Add cmdline boot option "pci-passthrough = = <boolean>" to enable or disable the PCI passthrough support on ARM.
Signed-off-by: Rahul Singh <rahul.si...@arm.com> Reviewed-by: Stefano Stabellini <sstabell...@kernel.org> Reviewed-by: Bertrand Marquis <bertrand.marq...@arm.com> --- Change in v5: none Change in v4: - Fixe minor comments - Added Reviewed-by: Bertrand Marquis <bertrand.marq...@arm.com> - Added Reviewed-by: Stefano Stabellini <sstabell...@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(+) 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__ */ -- 2.25.1