diff mbox series

[09/21] KVM: VMX: Modify NMI and INTR handlers to take intr_info as function argument

Message ID 20240227232100.478238-10-pbonzini@redhat.com (mailing list archive)
State New, archived
Headers show
Series TDX/SNP part 1 of n, for 6.9 | expand

Commit Message

Paolo Bonzini Feb. 27, 2024, 11:20 p.m. UTC 
From: Sean Christopherson <seanjc@google.com>

TDX uses different ABI to get information about VM exit.  Pass intr_info to
the NMI and INTR handlers instead of pulling it from vcpu_vmx in
preparation for sharing the bulk of the handlers with TDX.

When the guest TD exits to VMM, RAX holds status and exit reason, RCX holds
exit qualification etc rather than the VMCS fields because VMM doesn't have
access to the VMCS.  The eventual code will be

VMX:
  - get exit reason, intr_info, exit_qualification, and etc from VMCS
  - call NMI/INTR handlers (common code)

TDX:
  - get exit reason, intr_info, exit_qualification, and etc from guest
    registers
  - call NMI/INTR handlers (common code)

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <0396a9ae70d293c9d0b060349dae385a8a4fbcec.1705965635.git.isaku.yamahata@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/vmx/vmx.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

Comments

Xiaoyao Li March 4, 2024, 8:09 a.m. UTC | #1 
On 2/28/2024 7:20 AM, Paolo Bonzini wrote:
> From: Sean Christopherson <seanjc@google.com>
> 
> TDX uses different ABI to get information about VM exit.  Pass intr_info to
> the NMI and INTR handlers instead of pulling it from vcpu_vmx in
> preparation for sharing the bulk of the handlers with TDX.
> 
> When the guest TD exits to VMM, RAX holds status and exit reason, RCX holds
> exit qualification etc rather than the VMCS fields because VMM doesn't have
> access to the VMCS.  The eventual code will be
> 
> VMX:
>    - get exit reason, intr_info, exit_qualification, and etc from VMCS
>    - call NMI/INTR handlers (common code)
> 
> TDX:
>    - get exit reason, intr_info, exit_qualification, and etc from guest
>      registers
>    - call NMI/INTR handlers (common code)
> 
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
> Message-Id: <0396a9ae70d293c9d0b060349dae385a8a4fbcec.1705965635.git.isaku.yamahata@intel.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>

> ---
>   arch/x86/kvm/vmx/vmx.c | 16 +++++++---------
>   1 file changed, 7 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 3d8a7e4c8e37..8aedfe0fd78c 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -7000,24 +7000,22 @@ static void handle_nm_fault_irqoff(struct kvm_vcpu *vcpu)
>   		rdmsrl(MSR_IA32_XFD_ERR, vcpu->arch.guest_fpu.xfd_err);
>   }
>   
> -static void handle_exception_irqoff(struct vcpu_vmx *vmx)
> +static void handle_exception_irqoff(struct kvm_vcpu *vcpu, u32 intr_info)
>   {
> -	u32 intr_info = vmx_get_intr_info(&vmx->vcpu);
> -
>   	/* if exit due to PF check for async PF */
>   	if (is_page_fault(intr_info))
> -		vmx->vcpu.arch.apf.host_apf_flags = kvm_read_and_reset_apf_flags();
> +		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(&vmx->vcpu);
> +		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)
> +static void handle_external_interrupt_irqoff(struct kvm_vcpu *vcpu,
> +					     u32 intr_info)
>   {
> -	u32 intr_info = vmx_get_intr_info(vcpu);
>   	unsigned int vector = intr_info & INTR_INFO_VECTOR_MASK;
>   	gate_desc *desc = (gate_desc *)host_idt_base + vector;
>   
> @@ -7040,9 +7038,9 @@ void vmx_handle_exit_irqoff(struct kvm_vcpu *vcpu)
>   		return;
>   
>   	if (vmx->exit_reason.basic == EXIT_REASON_EXTERNAL_INTERRUPT)
> -		handle_external_interrupt_irqoff(vcpu);
> +		handle_external_interrupt_irqoff(vcpu, vmx_get_intr_info(vcpu));
>   	else if (vmx->exit_reason.basic == EXIT_REASON_EXCEPTION_NMI)
> -		handle_exception_irqoff(vmx);
> +		handle_exception_irqoff(vcpu, vmx_get_intr_info(vcpu));
>   }
>   
>   /*
Binbin Wu March 5, 2024, 1:42 p.m. UTC | #2 
On 2/28/2024 7:20 AM, Paolo Bonzini wrote:
> From: Sean Christopherson <seanjc@google.com>
>
> TDX uses different ABI to get information about VM exit.  Pass intr_info to
> the NMI and INTR handlers instead of pulling it from vcpu_vmx in
> preparation for sharing the bulk of the handlers with TDX.
>
> When the guest TD exits to VMM, RAX holds status and exit reason, RCX holds
> exit qualification etc rather than the VMCS fields because VMM doesn't have
> access to the VMCS.  The eventual code will be
>
> VMX:
>    - get exit reason, intr_info, exit_qualification, and etc from VMCS
>    - call NMI/INTR handlers (common code)
>
> TDX:
>    - get exit reason, intr_info, exit_qualification, and etc from guest
>      registers
>    - call NMI/INTR handlers (common code)
>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
> Message-Id: <0396a9ae70d293c9d0b060349dae385a8a4fbcec.1705965635.git.isaku.yamahata@intel.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>

> ---
>   arch/x86/kvm/vmx/vmx.c | 16 +++++++---------
>   1 file changed, 7 insertions(+), 9 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 3d8a7e4c8e37..8aedfe0fd78c 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -7000,24 +7000,22 @@ static void handle_nm_fault_irqoff(struct kvm_vcpu *vcpu)
>   		rdmsrl(MSR_IA32_XFD_ERR, vcpu->arch.guest_fpu.xfd_err);
>   }
>   
> -static void handle_exception_irqoff(struct vcpu_vmx *vmx)
> +static void handle_exception_irqoff(struct kvm_vcpu *vcpu, u32 intr_info)
>   {
> -	u32 intr_info = vmx_get_intr_info(&vmx->vcpu);
> -
>   	/* if exit due to PF check for async PF */
>   	if (is_page_fault(intr_info))
> -		vmx->vcpu.arch.apf.host_apf_flags = kvm_read_and_reset_apf_flags();
> +		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(&vmx->vcpu);
> +		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)
> +static void handle_external_interrupt_irqoff(struct kvm_vcpu *vcpu,
> +					     u32 intr_info)
>   {
> -	u32 intr_info = vmx_get_intr_info(vcpu);
>   	unsigned int vector = intr_info & INTR_INFO_VECTOR_MASK;
>   	gate_desc *desc = (gate_desc *)host_idt_base + vector;
>   
> @@ -7040,9 +7038,9 @@ void vmx_handle_exit_irqoff(struct kvm_vcpu *vcpu)
>   		return;
>   
>   	if (vmx->exit_reason.basic == EXIT_REASON_EXTERNAL_INTERRUPT)
> -		handle_external_interrupt_irqoff(vcpu);
> +		handle_external_interrupt_irqoff(vcpu, vmx_get_intr_info(vcpu));
>   	else if (vmx->exit_reason.basic == EXIT_REASON_EXCEPTION_NMI)
> -		handle_exception_irqoff(vmx);
> +		handle_exception_irqoff(vcpu, vmx_get_intr_info(vcpu));
>   }
>   
>   /*
Huang, Kai March 12, 2024, 1:43 a.m. UTC | #3 
On 28/02/2024 12:20 pm, Paolo Bonzini wrote:
> From: Sean Christopherson <seanjc@google.com>
> 
> TDX uses different ABI to get information about VM exit.  Pass intr_info to
> the NMI and INTR handlers instead of pulling it from vcpu_vmx in
> preparation for sharing the bulk of the handlers with TDX.
> 
> When the guest TD exits to VMM, RAX holds status and exit reason, RCX holds
> exit qualification etc rather than the VMCS fields because VMM doesn't have
> access to the VMCS.  

IMHO this can be simpler:

TDX conveys VM exit information via GPRs while normal VMX does via VMCS 
fields.

The eventual code will be
> 
> VMX:
>    - get exit reason, intr_info, exit_qualification, and etc from VMCS
>    - call NMI/INTR handlers (common code)
> 
> TDX:
>    - get exit reason, intr_info, exit_qualification, and etc from guest
>      registers
>    - call NMI/INTR handlers (common code)

It's kinda nicer to mention why to change handle_exception_irqoff()'s 
first argument from @vmx to @vcpu.

Anyway, doesn't matter ...

> 
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
> Message-Id: <0396a9ae70d293c9d0b060349dae385a8a4fbcec.1705965635.git.isaku.yamahata@intel.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

... Acked-by: Kai Huang <kai.huang@intel.com>

> ---
>   arch/x86/kvm/vmx/vmx.c | 16 +++++++---------
>   1 file changed, 7 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 3d8a7e4c8e37..8aedfe0fd78c 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -7000,24 +7000,22 @@ static void handle_nm_fault_irqoff(struct kvm_vcpu *vcpu)
>   		rdmsrl(MSR_IA32_XFD_ERR, vcpu->arch.guest_fpu.xfd_err);
>   }
>   
> -static void handle_exception_irqoff(struct vcpu_vmx *vmx)
> +static void handle_exception_irqoff(struct kvm_vcpu *vcpu, u32 intr_info)
>   {
> -	u32 intr_info = vmx_get_intr_info(&vmx->vcpu);
> -
>   	/* if exit due to PF check for async PF */
>   	if (is_page_fault(intr_info))
> -		vmx->vcpu.arch.apf.host_apf_flags = kvm_read_and_reset_apf_flags();
> +		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(&vmx->vcpu);
> +		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)
> +static void handle_external_interrupt_irqoff(struct kvm_vcpu *vcpu,
> +					     u32 intr_info)
>   {
> -	u32 intr_info = vmx_get_intr_info(vcpu);
>   	unsigned int vector = intr_info & INTR_INFO_VECTOR_MASK;
>   	gate_desc *desc = (gate_desc *)host_idt_base + vector;
>   
> @@ -7040,9 +7038,9 @@ void vmx_handle_exit_irqoff(struct kvm_vcpu *vcpu)
>   		return;
>   
>   	if (vmx->exit_reason.basic == EXIT_REASON_EXTERNAL_INTERRUPT)
> -		handle_external_interrupt_irqoff(vcpu);
> +		handle_external_interrupt_irqoff(vcpu, vmx_get_intr_info(vcpu));
>   	else if (vmx->exit_reason.basic == EXIT_REASON_EXCEPTION_NMI)
> -		handle_exception_irqoff(vmx);
> +		handle_exception_irqoff(vcpu, vmx_get_intr_info(vcpu));
>   }
>   
>   /*
diff mbox series

Patch

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 3d8a7e4c8e37..8aedfe0fd78c 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7000,24 +7000,22 @@  static void handle_nm_fault_irqoff(struct kvm_vcpu *vcpu)
 		rdmsrl(MSR_IA32_XFD_ERR, vcpu->arch.guest_fpu.xfd_err);
 }
 
-static void handle_exception_irqoff(struct vcpu_vmx *vmx)
+static void handle_exception_irqoff(struct kvm_vcpu *vcpu, u32 intr_info)
 {
-	u32 intr_info = vmx_get_intr_info(&vmx->vcpu);
-
 	/* if exit due to PF check for async PF */
 	if (is_page_fault(intr_info))
-		vmx->vcpu.arch.apf.host_apf_flags = kvm_read_and_reset_apf_flags();
+		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(&vmx->vcpu);
+		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)
+static void handle_external_interrupt_irqoff(struct kvm_vcpu *vcpu,
+					     u32 intr_info)
 {
-	u32 intr_info = vmx_get_intr_info(vcpu);
 	unsigned int vector = intr_info & INTR_INFO_VECTOR_MASK;
 	gate_desc *desc = (gate_desc *)host_idt_base + vector;
 
@@ -7040,9 +7038,9 @@  void vmx_handle_exit_irqoff(struct kvm_vcpu *vcpu)
 		return;
 
 	if (vmx->exit_reason.basic == EXIT_REASON_EXTERNAL_INTERRUPT)
-		handle_external_interrupt_irqoff(vcpu);
+		handle_external_interrupt_irqoff(vcpu, vmx_get_intr_info(vcpu));
 	else if (vmx->exit_reason.basic == EXIT_REASON_EXCEPTION_NMI)
-		handle_exception_irqoff(vmx);
+		handle_exception_irqoff(vcpu, vmx_get_intr_info(vcpu));
 }
 
 /*