diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2018-07-13 16:23:21 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-07-13 16:29:54 +0200 |
| commit | dd4bfa739a72508b75760b393d129ed7b431daab (patch) | |
| tree | a984a7c2f3a5874cbd3826a8879a3932f74bf20f /arch/x86/kvm/vmx.c | |
| parent | 4c6523ec59fe895ea352a650218a6be0653910b1 (diff) | |
| download | lwn-dd4bfa739a72508b75760b393d129ed7b431daab.tar.gz lwn-dd4bfa739a72508b75760b393d129ed7b431daab.zip | |
x86/kvm: Serialize L1D flush parameter setter
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
Diffstat (limited to 'arch/x86/kvm/vmx.c')
| -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 37c7ff581184..12b1a5dae767 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -193,6 +193,7 @@ 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; @@ -257,7 +258,7 @@ 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; @@ -277,7 +278,10 @@ 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) |