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 <brijesh.singh@xxxxxxx>
---
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 8771b878193f..50fddbe56981 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
@@ -1836,6 +1839,7 @@ 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;
@@ -1896,12 +1900,16 @@ 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 e40800e9c998..01953522097d 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -72,6 +72,7 @@ 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 */
@@ -246,6 +247,13 @@ static inline bool sev_es_guest(struct kvm *kvm)
#endif
}
+static 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;
--
2.17.1
