Re: [PATCH] xen/mcfg: Call PHYSDEVOP_pci_mmcfg_reserved for MCFG areas.

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

Resending it to LKML.
On Wed, Nov 06, 2013 at 03:32:23PM -0500, Konrad Rzeszutek Wilk wrote:
> The PCI MMCONFIG area is usually reserved via the E820 so the Xen hypervisor
> is aware of these regions. But they can also be enumerated in the ACPI
> DSDT which means the hypervisor won't know of them until the initial
> domain informs it of via PHYSDEVOP_pci_mmcfg_reserved.
> 
> This is what this patch does for all of the MCFG regions that the
> initial domain is aware of (E820 enumerated and ACPI).
> 
> Reported-by:  Santosh Jodh <Santosh.Jodh@citrix.com>
> CC: Jan Beulich <JBeulich@suse.com>
> CC: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> CC: David Vrabel <david.vrabel@citrix.com>
> CC: Mukesh Rathor <mukesh.rathor@oracle.com>
> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> [v1: Redid it a bit]
> [v2: Dropped the P2M 1-1 setting]
> [v3: Check for Xen in-case we are running under baremetal]
> ---
>  drivers/xen/pci.c               | 45 +++++++++++++++++++++++++++++++++++++++++
>  include/xen/interface/physdev.h | 11 ++++++++++
>  2 files changed, 56 insertions(+)
> 
> diff --git a/drivers/xen/pci.c b/drivers/xen/pci.c
> index 18fff88..0331fe9 100644
> --- a/drivers/xen/pci.c
> +++ b/drivers/xen/pci.c
> @@ -26,6 +26,7 @@
>  #include <asm/xen/hypervisor.h>
>  #include <asm/xen/hypercall.h>
>  #include "../pci/pci.h"
> +#include <asm/pci_x86.h>
>  
>  static bool __read_mostly pci_seg_supported = true;
>  
> @@ -192,3 +193,47 @@ static int __init register_xen_pci_notifier(void)
>  }
>  
>  arch_initcall(register_xen_pci_notifier);
> +
> +static int __init xen_mcfg_late(void)
> +{
> +	struct pci_mmcfg_region *cfg;
> +	int rc;
> +
> +	if (!xen_initial_domain())
> +		return 0;
> +
> +	if ((pci_probe & PCI_PROBE_MMCONF) == 0)
> +		return 0;
> +
> +	if (list_empty(&pci_mmcfg_list))
> +		return 0;
> +
> +	/* Check whether they are in the right area. */
> +	list_for_each_entry(cfg, &pci_mmcfg_list, list) {
> +		struct physdev_pci_mmcfg_reserved r;
> +
> +		r.address = cfg->address;
> +		r.segment = cfg->segment;
> +		r.start_bus = cfg->start_bus;
> +		r.end_bus = cfg->end_bus;
> +		r.flags = XEN_PCI_MMCFG_RESERVED;
> +
> +		rc = HYPERVISOR_physdev_op(PHYSDEVOP_pci_mmcfg_reserved, &r);
> +		switch (rc) {
> +		case 0:
> +		case -ENOSYS:
> +			continue;
> +
> +		default:
> +			pr_warn("Failed to report MMCONFIG reservation"
> +				" state for %s to hypervisor"
> +				" (%d)\n",
> +				cfg->name, rc);
> +		}
> +	}
> +	return 0;
> +}
> +/*
> + * Needs to be done after acpi_init which are subsys_initcall.
> + */
> +subsys_initcall_sync(xen_mcfg_late);
> diff --git a/include/xen/interface/physdev.h b/include/xen/interface/physdev.h
> index 7000bb1..42721d1 100644
> --- a/include/xen/interface/physdev.h
> +++ b/include/xen/interface/physdev.h
> @@ -231,6 +231,17 @@ struct physdev_get_free_pirq {
>  #define XEN_PCI_DEV_VIRTFN             0x2
>  #define XEN_PCI_DEV_PXM                0x4
>  
> +#define XEN_PCI_MMCFG_RESERVED         0x1
> +
> +#define PHYSDEVOP_pci_mmcfg_reserved    24
> +struct physdev_pci_mmcfg_reserved {
> +    uint64_t address;
> +    uint16_t segment;
> +    uint8_t start_bus;
> +    uint8_t end_bus;
> +    uint32_t flags;
> +};
> +
>  #define PHYSDEVOP_pci_device_add        25
>  struct physdev_pci_device_add {
>      /* IN */
> -- 
> 1.8.3.1
>