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| author | Louis Burda <quent.burda@gmail.com> | 2023-02-06 19:34:57 -0600 |
|---|---|---|
| committer | Louis Burda <quent.burda@gmail.com> | 2023-02-06 19:34:57 -0600 |
| commit | 15554c668705bcbaa9da3fbf2a1efe45bb42adc4 (patch) | |
| tree | 3c3cd73e4df4c4489b851b664d245a694de175b5 | |
| parent | 93ddfc5c264338ed8c8e7cb0940e2c9c70e5b64c (diff) | |
| download | cachepc-linux-15554c668705bcbaa9da3fbf2a1efe45bb42adc4.tar.gz cachepc-linux-15554c668705bcbaa9da3fbf2a1efe45bb42adc4.zip | |
fixup! Save registers to xmm to lower baseline counts and avoid timing issues with apic_oneshot
The cpu register state is cleared after vmrun in sev-es, as such we need to reload cpc_ds for probing and cpc_prime_probe. Since the access locations are constant, these extra loads will simply end up in the baseline. Additionally, the apic precision is not affected as the acceses happen *after* vmrun
| -rw-r--r-- | arch/x86/kvm/svm/vmenter.S | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S index 1a3e83e5a277..01cf98e16b57 100644 --- a/arch/x86/kvm/svm/vmenter.S +++ b/arch/x86/kvm/svm/vmenter.S @@ -289,6 +289,10 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run) 1: vmrun %_ASM_AX 2: cli + # in sev-es the cpu register state is not restored after vmrun.. + # xmm regs have been cleared so we need to do an extra accesses + movq cpc_ds_probe, %xmm8 + movq cpc_prime_probe, %xmm14 wrap_probe sev_es_vcpu_run #ifdef CONFIG_RETPOLINE |