diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2018-08-05 16:07:46 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-08-15 18:14:53 +0200 |
| commit | 383f160027af7f3e3c32c2988980652e708a2119 (patch) | |
| tree | 5ef2ed1d11481e68a17df49cb5f8a70dc625b916 /arch/x86/kvm/vmx.c | |
| parent | ee782edd87b482e66cc283cc23d1e984792874e8 (diff) | |
x86/speculation: Use ARCH_CAPABILITIES to skip L1D flush on vmentry
commit 8e0b2b916662e09dd4d09e5271cdf214c6b80e62 upstream
Bit 3 of ARCH_CAPABILITIES tells a hypervisor that L1D flush on vmentry is
not needed. Add a new value to enum vmx_l1d_flush_state, which is used
either if there is no L1TF bug at all, or if bit 3 is set in ARCH_CAPABILITIES.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/kvm/vmx.c')
| -rw-r--r-- | arch/x86/kvm/vmx.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 4596791dbb81..46f271803e6f 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -219,6 +219,16 @@ static int vmx_setup_l1d_flush(enum vmx_l1d_flush_state l1tf) return 0; } + if (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES)) { + u64 msr; + + rdmsrl(MSR_IA32_ARCH_CAPABILITIES, msr); + if (msr & ARCH_CAP_SKIP_VMENTRY_L1DFLUSH) { + l1tf_vmx_mitigation = VMENTER_L1D_FLUSH_NOT_REQUIRED; + return 0; + } + } + /* If set to auto use the default l1tf mitigation method */ if (l1tf == VMENTER_L1D_FLUSH_AUTO) { switch (l1tf_mitigation) { |