The patch adds initial support required to integrate Secure Encrypted
Virtualization (SEV) feature.
ASID management:
- Reserve asid range for SEV guest, SEV asid range is obtained through
CPUID Fn8000_001f[ECX]. A non-SEV guest can use any asid outside the SEV
asid range.
- SEV guest must have asid value within asid range obtained through CPUID.
- SEV guest must have the same asid for all vcpu's. A TLB flush is required
if different vcpu for the same ASID is to be run on the same host CPU.
Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 8 ++
arch/x86/kvm/svm.c | 189 +++++++++++++++++++++++++++++++++++++++
include/uapi/linux/kvm.h | 98 ++++++++++++++++++++
3 files changed, 294 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 62651ad..fcc4710 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -719,6 +719,12 @@ struct kvm_hv {
HV_REFERENCE_TSC_PAGE tsc_ref;
};
+struct kvm_sev_info {
+ unsigned int handle; /* firmware handle */
+ unsigned int asid; /* asid for this guest */
+ int sev_fd; /* SEV device fd */
+};
+
struct kvm_arch {
unsigned int n_used_mmu_pages;
unsigned int n_requested_mmu_pages;
@@ -805,6 +811,8 @@ struct kvm_arch {
bool x2apic_format;
bool x2apic_broadcast_quirk_disabled;
+
+ struct kvm_sev_info sev_info;
};
struct kvm_vm_stat {
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 8d8fe62..fb63398 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -36,6 +36,7 @@
#include <linux/slab.h>
#include <linux/amd-iommu.h>
#include <linux/hashtable.h>
+#include <linux/psp-sev.h>
#include <asm/apic.h>
#include <asm/perf_event.h>
@@ -211,6 +212,9 @@ struct vcpu_svm {
*/
struct list_head ir_list;
spinlock_t ir_list_lock;
+
+ /* which host cpu was used for running this vcpu */
+ bool last_cpuid;
};
/*
@@ -490,6 +494,64 @@ static inline bool gif_set(struct vcpu_svm *svm)
return !!(svm->vcpu.arch.hflags & HF_GIF_MASK);
}
+/* Secure Encrypted Virtualization */
+static unsigned int max_sev_asid;
+static unsigned long *sev_asid_bitmap;
+
+static bool kvm_sev_enabled(void)
+{
+ return max_sev_asid ? 1 : 0;
+}
+
+static inline struct kvm_sev_info *sev_get_info(struct kvm *kvm)
+{
+ struct kvm_arch *vm_data = &kvm->arch;
+
+ return &vm_data->sev_info;
+}
+
+static unsigned int sev_get_handle(struct kvm *kvm)
+{
+ struct kvm_sev_info *sev_info = sev_get_info(kvm);
+
+ return sev_info->handle;
+}
+
+static inline int sev_guest(struct kvm *kvm)
+{
+ return sev_get_handle(kvm);
+}
+
+static inline int sev_get_asid(struct kvm *kvm)
+{
+ struct kvm_sev_info *sev_info = sev_get_info(kvm);
+
+ if (!sev_info)
+ return -EINVAL;
+
+ return sev_info->asid;
+}
+
+static inline int sev_get_fd(struct kvm *kvm)
+{
+ struct kvm_sev_info *sev_info = sev_get_info(kvm);
+
+ if (!sev_info)
+ return -EINVAL;
+
+ return sev_info->sev_fd;
+}
+
+static inline void sev_set_asid(struct kvm *kvm, int asid)
+{
+ struct kvm_sev_info *sev_info = sev_get_info(kvm);
+
+ if (!sev_info)
+ return;
+
+ sev_info->asid = asid;
+}
+
static unsigned long iopm_base;
struct kvm_ldttss_desc {
@@ -511,6 +573,8 @@ struct svm_cpu_data {
struct kvm_ldttss_desc *tss_desc;
struct page *save_area;
+
+ struct vmcb **sev_vmcbs; /* index = sev_asid, value = vmcb pointer */
};
static DEFINE_PER_CPU(struct svm_cpu_data *, svm_data);
@@ -764,7 +828,7 @@ static int svm_hardware_enable(void)
sd->asid_generation = 1;
sd->max_asid = cpuid_ebx(SVM_CPUID_FUNC) - 1;
sd->next_asid = sd->max_asid + 1;
- sd->min_asid = 1;
+ sd->min_asid = max_sev_asid + 1;
native_store_gdt(&gdt_descr);
gdt = (struct desc_struct *)gdt_descr.address;
@@ -825,6 +889,7 @@ static void svm_cpu_uninit(int cpu)
per_cpu(svm_data, raw_smp_processor_id()) = NULL;
__free_page(sd->save_area);
+ kfree(sd->sev_vmcbs);
kfree(sd);
}
@@ -842,6 +907,14 @@ static int svm_cpu_init(int cpu)
if (!sd->save_area)
goto err_1;
+ if (kvm_sev_enabled()) {
+ sd->sev_vmcbs = kmalloc((max_sev_asid + 1) * sizeof(void *),
+ GFP_KERNEL);
+ r = -ENOMEM;
+ if (!sd->sev_vmcbs)
+ goto err_1;
+ }
+
per_cpu(svm_data, cpu) = sd;
return 0;
@@ -1017,6 +1090,61 @@ static int avic_ga_log_notifier(u32 ga_tag)
return 0;
}
+static __init void sev_hardware_setup(void)
+{
+ int ret, error, nguests;
+ struct sev_data_init *init;
+ struct sev_data_status *status;
+
+ /*
+ * Get maximum number of encrypted guest supported: Fn8001_001F[ECX]
+ * Bit 31:0: Number of supported guest
+ */
+ nguests = cpuid_ecx(0x8000001F);
+ if (!nguests)
+ return;
+
+ init = kzalloc(sizeof(*init), GFP_KERNEL);
+ if (!init)
+ return;
+
+ status = kzalloc(sizeof(*status), GFP_KERNEL);
+ if (!status)
+ goto err_1;
+
+ /* Initialize SEV firmware */
+ ret = sev_platform_init(init, &error);
+ if (ret) {
+ pr_err("SEV: PLATFORM_INIT ret=%d (%#x)\n", ret, error);
+ goto err_2;
+ }
+
+ /* Initialize SEV ASID bitmap */
+ sev_asid_bitmap = kcalloc(BITS_TO_LONGS(nguests),
+ sizeof(unsigned long), GFP_KERNEL);
+ if (IS_ERR(sev_asid_bitmap)) {
+ sev_platform_shutdown(&error);
+ goto err_2;
+ }
+
+ /* Query the platform status and print API version */
+ ret = sev_platform_status(status, &error);
+ if (ret) {
+ printk(KERN_ERR "SEV: PLATFORM_STATUS ret=%#x\n", error);
+ goto err_2;
+ }
+
+ max_sev_asid = nguests;
+
+ printk(KERN_INFO "kvm: SEV enabled\n");
+ printk(KERN_INFO "SEV API: %d.%d\n",
+ status->api_major, status->api_minor);
+err_2:
+ kfree(status);
+err_1:
+ kfree(init);
+}
+
static __init int svm_hardware_setup(void)
{
int cpu;
@@ -1052,6 +1180,9 @@ static __init int svm_hardware_setup(void)
kvm_enable_efer_bits(EFER_SVME | EFER_LMSLE);
}
+ if (boot_cpu_has(X86_FEATURE_SEV))
+ sev_hardware_setup();
+
for_each_possible_cpu(cpu) {
r = svm_cpu_init(cpu);
if (r)
@@ -1094,10 +1225,25 @@ static __init int svm_hardware_setup(void)
return r;
}
+static __exit void sev_hardware_unsetup(void)
+{
+ int ret, err;
+
+ ret = sev_platform_shutdown(&err);
+ if (ret)
+ printk(KERN_ERR "failed to shutdown PSP rc=%d (%#0x10x)\n",
+ ret, err);
+
+ kfree(sev_asid_bitmap);
+}
+
static __exit void svm_hardware_unsetup(void)
{
int cpu;
+ if (kvm_sev_enabled())
+ sev_hardware_unsetup();
+
for_each_possible_cpu(cpu)
svm_cpu_uninit(cpu);
@@ -1157,6 +1303,11 @@ static void avic_init_vmcb(struct vcpu_svm *svm)
svm->vcpu.arch.apicv_active = true;
}
+static void sev_init_vmcb(struct vcpu_svm *svm)
+{
+ svm->vmcb->control.nested_ctl |= SVM_NESTED_CTL_SEV_ENABLE;
+}
+
static void init_vmcb(struct vcpu_svm *svm)
{
struct vmcb_control_area *control = &svm->vmcb->control;
@@ -1271,6 +1422,9 @@ static void init_vmcb(struct vcpu_svm *svm)
if (avic)
avic_init_vmcb(svm);
+ if (sev_guest(svm->vcpu.kvm))
+ sev_init_vmcb(svm);
+
mark_all_dirty(svm->vmcb);
enable_gif(svm);
@@ -2084,6 +2238,11 @@ static int pf_interception(struct vcpu_svm *svm)
default:
error_code = svm->vmcb->control.exit_info_1;
+ /* In SEV mode, the guest physical address will have C-bit
+ * set. C-bit must be cleared before handling the fault.
+ */
+ if (sev_guest(svm->vcpu.kvm))
+ fault_address &= ~sme_me_mask;
trace_kvm_page_fault(fault_address, error_code);
if (!npt_enabled && kvm_event_needs_reinjection(&svm->vcpu))
kvm_mmu_unprotect_page_virt(&svm->vcpu, fault_address);
@@ -4258,12 +4417,40 @@ static void reload_tss(struct kvm_vcpu *vcpu)
load_TR_desc();
}
+static void pre_sev_run(struct vcpu_svm *svm)
+{
+ int asid = sev_get_asid(svm->vcpu.kvm);
+ int cpu = raw_smp_processor_id();
+ struct svm_cpu_data *sd = per_cpu(svm_data, cpu);
+
+ /* Assign the asid allocated for this SEV guest */
+ svm->vmcb->control.asid = asid;
+
+ /* Flush guest TLB:
+ * - when different VMCB for the same ASID is to be run on the
+ * same host CPU
+ * or
+ * - this VMCB was executed on different host cpu in previous VMRUNs.
+ */
+ if (sd->sev_vmcbs[asid] != (void *)svm->vmcb ||
+ svm->last_cpuid != cpu)
+ svm->vmcb->control.tlb_ctl = TLB_CONTROL_FLUSH_ALL_ASID;
+
+ svm->last_cpuid = cpu;
+ sd->sev_vmcbs[asid] = (void *)svm->vmcb;
+
+ mark_dirty(svm->vmcb, VMCB_ASID);
+}
+
static void pre_svm_run(struct vcpu_svm *svm)
{
int cpu = raw_smp_processor_id();
struct svm_cpu_data *sd = per_cpu(svm_data, cpu);
+ if (sev_guest(svm->vcpu.kvm))
+ return pre_sev_run(svm);
+
/* FIXME: handle wraparound of asid_generation */
if (svm->asid_generation != sd->asid_generation)
new_asid(svm, sd);
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index fef7d83..9df37a2 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1284,6 +1284,104 @@ struct kvm_s390_ucas_mapping {
/* Memory Encryption Commands */
#define KVM_MEMORY_ENCRYPT_OP _IOWR(KVMIO, 0xb8, unsigned long)
+/* Secure Encrypted Virtualization mode */
+enum sev_cmd_id {
+ /* Guest launch commands */
+ KVM_SEV_LAUNCH_START = 0,
+ KVM_SEV_LAUNCH_UPDATE_DATA,
+ KVM_SEV_LAUNCH_MEASURE,
+ KVM_SEV_LAUNCH_FINISH,
+ /* Guest migration commands (outgoing) */
+ KVM_SEV_SEND_START,
+ KVM_SEV_SEND_UPDATE_DATA,
+ KVM_SEV_SEND_FINISH,
+ /* Guest migration commands (incoming) */
+ KVM_SEV_RECEIVE_START,
+ KVM_SEV_RECEIVE_UPDATE_DATA,
+ KVM_SEV_RECEIVE_FINISH,
+ /* Guest status and debug commands */
+ KVM_SEV_GUEST_STATUS,
+ KVM_SEV_DBG_DECRYPT,
+ KVM_SEV_DBG_ENCRYPT,
+
+ KVM_SEV_NR_MAX,
+};
+
+struct kvm_sev_cmd {
+ __u32 id;
+ __u64 data;
+ __u32 error;
+ __u32 sev_fd;
+};
+
+struct kvm_sev_launch_start {
+ __u32 handle;
+ __u32 policy;
+ __u64 dh_cert_data;
+ __u32 dh_cert_length;
+ __u64 session_data;
+ __u32 session_length;
+};
+
+struct kvm_sev_launch_update_data {
+ __u64 address;
+ __u32 length;
+};
+
+struct kvm_sev_launch_measure {
+ __u64 address;
+ __u32 length;
+};
+
+struct kvm_sev_send_start {
+ __u64 pdh_cert_data;
+ __u32 pdh_cert_length;
+ __u64 plat_cert_data;
+ __u32 plat_cert_length;
+ __u64 amd_cert_data;
+ __u32 amd_cert_length;
+ __u64 session_data;
+ __u32 session_length;
+};
+
+struct kvm_sev_send_update_data {
+ __u64 hdr_data;
+ __u32 hdr_length;
+ __u64 guest_address;
+ __u32 guest_length;
+ __u64 host_address;
+ __u32 host_length;
+};
+
+struct kvm_sev_receive_start {
+ __u32 handle;
+ __u64 pdh_cert_data;
+ __u32 pdh_cert_length;
+ __u64 session_data;
+ __u32 session_length;
+};
+
+struct kvm_sev_receive_update_data {
+ __u64 hdr_data;
+ __u32 hdr_length;
+ __u64 guest_address;
+ __u32 guest_length;
+ __u64 host_address;
+ __u32 host_length;
+};
+
+struct kvm_sev_guest_status {
+ __u32 handle;
+ __u32 policy;
+ __u32 state;
+};
+
+struct kvm_sev_dbg {
+ __u64 src_addr;
+ __u64 dst_addr;
+ __u32 length;
+};
+
#define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0)
#define KVM_DEV_ASSIGN_PCI_2_3 (1 << 1)
#define KVM_DEV_ASSIGN_MASK_INTX (1 << 2)
