Merge tag 'kvm-x86-vmx-7.4' of https://github.com/kvm-x86/linux into HEAD

KVM VMX changes for 7.4

 - Enable Notify VM-Exits (now called Instruction Timeout in the SDM) and Bus
   Lock VM-Exits for TDX guests when they're enabled by userspace (KVM forgot
   to wire up the TDX Module knobs).

 - Move all common (between VMX and TDX) APIs/helpers to common.h/main.c, and
   change all namespace prefixes from "vmx" to "vt".

 - Fix a thankfully benign bug (due to other areas of KVM being hardened) where
   usersepace can bypass INIT_MEM_REGION's address wrap check by providing a
   nr_pages that will overflow a u64 when converted to bytes, and fix an also-
   benign off-by-one bug in the check (inclusive vs. exclusive).

 - Set the vmcs.GUEST_ACTIVITY_STATE back to ACTIVE when userspace sets KVM's
   mp_state to anything other than HALTED, e.g. so that a vCPU doesn't get
   stuck in HLT if userspace emulates RESET.

3 files changed, 16 insertions, 0 deletions

diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index 67b43c167045..48fa973b98d5 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -82,6 +82,7 @@ KVM_X86_OP(interrupt_allowed)
 KVM_X86_OP(nmi_allowed)
 KVM_X86_OP(get_nmi_mask)
 KVM_X86_OP(set_nmi_mask)
+KVM_X86_OP_OPTIONAL(clear_hlt)
 KVM_X86_OP(enable_nmi_window)
 KVM_X86_OP(enable_irq_window)
 KVM_X86_OP_OPTIONAL(update_cr8_intercept)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 2a0245fa7e26..0378577d9d8b 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1621,6 +1621,13 @@ struct kvm_x86_ops {
 	int (*nmi_allowed)(struct kvm_vcpu *vcpu, bool for_injection);
 	bool (*get_nmi_mask)(struct kvm_vcpu *vcpu);
 	void (*set_nmi_mask)(struct kvm_vcpu *vcpu, bool masked);
+	/*
+	 * Force the vCPU out of any hardware-tracked halted/inactive state so
+	 * that it will fetch and execute instructions on the next VM-Enter.
+	 * Only needed by VMX, where VMCS.GUEST_ACTIVITY_STATE persists across
+	 * VM-Exit/VM-Enter; SVM has no equivalent VMCB field.
+	 */
+	void (*clear_hlt)(struct kvm_vcpu *vcpu);
 	/* Whether or not a virtual NMI is pending in hardware. */
 	bool (*is_vnmi_pending)(struct kvm_vcpu *vcpu);
 	/*
diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index 3f1b3096ff04..e49b836c7313 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -20,6 +20,14 @@
 #include <asm/trapnr.h>
 #include <asm/vmxfeatures.h>
 
+/*
+ * UNDEFINED is a KVM-defined value used to indicate that the basic exit reason
+ * is undefined/invalid, e.g. on VM-Fail or if TDX never attempted VM-Enter.
+ * The value itself is arbitrary, it just needs to not collide with a real exit
+ * reason.
+ */
+#define EXIT_REASON_UNDEFINED			0xdead
+
 struct vmcs_hdr {
 	u32 revision_id:31;
 	u32 shadow_vmcs:1;