Re: [PATCH 4/4] tools/xen-mceinj: Pass in GPA when injecting through MSR_MCI_ADDR

["Egger, Christoph" <chegger@amazon.de>]

On 2015/09/15 10:29, Haozhong Zhang wrote:
> This patch removes the address translation in xen-mceinj which
> translates the guest physical address passed-in through the argument
> of '-p' to the host machine address.
> 
> Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>

Comments inline.

> ---
>  tools/tests/mce-test/tools/xen-mceinj.c | 135 +++++---------------------------
>  1 file changed, 19 insertions(+), 116 deletions(-)
> 
> diff --git a/tools/tests/mce-test/tools/xen-mceinj.c b/tools/tests/mce-test/tools/xen-mceinj.c
> index 0c2b640..7b9dd13 100644
> --- a/tools/tests/mce-test/tools/xen-mceinj.c
> +++ b/tools/tests/mce-test/tools/xen-mceinj.c
> @@ -238,7 +238,8 @@ static int add_msr_intpose(xc_interface *xc_handle,
>                             uint32_t cpu_nr,
>                             uint32_t flags,
>                             uint64_t msr,
> -                           uint64_t val)
> +                           uint64_t val,
> +                           domid_t domid)
>  {
>      uint32_t count;
>  
> @@ -256,6 +257,8 @@ static int add_msr_intpose(xc_interface *xc_handle,
>          msr_inj.mcinj_cpunr = cpu_nr;
>          msr_inj.mcinj_flags = flags;
>      }
> +    if ( flags & MC_MSRINJ_F_GPADDR )
> +        msr_inj.mcinj_domid = domid;
>      msr_inj.mcinj_msr[count].reg = msr;
>      msr_inj.mcinj_msr[count].value = val;
>      msr_inj.mcinj_count++;
> @@ -268,105 +271,15 @@ static int add_msr_bank_intpose(xc_interface *xc_handle,
>                                  uint32_t flags,
>                                  uint32_t type,
>                                  uint32_t bank,
> -                                uint64_t val)
> +                                uint64_t val,
> +                                domid_t domid)
>  {
>      uint64_t msr;
>  
>      msr = bank_addr(bank, type);
>      if ( msr == INVALID_MSR )
>          return -1;
> -    return add_msr_intpose(xc_handle, cpu_nr, flags, msr, val);
> -}
> -
> -#define MCE_INVALID_MFN ~0UL
> -#define mfn_valid(_mfn) (_mfn != MCE_INVALID_MFN)
> -#define mfn_to_pfn(_mfn) (live_m2p[(_mfn)])
> -static uint64_t guest_mfn(xc_interface *xc_handle,
> -                               uint32_t domain,
> -                               uint64_t gpfn)
> -{
> -    xen_pfn_t *live_m2p = NULL;
> -    int ret;
> -    unsigned long hvirt_start;
> -    unsigned int pt_levels;
> -    uint64_t * pfn_buf = NULL;
> -    unsigned long max_mfn = 0; /* max mfn of the whole machine */
> -    unsigned long m2p_mfn0;
> -    unsigned int guest_width;
> -    long max_gpfn,i;
> -    uint64_t mfn = MCE_INVALID_MFN;
> -
> -    if ( domain > DOMID_FIRST_RESERVED )
> -        return MCE_INVALID_MFN;
> -
> -    /* Get max gpfn */
> -    max_gpfn = do_memory_op(xc_handle, XENMEM_maximum_gpfn, &domain,
> -                               sizeof(domain)) + 1;
> -    if ( max_gpfn <= 0 )
> -        err(xc_handle, "Failed to get max_gpfn 0x%lx", max_gpfn);
> -
> -    Lprintf("Maxium gpfn for dom %d is 0x%lx", domain, max_gpfn);
> -
> -    /* Get max mfn */
> -    if ( !get_platform_info(xc_handle, domain,
> -                            &max_mfn, &hvirt_start,
> -                            &pt_levels, &guest_width) )
> -        err(xc_handle, "Failed to get platform information");
> -
> -    /* Get guest's pfn list */
> -    pfn_buf = calloc(max_gpfn, sizeof(uint64_t));
> -    if ( !pfn_buf )
> -        err(xc_handle, "Failed to alloc pfn buf");
> -
> -    ret = xc_get_pfn_list(xc_handle, domain, pfn_buf, max_gpfn);
> -    if ( ret < 0 ) {
> -        free(pfn_buf);
> -        err(xc_handle, "Failed to get pfn list %x", ret);
> -    }
> -
> -    /* Now get the m2p table */
> -    live_m2p = xc_map_m2p(xc_handle, max_mfn, PROT_READ, &m2p_mfn0);
> -    if ( !live_m2p )
> -        err(xc_handle, "Failed to map live M2P table");
> -
> -    /* match the mapping */
> -    for ( i = 0; i < max_gpfn; i++ )
> -    {
> -        uint64_t tmp;
> -        tmp = pfn_buf[i];
> -
> -        if (mfn_valid(tmp) &&  (mfn_to_pfn(tmp) == gpfn))
> -        {
> -            mfn = tmp;
> -            Lprintf("We get the mfn 0x%lx for this injection", mfn);
> -            break;
> -        }
> -    }
> -
> -    munmap(live_m2p, M2P_SIZE(max_mfn));
> -
> -    free(pfn_buf);
> -    return mfn;
> -}
> -
> -static uint64_t mca_gpfn_to_mfn(xc_interface *xc_handle,
> -                                uint32_t domain,
> -                                uint64_t gfn)
> -{
> -    uint64_t index;
> -    long max_gpfn;
> -
> -    /* If domain is xen, means we want pass index directly */
> -    if ( domain == DOMID_XEN )
> -        return gfn;
> -
> -    max_gpfn = do_memory_op(xc_handle, XENMEM_maximum_gpfn, &domain,
> -                               sizeof(domain)) + 1;
> -    if ( max_gpfn <= 0 )
> -        err(xc_handle, "Failed to get max_gpfn 0x%lx", max_gpfn);
> -    index = gfn % max_gpfn;
> -
> -    return guest_mfn(xc_handle, domain, index);
> +    return add_msr_intpose(xc_handle, cpu_nr, flags, msr, val, domid);
>  }
>  
>  static int inject_mcg_status(xc_interface *xc_handle,
> @@ -374,7 +287,7 @@ static int inject_mcg_status(xc_interface *xc_handle,
>                               uint64_t val)
>  {
>      return add_msr_intpose(xc_handle, cpu_nr, MC_MSRINJ_F_INTERPOSE,
> -                               MSR_IA32_MCG_STATUS, val);
> +                               MSR_IA32_MCG_STATUS, val, 0);

Why do you hardcode 0 here?
I think you should pass domid in here so that the DomU sees the right
status value.

>  }
>  
>  static int inject_mci_status(xc_interface *xc_handle,
> @@ -383,7 +296,7 @@ static int inject_mci_status(xc_interface *xc_handle,
>                               uint64_t val)
>  {
>      return add_msr_bank_intpose(xc_handle, cpu_nr, MC_MSRINJ_F_INTERPOSE,
> -                                    MCi_type_STATUS, bank, val);
> +                                    MCi_type_STATUS, bank, val, 0);

Why do you hardcode 0 here?
I think you should pass domid in here so that the DomU sees the right
status value.

>  }
>  
>  static int inject_mci_misc(xc_interface *xc_handle,
> @@ -392,22 +305,23 @@ static int inject_mci_misc(xc_interface *xc_handle,
>                               uint64_t val)
>  {
>      return add_msr_bank_intpose(xc_handle, cpu_nr, MC_MSRINJ_F_INTERPOSE,
> -                                    MCi_type_MISC, bank, val);
> +                                    MCi_type_MISC, bank, val, 0);
>  }
>  
>  static int inject_mci_addr(xc_interface *xc_handle,
>                               uint32_t cpu_nr,
>                               uint64_t bank,
> -                             uint64_t val)
> +                             uint64_t val,
> +                             domid_t domid)
>  {
> -    return add_msr_bank_intpose(xc_handle, cpu_nr, MC_MSRINJ_F_INTERPOSE,
> -                                    MCi_type_ADDR, bank, val);
> +    return add_msr_bank_intpose(xc_handle, cpu_nr,
> +                                    MC_MSRINJ_F_INTERPOSE | MC_MSRINJ_F_GPADDR,
> +                                    MCi_type_ADDR, bank, val, domid);
>  }
>  
>  static int inject(xc_interface *xc_handle, struct mce_info *mce,
>                    uint32_t cpu_nr, uint32_t domain, uint64_t gaddr)
>  {
> -    uint64_t gpfn, mfn, haddr;
>      int ret = 0;
>  
>      ret = inject_mcg_status(xc_handle, cpu_nr, mce->mcg_stat);
> @@ -424,12 +338,7 @@ static int inject(xc_interface *xc_handle, struct mce_info *mce,
>      if ( ret )
>          err(xc_handle, "Failed to inject MCi_MISC MSR");
>  
> -    gpfn = gaddr >> PAGE_SHIFT;
> -    mfn = mca_gpfn_to_mfn(xc_handle, domain, gpfn);
> -    if (!mfn_valid(mfn))
> -        err(xc_handle, "The MFN is not valid");
> -    haddr = (mfn << PAGE_SHIFT) | (gaddr & (PAGE_SIZE - 1));
> -    ret = inject_mci_addr(xc_handle, cpu_nr, mce->bank, haddr);
> +    ret = inject_mci_addr(xc_handle, cpu_nr, mce->bank, gaddr, domain);
>      if ( ret )
>          err(xc_handle, "Failed to inject MCi_ADDR MSR");
>  
> @@ -507,7 +416,7 @@ int main(int argc, char *argv[])
>      uint32_t domid;
>      xc_interface *xc_handle;
>      int cpu_nr;
> -    int64_t gaddr, gpfn, mfn, haddr, max_gpa;
> +    uint64_t gaddr, max_gpa;
>  
>      /* Default Value */
>      domid = DOMID_XEN;
> @@ -563,16 +472,10 @@ int main(int argc, char *argv[])
>      Lprintf("get gaddr of error inject is: 0x%lx", gaddr);
>  
>      if ( dump ) {
> -        gpfn = gaddr >> PAGE_SHIFT;
> -        mfn = mca_gpfn_to_mfn(xc_handle, domid, gpfn);
> -        if (!mfn_valid(mfn))
> -            err(xc_handle, "The MFN is not valid");
> -        haddr = (mfn << PAGE_SHIFT) | (gaddr & (PAGE_SIZE - 1));
>          if ( domid == DOMID_XEN )
> -            Lprintf("Xen: mfn=0x%lx, haddr=0x%lx", mfn, haddr);
> +            Lprintf("Xen: gaddr=0x%lx", gaddr);
>          else
> -            Lprintf("Dom%d: gaddr=0x%lx, gpfn=0x%lx, mfn=0x%lx, haddr=0x%lx",
> -                    domid, gaddr, gpfn, mfn, haddr);
> +            Lprintf("Dom%d: gaddr=0x%lx", domid, gaddr);
>          goto out;
>      }
>  
> 

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