c1456@syzkaller.appspotmail.com
Signed-off-by: NMagnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NBjörn Töpel <bjorn.topel@intel.com>
Link: https://lore.kernel.org/bpf/1603801921-2712-1-git-send-email-magnus.karlsson@gmail.com
      e5e1a4bc
    • D
      afs: Fix afs_invalidatepage to adjust the dirty region · f86726a6
      由 David Howells 提交于 
      Fix afs_invalidatepage() to adjust the dirty region recorded in
page->private when truncating a page.  If the dirty region is entirely
removed, then the private data is cleared and the page dirty state is
cleared.

Without this, if the page is truncated and then expanded again by truncate,
zeros from the expanded, but no-longer dirty region may get written back to
the server if the page gets laundered due to a conflicting 3rd-party write.

It mustn't, however, shorten the dirty region of the page if that page is
still mmapped and has been marked dirty by afs_page_mkwrite(), so a flag is
stored in page->private to record this.

Fixes: 4343d008 ("afs: Get rid of the afs_writeback record")
Signed-off-by: NDavid Howells <dhowells@redhat.com>
      f86726a6
    • D
      afs: Wrap page->private manipulations in inline functions · 185f0c70
      由 David Howells 提交于 
      The afs filesystem uses page->private to store the dirty range within a
page such that in the event of a conflicting 3rd-party write to the server,
we write back just the bits that got changed locally.

However, there are a couple of problems with this:

 (1) I need a bit to note if the page might be mapped so that partial
     invalidation doesn't shrink the range.

 (2) There aren't necessarily sufficient bits to store the entire range of
     data altered (say it's a 32-bit system with 64KiB pages or transparent
     huge pages are in use).

So wrap the accesses in inline functions so that future commits can change
how this works.

Also move them out of the tracing header into the in-directory header.
There's not really any need for them to be in the tracing header.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
      185f0c70