diff options
| author | Tom Lendacky <thomas.lendacky@amd.com> | 2020-03-20 11:07:07 -0500 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-03-23 09:01:04 -0400 |
| commit | 2e2409afe5f0c284c7dfe5504058e8d115806a7d (patch) | |
| tree | e1937efd10e18ce5c6d3d32142eeb40f359e4ea2 /lib/cmpdi2.c | |
| parent | 2da1ed62d55c6cbebbdee924f6af4e87bb6666e5 (diff) | |
KVM: SVM: Issue WBINVD after deactivating an SEV guest
Currently, CLFLUSH is used to flush SEV guest memory before the guest is
terminated (or a memory hotplug region is removed). However, CLFLUSH is
not enough to ensure that SEV guest tagged data is flushed from the cache.
With 33af3a7ef9e6 ("KVM: SVM: Reduce WBINVD/DF_FLUSH invocations"), the
original WBINVD was removed. This then exposed crashes at random times
because of a cache flush race with a page that had both a hypervisor and
a guest tag in the cache.
Restore the WBINVD when destroying an SEV guest and add a WBINVD to the
svm_unregister_enc_region() function to ensure hotplug memory is flushed
when removed. The DF_FLUSH can still be avoided at this point.
Fixes: 33af3a7ef9e6 ("KVM: SVM: Reduce WBINVD/DF_FLUSH invocations")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <c8bf9087ca3711c5770bdeaafa3e45b717dc5ef4.1584720426.git.thomas.lendacky@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'lib/cmpdi2.c')
0 files changed, 0 insertions, 0 deletions