Re: [PATCH] nested vmx: Fix the booting of L2 PAE guest

[Keir Fraser <keir.xen@gmail.com>]

On 24/06/2013 06:55, "Dongxiao Xu" <dongxiao.xu@intel.com> wrote:

> When doing virtual VM entry and virtual VM exit, we need to
> sychronize the PAE PDPTR related VMCS registers. With this fix,
> we can boot 32bit PAE L2 guest (Win7 & RHEL6.4) on "Xen on Xen"
> environment.
> 
> Signed-off-by: Dongxiao Xu <dongxiao.xu@intel.com>
> Tested-by: Yongjie Ren <yongjie.ren@intel.com>

Acked-by: Keir Fraser <keir@xen.org>

> ---
>  xen/arch/x86/hvm/vmx/vvmx.c | 27 +++++++++++++++------------
>  1 file changed, 15 insertions(+), 12 deletions(-)
> 
> diff --git a/xen/arch/x86/hvm/vmx/vvmx.c b/xen/arch/x86/hvm/vmx/vvmx.c
> index bb7688f..5dfbc54 100644
> --- a/xen/arch/x86/hvm/vmx/vvmx.c
> +++ b/xen/arch/x86/hvm/vmx/vvmx.c
> @@ -864,6 +864,13 @@ static const u16 vmcs_gstate_field[] = {
>      GUEST_SYSENTER_EIP,
>  };
>  
> +static const u16 gpdptr_fields[] = {
> +    GUEST_PDPTR0,
> +    GUEST_PDPTR1,
> +    GUEST_PDPTR2,
> +    GUEST_PDPTR3,
> +};
> +
>  /*
>   * Context: shadow -> virtual VMCS
>   */
> @@ -1053,18 +1060,6 @@ static void load_shadow_guest_state(struct vcpu *v)
>                       (__get_vvmcs(vvmcs, CR4_READ_SHADOW) & cr_gh_mask);
>      __vmwrite(CR4_READ_SHADOW, cr_read_shadow);
>  
> -    if ( nvmx_ept_enabled(v) && hvm_pae_enabled(v) &&
> -         (v->arch.hvm_vcpu.guest_efer & EFER_LMA) )
> -    {
> -        static const u16 gpdptr_fields[] = {
> -            GUEST_PDPTR0,
> -            GUEST_PDPTR1,
> -            GUEST_PDPTR2,
> -            GUEST_PDPTR3,
> -        };
> -        vvmcs_to_shadow_bulk(v, ARRAY_SIZE(gpdptr_fields), gpdptr_fields);
> -    }
> -
>      /* TODO: CR3 target control */
>  }
>  
> @@ -1159,6 +1154,10 @@ static void virtual_vmentry(struct cpu_user_regs *regs)
>      if ( lm_l1 != lm_l2 )
>          paging_update_paging_modes(v);
>  
> +    if ( nvmx_ept_enabled(v) && hvm_pae_enabled(v) &&
> +         !(v->arch.hvm_vcpu.guest_efer & EFER_LMA) )
> +        vvmcs_to_shadow_bulk(v, ARRAY_SIZE(gpdptr_fields), gpdptr_fields);
> +
>      regs->eip = __get_vvmcs(vvmcs, GUEST_RIP);
>      regs->esp = __get_vvmcs(vvmcs, GUEST_RSP);
>      regs->eflags = __get_vvmcs(vvmcs, GUEST_RFLAGS);
> @@ -1294,6 +1293,10 @@ static void virtual_vmexit(struct cpu_user_regs *regs)
>      sync_vvmcs_guest_state(v, regs);
>      sync_exception_state(v);
>  
> +    if ( nvmx_ept_enabled(v) && hvm_pae_enabled(v) &&
> +         !(v->arch.hvm_vcpu.guest_efer & EFER_LMA) )
> +        shadow_to_vvmcs_bulk(v, ARRAY_SIZE(gpdptr_fields), gpdptr_fields);
> +
>      vmx_vmcs_switch(v->arch.hvm_vmx.vmcs, nvcpu->nv_n1vmcx);
>  
>      nestedhvm_vcpu_exit_guestmode(v);