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From:   isaku.yamahata@intel.com
To:     kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     isaku.yamahata@intel.com, isaku.yamahata@gmail.com,
        Paolo Bonzini <pbonzini@redhat.com>, erdemaktas@google.com,
        Sean Christopherson <seanjc@google.com>,
        Sagi Shahar <sagis@google.com>,
        David Matlack <dmatlack@google.com>,
        Kai Huang <kai.huang@intel.com>,
        Zhi Wang <zhi.wang.linux@gmail.com>, chen.bo@intel.com,
        hang.yuan@intel.com, tina.zhang@intel.com,
        Sean Christopherson <sean.j.christopherson@intel.com>
Subject: [PATCH v16 080/116] KVM: VMX: Move NMI/exception handler to common helper
Date:   Mon, 16 Oct 2023 09:14:32 -0700
Message-Id: <96d44bcad72a8b40ad3996bed7a315f11d63e5f6.1697471314.git.isaku.yamahata@intel.com>
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From: Sean Christopherson <sean.j.christopherson@intel.com>

TDX mostly handles NMI/exception exit mostly the same to VMX case.  The
difference is how to retrieve exit qualification.  To share the code with
TDX, move NMI/exception to a common header, common.h.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
 arch/x86/kvm/vmx/common.h | 59 +++++++++++++++++++++++++++++++++
 arch/x86/kvm/vmx/vmx.c    | 68 +++++----------------------------------
 2 files changed, 67 insertions(+), 60 deletions(-)

diff --git a/arch/x86/kvm/vmx/common.h b/arch/x86/kvm/vmx/common.h
index 6f21d0d48809..632af7a76d0a 100644
--- a/arch/x86/kvm/vmx/common.h
+++ b/arch/x86/kvm/vmx/common.h
@@ -4,8 +4,67 @@
 
 #include <linux/kvm_host.h>
 
+#include <asm/traps.h>
+
 #include "posted_intr.h"
 #include "mmu.h"
+#include "vmcs.h"
+#include "x86.h"
+
+extern unsigned long vmx_host_idt_base;
+void vmx_do_interrupt_irqoff(unsigned long entry);
+void vmx_do_nmi_irqoff(void);
+
+static inline void vmx_handle_nm_fault_irqoff(struct kvm_vcpu *vcpu)
+{
+	/*
+	 * Save xfd_err to guest_fpu before interrupt is enabled, so the
+	 * MSR value is not clobbered by the host activity before the guest
+	 * has chance to consume it.
+	 *
+	 * Do not blindly read xfd_err here, since this exception might
+	 * be caused by L1 interception on a platform which doesn't
+	 * support xfd at all.
+	 *
+	 * Do it conditionally upon guest_fpu::xfd. xfd_err matters
+	 * only when xfd contains a non-zero value.
+	 *
+	 * Queuing exception is done in vmx_handle_exit. See comment there.
+	 */
+	if (vcpu->arch.guest_fpu.fpstate->xfd)
+		rdmsrl(MSR_IA32_XFD_ERR, vcpu->arch.guest_fpu.xfd_err);
+}
+
+static inline void vmx_handle_exception_irqoff(struct kvm_vcpu *vcpu,
+					       u32 intr_info)
+{
+	/* if exit due to PF check for async PF */
+	if (is_page_fault(intr_info))
+		vcpu->arch.apf.host_apf_flags = kvm_read_and_reset_apf_flags();
+	/* if exit due to NM, handle before interrupts are enabled */
+	else if (is_nm_fault(intr_info))
+		vmx_handle_nm_fault_irqoff(vcpu);
+	/* Handle machine checks before interrupts are enabled */
+	else if (is_machine_check(intr_info))
+		kvm_machine_check();
+}
+
+static inline void vmx_handle_external_interrupt_irqoff(struct kvm_vcpu *vcpu,
+							u32 intr_info)
+{
+	unsigned int vector = intr_info & INTR_INFO_VECTOR_MASK;
+	gate_desc *desc = (gate_desc *)vmx_host_idt_base + vector;
+
+	if (KVM_BUG(!is_external_intr(intr_info), vcpu->kvm,
+	    "unexpected VM-Exit interrupt info: 0x%x", intr_info))
+		return;
+
+	kvm_before_interrupt(vcpu, KVM_HANDLING_IRQ);
+	vmx_do_interrupt_irqoff(gate_offset(desc));
+	kvm_after_interrupt(vcpu);
+
+	vcpu->arch.at_instruction_boundary = true;
+}
 
 static inline int __vmx_handle_ept_violation(struct kvm_vcpu *vcpu, gpa_t gpa,
 					     unsigned long exit_qualification)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index b1c36525a81a..18b374b3f940 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -517,7 +517,7 @@ static inline void vmx_segment_cache_clear(struct vcpu_vmx *vmx)
 	vmx->segment_cache.bitmask = 0;
 }
 
-static unsigned long host_idt_base;
+unsigned long vmx_host_idt_base;
 
 #if IS_ENABLED(CONFIG_HYPERV)
 static bool __read_mostly enlightened_vmcs = true;
@@ -4277,7 +4277,7 @@ void vmx_set_constant_host_state(struct vcpu_vmx *vmx)
 	vmcs_write16(HOST_SS_SELECTOR, __KERNEL_DS);  /* 22.2.4 */
 	vmcs_write16(HOST_TR_SELECTOR, GDT_ENTRY_TSS*8);  /* 22.2.4 */
 
-	vmcs_writel(HOST_IDTR_BASE, host_idt_base);   /* 22.2.4 */
+	vmcs_writel(HOST_IDTR_BASE, vmx_host_idt_base);   /* 22.2.4 */
 
 	vmcs_writel(HOST_RIP, (unsigned long)vmx_vmexit); /* 22.2.5 */
 
@@ -5167,7 +5167,7 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu)
 	intr_info = vmx_get_intr_info(vcpu);
 
 	/*
-	 * Machine checks are handled by handle_exception_irqoff(), or by
+	 * Machine checks are handled by vmx_handle_exception_irqoff(), or by
 	 * vmx_vcpu_run() if a #MC occurs on VM-Entry.  NMIs are handled by
 	 * vmx_vcpu_enter_exit().
 	 */
@@ -5175,7 +5175,7 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu)
 		return 1;
 
 	/*
-	 * Queue the exception here instead of in handle_nm_fault_irqoff().
+	 * Queue the exception here instead of in vmx_handle_nm_fault_irqoff().
 	 * This ensures the nested_vmx check is not skipped so vmexit can
 	 * be reflected to L1 (when it intercepts #NM) before reaching this
 	 * point.
@@ -6890,59 +6890,6 @@ void vmx_load_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap)
 	vmcs_write64(EOI_EXIT_BITMAP3, eoi_exit_bitmap[3]);
 }
 
-void vmx_do_interrupt_irqoff(unsigned long entry);
-void vmx_do_nmi_irqoff(void);
-
-static void handle_nm_fault_irqoff(struct kvm_vcpu *vcpu)
-{
-	/*
-	 * Save xfd_err to guest_fpu before interrupt is enabled, so the
-	 * MSR value is not clobbered by the host activity before the guest
-	 * has chance to consume it.
-	 *
-	 * Do not blindly read xfd_err here, since this exception might
-	 * be caused by L1 interception on a platform which doesn't
-	 * support xfd at all.
-	 *
-	 * Do it conditionally upon guest_fpu::xfd. xfd_err matters
-	 * only when xfd contains a non-zero value.
-	 *
-	 * Queuing exception is done in vmx_handle_exit. See comment there.
-	 */
-	if (vcpu->arch.guest_fpu.fpstate->xfd)
-		rdmsrl(MSR_IA32_XFD_ERR, vcpu->arch.guest_fpu.xfd_err);
-}
-
-static void handle_exception_irqoff(struct kvm_vcpu *vcpu, u32 intr_info)
-{
-	/* if exit due to PF check for async PF */
-	if (is_page_fault(intr_info))
-		vcpu->arch.apf.host_apf_flags = kvm_read_and_reset_apf_flags();
-	/* if exit due to NM, handle before interrupts are enabled */
-	else if (is_nm_fault(intr_info))
-		handle_nm_fault_irqoff(vcpu);
-	/* Handle machine checks before interrupts are enabled */
-	else if (is_machine_check(intr_info))
-		kvm_machine_check();
-}
-
-static void handle_external_interrupt_irqoff(struct kvm_vcpu *vcpu,
-					     u32 intr_info)
-{
-	unsigned int vector = intr_info & INTR_INFO_VECTOR_MASK;
-	gate_desc *desc = (gate_desc *)host_idt_base + vector;
-
-	if (KVM_BUG(!is_external_intr(intr_info), vcpu->kvm,
-	    "unexpected VM-Exit interrupt info: 0x%x", intr_info))
-		return;
-
-	kvm_before_interrupt(vcpu, KVM_HANDLING_IRQ);
-	vmx_do_interrupt_irqoff(gate_offset(desc));
-	kvm_after_interrupt(vcpu);
-
-	vcpu->arch.at_instruction_boundary = true;
-}
-
 void vmx_handle_exit_irqoff(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
@@ -6951,9 +6898,10 @@ void vmx_handle_exit_irqoff(struct kvm_vcpu *vcpu)
 		return;
 
 	if (vmx->exit_reason.basic == EXIT_REASON_EXTERNAL_INTERRUPT)
-		handle_external_interrupt_irqoff(vcpu, vmx_get_intr_info(vcpu));
+		vmx_handle_external_interrupt_irqoff(vcpu,
+						     vmx_get_intr_info(vcpu));
 	else if (vmx->exit_reason.basic == EXIT_REASON_EXCEPTION_NMI)
-		handle_exception_irqoff(vcpu, vmx_get_intr_info(vcpu));
+		vmx_handle_exception_irqoff(vcpu, vmx_get_intr_info(vcpu));
 }
 
 /*
@@ -8244,7 +8192,7 @@ __init int vmx_hardware_setup(void)
 	for_each_possible_cpu(cpu)
 		INIT_LIST_HEAD(&per_cpu(loaded_vmcss_on_cpu, cpu));
 	store_idt(&dt);
-	host_idt_base = dt.address;
+	vmx_host_idt_base = dt.address;
 
 	vmx_setup_user_return_msrs();
 
-- 
2.25.1