[PATCH 0/2] x86/spec-ctrl: Reduce HVM RSB overhead

Andrew Cooper posted 2 patches 1 year, 7 months ago
Test gitlab-ci failed
Patches applied successfully (tree, apply log)
git fetch https://gitlab.com/xen-project/patchew/xen tags/patchew/20220809170016.25148-1-andrew.cooper3@citrix.com
xen/arch/x86/hvm/vmx/entry.S           |   1 +
xen/arch/x86/hvm/vmx/vmx.c             |  20 ++++++-
xen/arch/x86/include/asm/cpufeatures.h |   1 +
xen/arch/x86/include/asm/msr-index.h   |   1 +
xen/arch/x86/msr.c                     |   5 +-
xen/arch/x86/spec_ctrl.c               | 106 +++++++++++++++++++++++++++++++--
6 files changed, 126 insertions(+), 8 deletions(-)
[PATCH 0/2] x86/spec-ctrl: Reduce HVM RSB overhead
Posted by Andrew Cooper 1 year, 7 months ago
Xen happens to be not vulnerable to PBRSB, but it turns out we can improve the
performance on all eIBRS systems.

Andrew Cooper (2):
  x86/spec-ctrl: Enumeration for PBRSB_NO
  x86/spec-ctrl: Reduce HVM RSB overhead where possible

 xen/arch/x86/hvm/vmx/entry.S           |   1 +
 xen/arch/x86/hvm/vmx/vmx.c             |  20 ++++++-
 xen/arch/x86/include/asm/cpufeatures.h |   1 +
 xen/arch/x86/include/asm/msr-index.h   |   1 +
 xen/arch/x86/msr.c                     |   5 +-
 xen/arch/x86/spec_ctrl.c               | 106 +++++++++++++++++++++++++++++++--
 6 files changed, 126 insertions(+), 8 deletions(-)

-- 
2.11.0
Re: [PATCH 0/2] x86/spec-ctrl: Reduce HVM RSB overhead
Posted by Andrew Cooper 1 year, 7 months ago
On 09/08/2022 18:00, Andrew Cooper wrote:
> Xen happens to be not vulnerable to PBRSB, but it turns out we can improve the
> performance on all eIBRS systems.
>
> Andrew Cooper (2):
>   x86/spec-ctrl: Enumeration for PBRSB_NO
>   x86/spec-ctrl: Reduce HVM RSB overhead where possible

Network perf testing on IceLake Server says this turns into a 2% guest
bandwidth improvement.

~Andrew