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Subject[RFC PATCH 02/35] KVM: SVM: Add support for SEV-ES capability in KVM
Date
From: Tom Lendacky <thomas.lendacky@amd.com>

Add support to KVM for determining if a system is capable of supporting
SEV-ES as well as determining if a guest is an SEV-ES guest.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
arch/x86/kvm/Kconfig | 3 ++-
arch/x86/kvm/svm/sev.c | 47 ++++++++++++++++++++++++++++++++++--------
arch/x86/kvm/svm/svm.c | 20 +++++++++---------
arch/x86/kvm/svm/svm.h | 17 ++++++++++++++-
4 files changed, 66 insertions(+), 21 deletions(-)

diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index fbd5bd7a945a..4e8924aab05e 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -99,7 +99,8 @@ config KVM_AMD_SEV
depends on KVM_AMD && X86_64
depends on CRYPTO_DEV_SP_PSP && !(KVM_AMD=y && CRYPTO_DEV_CCP_DD=m)
help
- Provides support for launching Encrypted VMs on AMD processors.
+ Provides support for launching Encrypted VMs (SEV) and Encrypted VMs
+ with Encrypted State (SEV-ES) on AMD processors.

config KVM_MMU_AUDIT
bool "Audit KVM MMU"
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index fab382e2dad2..48379e21ed43 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -923,7 +923,7 @@ int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
struct kvm_sev_cmd sev_cmd;
int r;

- if (!svm_sev_enabled())
+ if (!svm_sev_enabled() || !sev)
return -ENOTTY;

if (!argp)
@@ -1115,29 +1115,58 @@ void sev_vm_destroy(struct kvm *kvm)
sev_asid_free(sev->asid);
}

-int __init sev_hardware_setup(void)
+void __init sev_hardware_setup(void)
{
+ unsigned int eax, ebx, ecx, edx;
+ bool sev_es_supported = false;
+ bool sev_supported = false;
+
+ /* Does the CPU support SEV? */
+ if (!boot_cpu_has(X86_FEATURE_SEV))
+ goto out;
+
+ /* Retrieve SEV CPUID information */
+ cpuid(0x8000001f, &eax, &ebx, &ecx, &edx);
+
/* Maximum number of encrypted guests supported simultaneously */
- max_sev_asid = cpuid_ecx(0x8000001F);
+ max_sev_asid = ecx;

if (!svm_sev_enabled())
- return 1;
+ goto out;

/* Minimum ASID value that should be used for SEV guest */
- min_sev_asid = cpuid_edx(0x8000001F);
+ min_sev_asid = edx;

/* Initialize SEV ASID bitmaps */
sev_asid_bitmap = bitmap_zalloc(max_sev_asid, GFP_KERNEL);
if (!sev_asid_bitmap)
- return 1;
+ goto out;

sev_reclaim_asid_bitmap = bitmap_zalloc(max_sev_asid, GFP_KERNEL);
if (!sev_reclaim_asid_bitmap)
- return 1;
+ goto out;

- pr_info("SEV supported\n");
+ pr_info("SEV supported: %u ASIDs\n", max_sev_asid - min_sev_asid + 1);
+ sev_supported = true;

- return 0;
+ /* SEV-ES support requested? */
+ if (!sev_es)
+ goto out;
+
+ /* Does the CPU support SEV-ES? */
+ if (!boot_cpu_has(X86_FEATURE_SEV_ES))
+ goto out;
+
+ /* Has the system been allocated ASIDs for SEV-ES? */
+ if (min_sev_asid == 1)
+ goto out;
+
+ pr_info("SEV-ES supported: %u ASIDs\n", min_sev_asid - 1);
+ sev_es_supported = true;
+
+out:
+ sev = sev_supported;
+ sev_es = sev_es_supported;
}

void sev_hardware_teardown(void)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 4368b66615c1..83292fc44b4e 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -187,9 +187,13 @@ static int vgif = true;
module_param(vgif, int, 0444);

/* enable/disable SEV support */
-static int sev = IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT);
+int sev = IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT);
module_param(sev, int, 0444);

+/* enable/disable SEV-ES support */
+int sev_es = IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT);
+module_param(sev_es, int, 0444);
+
static bool __read_mostly dump_invalid_vmcb = 0;
module_param(dump_invalid_vmcb, bool, 0644);

@@ -860,15 +864,11 @@ static __init int svm_hardware_setup(void)
kvm_enable_efer_bits(EFER_SVME | EFER_LMSLE);
}

- if (sev) {
- if (boot_cpu_has(X86_FEATURE_SEV) &&
- IS_ENABLED(CONFIG_KVM_AMD_SEV)) {
- r = sev_hardware_setup();
- if (r)
- sev = false;
- } else {
- sev = false;
- }
+ if (IS_ENABLED(CONFIG_KVM_AMD_SEV) && sev) {
+ sev_hardware_setup();
+ } else {
+ sev = false;
+ sev_es = false;
}

svm_adjust_mmio_mask();
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index a798e1731709..2692ddf30c8d 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -60,6 +60,7 @@ enum {

struct kvm_sev_info {
bool active; /* SEV enabled guest */
+ bool es_active; /* SEV-ES enabled guest */
unsigned int asid; /* ASID used for this guest */
unsigned int handle; /* SEV firmware handle */
int fd; /* SEV device fd */
@@ -348,6 +349,9 @@ static inline bool gif_set(struct vcpu_svm *svm)
#define MSR_CR3_LONG_RESERVED_MASK 0xfff0000000000fe7U
#define MSR_INVALID 0xffffffffU

+extern int sev;
+extern int sev_es;
+
u32 svm_msrpm_offset(u32 msr);
void svm_set_efer(struct kvm_vcpu *vcpu, u64 efer);
void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0);
@@ -474,6 +478,17 @@ static inline bool sev_guest(struct kvm *kvm)
#endif
}

+static inline bool sev_es_guest(struct kvm *kvm)
+{
+#ifdef CONFIG_KVM_AMD_SEV
+ struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
+
+ return sev_guest(kvm) && sev->es_active;
+#else
+ return false;
+#endif
+}
+
static inline bool svm_sev_enabled(void)
{
return IS_ENABLED(CONFIG_KVM_AMD_SEV) ? max_sev_asid : 0;
@@ -486,7 +501,7 @@ int svm_register_enc_region(struct kvm *kvm,
int svm_unregister_enc_region(struct kvm *kvm,
struct kvm_enc_region *range);
void pre_sev_run(struct vcpu_svm *svm, int cpu);
-int __init sev_hardware_setup(void);
+void __init sev_hardware_setup(void);
void sev_hardware_teardown(void);

#endif
--
2.28.0
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