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| author | Thomas Gleixner <tglx@linutronix.de> | 2018-07-13 17:23:21 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-08-15 19:14:50 +0300 |
| commit | 6ccf633238db85cbadd3fa0830eab88fe949dd67 (patch) | |
| tree | ca086d83bf15d62bcd3a8cfc2d35ceaae47c8631 | |
| parent | dff0982c5719eaedff58c026be9871ea63af992c (diff) | |
| download | linux-6ccf633238db85cbadd3fa0830eab88fe949dd67.tar.xz | |
x86/kvm: Serialize L1D flush parameter setter
commit dd4bfa739a72508b75760b393d129ed7b431daab upstream
Writes to the parameter files are not serialized at the sysfs core
level, so local serialization is required.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20180713142322.873642605@linutronix.de
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/kvm/vmx.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 332d92d2ee75..ad51ebb54153 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -194,6 +194,7 @@ extern const ulong vmx_return; static DEFINE_STATIC_KEY_FALSE(vmx_l1d_should_flush); static DEFINE_STATIC_KEY_FALSE(vmx_l1d_flush_always); +static DEFINE_MUTEX(vmx_l1d_flush_mutex); /* Storage for pre module init parameter parsing */ static enum vmx_l1d_flush_state __read_mostly vmentry_l1d_flush_param = VMENTER_L1D_FLUSH_AUTO; @@ -258,7 +259,7 @@ static int vmentry_l1d_flush_parse(const char *s) static int vmentry_l1d_flush_set(const char *s, const struct kernel_param *kp) { - int l1tf; + int l1tf, ret; if (!boot_cpu_has(X86_BUG_L1TF)) return 0; @@ -278,7 +279,10 @@ static int vmentry_l1d_flush_set(const char *s, const struct kernel_param *kp) return 0; } - return vmx_setup_l1d_flush(l1tf); + mutex_lock(&vmx_l1d_flush_mutex); + ret = vmx_setup_l1d_flush(l1tf); + mutex_unlock(&vmx_l1d_flush_mutex); + return ret; } static int vmentry_l1d_flush_get(char *s, const struct kernel_param *kp) |