diff mbox series

[v4,33/34] KVM: x86/vmx: call external_interrupt() for IRQ reinjection when FRED is enabled

Message ID 20230302052511.1918-34-xin3.li@intel.com
State New
Headers
Series x86: enable FRED for x86-64 |

Commit Message

Li, Xin3 March 2, 2023, 5:25 a.m. UTC 
  When FRED is enabled, IDT is gone, thus call external_interrupt() for IRQ
reinjection.

Create an event return stack frame with the host context immediately after
a VM exit for calling external_interrupt(). All other fields of the pt_regs
structure are cleared to 0. Refer to the discussion about the register values
in the pt_regs structure at:

  https://lore.kernel.org/kvm/ef2c54f7-14b9-dcbb-c3c4-1533455e7a18@redhat.com/

Tested-by: Shan Kang <shan.kang@intel.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
---
 arch/x86/kvm/vmx/vmx.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

Comments

Li, Xin3 March 6, 2023, 9:32 a.m. UTC | #1 
>  arch/x86/kvm/vmx/vmx.c | 22 +++++++++++++++++++++-
>  1 file changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index
> bcac3efcde41..30f854015c8c 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -47,6 +47,7 @@
>  #include <asm/mshyperv.h>
>  #include <asm/mwait.h>
>  #include <asm/spec-ctrl.h>
> +#include <asm/traps.h>
>  #include <asm/virtext.h>
>  #include <asm/vmx.h>
> 
> @@ -6923,7 +6924,26 @@ static void handle_external_interrupt_irqoff(struct
> kvm_vcpu *vcpu)
>  		return;
> 
>  	kvm_before_interrupt(vcpu, KVM_HANDLING_IRQ);
> -	vmx_do_interrupt_irqoff(gate_offset(desc));
> +	if (cpu_feature_enabled(X86_FEATURE_FRED)) {
> +		struct vcpu_vmx *vmx = to_vmx(vcpu);
> +		struct pt_regs regs = {};
> +
> +		/*
> +		 * Create an event return stack frame with the
> +		 * host context immediately after a VM exit.
> +		 *
> +		 * All other fields of the pt_regs structure are
> +		 * cleared to 0.
> +		 */
> +		regs.ssx	= __KERNEL_DS;

This breaks i386 build, and should use ss.

> +		regs.sp		= vmx->loaded_vmcs->host_state.rsp;
> +		regs.flags	= X86_EFLAGS_FIXED;
> +		regs.csx	= __KERNEL_CS;

And cs.

> +		regs.ip		= (unsigned long)vmx_vmexit;
> +
> +		external_interrupt(&regs, vector);
> +	} else
> +		vmx_do_interrupt_irqoff(gate_offset(desc));
>  	kvm_after_interrupt(vcpu);
> 
>  	vcpu->arch.at_instruction_boundary = true;
> --
> 2.34.1
diff mbox series

Patch

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index bcac3efcde41..30f854015c8c 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -47,6 +47,7 @@ 
 #include <asm/mshyperv.h>
 #include <asm/mwait.h>
 #include <asm/spec-ctrl.h>
+#include <asm/traps.h>
 #include <asm/virtext.h>
 #include <asm/vmx.h>
 
@@ -6923,7 +6924,26 @@  static void handle_external_interrupt_irqoff(struct kvm_vcpu *vcpu)
 		return;
 
 	kvm_before_interrupt(vcpu, KVM_HANDLING_IRQ);
-	vmx_do_interrupt_irqoff(gate_offset(desc));
+	if (cpu_feature_enabled(X86_FEATURE_FRED)) {
+		struct vcpu_vmx *vmx = to_vmx(vcpu);
+		struct pt_regs regs = {};
+
+		/*
+		 * Create an event return stack frame with the
+		 * host context immediately after a VM exit.
+		 *
+		 * All other fields of the pt_regs structure are
+		 * cleared to 0.
+		 */
+		regs.ssx	= __KERNEL_DS;
+		regs.sp		= vmx->loaded_vmcs->host_state.rsp;
+		regs.flags	= X86_EFLAGS_FIXED;
+		regs.csx	= __KERNEL_CS;
+		regs.ip		= (unsigned long)vmx_vmexit;
+
+		external_interrupt(&regs, vector);
+	} else
+		vmx_do_interrupt_irqoff(gate_offset(desc));
 	kvm_after_interrupt(vcpu);
 
 	vcpu->arch.at_instruction_boundary = true;