[PATCH] x86/pvh: Do not add DSDT and FACS to PVH dom0 XSDT

[PATCH] x86/pvh: Do not add DSDT and FACS to PVH dom0 XSDT

[Boris Ostrovsky]

These tables are pointed to from FADT. Adding them will
result in duplicate entries in the guest's tables.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
 xen/arch/x86/hvm/dom0_build.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/hvm/dom0_build.c b/xen/arch/x86/hvm/dom0_build.c
index a67071c..c878bba 100644
--- a/xen/arch/x86/hvm/dom0_build.c
+++ b/xen/arch/x86/hvm/dom0_build.c
@@ -818,6 +818,19 @@ static bool __init pvh_acpi_table_allowed(const char *sig)
     return true;
 }
 
+static bool __init pvh_acpi_table_in_xsdt(const char *sig)
+{
+    /*
+     * DSDT and FACS are pointed to from FADT and thus don't belong
+     * in XSDT.
+     */
+    if ( !strncmp(sig, ACPI_SIG_DSDT, ACPI_NAME_SIZE) ||
+         !strncmp(sig, ACPI_SIG_FACS, ACPI_NAME_SIZE) )
+        return false;
+
+    return true;
+}
+
 static int __init pvh_setup_acpi_xsdt(struct domain *d, paddr_t madt_addr,
                                       paddr_t *addr)
 {
@@ -841,7 +854,7 @@ static int __init pvh_setup_acpi_xsdt(struct domain *d, paddr_t madt_addr,
     {
         const char *sig = acpi_gbl_root_table_list.tables[i].signature.ascii;
 
-        if ( pvh_acpi_table_allowed(sig) )
+        if ( pvh_acpi_table_allowed(sig) && pvh_acpi_table_in_xsdt(sig) )
             num_tables++;
     }
 
@@ -888,7 +901,7 @@ static int __init pvh_setup_acpi_xsdt(struct domain *d, paddr_t madt_addr,
     {
         const char *sig = acpi_gbl_root_table_list.tables[i].signature.ascii;
 
-        if ( pvh_acpi_table_allowed(sig) )
+        if ( pvh_acpi_table_allowed(sig) && pvh_acpi_table_in_xsdt(sig) )
             xsdt->table_offset_entry[j++] =
                 acpi_gbl_root_table_list.tables[i].address;
     }
-- 
1.8.3.1


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Re: [PATCH] x86/pvh: Do not add DSDT and FACS to PVH dom0 XSDT

[Jan Beulich]

>>> On 08.11.17 at 21:19, <boris.ostrovsky@oracle.com> wrote:
> These tables are pointed to from FADT. Adding them will
> result in duplicate entries in the guest's tables.

Oh, indeed. Just one small adjustment request:

> +static bool __init pvh_acpi_table_in_xsdt(const char *sig)
> +{
> +    /*
> +     * DSDT and FACS are pointed to from FADT and thus don't belong
> +     * in XSDT.
> +     */
> +    if ( !strncmp(sig, ACPI_SIG_DSDT, ACPI_NAME_SIZE) ||
> +         !strncmp(sig, ACPI_SIG_FACS, ACPI_NAME_SIZE) )
> +        return false;
> +
> +    return true;
> +}

Please don't use two return statements in cases like this one -
all can be had with a single one and no explicit uses of true or
false.

Jan


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Re: [PATCH] x86/pvh: Do not add DSDT and FACS to PVH dom0 XSDT

[Roger Pau Monné]

On Wed, Nov 08, 2017 at 03:19:27PM -0500, Boris Ostrovsky wrote:
> These tables are pointed to from FADT. Adding them will
> result in duplicate entries in the guest's tables.
> 
> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> ---
>  xen/arch/x86/hvm/dom0_build.c | 17 +++++++++++++++--
>  1 file changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/xen/arch/x86/hvm/dom0_build.c b/xen/arch/x86/hvm/dom0_build.c
> index a67071c..c878bba 100644
> --- a/xen/arch/x86/hvm/dom0_build.c
> +++ b/xen/arch/x86/hvm/dom0_build.c
> @@ -818,6 +818,19 @@ static bool __init pvh_acpi_table_allowed(const char *sig)
>      return true;
>  }
>  
> +static bool __init pvh_acpi_table_in_xsdt(const char *sig)
> +{
> +    /*
> +     * DSDT and FACS are pointed to from FADT and thus don't belong
> +     * in XSDT.
> +     */
> +    if ( !strncmp(sig, ACPI_SIG_DSDT, ACPI_NAME_SIZE) ||
> +         !strncmp(sig, ACPI_SIG_FACS, ACPI_NAME_SIZE) )
> +        return false;
> +
> +    return true;
> +}

What about adding something like:

static bool __init pvh_acpi_xsdt_table_allowed(const char *sig)
{
    return pvh_acpi_table_allowed(sig) &&
           strncmp(sig, ACPI_SIG_DSDT, ACPI_NAME_SIZE) &&
           strncmp(sig, ACPI_SIG_FACS, ACPI_NAME_SIZE);
}

And replacing the pvh_acpi_table_allowed calls in pvh_setup_acpi_xsdt
with that?

Thanks, Roger.

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