Re: [v3 07/15] vmx: Initialize VT-d Posted-Interrupts Descriptor

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 24/06/15 06:18, Feng Wu wrote:
> This patch initializes the VT-d Posted-interrupt Descriptor.
>
> Signed-off-by: Feng Wu <feng.wu@intel.com>
> ---
> v3:
> - Move pi_desc_init() to xen/arch/x86/hvm/vmx/vmcs.c
> - Remove the 'inline' flag of pi_desc_init()
>
>  xen/arch/x86/hvm/vmx/vmcs.c       | 18 ++++++++++++++++++
>  xen/include/asm-x86/hvm/vmx/vmx.h |  2 ++
>  2 files changed, 20 insertions(+)
>
> diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c
> index 3aff365..11dc1b5 100644
> --- a/xen/arch/x86/hvm/vmx/vmcs.c
> +++ b/xen/arch/x86/hvm/vmx/vmcs.c
> @@ -40,6 +40,7 @@
>  #include <asm/flushtlb.h>
>  #include <asm/shadow.h>
>  #include <asm/tboot.h>
> +#include <asm/apic.h>
>  
>  static bool_t __read_mostly opt_vpid_enabled = 1;
>  boolean_param("vpid", opt_vpid_enabled);
> @@ -921,6 +922,20 @@ void virtual_vmcs_vmwrite(void *vvmcs, u32 vmcs_encoding, u64 val)
>      virtual_vmcs_exit(vvmcs);
>  }
>  
> +static void pi_desc_init(struct vcpu *v)
> +{
> +    uint32_t dest;
> +
> +    v->arch.hvm_vmx.pi_desc.nv = posted_intr_vector;
> +
> +    dest = cpu_physical_id(v->processor);

I am fairly sure that this is not a safe use of v->processor. 
Everything else in this patch looks fine, but I would like review from
people more familiar with scheduling.

~Andrew

> +
> +    if ( x2apic_enabled )
> +        v->arch.hvm_vmx.pi_desc.ndst = dest;
> +    else
> +        v->arch.hvm_vmx.pi_desc.ndst = MASK_INSR(dest, PI_xAPIC_NDST_MASK);
> +}
> +
>  static int construct_vmcs(struct vcpu *v)
>  {
>      struct domain *d = v->domain;
> @@ -1054,6 +1069,9 @@ static int construct_vmcs(struct vcpu *v)
>  
>      if ( cpu_has_vmx_posted_intr_processing )
>      {
> +        if ( iommu_intpost )
> +            pi_desc_init(v);
> +
>          __vmwrite(PI_DESC_ADDR, virt_to_maddr(&v->arch.hvm_vmx.pi_desc));
>          __vmwrite(POSTED_INTR_NOTIFICATION_VECTOR, posted_intr_vector);
>      }
> diff --git a/xen/include/asm-x86/hvm/vmx/vmx.h b/xen/include/asm-x86/hvm/vmx/vmx.h
> index 35f804a..5853563 100644
> --- a/xen/include/asm-x86/hvm/vmx/vmx.h
> +++ b/xen/include/asm-x86/hvm/vmx/vmx.h
> @@ -89,6 +89,8 @@ typedef enum {
>  #define EPT_EMT_WB              6
>  #define EPT_EMT_RSV2            7
>  
> +#define PI_xAPIC_NDST_MASK      0xFF00
> +
>  void vmx_asm_vmexit_handler(struct cpu_user_regs);
>  void vmx_asm_do_vmentry(void);
>  void vmx_intr_assist(void);