[PATCH 1/2] x86: Enable ack interrupt on vmexit

Yang Zhang
2012-12-13T07:34:09Z

From: Yang Zhang <yang.z.zhang@Intel.com>

Ack interrupt on vmexit is required by Posted Interrupt. With it,
when external interrupt caused vmexit, the cpu will acknowledge the
interrupt controller and save the interrupt's vector in vmcs. Only
enable it when posted interrupt is enabled.

There are several approaches to enable it. This patch uses a simply
way: re-generate an interrupt via self ipi.

Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
---
arch/x86/kvm/vmx.c | 20 +++++++++++++++++---
1 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 8cd9eb7..6b6bd03 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2549,7 +2549,7 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf)
#ifdef CONFIG_X86_64
min |= VM_EXIT_HOST_ADDR_SPACE_SIZE;
#endif
- opt = VM_EXIT_SAVE_IA32_PAT | VM_EXIT_LOAD_IA32_PAT;
+ opt = VM_EXIT_SAVE_IA32_PAT | VM_EXIT_LOAD_IA32_PAT | VM_EXIT_ACK_INTR_ON_EXIT;
if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_EXIT_CTLS,
&_vmexit_control) < 0)
return -EIO;
@@ -3913,6 +3913,7 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
unsigned long a;
#endif
int i;
+ u32 vmexit_ctrl = vmcs_config.vmexit_ctrl;

/* I/O */
vmcs_write64(IO_BITMAP_A, __pa(vmx_io_bitmap_a));
@@ -3996,8 +3997,10 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
vmx->guest_msrs[j].mask = -1ull;
++vmx->nmsrs;
}
-
- vmcs_write32(VM_EXIT_CONTROLS, vmcs_config.vmexit_ctrl);
+
+ if(!enable_apicv_pi)
+ vmexit_ctrl &= ~VM_EXIT_ACK_INTR_ON_EXIT;
+ vmcs_write32(VM_EXIT_CONTROLS, vmexit_ctrl);

/* 22.2.1, 20.8.1 */
vmcs_write32(VM_ENTRY_CONTROLS, vmcs_config.vmentry_ctrl);
@@ -6267,6 +6270,17 @@ static void vmx_complete_atomic_exit(struct vcpu_vmx *vmx)
asm("int $2");
kvm_after_handle_nmi(&vmx->vcpu);
}
+ if ((exit_intr_info & INTR_INFO_INTR_TYPE_MASK) == INTR_TYPE_EXT_INTR &&
+ (exit_intr_info & INTR_INFO_VALID_MASK) && enable_apicv_pi) {
+ unsigned int vector, tmr;
+
+ vector = exit_intr_info & INTR_INFO_VECTOR_MASK;
+ tmr = apic_read(APIC_TMR + ((vector & ~0x1f) >> 1));
+ apic_eoi();
+ if ( !((1 << (vector % 32)) & tmr) )
+ apic->send_IPI_self(vector);
+ }
+
}

static void vmx_recover_nmi_blocking(struct vcpu_vmx *vmx)
--
1.7.1