[RFC 1/4] ppc/spapr: Add VFIO EEH error injection backend

[Narayana Murty N <nnmlinux@linux.ibm.com>]

Introduce 'spapr_phb_vfio_errinjct()' to inject PCI PHB error events via
the VFIO passthrough backend. This function translates RTAS error injection
parameters into VFIO EEH injection commands suitable for hardware emulation.

The patch adds:
    - A minimal 'enum rtas_err_type' for error types used in VFIO path
    - EEH function code macros ('EEH_ERR_FUNC_...')
    - Backend stub and integration into 'spapr_pci_vfio.c'
    - Necessary header declarations for interfacing

This forms the foundational layer for PCI error injection testing using VFIO
passthrough devices on pseries guests.

Signed-off-by: Narayana Murty N <nnmlinux@linux.ibm.com>
---
 include/hw/pci-host/spapr.h |  7 +++++
 include/hw/ppc/spapr.h      | 44 ++++++++++++++++++++++++++++++
 hw/ppc/spapr_pci_vfio.c     | 53 +++++++++++++++++++++++++++++++++++++
 3 files changed, 104 insertions(+)

diff --git a/include/hw/pci-host/spapr.h b/include/hw/pci-host/spapr.h
index 0db87f1281..2e91e0fb38 100644
--- a/include/hw/pci-host/spapr.h
+++ b/include/hw/pci-host/spapr.h
@@ -125,6 +125,8 @@ int spapr_phb_vfio_eeh_get_state(SpaprPhbState *sphb, int *state);
 int spapr_phb_vfio_eeh_reset(SpaprPhbState *sphb, int option);
 int spapr_phb_vfio_eeh_configure(SpaprPhbState *sphb);
 void spapr_phb_vfio_reset(DeviceState *qdev);
+int spapr_phb_vfio_errinjct(SpaprPhbState *sphb, uint32_t func,
+                            uint64_t addr, uint64_t mask, uint32_t type);
 #else
 static inline bool spapr_phb_eeh_available(SpaprPhbState *sphb)
 {
@@ -151,6 +153,11 @@ static inline int spapr_phb_vfio_eeh_configure(SpaprPhbState *sphb)
 static inline void spapr_phb_vfio_reset(DeviceState *qdev)
 {
 }
+static int spapr_phb_vfio_errinjct(SpaprPhbState *sphb, uint32_t func,
+                                   uint64_t addr, uint64_t mask, uint32_t type)
+{
+    return RTAS_OUT_HW_ERROR;
+}
 #endif
 
 void spapr_phb_dma_reset(SpaprPhbState *sphb);
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 39bd5bd5ed..331946ee57 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -691,6 +691,50 @@ void push_sregs_to_kvm_pr(SpaprMachineState *spapr);
 #define RTAS_EEH_PE_UNAVAIL_INFO         1000
 #define RTAS_EEH_PE_RECOVER_INFO         0
 
+/* EEH error types and functions */
+#define EEH_ERR_FUNC_MIN                0
+#define EEH_ERR_FUNC_LD_MEM_ADDR        0       /* Memory load  */
+#define EEH_ERR_FUNC_LD_MEM_DATA        1
+#define EEH_ERR_FUNC_LD_IO_ADDR         2       /* IO load      */
+#define EEH_ERR_FUNC_LD_IO_DATA         3
+#define EEH_ERR_FUNC_LD_CFG_ADDR        4       /* Config load  */
+#define EEH_ERR_FUNC_LD_CFG_DATA        5
+#define EEH_ERR_FUNC_ST_MEM_ADDR        6       /* Memory store */
+#define EEH_ERR_FUNC_ST_MEM_DATA        7
+#define EEH_ERR_FUNC_ST_IO_ADDR         8       /* IO store     */
+#define EEH_ERR_FUNC_ST_IO_DATA         9
+#define EEH_ERR_FUNC_ST_CFG_ADDR        10      /* Config store */
+#define EEH_ERR_FUNC_ST_CFG_DATA        11
+#define EEH_ERR_FUNC_DMA_RD_ADDR        12      /* DMA read     */
+#define EEH_ERR_FUNC_DMA_RD_DATA        13
+#define EEH_ERR_FUNC_DMA_RD_MASTER      14
+#define EEH_ERR_FUNC_DMA_RD_TARGET      15
+#define EEH_ERR_FUNC_DMA_WR_ADDR        16      /* DMA write    */
+#define EEH_ERR_FUNC_DMA_WR_DATA        17
+#define EEH_ERR_FUNC_DMA_WR_MASTER      18
+#define EEH_ERR_FUNC_DMA_WR_TARGET      19
+#define EEH_ERR_FUNC_MAX                EEH_ERR_FUNC_DMA_WR_TARGET
+
+/* RTAS PCI Error Injection Token Types */
+enum rtas_err_type {
+    RTAS_ERR_TYPE_FATAL                   = 0x1,
+    RTAS_ERR_TYPE_RECOVERED_RANDOM_EVENT  = 0x2,
+    RTAS_ERR_TYPE_RECOVERED_SPECIAL_EVENT = 0x3,
+    RTAS_ERR_TYPE_CORRUPTED_PAGE          = 0x4,
+    RTAS_ERR_TYPE_CORRUPTED_SLB           = 0x5,
+    RTAS_ERR_TYPE_TRANSLATOR_FAILURE      = 0x6,
+    RTAS_ERR_TYPE_IOA_BUS_ERROR           = 0x7,
+    RTAS_ERR_TYPE_PLATFORM_SPECIFIC       = 0x8,
+    RTAS_ERR_TYPE_CORRUPTED_DCACHE_START  = 0x9,
+    RTAS_ERR_TYPE_CORRUPTED_DCACHE_END    = 0xA,
+    RTAS_ERR_TYPE_CORRUPTED_ICACHE_START  = 0xB,
+    RTAS_ERR_TYPE_CORRUPTED_ICACHE_END    = 0xC,
+    RTAS_ERR_TYPE_CORRUPTED_TLB_START     = 0xD,
+    RTAS_ERR_TYPE_CORRUPTED_TLB_END       = 0xE,
+    RTAS_ERR_TYPE_IOA_BUS_ERROR_64        = 0xF,
+    RTAS_ERR_TYPE_UPSTREAM_IO_ERROR       = 0x10
+};
+
 /* ibm,set-slot-reset */
 #define RTAS_SLOT_RESET_DEACTIVATE       0
 #define RTAS_SLOT_RESET_HOT              1
diff --git a/hw/ppc/spapr_pci_vfio.c b/hw/ppc/spapr_pci_vfio.c
index a748a0bf4c..ed0b22a84a 100644
--- a/hw/ppc/spapr_pci_vfio.c
+++ b/hw/ppc/spapr_pci_vfio.c
@@ -317,6 +317,55 @@ int spapr_phb_vfio_eeh_configure(SpaprPhbState *sphb)
     return RTAS_OUT_SUCCESS;
 }
 
+int spapr_phb_vfio_errinjct(SpaprPhbState *sphb,
+                            uint32_t func, uint64_t addr,
+                            uint64_t mask, uint32_t type)
+{
+    VFIOLegacyContainer *container = vfio_eeh_as_container(&sphb->iommu_as);
+    struct vfio_eeh_pe_op op = {
+        .op = VFIO_EEH_PE_INJECT_ERR,
+        .argsz = sizeof(op),
+    };
+
+    /* Set error type, address, and mask */
+    op.err.type = type;
+    op.err.addr = addr;
+    op.err.mask = mask;
+
+    /* Validate and set function code */
+    switch (func) {
+    case EEH_ERR_FUNC_LD_MEM_ADDR:
+    case EEH_ERR_FUNC_LD_MEM_DATA:
+    case EEH_ERR_FUNC_LD_IO_ADDR:
+    case EEH_ERR_FUNC_LD_IO_DATA:
+    case EEH_ERR_FUNC_LD_CFG_ADDR:
+    case EEH_ERR_FUNC_LD_CFG_DATA:
+    case EEH_ERR_FUNC_ST_MEM_ADDR:
+    case EEH_ERR_FUNC_ST_MEM_DATA:
+    case EEH_ERR_FUNC_ST_IO_ADDR:
+    case EEH_ERR_FUNC_ST_IO_DATA:
+    case EEH_ERR_FUNC_ST_CFG_ADDR:
+    case EEH_ERR_FUNC_ST_CFG_DATA:
+    case EEH_ERR_FUNC_DMA_RD_ADDR:
+    case EEH_ERR_FUNC_DMA_RD_DATA:
+    case EEH_ERR_FUNC_DMA_RD_MASTER:
+    case EEH_ERR_FUNC_DMA_RD_TARGET:
+    case EEH_ERR_FUNC_DMA_WR_ADDR:
+    case EEH_ERR_FUNC_DMA_WR_DATA:
+    case EEH_ERR_FUNC_DMA_WR_MASTER:
+        op.err.func = func;
+        break;
+    default:
+        return RTAS_OUT_PARAM_ERROR;
+    }
+
+    /* Perform the ioctl to inject the error */
+    if (ioctl(container->fd, VFIO_EEH_PE_OP, &op) < 0) {
+        return RTAS_OUT_HW_ERROR;
+    }
+
+    return RTAS_OUT_SUCCESS;
+}
 #else
 
 bool spapr_phb_eeh_available(SpaprPhbState *sphb)
@@ -349,4 +398,8 @@ int spapr_phb_vfio_eeh_configure(SpaprPhbState *sphb)
     return RTAS_OUT_NOT_SUPPORTED;
 }
 
+int spapr_phb_vfio_errinjct(SpaprPhbState *sphb, int option)
+{
+    return RTAS_OUT_NOT_SUPPORTED;
+}
 #endif /* CONFIG_VFIO_PCI */
-- 
2.51.0