[RFC,gmem,v1,6/8] KVM: x86: Add KVM_X86_SNP_VM vm_type

Commit Message

Michael Roth Oct. 16, 2023, 11:50 a.m. UTC

In some cases, such as detecting whether a page fault should be handled
as a private fault or not, KVM will need to handle things differently
versus the existing KVM_X86_PROTECTED_VM type.

Add a new KVM_X86_SNP_VM to allow for this, along with a helper to query
the vm_type.

Signed-off-by: Michael Roth <[e-mail]>
---
 arch/x86/include/asm/kvm_host.h | 2 ++
 arch/x86/include/uapi/asm/kvm.h | 1 +
 arch/x86/kvm/x86.c              | 8 +++++++-
 3 files changed, 10 insertions(+), 1 deletion(-)

Patch

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index dbec74783f48..cdc235277a6f 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -2089,6 +2089,8 @@  void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level,
 #define kvm_arch_has_private_mem(kvm) false
 #endif
 
+bool kvm_is_vm_type(struct kvm *kvm, unsigned long type);
+
 static inline u16 kvm_read_ldt(void)
 {
 	u16 ldt;
diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index a448d0964fc0..57e4ba484aa2 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -564,5 +564,6 @@  struct kvm_pmu_event_filter {
 
 #define KVM_X86_DEFAULT_VM	0
 #define KVM_X86_SW_PROTECTED_VM	1
+#define KVM_X86_SNP_VM		3
 
 #endif /* _ASM_X86_KVM_H */
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0e95c3a95e59..12f9e99c7ad0 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4444,10 +4444,16 @@  static int kvm_ioctl_get_supported_hv_cpuid(struct kvm_vcpu *vcpu,
 static bool kvm_is_vm_type_supported(unsigned long type)
 {
 	return type == KVM_X86_DEFAULT_VM ||
-	       (type == KVM_X86_SW_PROTECTED_VM &&
+	       ((type == KVM_X86_SW_PROTECTED_VM ||
+		 type == KVM_X86_SNP_VM) &&
 		IS_ENABLED(CONFIG_KVM_SW_PROTECTED_VM) && tdp_enabled);
 }
 
+bool kvm_is_vm_type(struct kvm *kvm, unsigned long type)
+{
+	return kvm->arch.vm_type == type;
+}
+
 int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 {
 	int r = 0;