diff mbox series

[v5,03/11] xen/arm: Add cmdline boot option "pci-passthrough = <boolean>"

Message ID e7d91ded71816d07f559b98027e5be1ff172dcab.1633540842.git.rahul.singh@arm.com (mailing list archive)
State New, archived
Headers show
Series PCI devices passthrough on Arm | expand

Commit Message

Rahul Singh Oct. 6, 2021, 5:40 p.m. UTC 
Add cmdline boot option "pci-passthrough = = <boolean>" to enable or
disable the PCI passthrough support on ARM.

Signed-off-by: Rahul Singh <rahul.singh@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
---
Change in v5: none
Change in v4:
- Fixe minor comments
- Added Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
- Added Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Change in v3:
- Remove "define pci_passthrough_enabled (false)"
- Fixed coding style and minor comment
Change in v2:
- Add option in xen-command-line.pandoc
- Change pci option to pci-passthrough
- modify option from custom_param to boolean param
---
---
 docs/misc/xen-command-line.pandoc |  7 +++++++
 xen/arch/arm/pci/pci.c            | 12 ++++++++++++
 xen/drivers/pci/physdev.c         |  6 ++++++
 xen/include/asm-arm/pci.h         | 11 +++++++++++
 xen/include/asm-x86/pci.h         |  6 ++++++
 5 files changed, 42 insertions(+)

Comments

Jan Beulich Oct. 7, 2021, 8:27 a.m. UTC | #1 
On 06.10.2021 19:40, Rahul Singh wrote:
> @@ -62,8 +63,19 @@ static int __init acpi_pci_init(void)
>  }
>  #endif
>  
> +/* By default pci passthrough is disabled. */
> +bool __read_mostly pci_passthrough_enabled;

You properly use "bool " here. Why ...

> --- a/xen/include/asm-arm/pci.h
> +++ b/xen/include/asm-arm/pci.h
> @@ -19,14 +19,25 @@
>  
>  #define pci_to_dev(pcidev) (&(pcidev)->arch.dev)
>  
> +extern bool_t pci_passthrough_enabled;

... the being phased out "bool_t" here?

Jan
Rahul Singh Oct. 7, 2021, 8:32 a.m. UTC | #2 
Hi Jan,

> On 7 Oct 2021, at 9:27 am, Jan Beulich <jbeulich@suse.com> wrote:
> 
> On 06.10.2021 19:40, Rahul Singh wrote:
>> @@ -62,8 +63,19 @@ static int __init acpi_pci_init(void)
>> }
>> #endif
>> 
>> +/* By default pci passthrough is disabled. */
>> +bool __read_mostly pci_passthrough_enabled;
> 
> You properly use "bool " here. Why ...
> 
>> --- a/xen/include/asm-arm/pci.h
>> +++ b/xen/include/asm-arm/pci.h
>> @@ -19,14 +19,25 @@
>> 
>> #define pci_to_dev(pcidev) (&(pcidev)->arch.dev)
>> 
>> +extern bool_t pci_passthrough_enabled;
> 
> ... the being phased out "bool_t" here?

I missed that I will fix this.

Regards,
Rahul
> 
> Jan
>
Jan Beulich Oct. 7, 2021, 12:59 p.m. UTC | #3 
On 06.10.2021 19:40, Rahul Singh wrote:
> Add cmdline boot option "pci-passthrough = = <boolean>" to enable or
> disable the PCI passthrough support on ARM.
> 
> Signed-off-by: Rahul Singh <rahul.singh@arm.com>
> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
> Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>

Acked-by: Jan Beulich <jbeulich@suse.com>
diff mbox series

Patch

diff --git a/docs/misc/xen-command-line.pandoc b/docs/misc/xen-command-line.pandoc
index 5cae4adc58..b1f7978aa4 100644
--- a/docs/misc/xen-command-line.pandoc
+++ b/docs/misc/xen-command-line.pandoc
@@ -1819,6 +1819,13 @@  All numbers specified must be hexadecimal ones.
 
 This option can be specified more than once (up to 8 times at present).
 
+### pci-passthrough (arm)
+> `= <boolean>`
+
+> Default: `false`
+
+Flag to enable or disable support for PCI passthrough
+
 ### pcid (x86)
 > `= <boolean> | xpti=<bool>`
 
diff --git a/xen/arch/arm/pci/pci.c b/xen/arch/arm/pci/pci.c
index e359bab9ea..73540045d1 100644
--- a/xen/arch/arm/pci/pci.c
+++ b/xen/arch/arm/pci/pci.c
@@ -16,6 +16,7 @@ 
 #include <xen/device_tree.h>
 #include <xen/errno.h>
 #include <xen/init.h>
+#include <xen/param.h>
 #include <xen/pci.h>
 
 /*
@@ -62,8 +63,19 @@  static int __init acpi_pci_init(void)
 }
 #endif
 
+/* By default pci passthrough is disabled. */
+bool __read_mostly pci_passthrough_enabled;
+boolean_param("pci-passthrough", pci_passthrough_enabled);
+
 static int __init pci_init(void)
 {
+    /*
+     * Enable PCI passthrough when has been enabled explicitly
+     * (pci-passthrough=on).
+     */
+    if ( !pci_passthrough_enabled )
+        return 0;
+
     pci_segments_init();
 
     if ( acpi_disabled )
diff --git a/xen/drivers/pci/physdev.c b/xen/drivers/pci/physdev.c
index 4f3e1a96c0..42db3e6d13 100644
--- a/xen/drivers/pci/physdev.c
+++ b/xen/drivers/pci/physdev.c
@@ -18,6 +18,9 @@  ret_t pci_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
         struct pci_dev_info pdev_info;
         nodeid_t node = NUMA_NO_NODE;
 
+        if ( !is_pci_passthrough_enabled() )
+            return -EOPNOTSUPP;
+
         ret = -EFAULT;
         if ( copy_from_guest(&add, arg, 1) != 0 )
             break;
@@ -53,6 +56,9 @@  ret_t pci_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
     case PHYSDEVOP_pci_device_remove: {
         struct physdev_pci_device dev;
 
+        if ( !is_pci_passthrough_enabled() )
+            return -EOPNOTSUPP;
+
         ret = -EFAULT;
         if ( copy_from_guest(&dev, arg, 1) != 0 )
             break;
diff --git a/xen/include/asm-arm/pci.h b/xen/include/asm-arm/pci.h
index 7dd9eb3dba..0cf849e26f 100644
--- a/xen/include/asm-arm/pci.h
+++ b/xen/include/asm-arm/pci.h
@@ -19,14 +19,25 @@ 
 
 #define pci_to_dev(pcidev) (&(pcidev)->arch.dev)
 
+extern bool_t pci_passthrough_enabled;
+
 /* Arch pci dev struct */
 struct arch_pci_dev {
     struct device dev;
 };
 
+static always_inline bool is_pci_passthrough_enabled(void)
+{
+    return pci_passthrough_enabled;
+}
 #else   /*!CONFIG_HAS_PCI*/
 
 struct arch_pci_dev { };
 
+static always_inline bool is_pci_passthrough_enabled(void)
+{
+    return false;
+}
+
 #endif  /*!CONFIG_HAS_PCI*/
 #endif /* __ARM_PCI_H__ */
diff --git a/xen/include/asm-x86/pci.h b/xen/include/asm-x86/pci.h
index cc05045e9c..e076951032 100644
--- a/xen/include/asm-x86/pci.h
+++ b/xen/include/asm-x86/pci.h
@@ -32,4 +32,10 @@  bool_t pci_ro_mmcfg_decode(unsigned long mfn, unsigned int *seg,
 extern int pci_mmcfg_config_num;
 extern struct acpi_mcfg_allocation *pci_mmcfg_config;
 
+/* Unlike ARM, PCI passthrough is always enabled for x86. */
+static always_inline bool is_pci_passthrough_enabled(void)
+{
+    return true;
+}
+
 #endif /* __X86_PCI_H__ */