On Wed, Jan 16, 2013 at 05:00:48PM +0800, Yang Zhang wrote: > From: Yang Zhang <[email protected]> > > The "acknowledge interrupt on exit" feature controls processor behavior > for external interrupt acknowledgement. When this control is set, the > processor acknowledges the interrupt controller to acquire the > interrupt vector on VM exit. > > This feature is required by Posted Interrupt. It will be turnned on only > when posted interrupt is enabled. > Why? Always enable it. It is faster than current approach.
> Refer to Intel SDM volum 3, chapter 33.2. > Please CC H. Peter Anvin <[email protected]> on the next version. > Signed-off-by: Yang Zhang <[email protected]> > --- > arch/x86/kvm/vmx.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++-- > 1 files changed, 49 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index dd2a85c..d1ed9ae 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -2565,7 +2565,7 @@ 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; > @@ -3926,7 +3926,7 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx) > ++vmx->nmsrs; > } > > - vmcs_write32(VM_EXIT_CONTROLS, vmcs_config.vmexit_ctrl); > + vmcs_write32(VM_EXIT_CONTROLS, vmcs_config.vmexit_ctrl & > ~VM_EXIT_ACK_INTR_ON_EXIT); > > /* 22.2.1, 20.8.1 */ > vmcs_write32(VM_ENTRY_CONTROLS, vmcs_config.vmentry_ctrl); > @@ -6096,6 +6096,52 @@ static void vmx_complete_atomic_exit(struct vcpu_vmx > *vmx) > } > } > > + > +static noinline void vmx_handle_external_intr(struct kvm_vcpu *vcpu) > +{ > + u32 exit_intr_info = vmcs_read32(VM_EXIT_INTR_INFO); > + > + if ((exit_intr_info & INTR_INFO_INTR_TYPE_MASK) == INTR_TYPE_EXT_INTR && > + (exit_intr_info & INTR_INFO_VALID_MASK) ) { if (exit_intr_info & (INTR_INFO_VALID_MASK | INTR_INFO_INTR_TYPE_MASK) == (INTR_INFO_VALID_MASK | INTR_TYPE_EXT_INTR)) > + unsigned int vector; > + unsigned long entry; > + struct desc_ptr dt; > + gate_desc *desc; > + > + native_store_idt(&dt); This does not change. Store it in vcpu during vcpu creation instead of reading it each time. > + > + vector = exit_intr_info & INTR_INFO_VECTOR_MASK; > + desc = (void *)dt.address + vector * 16; > + > + entry = gate_offset(*desc); > + asm( > + "mov %0, %%" _ASM_DX "\n\t" > + "mov %%" _ASM_SP ", %%" _ASM_BX "\n\t" > +#ifdef CONFIG_X86_64 > + "and $0xfffffffffffffff0, %%" _ASM_SP "\n\t" > +#endif > + "mov %%ss, %%" _ASM_AX "\n\t" > + "push %%" _ASM_AX "\n\t" > + "push %%" _ASM_BX "\n\t" For 32bit you do not need to save ss:esp. > + "pushf\n\t" > + "mov %%cs, %%" _ASM_AX "\n\t" > + "push %%" _ASM_AX "\n\t" > + "push intr_return\n\t" > + "jmp *%% " _ASM_DX "\n\t" > + ".pushsection .rodata \n\t" > + ".global intr_return \n\t" > + "intr_return: " _ASM_PTR " 1b \n\t" > + ".popsection\n\t" > + : :"m"(entry) : > +#ifdef CONFIG_X86_64 > + "rax", "rbx", "rdx" > +#else > + "eax", "ebx", "edx" > +#endif > + ); > + } > +} > + > static void vmx_recover_nmi_blocking(struct vcpu_vmx *vmx) > { > u32 exit_intr_info; > @@ -6431,6 +6477,7 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu > *vcpu) > vmx_complete_atomic_exit(vmx); > vmx_recover_nmi_blocking(vmx); > vmx_complete_interrupts(vmx); > + vmx_handle_external_intr(vcpu); This should be done just before enabling interrupts, otherwise we are taking an interrupt before vmexit is fully complete. -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
