No description
  • C 98.2%
  • Assembly 1%
  • Makefile 0.3%
  • Shell 0.2%
  • Python 0.1%
Find a file
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Greg Kurz 97c9c012fe KVM: PPC: Book3S HV: XIVE: Free previous EQ page when setting up a new one
commit 31a88c82b466d2f31a44e21c479f45b4732ccfd0 upstream.

The EQ page is allocated by the guest and then passed to the hypervisor
with the H_INT_SET_QUEUE_CONFIG hcall. A reference is taken on the page
before handing it over to the HW. This reference is dropped either when
the guest issues the H_INT_RESET hcall or when the KVM device is released.
But, the guest can legitimately call H_INT_SET_QUEUE_CONFIG several times,
either to reset the EQ (vCPU hot unplug) or to set a new EQ (guest reboot).
In both cases the existing EQ page reference is leaked because we simply
overwrite it in the XIVE queue structure without calling put_page().

This is especially visible when the guest memory is backed with huge pages:
start a VM up to the guest userspace, either reboot it or unplug a vCPU,
quit QEMU. The leak is observed by comparing the value of HugePages_Free in
/proc/meminfo before and after the VM is run.

Ideally we'd want the XIVE code to handle the EQ page de-allocation at the
platform level. This isn't the case right now because the various XIVE
drivers have different allocation needs. It could maybe worth introducing
hooks for this purpose instead of exposing XIVE internals to the drivers,
but this is certainly a huge work to be done later.

In the meantime, for easier backport, fix both vCPU unplug and guest reboot
leaks by introducing a wrapper around xive_native_configure_queue() that
does the necessary cleanup.

Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # v5.2
Fixes: 13ce3297c5 ("KVM: PPC: Book3S HV: XIVE: Add controls for the EQ configuration")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
Tested-by: Lijun Pan <ljp@linux.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-13 08:42:58 +01:00
arch KVM: PPC: Book3S HV: XIVE: Free previous EQ page when setting up a new one 2019-12-13 08:42:58 +01:00
block iocost: check active_list of all the ancestors in iocg_activate() 2019-11-14 13:56:54 -07:00
certs
crypto Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
Documentation x86/speculation: Fix incorrect MDS/TAA mitigation status 2019-11-29 10:09:46 +01:00
drivers drm/i810: Prevent underflow in ioctl 2019-12-13 08:42:56 +01:00
fs kernfs: fix ino wrap-around detection 2019-12-13 08:42:53 +01:00
include jbd2: Fix possible overflow in jbd2_log_space_left() 2019-12-13 08:42:53 +01:00
init Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
ipc
kernel time: Zero the upper 32-bits in __kernel_timespec on 32-bit 2019-12-13 08:42:18 +01:00
lib lib/xz: fix XZ_DYNALLOC to avoid useless memory reallocations 2019-11-15 18:34:00 -08:00
LICENSES
mm mm/ksm.c: don't WARN if page is still mapped in remove_stable_node() 2019-11-22 09:11:18 -08:00
net SUNRPC: Avoid RPC delays when exiting suspend 2019-12-13 08:42:34 +01:00
samples samples/bpf: fix build by setting HAVE_ATTR_TEST to zero 2019-10-31 21:39:15 +01:00
scripts arm64 fix for -rc8 / final 2019-11-15 09:14:23 -08:00
security efi/efi_test: Lock down /dev/efi_test and require CAP_SYS_ADMIN 2019-10-31 09:40:21 +01:00
sound ALSA: hda: Modify stream stripe mask only when needed 2019-12-13 08:42:39 +01:00
tools perf scripts python: exported-sql-viewer.py: Fix use of TRUE with SQLite 2019-12-13 08:42:16 +01:00
usr kbuild: update compile-test header list for v5.4-rc2 2019-10-05 15:29:49 +09:00
virt KVM: Add a comment describing the /dev/kvm no_compat handling 2019-11-15 10:14:04 +01:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap ARM: SoC fixes 2019-11-10 13:41:59 -08:00
COPYING
CREDITS MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer 2019-10-10 08:12:51 -07:00
Kbuild
Kconfig
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-22 14:28:14 -08:00
Makefile Linux 5.4.2 2019-12-04 22:31:09 +01:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.