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| author | Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> | 2012-10-24 10:07:59 +0400 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2012-11-01 02:36:30 +0400 |
| commit | 87da7e66a40532b743cd50972fcf85a1f15b14ea (patch) | |
| tree | e553258648881176136774013f0fecff876644bb /crypto/blkcipher.c | |
| parent | 35fd3dc58da675d659513384221349ef90749a01 (diff) | |
| download | linux-87da7e66a40532b743cd50972fcf85a1f15b14ea.tar.xz | |
KVM: x86: fix vcpu->mmio_fragments overflow
After commit b3356bf0dbb349 (KVM: emulator: optimize "rep ins" handling),
the pieces of io data can be collected and write them to the guest memory
or MMIO together
Unfortunately, kvm splits the mmio access into 8 bytes and store them to
vcpu->mmio_fragments. If the guest uses "rep ins" to move large data, it
will cause vcpu->mmio_fragments overflow
The bug can be exposed by isapc (-M isapc):
[23154.818733] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC
[ ......]
[23154.858083] Call Trace:
[23154.859874] [<ffffffffa04f0e17>] kvm_get_cr8+0x1d/0x28 [kvm]
[23154.861677] [<ffffffffa04fa6d4>] kvm_arch_vcpu_ioctl_run+0xcda/0xe45 [kvm]
[23154.863604] [<ffffffffa04f5a1a>] ? kvm_arch_vcpu_load+0x17b/0x180 [kvm]
Actually, we can use one mmio_fragment to store a large mmio access then
split it when we pass the mmio-exit-info to userspace. After that, we only
need two entries to store mmio info for the cross-mmio pages access
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'crypto/blkcipher.c')
0 files changed, 0 insertions, 0 deletions