Re: [Xen-devel] [PATCH 16/16] vmx: nest: expose cpuid and CR4.VMXE

[Christoph Egger <Christoph.Egger@xxxxxxx>]

On Wednesday 08 September 2010 17:22:24 Qing He wrote:
> expose VMX cpuid and allow guest to enable VMX.
>
> Signed-off-by: Qing He <qing.he@xxxxxxxxx>
> Signed-off-by: Eddie Dong <eddie.dong@xxxxxxxxx>
>
> ---
>
> diff -r 3f40a1f79cf8 tools/libxc/xc_cpuid_x86.c
> --- a/tools/libxc/xc_cpuid_x86.c      Wed Sep 08 19:47:39 2010 +0800
> +++ b/tools/libxc/xc_cpuid_x86.c      Wed Sep 08 19:49:06 2010 +0800
> @@ -128,8 +128,17 @@
>      const unsigned int *input, unsigned int *regs,
>      int is_pae)
>  {
> +    unsigned long nest;
> +
>      switch ( input[0] )
>      {
> +    case 0x00000001:
> +        /* ECX[5] is availability of VMX */
> +        xc_get_hvm_param(xch, domid, HVM_PARAM_NESTEDHVM, &nest);
> +        if (nest)
> +            regs[2] |= 0x20;
> +        break;
> +

I merged this part into my tools patch this way:

              /* ECX[5] is availability of VMX */
              if (is_nstedhvm)
                  set_bit(X86_FEATURE_VMXE, regs[2]);
              break;


>      case 0x00000004:
>          /*
>           * EAX[31:26] is Maximum Cores Per Package (minus one).
> diff -r 3f40a1f79cf8 xen/include/asm-x86/hvm/hvm.h
> --- a/xen/include/asm-x86/hvm/hvm.h   Wed Sep 08 19:47:39 2010 +0800
> +++ b/xen/include/asm-x86/hvm/hvm.h   Wed Sep 08 19:49:06 2010 +0800
> @@ -295,7 +295,8 @@
>          X86_CR4_DE  | X86_CR4_PSE | X86_CR4_PAE |       \
>          X86_CR4_MCE | X86_CR4_PGE | X86_CR4_PCE |       \
>          X86_CR4_OSFXSR | X86_CR4_OSXMMEXCPT |           \
> -        (cpu_has_xsave ? X86_CR4_OSXSAVE : 0))))
> +        (cpu_has_xsave ? X86_CR4_OSXSAVE : 0)   |       \
> +        X86_CR4_VMXE)))


I changed this to

         (cpu_has_vmx ? X86_CR4_VMXE : 0))))

where cpu_has vmx is in <asm/cpufeature.h> defined as

 #define cpu_has_vmx  boot_cpu_has(X86_FEATURE_VMXE)

Christoph

>  /* These exceptions must always be intercepted. */
>  #define HVM_TRAP_MASK ((1U << TRAP_machine_check) | (1U <<
> TRAP_invalid_op))
>



-- 
---to satisfy European Law for business letters:
Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach b. Muenchen
Geschaeftsfuehrer: Alberto Bozzo, Andrew Bowd
Sitz: Dornach, Gemeinde Aschheim, Landkreis Muenchen
Registergericht Muenchen, HRB Nr. 43632


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel