Re: [Qemu-devel] [PATCH 2/2] spapr: populate ibm,loc-code

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 03/26/2015 05:42 PM, Nikunj A Dadhania wrote:
> Each hardware instance has a platform unique location code.  The OF
> device tree that describes a part of a hardware entity must include
> the “ibm,loc-code” property with a value that represents the location
> code for that hardware entity.
>
> Introduce an hcall to populate ibm,loc-cde.
> 1) PCI passthru devices need to identify with its own ibm,loc-code
>     available on the host.
> 2) Emulated devices encode as following: qemu_<name>:<slot>.<fn>
>
> Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
> ---
>   hw/ppc/spapr_hcall.c          | 10 +++++++++
>   hw/ppc/spapr_pci.c            | 49 +++++++++++++++++++++++++++++++++++++++++++
>   hw/vfio/pci.c                 | 18 ++++++++++++++++
>   include/hw/ppc/spapr.h        |  8 ++++++-
>   include/hw/vfio/vfio-common.h |  1 +
>   5 files changed, 85 insertions(+), 1 deletion(-)
>
> diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
> index 4f76f1c..a577395 100644
> --- a/hw/ppc/spapr_hcall.c
> +++ b/hw/ppc/spapr_hcall.c
> @@ -928,6 +928,15 @@ static target_ulong h_client_architecture_support(PowerPCCPU *cpu_,
>       return H_SUCCESS;
>   }
>
> +static target_ulong h_get_loc_code(PowerPCCPU *cpu, sPAPREnvironment *spapr,
> +				   target_ulong opcode, target_ulong *args)
> +{
> +    if (!spapr_h_get_loc_code(spapr, args[0], args[1], args[2], args[3])) {
> +        return H_PARAMETER;
> +    }
> +    return H_SUCCESS;
> +}
> +
>   static spapr_hcall_fn papr_hypercall_table[(MAX_HCALL_OPCODE / 4) + 1];
>   static spapr_hcall_fn kvmppc_hypercall_table[KVMPPC_HCALL_MAX - KVMPPC_HCALL_BASE + 1];
>
> @@ -1010,6 +1019,7 @@ static void hypercall_register_types(void)
>
>       /* ibm,client-architecture-support support */
>       spapr_register_hypercall(KVMPPC_H_CAS, h_client_architecture_support);
> +    spapr_register_hypercall(KVMPPC_H_GET_LOC_CODE, h_get_loc_code);
>   }
>
>   type_init(hypercall_register_types)
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index 05f4fac..65cdb91 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -35,6 +35,7 @@
>   #include "qemu/error-report.h"
>
>   #include "hw/pci/pci_bus.h"
> +#include "hw/vfio/vfio-common.h"
>
>   /* Copied from the kernel arch/powerpc/platforms/pseries/msi.c */
>   #define RTAS_QUERY_FN           0
> @@ -248,6 +249,54 @@ static void spapr_msi_setmsg(PCIDevice *pdev, hwaddr addr, bool msix,
>       }
>   }
>
> +bool spapr_h_get_loc_code(sPAPREnvironment *spapr, target_ulong config_addr, target_ulong buid,
> +                          target_ulong loc_code, target_ulong size)
> +{
> +    sPAPRPHBState *sphb = NULL;
> +    PCIDevice *pdev = NULL;
> +    char *buf, path[PATH_MAX];
> +    struct stat st;
> +
> +    sphb = find_phb(spapr, buid);
> +    if (sphb) {
> +        pdev = find_dev(spapr, buid, config_addr);
> +    }
> +

I would define a sPAPRPHBClass::get_loc_code(sPAPRPHBState *sphb,  uint32_t 
config_addr) and implement it for "spapr-pci-vfio-host-bridge" as you did 
below.


> +    if (!sphb || !pdev) {
> +        error_report("spapr_h_get_loc_code: Device not found");
> +        return false;
> +    }
> +
> +    /* For a VFIO device, get the location in the device tree */
> +    if (pdev->is_vfio && vfio_get_devspec(pdev, &buf)) {
> +        snprintf(path, sizeof(path), "/proc/device-tree%s/ibm,loc-code", buf);
> +        g_free(buf);
> +        if (stat(path, &st) < 0) {
> +            goto fail;
> +        }
> +
> +        /* A valid file, now read the loc-code */
> +        if (g_file_get_contents(path, &buf, NULL, NULL)) {
> +            cpu_physical_memory_write(loc_code, buf, strlen(buf));
> +            g_free(buf);
> +            goto out;
> +        }
> +    }
> +
> +fail:
> +    /*
> +     * For non-vfio devices and failure cases, make up the location
> +     * code out of the name, slot and function.
> +     *
> +     *       qemu_<name>:<slot>.<fn>
> +     */
> +    snprintf(path, sizeof(path), "qemu_%s:%02d.%1d", pdev->name,
> +             PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn));
> +    cpu_physical_memory_write(loc_code, path, size);
> + out:
> +    return true;
> +}
> +
>   static void rtas_ibm_change_msi(PowerPCCPU *cpu, sPAPREnvironment *spapr,
>                                   uint32_t token, uint32_t nargs,
>                                   target_ulong args, uint32_t nret,
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index 95d666e..dd97258 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -3319,6 +3319,24 @@ static void vfio_unregister_req_notifier(VFIOPCIDevice *vdev)
>       vdev->req_enabled = false;
>   }
>
> +bool vfio_get_devspec(PCIDevice *pdev, char **value)


This function can live in hw/ppc/spapr_pci_vfio.c. Something like 
object_property_get_str(OBJECT(pdev), "host", NULL) will return the host 
address, and this is all you really want from VFIO here.


> +{
> +    VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
> +    char path[PATH_MAX];
> +    struct stat st;
> +
> +    snprintf(path, sizeof(path),
> +             "/sys/bus/pci/devices/%04x:%02x:%02x.%01x/devspec",
> +             vdev->host.domain, vdev->host.bus, vdev->host.slot,
> +             vdev->host.function);
> +
> +    if (stat(path, &st) < 0) {
> +        return false;
> +    }
> +
> +    return g_file_get_contents(path, value, NULL, NULL);
> +}
> +
>   static int vfio_initfn(PCIDevice *pdev)
>   {
>       VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index af71e8b..d3fad67 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -310,7 +310,10 @@ typedef struct sPAPREnvironment {
>   #define KVMPPC_H_LOGICAL_MEMOP  (KVMPPC_HCALL_BASE + 0x1)
>   /* Client Architecture support */
>   #define KVMPPC_H_CAS            (KVMPPC_HCALL_BASE + 0x2)
> -#define KVMPPC_HCALL_MAX        KVMPPC_H_CAS
> +#define KVMPPC_H_RTAS_UPDATE    (KVMPPC_HCALL_BASE + 0x3)
> +#define KVMPPC_H_REPORT_MC_ERR  (KVMPPC_HCALL_BASE + 0x4)
> +#define KVMPPC_H_GET_LOC_CODE   (KVMPPC_HCALL_BASE + 0x5)


Are you adding KVMPPC_H_GET_LOC_CODE or all three? :)


> +#define KVMPPC_HCALL_MAX        KVMPPC_H_GET_LOC_CODE
>
>   extern sPAPREnvironment *spapr;
>
> @@ -522,6 +525,9 @@ int spapr_tcet_dma_dt(void *fdt, int node_off, const char *propname,
>                         sPAPRTCETable *tcet);
>   void spapr_pci_switch_vga(bool big_endian);
>
> +bool spapr_h_get_loc_code(sPAPREnvironment *spapr, target_ulong config_addr, target_ulong build,

s/build/buid/  and please put buid before config_addr in the parameters lice.


> +			  target_ulong loc_code, target_ulong size);
> +
>   #define TYPE_SPAPR_RTC "spapr-rtc"
>
>   void spapr_rtc_read(DeviceState *dev, struct tm *tm, uint32_t *ns);
> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> index 0d1fb80..6dffa8c 100644
> --- a/include/hw/vfio/vfio-common.h
> +++ b/include/hw/vfio/vfio-common.h
> @@ -140,6 +140,7 @@ VFIOGroup *vfio_get_group(int groupid, AddressSpace *as);
>   void vfio_put_group(VFIOGroup *group);
>   int vfio_get_device(VFIOGroup *group, const char *name,
>                       VFIODevice *vbasedev);
> +bool vfio_get_devspec(PCIDevice *pdev, char **value);
>
>   extern const MemoryRegionOps vfio_region_ops;
>   extern QLIST_HEAD(vfio_group_head, VFIOGroup) vfio_group_list;
>


-- 
Alexey