Re: [PATCH v2 0/6] Spectre v2 updates

[Paolo Bonzini]

On 11/02/2018 00:39, David Woodhouse wrote:
> Using retpoline ensures the kernel is safe because it doesn't contain
> any indirect branches, but firmware still can â and we make calls into
> firmware at runtime. Where the IBRS microcode support is available, use
> that before calling into firmware.
> 
> While doing that, I noticed that we were calling C functions without
> telling the compiler about the call-clobbered registers. Stop that.
> 
> This also contains the always_inline fix for the performance problem
> introduced by retpoline in KVM code, and fixes some other issues with
> the per-vCPU KVM handling for the SPEC_CTRL MSR.
> 
> Finally, update the microcode blacklist to reflect the latest
> information from Intel.
> 
> v2: Drop IBRS_ALL patch for the time being
>     Add KVM MSR fixes (karahmed)
>     Update microcode blacklist
> 
> 
> 
> David Woodhouse (4):
>   x86/speculation: Update Speculation Control microcode blacklist
>   Revert "x86/speculation: Simplify
>     indirect_branch_prediction_barrier()"
>   KVM: x86: Reduce retpoline performance impact in
>     slot_handle_level_range()
>   x86/speculation: Use IBRS if available before calling into firmware
> 
> KarimAllah Ahmed (2):
>   X86/nVMX: Properly set spec_ctrl and pred_cmd before merging MSRs
>   KVM/nVMX: Set the CPU_BASED_USE_MSR_BITMAPS if we have a valid L02 MSR
>     bitmap
> 
>  arch/x86/include/asm/apm.h           |  6 ++++++
>  arch/x86/include/asm/cpufeatures.h   |  1 +
>  arch/x86/include/asm/efi.h           | 17 +++++++++++++++--
>  arch/x86/include/asm/nospec-branch.h | 32 ++++++++++++++++++++++++++++----
>  arch/x86/include/asm/processor.h     |  3 ---
>  arch/x86/kernel/cpu/bugs.c           | 18 +++++++++++-------
>  arch/x86/kernel/cpu/intel.c          |  4 ----
>  arch/x86/kvm/mmu.c                   | 10 +++++-----
>  arch/x86/kvm/vmx.c                   |  7 ++++---
>  drivers/watchdog/hpwdt.c             |  3 +++
>  10 files changed, 73 insertions(+), 28 deletions(-)
> 

Acked-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>