Messages in this thread | | | Date | Mon, 20 Aug 2018 18:00:51 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH] x86/spectre: Expand test for vulnerability to empty RSB exploits |
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On Tue, 7 Aug 2018, Jim Mattson wrote:
> Skylake-era Intel CPUs are vulnerable to exploits of empty RSB > conditions. On hardware, platform vulnerability can be determined > simply by checking the processor's DisplayModel/DisplayFamily > signature. However, when running in a VM, the operating system should > also query IA32_ARCH_CAPABILITIES.RSBA[bit 2], a synthetic bit that > can be set by a hypervisor to indicate that the VM might run on a > vulnerable physical processor, regardless of the > DisplayModel/DisplayFamily reported by CPUID. > > Note that IA32_ARCH_CAPABILITIES.RSBA[bit 2] is always clear on > hardware, so the DisplayModel/DisplayFamily check is still required. > > For all of the details, see the Intel white paper, "Retpoline: A > Branch Target Injection Mitigation" (document number 337131-001), > section 5.3: Virtual Machine CPU Identification. > > Signed-off-by: Jim Mattson <jmattson@google.com> > Reviewed-by: Peter Shier <pshier@google.com>
That has been superseeded by:
fdf82a7856b3 ("x86/speculation: Protect against userspace-userspace spectreRSB")
right? At least it does not apply anymore...
Thanks,
tglx
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