From: Amit Shah <amit.shah@xxxxxxx> Newer AMD CPUs (Turin+) have the ERAPS feature bit that allows us to remove the RSB filling loops required during context switches and VM exits. This patchset implements the feature to: * remove the need for RSB filling on context switches and VMEXITs in host and guests * allow KVM guests to use the full default RSB stack Amit Shah (2): x86: cpu/bugs: add support for AMD ERAPS feature x86: kvm: svm: add support for ERAPS and FLUSH_RAP_ON_VMRUN Documentation/admin-guide/hw-vuln/spectre.rst | 5 ++- arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/include/asm/nospec-branch.h | 11 +++++ arch/x86/include/asm/svm.h | 6 ++- arch/x86/kernel/cpu/bugs.c | 36 ++++++++++----- arch/x86/kvm/cpuid.c | 15 ++++++- arch/x86/kvm/svm/svm.c | 44 +++++++++++++++++++ arch/x86/kvm/svm/svm.h | 15 +++++++ 8 files changed, 118 insertions(+), 15 deletions(-) -- 2.47.0
