Introduce Xen PCI Passthrough, qdevice

A more complete history can be found here:
git://xenbits.xensource.com/qemu-xen-unstable.git

Signed-off-by: Allen Kay <allen.m.kay@intel.com>
Signed-off-by: Guy Zana <guy@neocleus.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

hw/i386/Makefile.objs

@@ -8,6 +8,7 @@ obj-y += pc_piix.o
 obj-y += pc_sysfw.o
 obj-$(CONFIG_XEN) += xen_platform.o xen_apic.o
 obj-$(CONFIG_XEN_PCI_PASSTHROUGH) += xen-host-pci-device.o
+obj-$(CONFIG_XEN_PCI_PASSTHROUGH) += xen_pt.o xen_pt_config_init.o
 obj-y += kvm/
 obj-$(CONFIG_SPICE) += qxl.o qxl-logger.o qxl-render.o
 

hw/xen_common.h

@@ -150,4 +150,7 @@ static inline int xen_xc_hvm_inject_msi(XenXC xen_xc, domid_t dom,
 
 void destroy_hvm_domain(bool reboot);
 
+/* shutdown/destroy current domain because of an error */
+void xen_shutdown_fatal_error(const char *fmt, ...) GCC_FMT_ATTR(1, 2);
+
 #endif /* QEMU_HW_XEN_COMMON_H */

hw/xen_pt.h

@@ -0,0 +1,248 @@
+#ifndef XEN_PT_H
+#define XEN_PT_H
+
+#include "qemu-common.h"
+#include "xen_common.h"
+#include "pci.h"
+#include "xen-host-pci-device.h"
+
+void xen_pt_log(const PCIDevice *d, const char *f, ...) GCC_FMT_ATTR(2, 3);
+
+#define XEN_PT_ERR(d, _f, _a...) xen_pt_log(d, "%s: Error: "_f, __func__, ##_a)
+
+#ifdef XEN_PT_LOGGING_ENABLED
+#  define XEN_PT_LOG(d, _f, _a...)  xen_pt_log(d, "%s: " _f, __func__, ##_a)
+#  define XEN_PT_WARN(d, _f, _a...) \
+    xen_pt_log(d, "%s: Warning: "_f, __func__, ##_a)
+#else
+#  define XEN_PT_LOG(d, _f, _a...)
+#  define XEN_PT_WARN(d, _f, _a...)
+#endif
+
+#ifdef XEN_PT_DEBUG_PCI_CONFIG_ACCESS
+#  define XEN_PT_LOG_CONFIG(d, addr, val, len) \
+    xen_pt_log(d, "%s: address=0x%04x val=0x%08x len=%d\n", \
+               __func__, addr, val, len)
+#else
+#  define XEN_PT_LOG_CONFIG(d, addr, val, len)
+#endif
+
+
+/* Helper */
+#define XEN_PFN(x) ((x) >> XC_PAGE_SHIFT)
+
+typedef struct XenPTRegInfo XenPTRegInfo;
+typedef struct XenPTReg XenPTReg;
+
+typedef struct XenPCIPassthroughState XenPCIPassthroughState;
+
+/* function type for config reg */
+typedef int (*xen_pt_conf_reg_init)
+    (XenPCIPassthroughState *, XenPTRegInfo *, uint32_t real_offset,
+     uint32_t *data);
+typedef int (*xen_pt_conf_dword_write)
+    (XenPCIPassthroughState *, XenPTReg *cfg_entry,
+     uint32_t *val, uint32_t dev_value, uint32_t valid_mask);
+typedef int (*xen_pt_conf_word_write)
+    (XenPCIPassthroughState *, XenPTReg *cfg_entry,
+     uint16_t *val, uint16_t dev_value, uint16_t valid_mask);
+typedef int (*xen_pt_conf_byte_write)
+    (XenPCIPassthroughState *, XenPTReg *cfg_entry,
+     uint8_t *val, uint8_t dev_value, uint8_t valid_mask);
+typedef int (*xen_pt_conf_dword_read)
+    (XenPCIPassthroughState *, XenPTReg *cfg_entry,
+     uint32_t *val, uint32_t valid_mask);
+typedef int (*xen_pt_conf_word_read)
+    (XenPCIPassthroughState *, XenPTReg *cfg_entry,
+     uint16_t *val, uint16_t valid_mask);
+typedef int (*xen_pt_conf_byte_read)
+    (XenPCIPassthroughState *, XenPTReg *cfg_entry,
+     uint8_t *val, uint8_t valid_mask);
+
+#define XEN_PT_BAR_ALLF 0xFFFFFFFF
+#define XEN_PT_BAR_UNMAPPED (-1)
+
+
+typedef enum {
+    XEN_PT_GRP_TYPE_HARDWIRED = 0,  /* 0 Hardwired reg group */
+    XEN_PT_GRP_TYPE_EMU,            /* emul reg group */
+} XenPTRegisterGroupType;
+
+typedef enum {
+    XEN_PT_BAR_FLAG_MEM = 0,        /* Memory type BAR */
+    XEN_PT_BAR_FLAG_IO,             /* I/O type BAR */
+    XEN_PT_BAR_FLAG_UPPER,          /* upper 64bit BAR */
+    XEN_PT_BAR_FLAG_UNUSED,         /* unused BAR */
+} XenPTBarFlag;
+
+
+typedef struct XenPTRegion {
+    /* BAR flag */
+    XenPTBarFlag bar_flag;
+    /* Translation of the emulated address */
+    union {
+        uint64_t maddr;
+        uint64_t pio_base;
+        uint64_t u;
+    } access;
+} XenPTRegion;
+
+/* XenPTRegInfo declaration
+ * - only for emulated register (either a part or whole bit).
+ * - for passthrough register that need special behavior (like interacting with
+ *   other component), set emu_mask to all 0 and specify r/w func properly.
+ * - do NOT use ALL F for init_val, otherwise the tbl will not be registered.
+ */
+
+/* emulated register infomation */
+struct XenPTRegInfo {
+    uint32_t offset;
+    uint32_t size;
+    uint32_t init_val;
+    /* reg read only field mask (ON:RO/ROS, OFF:other) */
+    uint32_t ro_mask;
+    /* reg emulate field mask (ON:emu, OFF:passthrough) */
+    uint32_t emu_mask;
+    /* no write back allowed */
+    uint32_t no_wb;
+    xen_pt_conf_reg_init init;
+    /* read/write function pointer
+     * for double_word/word/byte size */
+    union {
+        struct {
+            xen_pt_conf_dword_write write;
+            xen_pt_conf_dword_read read;
+        } dw;
+        struct {
+            xen_pt_conf_word_write write;
+            xen_pt_conf_word_read read;
+        } w;
+        struct {
+            xen_pt_conf_byte_write write;
+            xen_pt_conf_byte_read read;
+        } b;
+    } u;
+};
+
+/* emulated register management */
+struct XenPTReg {
+    QLIST_ENTRY(XenPTReg) entries;
+    XenPTRegInfo *reg;
+    uint32_t data; /* emulated value */
+};
+
+typedef struct XenPTRegGroupInfo XenPTRegGroupInfo;
+
+/* emul reg group size initialize method */
+typedef int (*xen_pt_reg_size_init_fn)
+    (XenPCIPassthroughState *, const XenPTRegGroupInfo *,
+     uint32_t base_offset, uint8_t *size);
+
+/* emulated register group infomation */
+struct XenPTRegGroupInfo {
+    uint8_t grp_id;
+    XenPTRegisterGroupType grp_type;
+    uint8_t grp_size;
+    xen_pt_reg_size_init_fn size_init;
+    XenPTRegInfo *emu_regs;
+};
+
+/* emul register group management table */
+typedef struct XenPTRegGroup {
+    QLIST_ENTRY(XenPTRegGroup) entries;
+    const XenPTRegGroupInfo *reg_grp;
+    uint32_t base_offset;
+    uint8_t size;
+    QLIST_HEAD(, XenPTReg) reg_tbl_list;
+} XenPTRegGroup;
+
+
+#define XEN_PT_UNASSIGNED_PIRQ (-1)
+
+struct XenPCIPassthroughState {
+    PCIDevice dev;
+
+    PCIHostDeviceAddress hostaddr;
+    bool is_virtfn;
+    XenHostPCIDevice real_device;
+    XenPTRegion bases[PCI_NUM_REGIONS]; /* Access regions */
+    QLIST_HEAD(, XenPTRegGroup) reg_grps;
+
+    uint32_t machine_irq;
+
+    MemoryRegion bar[PCI_NUM_REGIONS - 1];
+    MemoryRegion rom;
+
+    MemoryListener memory_listener;
+};
+
+int xen_pt_config_init(XenPCIPassthroughState *s);
+void xen_pt_config_delete(XenPCIPassthroughState *s);
+XenPTRegGroup *xen_pt_find_reg_grp(XenPCIPassthroughState *s, uint32_t address);
+XenPTReg *xen_pt_find_reg(XenPTRegGroup *reg_grp, uint32_t address);
+int xen_pt_bar_offset_to_index(uint32_t offset);
+
+static inline pcibus_t xen_pt_get_emul_size(XenPTBarFlag flag, pcibus_t r_size)
+{
+    /* align resource size (memory type only) */
+    if (flag == XEN_PT_BAR_FLAG_MEM) {
+        return (r_size + XC_PAGE_SIZE - 1) & XC_PAGE_MASK;
+    } else {
+        return r_size;
+    }
+}
+
+/* INTx */
+/* The PCI Local Bus Specification, Rev. 3.0,
+ * Section 6.2.4 Miscellaneous Registers, pp 223
+ * outlines 5 valid values for the interrupt pin (intx).
+ *  0: For devices (or device functions) that don't use an interrupt in
+ *  1: INTA#
+ *  2: INTB#
+ *  3: INTC#
+ *  4: INTD#
+ *
+ * Xen uses the following 4 values for intx
+ *  0: INTA#
+ *  1: INTB#
+ *  2: INTC#
+ *  3: INTD#
+ *
+ * Observing that these list of values are not the same, xen_pt_pci_read_intx()
+ * uses the following mapping from hw to xen values.
+ * This seems to reflect the current usage within Xen.
+ *
+ * PCI hardware    | Xen | Notes
+ * ----------------+-----+----------------------------------------------------
+ * 0               | 0   | No interrupt
+ * 1               | 0   | INTA#
+ * 2               | 1   | INTB#
+ * 3               | 2   | INTC#
+ * 4               | 3   | INTD#
+ * any other value | 0   | This should never happen, log error message
+ */
+
+static inline uint8_t xen_pt_pci_read_intx(XenPCIPassthroughState *s)
+{
+    uint8_t v = 0;
+    xen_host_pci_get_byte(&s->real_device, PCI_INTERRUPT_PIN, &v);
+    return v;
+}
+
+static inline uint8_t xen_pt_pci_intx(XenPCIPassthroughState *s)
+{
+    uint8_t r_val = xen_pt_pci_read_intx(s);
+
+    XEN_PT_LOG(&s->dev, "intx=%i\n", r_val);
+    if (r_val < 1 || r_val > 4) {
+        XEN_PT_LOG(&s->dev, "Interrupt pin read from hardware is out of range:"
+                   " value=%i, acceptable range is 1 - 4\n", r_val);
+        r_val = 0;
+    } else {
+        r_val -= 1;
+    }
+
+    return r_val;
+}
+
+#endif /* !XEN_PT_H */

hw/xen_pt_config_init.c

@@ -0,0 +1,11 @@
+#include "xen_pt.h"
+
+XenPTRegGroup *xen_pt_find_reg_grp(XenPCIPassthroughState *s, uint32_t address)
+{
+    return NULL;
+}
+
+XenPTReg *xen_pt_find_reg(XenPTRegGroup *reg_grp, uint32_t address)
+{
+    return NULL;
+}

xen-all.c

@@ -1191,3 +1191,15 @@ void xen_register_framebuffer(MemoryRegion *mr)
 {
     framebuffer = mr;
 }
+
+void xen_shutdown_fatal_error(const char *fmt, ...)
+{
+    va_list ap;
+
+    va_start(ap, fmt);
+    vfprintf(stderr, fmt, ap);
+    va_end(ap);
+    fprintf(stderr, "Will destroy the domain.\n");
+    /* destroy the domain */
+    qemu_system_shutdown_request();
+}