diff options
| author | Junaid Shahid <junaids@google.com> | 2019-11-04 12:22:03 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-11-16 10:29:57 +0100 |
| commit | c6e94acbf6abab3e3c25fcdd3343d0c2a3f160ca (patch) | |
| tree | 1a9b673c13ee303a6a4a40d6ab497f48ee52fad1 /Documentation | |
| parent | 61e191b467f1edea6fae9123c37355133273a31a (diff) | |
kvm: x86: mmu: Recovery of shattered NX large pages
commit 1aa9b9572b10529c2e64e2b8f44025d86e124308 upstream.
The page table pages corresponding to broken down large pages are zapped in
FIFO order, so that the large page can potentially be recovered, if it is
not longer being used for execution. This removes the performance penalty
for walking deeper EPT page tables.
By default, one large page will last about one hour once the guest
reaches a steady state.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 4.9:
- Update another error path in kvm_create_vm() to use out_err_no_mmu_notifier
- Adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 32ab3ec06fd7..c81a008d6512 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1988,6 +1988,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. If the software workaround is enabled for the host, guests do need not to enable it for nested guests. + kvm.nx_huge_pages_recovery_ratio= + [KVM] Controls how many 4KiB pages are periodically zapped + back to huge pages. 0 disables the recovery, otherwise if + the value is N KVM will zap 1/Nth of the 4KiB pages every + minute. The default is 60. + kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM. Default is 1 (enabled) |