linux/include
Michal Luczaj 52491a38b2 KVM: Initialize gfn_to_pfn_cache locks in dedicated helper
Move the gfn_to_pfn_cache lock initialization to another helper and
call the new helper during VM/vCPU creation.  There are race
conditions possible due to kvm_gfn_to_pfn_cache_init()'s
ability to re-initialize the cache's locks.

For example: a race between ioctl(KVM_XEN_HVM_EVTCHN_SEND) and
kvm_gfn_to_pfn_cache_init() leads to a corrupted shinfo gpc lock.

                (thread 1)                |           (thread 2)
                                          |
 kvm_xen_set_evtchn_fast                  |
  read_lock_irqsave(&gpc->lock, ...)      |
                                          | kvm_gfn_to_pfn_cache_init
                                          |  rwlock_init(&gpc->lock)
  read_unlock_irqrestore(&gpc->lock, ...) |

Rename "cache_init" and "cache_destroy" to activate+deactivate to
avoid implying that the cache really is destroyed/freed.

Note, there more races in the newly named kvm_gpc_activate() that will
be addressed separately.

Fixes: 982ed0de47 ("KVM: Reinstate gfn_to_pfn_cache with invalidation support")
Cc: stable@vger.kernel.org
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
[sean: call out that this is a bug fix]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221013211234.1318131-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-27 06:47:53 -04:00
..
acpi platform-drivers-x86 for v6.1-1 2022-10-05 10:38:24 -07:00
asm-generic - hfs and hfsplus kmap API modernization from Fabio Francesco 2022-10-12 11:00:22 -07:00
clocksource
crypto crypto: scatterwalk - Remove unused inline function scatterwalk_aligned() 2022-09-30 13:59:13 +08:00
drm Driver core changes for 6.1-rc1 2022-10-07 17:04:10 -07:00
dt-bindings These are the pin control changes for the v6.1 kernel cycle: 2022-10-11 10:59:59 -07:00
keys
kunit kunit: declare kunit_assert structs as const 2022-10-07 10:19:18 -06:00
kvm
linux KVM: Initialize gfn_to_pfn_cache locks in dedicated helper 2022-10-27 06:47:53 -04:00
math-emu
media USB/Thunderbolt changes for 6.1-rc1 2022-10-07 16:48:26 -07:00
memory
misc
net Random number generator fixes for Linux 6.1-rc1. 2022-10-16 15:27:07 -07:00
pcmcia
ras
rdma RDMA/core: Add UVERBS_ATTR_RAW_FD 2022-09-27 10:15:24 -03:00
rv
scsi SCSI misc on 20221007 2022-10-07 12:33:18 -07:00
soc RISC-V Patches for the 6.1 Merge Window, Part 2 2022-10-14 11:21:11 -07:00
sound ALSA: hda: Update register polling macros 2022-10-09 12:34:32 +02:00
target
trace f2fs-for-6.1-rc1 2022-10-10 20:28:41 -07:00
uapi This pull request contains updates for UBI and UBIFS 2022-10-14 18:23:23 -07:00
ufs SCSI misc on 20221007 2022-10-07 12:33:18 -07:00
vdso
video
xen xen/virtio: enable grant based virtio on x86 2022-10-10 14:31:26 +02:00