[RFC PATCH v3 14/59] KVM: x86: Add vm_type to differentiate legacy VMs from protected VMs

isaku.yamahata
2021-11-25T00:21:28Z

From: Sean Christopherson <sean.j.christopherson@intel.com>

Add a capability to effectively allow userspace to query what VM types
are supported by KVM.

Co-developed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
arch/x86/include/asm/kvm-x86-ops.h | 1 +
arch/x86/include/asm/kvm_host.h | 2 ++
arch/x86/include/uapi/asm/kvm.h | 4 ++++
arch/x86/kvm/svm/svm.c | 6 ++++++
arch/x86/kvm/vmx/vmx.c | 6 ++++++
arch/x86/kvm/x86.c | 9 ++++++++-
include/uapi/linux/kvm.h | 2 ++
tools/arch/x86/include/uapi/asm/kvm.h | 4 ++++
tools/include/uapi/linux/kvm.h | 2 ++
9 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index cefe1d81e2e8..4aa0a1c10b84 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -18,6 +18,7 @@ KVM_X86_OP_NULL(hardware_unsetup)
KVM_X86_OP_NULL(cpu_has_accelerated_tpr)
KVM_X86_OP(has_emulated_msr)
KVM_X86_OP(vcpu_after_set_cpuid)
+KVM_X86_OP(is_vm_type_supported)
KVM_X86_OP(vm_init)
KVM_X86_OP_NULL(vm_destroy)
KVM_X86_OP(vcpu_create)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 5b31d8e5fcbf..cdb908ed7d5b 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1037,6 +1037,7 @@ struct kvm_x86_msr_filter {
#define APICV_INHIBIT_REASON_BLOCKIRQ 6

struct kvm_arch {
+ unsigned long vm_type;
unsigned long n_used_mmu_pages;
unsigned long n_requested_mmu_pages;
unsigned long n_max_mmu_pages;
@@ -1311,6 +1312,7 @@ struct kvm_x86_ops {
bool (*has_emulated_msr)(struct kvm *kvm, u32 index);
void (*vcpu_after_set_cpuid)(struct kvm_vcpu *vcpu);

+ bool (*is_vm_type_supported)(unsigned long vm_type);
unsigned int vm_size;
int (*vm_init)(struct kvm *kvm);
void (*vm_destroy)(struct kvm *kvm);
diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index 5a776a08f78c..a0805a2a81f8 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -508,4 +508,8 @@ struct kvm_pmu_event_filter {
#define KVM_VCPU_TSC_CTRL 0 /* control group for the timestamp counter (TSC) */
#define KVM_VCPU_TSC_OFFSET 0 /* attribute for the TSC offset */

+#define KVM_X86_LEGACY_VM 0
+#define KVM_X86_SEV_ES_VM 1
+#define KVM_X86_TDX_VM 2
+
#endif /* _ASM_X86_KVM_H */
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 5630c241d5f6..2ef77d4566a9 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4562,6 +4562,11 @@ static void svm_vm_destroy(struct kvm *kvm)
sev_vm_destroy(kvm);
}

+static bool svm_is_vm_type_supported(unsigned long type)
+{
+ return type == KVM_X86_LEGACY_VM;
+}
+
static int svm_vm_init(struct kvm *kvm)
{
if (!pause_filter_count || !pause_filter_thresh)
@@ -4589,6 +4594,7 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
.vcpu_free = svm_free_vcpu,
.vcpu_reset = svm_vcpu_reset,

+ .is_vm_type_supported = svm_is_vm_type_supported,
.vm_size = sizeof(struct kvm_svm),
.vm_init = svm_vm_init,
.vm_destroy = svm_vm_destroy,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index fe4f3ee61db3..f2905e00b063 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6851,6 +6851,11 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu)
return err;
}

+static bool vmx_is_vm_type_supported(unsigned long type)
+{
+ return type == KVM_X86_LEGACY_VM;
+}
+
#define L1TF_MSG_SMT "L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details.\n"
#define L1TF_MSG_L1D "L1TF CPU bug present and virtualization mitigation disabled, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details.\n"

@@ -7505,6 +7510,7 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = {
.cpu_has_accelerated_tpr = report_flexpriority,
.has_emulated_msr = vmx_has_emulated_msr,

+ .is_vm_type_supported = vmx_is_vm_type_supported,
.vm_size = sizeof(struct kvm_vmx),
.vm_init = vmx_vm_init,

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6f3c77524426..5f4b6f70489b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4225,6 +4225,11 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
else
r = 0;
break;
+ case KVM_CAP_VM_TYPES:
+ r = BIT(KVM_X86_LEGACY_VM);
+ if (static_call(kvm_x86_is_vm_type_supported)(KVM_X86_TDX_VM))
+ r |= BIT(KVM_X86_TDX_VM);
+ break;
default:
break;
}
@@ -11320,9 +11325,11 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
int ret;
unsigned long flags;

- if (type)
+ if (!static_call(kvm_x86_is_vm_type_supported)(type))
return -EINVAL;

+ kvm->arch.vm_type = type;
+
ret = kvm_page_track_init(kvm);
if (ret)
return ret;
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 1daa45268de2..bb49e095867e 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1132,6 +1132,8 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_ARM_MTE 205
#define KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM 206

+#define KVM_CAP_VM_TYPES 1000
+
#ifdef KVM_CAP_IRQ_ROUTING

struct kvm_irq_routing_irqchip {
diff --git a/tools/arch/x86/include/uapi/asm/kvm.h b/tools/arch/x86/include/uapi/asm/kvm.h
index 2ef1f6513c68..96b0064cff5c 100644
--- a/tools/arch/x86/include/uapi/asm/kvm.h
+++ b/tools/arch/x86/include/uapi/asm/kvm.h
@@ -504,4 +504,8 @@ struct kvm_pmu_event_filter {
#define KVM_PMU_EVENT_ALLOW 0
#define KVM_PMU_EVENT_DENY 1

+#define KVM_X86_LEGACY_VM 0
+#define KVM_X86_SEV_ES_VM 1
+#define KVM_X86_TDX_VM 2
+
#endif /* _ASM_X86_KVM_H */
diff --git a/tools/include/uapi/linux/kvm.h b/tools/include/uapi/linux/kvm.h
index a067410ebea5..e5aadad54ced 100644
--- a/tools/include/uapi/linux/kvm.h
+++ b/tools/include/uapi/linux/kvm.h
@@ -1113,6 +1113,8 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_EXIT_ON_EMULATION_FAILURE 204
#define KVM_CAP_ARM_MTE 205

+#define KVM_CAP_VM_TYPES 1000
+
#ifdef KVM_CAP_IRQ_ROUTING

struct kvm_irq_routing_irqchip {
--
2.25.1