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| author | Paolo Bonzini <pbonzini@redhat.com> | 2018-08-05 16:07:46 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-08-15 18:13:00 +0200 |
| commit | c15396d3f74f6cd7c084bdcc1004714a40cb268a (patch) | |
| tree | 486bcfe53caa7cbcbabe5320830eaf4490baeb97 /arch/x86/kvm | |
| parent | 6a0bea042dcacc087587e6b44fb3e74ce0c26e5c (diff) | |
| download | linux-stable-c15396d3f74f6cd7c084bdcc1004714a40cb268a.tar.gz linux-stable-c15396d3f74f6cd7c084bdcc1004714a40cb268a.tar.bz2 linux-stable-c15396d3f74f6cd7c084bdcc1004714a40cb268a.zip | |
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/kvm')
| -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 bbaa5421c237..63ec03108b5d 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -221,6 +221,16 @@ 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) { |