[PATCH v19 019/130] KVM: x86: Add is_vm_type_supported callback

isaku.yamahata
2024-02-26T08:27:49Z

From: Isaku Yamahata <isaku.yamahata@intel.com>

For SEV_SNP and TDX, allow the backend can override the supported vm type.
Add KVM_X86_SNP_VM and KVM_X86_TDX_VM to reserve the bit.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>

---
v19:
- Mention KVM_X86_SNP_VM to the commit message

v18:
- include into TDX KVM patch series v18

Changes v3 -> v4:
- Added KVM_X86_SNP_VM

Changes v2 -> v3:
- no change
- didn't bother to rename KVM_X86_PROTECTED_VM to KVM_X86_SW_PROTECTED_VM

Changes v1 -> v2
- no change

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 | 1 +
arch/x86/include/uapi/asm/kvm.h | 2 ++
arch/x86/kvm/svm/svm.c | 7 +++++++
arch/x86/kvm/vmx/vmx.c | 7 +++++++
arch/x86/kvm/x86.c | 12 +++++++++++-
arch/x86/kvm/x86.h | 2 ++
7 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index 156832f01ebe..8be71a5c5c87 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 28314e7d546c..37cda8aa07b6 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1603,6 +1603,7 @@ 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 a448d0964fc0..aa7a56a47564 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -564,5 +564,7 @@ struct kvm_pmu_event_filter {

#define KVM_X86_DEFAULT_VM 0
#define KVM_X86_SW_PROTECTED_VM 1
+#define KVM_X86_TDX_VM 2
+#define KVM_X86_SNP_VM 3

#endif /* _ASM_X86_KVM_H */
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index e90b429c84f1..f76dd52d29ba 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4886,6 +4886,12 @@ 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-SNP. */
+ return __kvm_is_vm_type_supported(type);
+}
+
static int svm_vm_init(struct kvm *kvm)
{
if (!pause_filter_count || !pause_filter_thresh)
@@ -4914,6 +4920,7 @@ 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/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 1111d9d08903..fca3457dd050 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7541,6 +7541,12 @@ static int vmx_vcpu_create(struct kvm_vcpu *vcpu)
return err;
}

+static bool vmx_is_vm_type_supported(unsigned long type)
+{
+ /* TODO: Check if TDX is supported. */
+ return __kvm_is_vm_type_supported(type);
+}
+
#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"

@@ -8263,6 +8269,7 @@ static struct kvm_x86_ops vmx_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/x86.c b/arch/x86/kvm/x86.c
index 03dab4266172..442b356e4939 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4576,12 +4576,18 @@ static int kvm_ioctl_get_supported_hv_cpuid(struct kvm_vcpu *vcpu,
}
#endif

-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_SW_PROTECTED_VM &&
IS_ENABLED(CONFIG_KVM_SW_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)
{
@@ -4784,6 +4790,10 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
r = BIT(KVM_X86_DEFAULT_VM);
if (kvm_is_vm_type_supported(KVM_X86_SW_PROTECTED_VM))
r |= BIT(KVM_X86_SW_PROTECTED_VM);
+ if (kvm_is_vm_type_supported(KVM_X86_TDX_VM))
+ r |= BIT(KVM_X86_TDX_VM);
+ if (kvm_is_vm_type_supported(KVM_X86_SNP_VM))
+ r |= BIT(KVM_X86_SNP_VM);
break;
default:
break;
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 2f7e19166658..4e40c23d66ed 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -9,6 +9,8 @@
#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;
--
2.25.1