| Message ID | 20210521102449.21505-1-ilstam@amazon.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | KVM: Implement nested TSC scaling | expand |
On 21/05/21 12:24, Ilias Stamatis wrote: > KVM currently supports hardware-assisted TSC scaling but only for L1; > the feature is not exposed to nested guests. This patch series adds > support for nested TSC scaling and allows both L1 and L2 to be scaled > with different scaling factors. That is achieved by "merging" the 01 and > 02 values together. > > Most of the logic in this series is implemented in common code (by doing > the necessary restructurings), however the patches add support for VMX > only. Adding support for SVM should be easy at this point and Maxim > Levitsky has volunteered to do this (thanks!). > > Changelog: > v3: > - Applied Sean's feedback > - Refactored patches 7 to 10 > > v2: > - Applied all of Maxim's feedback > - Added a mul_s64_u64_shr function in math64.h > - Added a separate kvm_scale_tsc_l1 function instead of passing an > argument to kvm_scale_tsc > - Implemented the 02 fields calculations in common code > - Moved all of write_l1_tsc_offset's logic to common code > - Added a check for whether the TSC is stable in patch 10 > - Used a random L1 factor and a negative offset in patch 10 > > Ilias Stamatis (12): > math64.h: Add mul_s64_u64_shr() > KVM: X86: Store L1's TSC scaling ratio in 'struct kvm_vcpu_arch' > KVM: X86: Rename kvm_compute_tsc_offset() to > kvm_compute_tsc_offset_l1() > KVM: X86: Add a ratio parameter to kvm_scale_tsc() > KVM: VMX: Add a TSC multiplier field in VMCS12 > KVM: X86: Add functions for retrieving L2 TSC fields from common code > KVM: X86: Add functions that calculate L2's TSC offset and multiplier > KVM: X86: Move write_l1_tsc_offset() logic to common code and rename > it > KVM: VMX: Remove vmx->current_tsc_ratio and decache_tsc_multiplier() > KVM: VMX: Set the TSC offset and multiplier on nested entry and exit > KVM: VMX: Expose TSC scaling to L2 > KVM: selftests: x86: Add vmx_nested_tsc_scaling_test > > arch/x86/include/asm/kvm-x86-ops.h | 4 +- > arch/x86/include/asm/kvm_host.h | 14 +- > arch/x86/kvm/svm/svm.c | 29 ++- > arch/x86/kvm/vmx/nested.c | 33 ++- > arch/x86/kvm/vmx/vmcs12.c | 1 + > arch/x86/kvm/vmx/vmcs12.h | 4 +- > arch/x86/kvm/vmx/vmx.c | 49 ++-- > arch/x86/kvm/vmx/vmx.h | 11 +- > arch/x86/kvm/x86.c | 91 +++++-- > include/linux/math64.h | 19 ++ > tools/testing/selftests/kvm/.gitignore | 1 + > tools/testing/selftests/kvm/Makefile | 1 + > .../kvm/x86_64/vmx_nested_tsc_scaling_test.c | 242 ++++++++++++++++++ > 13 files changed, 417 insertions(+), 82 deletions(-) > create mode 100644 tools/testing/selftests/kvm/x86_64/vmx_nested_tsc_scaling_test.c > > -- > 2.17.1 > Queued, thanks. The new kvm_x86_ops should go in kvm_x86_ops.nested, but those are not yet static_calls so we can leave that for later. Paolo
KVM currently supports hardware-assisted TSC scaling but only for L1; the feature is not exposed to nested guests. This patch series adds support for nested TSC scaling and allows both L1 and L2 to be scaled with different scaling factors. That is achieved by "merging" the 01 and 02 values together. Most of the logic in this series is implemented in common code (by doing the necessary restructurings), however the patches add support for VMX only. Adding support for SVM should be easy at this point and Maxim Levitsky has volunteered to do this (thanks!). Changelog: v3: - Applied Sean's feedback - Refactored patches 7 to 10 v2: - Applied all of Maxim's feedback - Added a mul_s64_u64_shr function in math64.h - Added a separate kvm_scale_tsc_l1 function instead of passing an argument to kvm_scale_tsc - Implemented the 02 fields calculations in common code - Moved all of write_l1_tsc_offset's logic to common code - Added a check for whether the TSC is stable in patch 10 - Used a random L1 factor and a negative offset in patch 10 Ilias Stamatis (12): math64.h: Add mul_s64_u64_shr() KVM: X86: Store L1's TSC scaling ratio in 'struct kvm_vcpu_arch' KVM: X86: Rename kvm_compute_tsc_offset() to kvm_compute_tsc_offset_l1() KVM: X86: Add a ratio parameter to kvm_scale_tsc() KVM: VMX: Add a TSC multiplier field in VMCS12 KVM: X86: Add functions for retrieving L2 TSC fields from common code KVM: X86: Add functions that calculate L2's TSC offset and multiplier KVM: X86: Move write_l1_tsc_offset() logic to common code and rename it KVM: VMX: Remove vmx->current_tsc_ratio and decache_tsc_multiplier() KVM: VMX: Set the TSC offset and multiplier on nested entry and exit KVM: VMX: Expose TSC scaling to L2 KVM: selftests: x86: Add vmx_nested_tsc_scaling_test arch/x86/include/asm/kvm-x86-ops.h | 4 +- arch/x86/include/asm/kvm_host.h | 14 +- arch/x86/kvm/svm/svm.c | 29 ++- arch/x86/kvm/vmx/nested.c | 33 ++- arch/x86/kvm/vmx/vmcs12.c | 1 + arch/x86/kvm/vmx/vmcs12.h | 4 +- arch/x86/kvm/vmx/vmx.c | 49 ++-- arch/x86/kvm/vmx/vmx.h | 11 +- arch/x86/kvm/x86.c | 91 +++++-- include/linux/math64.h | 19 ++ tools/testing/selftests/kvm/.gitignore | 1 + tools/testing/selftests/kvm/Makefile | 1 + .../kvm/x86_64/vmx_nested_tsc_scaling_test.c | 242 ++++++++++++++++++ 13 files changed, 417 insertions(+), 82 deletions(-) create mode 100644 tools/testing/selftests/kvm/x86_64/vmx_nested_tsc_scaling_test.c -- 2.17.1