From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Unlike default VMs, confidential VMs (Intel TDX and AMD SEV-ES) don't allow
some operations (e.g., memory read/write, register state access, etc).
Introduce vm_type to track the type of the VM to x86 KVM. Other arch KVMs
already use vm_type, KVM_INIT_VM accepts vm_type, and x86 KVM callback
vm_init accepts vm_type. So follow them. Further, a different policy can
be made based on vm_type. Define KVM_X86_DEFAULT_VM for default VM as
default and define KVM_X86_TDX_VM for Intel TDX VM. The wrapper function
will be defined as "bool is_td(kvm) { return vm_type == VM_TYPE_TDX; }"
Add a capability KVM_CAP_VM_TYPES to effectively allow device model,
e.g. qemu, to query what VM types are supported by KVM. This (introduce a
new capability and add vm_type) is chosen to align with other arch KVMs
that have VM types already. Other arch KVMs use different names to query
supported vm types and there is no common name for it, so new name was
chosen.
Co-developed-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
Documentation/virt/kvm/api.rst | 4 +++-
arch/x86/include/asm/kvm-x86-ops.h | 1 +
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/svm/svm.c | 7 +++++++
arch/x86/kvm/vmx/main.c | 1 +
arch/x86/kvm/vmx/vmx.c | 5 +++++
arch/x86/kvm/vmx/x86_ops.h | 1 +
arch/x86/kvm/x86.c | 8 +++++++-
arch/x86/kvm/x86.h | 2 ++
tools/arch/x86/include/uapi/asm/kvm.h | 3 +++
tools/include/uapi/linux/kvm.h | 1 +
11 files changed, 32 insertions(+), 2 deletions(-)
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 191aabc3af8c..fbff5cd6e404 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -150,7 +150,9 @@ You probably want to use 0 as machine type.
X86:
^^^^
-Supported X86 VM types can be queried via KVM_CAP_VM_TYPES.
+Supported X86 VM types can be queried via KVM_CAP_VM_TYPES, which returns the
+bitmap of supported vm types. The 1-setting of bit @n means vm type with value
+@n is supported.
S390:
^^^^^
diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index 8dc345cc6318..eac4b65d1b01 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -20,6 +20,7 @@ KVM_X86_OP(hardware_disable)
KVM_X86_OP(hardware_unsetup)
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_OPTIONAL(vm_destroy)
KVM_X86_OP_OPTIONAL_RET0(vcpu_precreate)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 8344945dece3..ffb85c35cacc 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1546,6 +1546,7 @@ 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/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 8ed7e177e73d..d0b01956e420 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4682,6 +4682,12 @@ static void svm_vm_destroy(struct kvm *kvm)
sev_vm_destroy(kvm);
}
+static bool svm_is_vm_type_supported(unsigned long type)
+{
+ /* FIXME: Check if CPU is capable of SEV. */
+ return __kvm_is_vm_type_supported(type);
+}
+
static int svm_vm_init(struct kvm *kvm)
{
if (!pause_filter_count || !pause_filter_thresh)
@@ -4710,6 +4716,7 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
.vcpu_free = svm_vcpu_free,
.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/main.c b/arch/x86/kvm/vmx/main.c
index d21a7c7d18ea..e1bbe06517b7 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -45,6 +45,7 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
.hardware_disable = vmx_hardware_disable,
.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,
.vm_destroy = vmx_vm_destroy,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index bddbdd2988f4..5bfdfc6f2190 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7470,6 +7470,11 @@ int vmx_vcpu_create(struct kvm_vcpu *vcpu)
return err;
}
+bool vmx_is_vm_type_supported(unsigned long type)
+{
+ return type == KVM_X86_DEFAULT_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"
diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
index 0f200aead411..e4dae9842550 100644
--- a/arch/x86/kvm/vmx/x86_ops.h
+++ b/arch/x86/kvm/vmx/x86_ops.h
@@ -32,6 +32,7 @@ void vmx_hardware_unsetup(void);
int vmx_check_processor_compat(void);
int vmx_hardware_enable(void);
void vmx_hardware_disable(void);
+bool vmx_is_vm_type_supported(unsigned long type);
int vmx_vm_init(struct kvm *kvm);
void vmx_vm_destroy(struct kvm *kvm);
int vmx_vcpu_precreate(struct kvm *kvm);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 45330273bad6..589844a27349 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4352,12 +4352,18 @@ static int kvm_ioctl_get_supported_hv_cpuid(struct kvm_vcpu *vcpu,
return 0;
}
-static bool kvm_is_vm_type_supported(unsigned long type)
+bool __kvm_is_vm_type_supported(unsigned long type)
{
return type == KVM_X86_DEFAULT_VM ||
(type == KVM_X86_PROTECTED_VM &&
IS_ENABLED(CONFIG_KVM_PROTECTED_VM) && tdp_enabled);
}
+EXPORT_SYMBOL_GPL(__kvm_is_vm_type_supported);
+
+static bool kvm_is_vm_type_supported(unsigned long type)
+{
+ return static_call(kvm_x86_is_vm_type_supported)(type);
+}
int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
{
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 9de72586f406..888f34224bba 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -8,6 +8,8 @@
#include "kvm_cache_regs.h"
#include "kvm_emulate.h"
+bool __kvm_is_vm_type_supported(unsigned long type);
+
struct kvm_caps {
/* control of guest tsc rate supported? */
bool has_tsc_control;
diff --git a/tools/arch/x86/include/uapi/asm/kvm.h b/tools/arch/x86/include/uapi/asm/kvm.h
index e48deab8901d..53ce363ba5fe 100644
--- a/tools/arch/x86/include/uapi/asm/kvm.h
+++ b/tools/arch/x86/include/uapi/asm/kvm.h
@@ -529,4 +529,7 @@ 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_DEFAULT_VM 0
+#define KVM_X86_PROTECTED_VM 1
+
#endif /* _ASM_X86_KVM_H */
diff --git a/tools/include/uapi/linux/kvm.h b/tools/include/uapi/linux/kvm.h
index 55155e262646..63474f72ea34 100644
--- a/tools/include/uapi/linux/kvm.h
+++ b/tools/include/uapi/linux/kvm.h
@@ -1175,6 +1175,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_DIRTY_LOG_RING_ACQ_REL 223
#define KVM_CAP_S390_PROTECTED_ASYNC_DISABLE 224
#define KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP 225
+#define KVM_CAP_VM_TYPES 227
#ifdef KVM_CAP_IRQ_ROUTING
--
2.25.1
