[PATCH RFC v9 27/51] KVM: SVM: Add initial SEV-SNP support
From: Michael Roth <hidden>
Date: 2023-06-12 04:39:10
Also in:
kvm, linux-crypto, linux-mm, lkml
Subsystem:
kernel virtual machine for x86 (kvm/x86), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Sean Christopherson, Paolo Bonzini, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Brijesh Singh <redacted> The next generation of SEV is called SEV-SNP (Secure Nested Paging). SEV-SNP builds upon existing SEV and SEV-ES functionality while adding new hardware based security protection. SEV-SNP adds strong memory encryption integrity protection to help prevent malicious hypervisor-based attacks such as data replay, memory re-mapping, and more, to create an isolated execution environment. The SNP feature is added incrementally, the later patches adds a new module parameters that can be used to enabled SEV-SNP in the KVM. Signed-off-by: Brijesh Singh <redacted> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> Signed-off-by: Michael Roth <redacted> --- arch/x86/kvm/svm/sev.c | 10 +++++++++- arch/x86/kvm/svm/svm.h | 8 ++++++++ 2 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 69b57e8f0a7f..f5fcf6c33583 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c@@ -58,6 +58,9 @@ module_param_named(sev_es, sev_es_enabled, bool, 0444); #define sev_es_enabled false #endif /* CONFIG_KVM_AMD_SEV */ +/* enable/disable SEV-SNP support */ +static bool sev_snp_enabled; + #define AP_RESET_HOLD_NONE 0 #define AP_RESET_HOLD_NAE_EVENT 1 #define AP_RESET_HOLD_MSR_PROTO 2
@@ -2169,6 +2172,7 @@ void __init sev_hardware_setup(void) { #ifdef CONFIG_KVM_AMD_SEV unsigned int eax, ebx, ecx, edx, sev_asid_count, sev_es_asid_count; + bool sev_snp_supported = false; bool sev_es_supported = false; bool sev_supported = false;
@@ -2248,12 +2252,16 @@ void __init sev_hardware_setup(void) if (misc_cg_set_capacity(MISC_CG_RES_SEV_ES, sev_es_asid_count)) goto out; - pr_info("SEV-ES supported: %u ASIDs\n", sev_es_asid_count); sev_es_supported = true; + sev_snp_supported = sev_snp_enabled && cpu_feature_enabled(X86_FEATURE_SEV_SNP); + + pr_info("SEV-ES %ssupported: %u ASIDs\n", + sev_snp_supported ? "and SEV-SNP " : "", sev_es_asid_count); out: sev_enabled = sev_supported; sev_es_enabled = sev_es_supported; + sev_snp_enabled = sev_snp_supported; #endif }
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index e45b54e95495..6974d63c84f9 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h@@ -77,6 +77,7 @@ enum { struct kvm_sev_info { bool active; /* SEV enabled guest */ bool es_active; /* SEV-ES enabled guest */ + bool snp_active; /* SEV-SNP enabled guest */ unsigned int asid; /* ASID used for this guest */ unsigned int handle; /* SEV firmware handle */ int fd; /* SEV device fd */
@@ -346,6 +347,13 @@ static __always_inline bool sev_es_guest(struct kvm *kvm) #endif } +static __always_inline bool sev_snp_guest(struct kvm *kvm) +{ + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + + return sev_es_guest(kvm) && sev->snp_active; +} + static inline void vmcb_mark_all_dirty(struct vmcb *vmcb) { vmcb->control.clean = 0;
--
2.25.1