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| author | Tom Lendacky <thomas.lendacky@amd.com> | 2020-12-10 20:10:08 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-12-15 13:20:59 +0300 |
| commit | 16809ecdc1e8ab7278f1d60021ac809edd17d060 (patch) | |
| tree | ac996579409605ab784a82b13839c39226ac8664 /arch/x86/kvm/svm/vmenter.S | |
| parent | 861377730aa9db4cbaa0f3bd3f4d295c152732c4 (diff) | |
| download | linux-16809ecdc1e8ab7278f1d60021ac809edd17d060.tar.xz | |
KVM: SVM: Provide an updated VMRUN invocation for SEV-ES guests
The run sequence is different for an SEV-ES guest compared to a legacy or
even an SEV guest. The guest vCPU register state of an SEV-ES guest will
be restored on VMRUN and saved on VMEXIT. There is no need to restore the
guest registers directly and through VMLOAD before VMRUN and no need to
save the guest registers directly and through VMSAVE on VMEXIT.
Update the svm_vcpu_run() function to skip register state saving and
restoring and provide an alternative function for running an SEV-ES guest
in vmenter.S
Additionally, certain host state is restored across an SEV-ES VMRUN. As
a result certain register states are not required to be restored upon
VMEXIT (e.g. FS, GS, etc.), so only do that if the guest is not an SEV-ES
guest.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <fb1c66d32f2194e171b95fc1a8affd6d326e10c1.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/svm/vmenter.S')
| -rw-r--r-- | arch/x86/kvm/svm/vmenter.S | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S index 1ec1ac40e328..6feb8c08f45a 100644 --- a/arch/x86/kvm/svm/vmenter.S +++ b/arch/x86/kvm/svm/vmenter.S @@ -168,3 +168,53 @@ SYM_FUNC_START(__svm_vcpu_run) pop %_ASM_BP ret SYM_FUNC_END(__svm_vcpu_run) + +/** + * __svm_sev_es_vcpu_run - Run a SEV-ES vCPU via a transition to SVM guest mode + * @vmcb_pa: unsigned long + */ +SYM_FUNC_START(__svm_sev_es_vcpu_run) + push %_ASM_BP +#ifdef CONFIG_X86_64 + push %r15 + push %r14 + push %r13 + push %r12 +#else + push %edi + push %esi +#endif + push %_ASM_BX + + /* Enter guest mode */ + mov %_ASM_ARG1, %_ASM_AX + sti + +1: vmrun %_ASM_AX + jmp 3f +2: cmpb $0, kvm_rebooting + jne 3f + ud2 + _ASM_EXTABLE(1b, 2b) + +3: cli + +#ifdef CONFIG_RETPOLINE + /* IMPORTANT: Stuff the RSB immediately after VM-Exit, before RET! */ + FILL_RETURN_BUFFER %_ASM_AX, RSB_CLEAR_LOOPS, X86_FEATURE_RETPOLINE +#endif + + pop %_ASM_BX + +#ifdef CONFIG_X86_64 + pop %r12 + pop %r13 + pop %r14 + pop %r15 +#else + pop %esi + pop %edi +#endif + pop %_ASM_BP + ret +SYM_FUNC_END(__svm_sev_es_vcpu_run) |