[Qemu-devel] [PATCH v2] spapr: populate ibm,loc-code

[Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>]

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-code.
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>
---

Changelog
v1:
* Dropped is_vfio patch and using TYPE_SPAPR_PCI_VFIO_HOST_BRIDGE 
  to recognise vfio devices
* Removed wrapper for hcall
* Added sPAPRPHBClass::get_loc_code

 hw/ppc/spapr_hcall.c        |  1 +
 hw/ppc/spapr_pci.c          | 38 +++++++++++++++++++++++++++++++++
 hw/ppc/spapr_pci_vfio.c     | 51 +++++++++++++++++++++++++++++++++++++++++++++
 include/hw/pci-host/spapr.h |  1 +
 include/hw/ppc/spapr.h      |  8 ++++++-
 5 files changed, 98 insertions(+), 1 deletion(-)

diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
index 4f76f1c..b394681 100644
--- a/hw/ppc/spapr_hcall.c
+++ b/hw/ppc/spapr_hcall.c
@@ -1010,6 +1010,7 @@ 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, phb_get_loc_code);
 }
 
 type_init(hypercall_register_types)
diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
index 05f4fac..c2ee476 100644
--- a/hw/ppc/spapr_pci.c
+++ b/hw/ppc/spapr_pci.c
@@ -248,6 +248,44 @@ static void spapr_msi_setmsg(PCIDevice *pdev, hwaddr addr, bool msix,
     }
 }
 
+target_ulong phb_get_loc_code(PowerPCCPU *cpu, sPAPREnvironment *spapr,
+                              target_ulong opcode, target_ulong *args)
+{
+    sPAPRPHBState *sphb = NULL;
+    sPAPRPHBClass *spc = NULL;
+    char *buf = NULL, path[PATH_MAX];
+    PCIDevice *pdev;
+    target_ulong buid = args[0];
+    target_ulong config_addr = args[1];
+    target_ulong loc_code = args[2];
+    target_ulong size = args[3];
+
+    sphb = find_phb(spapr, buid);
+    pdev = find_dev(spapr, buid, config_addr);
+
+    if (!sphb || !pdev) {
+        return H_PARAMETER;
+    }
+
+    spc = SPAPR_PCI_HOST_BRIDGE_GET_CLASS(sphb);
+    if (spc->get_loc_code && spc->get_loc_code(sphb, pdev, &buf)) {
+        cpu_physical_memory_write(loc_code, buf, strlen(buf));
+        g_free(buf);
+        return H_SUCCESS;
+    }
+
+    /*
+     * For non-vfio devices and failures 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);
+    return H_SUCCESS;
+}
+
 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/ppc/spapr_pci_vfio.c b/hw/ppc/spapr_pci_vfio.c
index 99a1be5..bfdfa67 100644
--- a/hw/ppc/spapr_pci_vfio.c
+++ b/hw/ppc/spapr_pci_vfio.c
@@ -171,6 +171,56 @@ static int spapr_phb_vfio_eeh_reset(sPAPRPHBState *sphb, int option)
     return RTAS_OUT_SUCCESS;
 }
 
+static bool spapr_phb_vfio_get_devspec(PCIDevice *pdev, char **value)
+{
+    char *host;
+    char path[PATH_MAX];
+    struct stat st;
+
+    host = object_property_get_str(OBJECT(pdev), "host", NULL);
+    if (!host) {
+        return false;
+    }
+
+    snprintf(path, sizeof(path), "/sys/bus/pci/devices/%s/devspec", host);
+    g_free(host);
+    if (stat(path, &st) < 0) {
+        return false;
+    }
+
+    return g_file_get_contents(path, value, NULL, NULL);
+}
+
+static int spapr_phb_vfio_get_loc_code(sPAPRPHBState *sphb,  PCIDevice *pdev,
+                                        char **loc_code)
+{
+    sPAPRPHBVFIOState *svphb = SPAPR_PCI_VFIO_HOST_BRIDGE(sphb);
+    char path[PATH_MAX], *buf = NULL;
+    struct stat st;
+
+    /* Non VFIO devices */
+    if (!svphb) {
+        return false;
+    }
+
+    /* We have a vfio host bridge lets get the path. */
+    if (!spapr_phb_vfio_get_devspec(pdev, &buf)) {
+        return false;
+    }
+
+    snprintf(path, sizeof(path), "/proc/device-tree%s/ibm,loc-code", buf);
+    g_free(buf);
+    if (stat(path, &st) < 0) {
+            return false;
+    }
+
+    /* A valid file, now read the loc-code */
+    if (g_file_get_contents(path, loc_code, NULL, NULL)) {
+        return true;
+    }
+    return false;
+}
+
 static int spapr_phb_vfio_eeh_configure(sPAPRPHBState *sphb)
 {
     sPAPRPHBVFIOState *svphb = SPAPR_PCI_VFIO_HOST_BRIDGE(sphb);
@@ -199,6 +249,7 @@ static void spapr_phb_vfio_class_init(ObjectClass *klass, void *data)
     spc->eeh_get_state = spapr_phb_vfio_eeh_get_state;
     spc->eeh_reset = spapr_phb_vfio_eeh_reset;
     spc->eeh_configure = spapr_phb_vfio_eeh_configure;
+    spc->get_loc_code = spapr_phb_vfio_get_loc_code;
 }
 
 static const TypeInfo spapr_phb_vfio_info = {
diff --git a/include/hw/pci-host/spapr.h b/include/hw/pci-host/spapr.h
index 895d273..1ff50b4 100644
--- a/include/hw/pci-host/spapr.h
+++ b/include/hw/pci-host/spapr.h
@@ -53,6 +53,7 @@ struct sPAPRPHBClass {
     int (*eeh_get_state)(sPAPRPHBState *sphb, int *state);
     int (*eeh_reset)(sPAPRPHBState *sphb, int option);
     int (*eeh_configure)(sPAPRPHBState *sphb);
+    int (*get_loc_code)(sPAPRPHBState *sphb,  PCIDevice *pdev, char **loc_code);
 };
 
 typedef struct spapr_pci_msi {
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index af71e8b..95157ac 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)
+#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);
 
+target_ulong phb_get_loc_code(PowerPCCPU *cpu, sPAPREnvironment *spapr,
+                              target_ulong opcode, target_ulong *args);
+
 #define TYPE_SPAPR_RTC "spapr-rtc"
 
 void spapr_rtc_read(DeviceState *dev, struct tm *tm, uint32_t *ns);
-- 
1.8.3.1