Introduce Xen PCI Passthrough, MSI

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

Signed-off-by: Jiang Yunhong <yunhong.jiang@intel.com>
Signed-off-by: Shan Haitao <haitao.shan@intel.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

1 files changed, 620 insertions, 0 deletions

diff --git a/hw/xen_pt_msi.c b/hw/xen_pt_msi.c
new file mode 100644
index 0000000..2299cc7
--- /dev/null
+++ b/hw/xen_pt_msi.c
@@ -0,0 +1,620 @@
+/*
+ * Copyright (c) 2007, Intel Corporation.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ * Jiang Yunhong <yunhong.jiang@intel.com>
+ *
+ * This file implements direct PCI assignment to a HVM guest
+ */
+
+#include <sys/mman.h>
+
+#include "xen_backend.h"
+#include "xen_pt.h"
+#include "apic-msidef.h"
+
+
+#define XEN_PT_AUTO_ASSIGN -1
+
+/* shift count for gflags */
+#define XEN_PT_GFLAGS_SHIFT_DEST_ID        0
+#define XEN_PT_GFLAGS_SHIFT_RH             8
+#define XEN_PT_GFLAGS_SHIFT_DM             9
+#define XEN_PT_GFLAGSSHIFT_DELIV_MODE     12
+#define XEN_PT_GFLAGSSHIFT_TRG_MODE       15
+
+
+/*
+ * Helpers
+ */
+
+static inline uint8_t msi_vector(uint32_t data)
+{
+    return (data & MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
+}
+
+static inline uint8_t msi_dest_id(uint32_t addr)
+{
+    return (addr & MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
+}
+
+static inline uint32_t msi_ext_dest_id(uint32_t addr_hi)
+{
+    return addr_hi & 0xffffff00;
+}
+
+static uint32_t msi_gflags(uint32_t data, uint64_t addr)
+{
+    uint32_t result = 0;
+    int rh, dm, dest_id, deliv_mode, trig_mode;
+
+    rh = (addr >> MSI_ADDR_REDIRECTION_SHIFT) & 0x1;
+    dm = (addr >> MSI_ADDR_DEST_MODE_SHIFT) & 0x1;
+    dest_id = msi_dest_id(addr);
+    deliv_mode = (data >> MSI_DATA_DELIVERY_MODE_SHIFT) & 0x7;
+    trig_mode = (data >> MSI_DATA_TRIGGER_SHIFT) & 0x1;
+
+    result = dest_id | (rh << XEN_PT_GFLAGS_SHIFT_RH)
+        | (dm << XEN_PT_GFLAGS_SHIFT_DM)
+        | (deliv_mode << XEN_PT_GFLAGSSHIFT_DELIV_MODE)
+        | (trig_mode << XEN_PT_GFLAGSSHIFT_TRG_MODE);
+
+    return result;
+}
+
+static inline uint64_t msi_addr64(XenPTMSI *msi)
+{
+    return (uint64_t)msi->addr_hi << 32 | msi->addr_lo;
+}
+
+static int msi_msix_enable(XenPCIPassthroughState *s,
+                           uint32_t address,
+                           uint16_t flag,
+                           bool enable)
+{
+    uint16_t val = 0;
+
+    if (!address) {
+        return -1;
+    }
+
+    xen_host_pci_get_word(&s->real_device, address, &val);
+    if (enable) {
+        val |= flag;
+    } else {
+        val &= ~flag;
+    }
+    xen_host_pci_set_word(&s->real_device, address, val);
+    return 0;
+}
+
+static int msi_msix_setup(XenPCIPassthroughState *s,
+                          uint64_t addr,
+                          uint32_t data,
+                          int *ppirq,
+                          bool is_msix,
+                          int msix_entry,
+                          bool is_not_mapped)
+{
+    uint8_t gvec = msi_vector(data);
+    int rc = 0;
+
+    assert((!is_msix && msix_entry == 0) || is_msix);
+
+    if (gvec == 0) {
+        /* if gvec is 0, the guest is asking for a particular pirq that
+         * is passed as dest_id */
+        *ppirq = msi_ext_dest_id(addr >> 32) | msi_dest_id(addr);
+        if (!*ppirq) {
+            /* this probably identifies an misconfiguration of the guest,
+             * try the emulated path */
+            *ppirq = XEN_PT_UNASSIGNED_PIRQ;
+        } else {
+            XEN_PT_LOG(&s->dev, "requested pirq %d for MSI%s"
+                       " (vec: %#x, entry: %#x)\n",
+                       *ppirq, is_msix ? "-X" : "", gvec, msix_entry);
+        }
+    }
+
+    if (is_not_mapped) {
+        uint64_t table_base = 0;
+
+        if (is_msix) {
+            table_base = s->msix->table_base;
+        }
+
+        rc = xc_physdev_map_pirq_msi(xen_xc, xen_domid, XEN_PT_AUTO_ASSIGN,
+                                     ppirq, PCI_DEVFN(s->real_device.dev,
+                                                      s->real_device.func),
+                                     s->real_device.bus,
+                                     msix_entry, table_base);
+        if (rc) {
+            XEN_PT_ERR(&s->dev,
+                       "Mapping of MSI%s (rc: %i, vec: %#x, entry %#x)\n",
+                       is_msix ? "-X" : "", rc, gvec, msix_entry);
+            return rc;
+        }
+    }
+
+    return 0;
+}
+static int msi_msix_update(XenPCIPassthroughState *s,
+                           uint64_t addr,
+                           uint32_t data,
+                           int pirq,
+                           bool is_msix,
+                           int msix_entry,
+                           int *old_pirq)
+{
+    PCIDevice *d = &s->dev;
+    uint8_t gvec = msi_vector(data);
+    uint32_t gflags = msi_gflags(data, addr);
+    int rc = 0;
+    uint64_t table_addr = 0;
+
+    XEN_PT_LOG(d, "Updating MSI%s with pirq %d gvec %#x gflags %#x"
+               " (entry: %#x)\n",
+               is_msix ? "-X" : "", pirq, gvec, gflags, msix_entry);
+
+    if (is_msix) {
+        table_addr = s->msix->mmio_base_addr;
+    }
+
+    rc = xc_domain_update_msi_irq(xen_xc, xen_domid, gvec,
+                                  pirq, gflags, table_addr);
+
+    if (rc) {
+        XEN_PT_ERR(d, "Updating of MSI%s failed. (rc: %d)\n",
+                   is_msix ? "-X" : "", rc);
+
+        if (xc_physdev_unmap_pirq(xen_xc, xen_domid, *old_pirq)) {
+            XEN_PT_ERR(d, "Unmapping of MSI%s pirq %d failed.\n",
+                       is_msix ? "-X" : "", *old_pirq);
+        }
+        *old_pirq = XEN_PT_UNASSIGNED_PIRQ;
+    }
+    return rc;
+}
+
+static int msi_msix_disable(XenPCIPassthroughState *s,
+                            uint64_t addr,
+                            uint32_t data,
+                            int pirq,
+                            bool is_msix,
+                            bool is_binded)
+{
+    PCIDevice *d = &s->dev;
+    uint8_t gvec = msi_vector(data);
+    uint32_t gflags = msi_gflags(data, addr);
+    int rc = 0;
+
+    if (pirq == XEN_PT_UNASSIGNED_PIRQ) {
+        return 0;
+    }
+
+    if (is_binded) {
+        XEN_PT_LOG(d, "Unbind MSI%s with pirq %d, gvec %#x\n",
+                   is_msix ? "-X" : "", pirq, gvec);
+        rc = xc_domain_unbind_msi_irq(xen_xc, xen_domid, gvec, pirq, gflags);
+        if (rc) {
+            XEN_PT_ERR(d, "Unbinding of MSI%s failed. (pirq: %d, gvec: %#x)\n",
+                       is_msix ? "-X" : "", pirq, gvec);
+            return rc;
+        }
+    }
+
+    XEN_PT_LOG(d, "Unmap MSI%s pirq %d\n", is_msix ? "-X" : "", pirq);
+    rc = xc_physdev_unmap_pirq(xen_xc, xen_domid, pirq);
+    if (rc) {
+        XEN_PT_ERR(d, "Unmapping of MSI%s pirq %d failed. (rc: %i)\n",
+                   is_msix ? "-X" : "", pirq, rc);
+        return rc;
+    }
+
+    return 0;
+}
+
+/*
+ * MSI virtualization functions
+ */
+
+int xen_pt_msi_set_enable(XenPCIPassthroughState *s, bool enable)
+{
+    XEN_PT_LOG(&s->dev, "%s MSI.\n", enable ? "enabling" : "disabling");
+
+    if (!s->msi) {
+        return -1;
+    }
+
+    return msi_msix_enable(s, s->msi->ctrl_offset, PCI_MSI_FLAGS_ENABLE,
+                           enable);
+}
+
+/* setup physical msi, but don't enable it */
+int xen_pt_msi_setup(XenPCIPassthroughState *s)
+{
+    int pirq = XEN_PT_UNASSIGNED_PIRQ;
+    int rc = 0;
+    XenPTMSI *msi = s->msi;
+
+    if (msi->initialized) {
+        XEN_PT_ERR(&s->dev,
+                   "Setup physical MSI when it has been properly initialized.\n");
+        return -1;
+    }
+
+    rc = msi_msix_setup(s, msi_addr64(msi), msi->data, &pirq, false, 0, true);
+    if (rc) {
+        return rc;
+    }
+
+    if (pirq < 0) {
+        XEN_PT_ERR(&s->dev, "Invalid pirq number: %d.\n", pirq);
+        return -1;
+    }
+
+    msi->pirq = pirq;
+    XEN_PT_LOG(&s->dev, "MSI mapped with pirq %d.\n", pirq);
+
+    return 0;
+}
+
+int xen_pt_msi_update(XenPCIPassthroughState *s)
+{
+    XenPTMSI *msi = s->msi;
+    return msi_msix_update(s, msi_addr64(msi), msi->data, msi->pirq,
+                           false, 0, &msi->pirq);
+}
+
+void xen_pt_msi_disable(XenPCIPassthroughState *s)
+{
+    XenPTMSI *msi = s->msi;
+
+    if (!msi) {
+        return;
+    }
+
+    xen_pt_msi_set_enable(s, false);
+
+    msi_msix_disable(s, msi_addr64(msi), msi->data, msi->pirq, false,
+                     msi->initialized);
+
+    /* clear msi info */
+    msi->flags = 0;
+    msi->mapped = false;
+    msi->pirq = XEN_PT_UNASSIGNED_PIRQ;
+}
+
+/*
+ * MSI-X virtualization functions
+ */
+
+static int msix_set_enable(XenPCIPassthroughState *s, bool enabled)
+{
+    XEN_PT_LOG(&s->dev, "%s MSI-X.\n", enabled ? "enabling" : "disabling");
+
+    if (!s->msix) {
+        return -1;
+    }
+
+    return msi_msix_enable(s, s->msix->ctrl_offset, PCI_MSIX_FLAGS_ENABLE,
+                           enabled);
+}
+
+static int xen_pt_msix_update_one(XenPCIPassthroughState *s, int entry_nr)
+{
+    XenPTMSIXEntry *entry = NULL;
+    int pirq;
+    int rc;
+
+    if (entry_nr < 0 || entry_nr >= s->msix->total_entries) {
+        return -EINVAL;
+    }
+
+    entry = &s->msix->msix_entry[entry_nr];
+
+    if (!entry->updated) {
+        return 0;
+    }
+
+    pirq = entry->pirq;
+
+    rc = msi_msix_setup(s, entry->data, entry->data, &pirq, true, entry_nr,
+                        entry->pirq == XEN_PT_UNASSIGNED_PIRQ);
+    if (rc) {
+        return rc;
+    }
+    if (entry->pirq == XEN_PT_UNASSIGNED_PIRQ) {
+        entry->pirq = pirq;
+    }
+
+    rc = msi_msix_update(s, entry->addr, entry->data, pirq, true,
+                         entry_nr, &entry->pirq);
+
+    if (!rc) {
+        entry->updated = false;
+    }
+
+    return rc;
+}
+
+int xen_pt_msix_update(XenPCIPassthroughState *s)
+{
+    XenPTMSIX *msix = s->msix;
+    int i;
+
+    for (i = 0; i < msix->total_entries; i++) {
+        xen_pt_msix_update_one(s, i);
+    }
+
+    return 0;
+}
+
+void xen_pt_msix_disable(XenPCIPassthroughState *s)
+{
+    int i = 0;
+
+    msix_set_enable(s, false);
+
+    for (i = 0; i < s->msix->total_entries; i++) {
+        XenPTMSIXEntry *entry = &s->msix->msix_entry[i];
+
+        msi_msix_disable(s, entry->addr, entry->data, entry->pirq, true, true);
+
+        /* clear MSI-X info */
+        entry->pirq = XEN_PT_UNASSIGNED_PIRQ;
+        entry->updated = false;
+    }
+}
+
+int xen_pt_msix_update_remap(XenPCIPassthroughState *s, int bar_index)
+{
+    XenPTMSIXEntry *entry;
+    int i, ret;
+
+    if (!(s->msix && s->msix->bar_index == bar_index)) {
+        return 0;
+    }
+
+    for (i = 0; i < s->msix->total_entries; i++) {
+        entry = &s->msix->msix_entry[i];
+        if (entry->pirq != XEN_PT_UNASSIGNED_PIRQ) {
+            ret = xc_domain_unbind_pt_irq(xen_xc, xen_domid, entry->pirq,
+                                          PT_IRQ_TYPE_MSI, 0, 0, 0, 0);
+            if (ret) {
+                XEN_PT_ERR(&s->dev, "unbind MSI-X entry %d failed\n",
+                           entry->pirq);
+            }
+            entry->updated = true;
+        }
+    }
+    return xen_pt_msix_update(s);
+}
+
+static uint32_t get_entry_value(XenPTMSIXEntry *e, int offset)
+{
+    switch (offset) {
+    case PCI_MSIX_ENTRY_LOWER_ADDR:
+        return e->addr & UINT32_MAX;
+    case PCI_MSIX_ENTRY_UPPER_ADDR:
+        return e->addr >> 32;
+    case PCI_MSIX_ENTRY_DATA:
+        return e->data;
+    case PCI_MSIX_ENTRY_VECTOR_CTRL:
+        return e->vector_ctrl;
+    default:
+        return 0;
+    }
+}
+
+static void set_entry_value(XenPTMSIXEntry *e, int offset, uint32_t val)
+{
+    switch (offset) {
+    case PCI_MSIX_ENTRY_LOWER_ADDR:
+        e->addr = (e->addr & ((uint64_t)UINT32_MAX << 32)) | val;
+        break;
+    case PCI_MSIX_ENTRY_UPPER_ADDR:
+        e->addr = (uint64_t)val << 32 | (e->addr & UINT32_MAX);
+        break;
+    case PCI_MSIX_ENTRY_DATA:
+        e->data = val;
+        break;
+    case PCI_MSIX_ENTRY_VECTOR_CTRL:
+        e->vector_ctrl = val;
+        break;
+    }
+}
+
+static void pci_msix_write(void *opaque, target_phys_addr_t addr,
+                           uint64_t val, unsigned size)
+{
+    XenPCIPassthroughState *s = opaque;
+    XenPTMSIX *msix = s->msix;
+    XenPTMSIXEntry *entry;
+    int entry_nr, offset;
+
+    entry_nr = addr / PCI_MSIX_ENTRY_SIZE;
+    if (entry_nr < 0 || entry_nr >= msix->total_entries) {
+        XEN_PT_ERR(&s->dev, "asked MSI-X entry '%i' invalid!\n", entry_nr);
+        return;
+    }
+    entry = &msix->msix_entry[entry_nr];
+    offset = addr % PCI_MSIX_ENTRY_SIZE;
+
+    if (offset != PCI_MSIX_ENTRY_VECTOR_CTRL) {
+        const volatile uint32_t *vec_ctrl;
+
+        if (get_entry_value(entry, offset) == val) {
+            return;
+        }
+
+        /*
+         * If Xen intercepts the mask bit access, entry->vec_ctrl may not be
+         * up-to-date. Read from hardware directly.
+         */
+        vec_ctrl = s->msix->phys_iomem_base + entry_nr * PCI_MSIX_ENTRY_SIZE
+            + PCI_MSIX_ENTRY_VECTOR_CTRL;
+
+        if (msix->enabled && !(*vec_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT)) {
+            XEN_PT_ERR(&s->dev, "Can't update msix entry %d since MSI-X is"
+                       " already enabled.\n", entry_nr);
+            return;
+        }
+
+        entry->updated = true;
+    }
+
+    set_entry_value(entry, offset, val);
+
+    if (offset == PCI_MSIX_ENTRY_VECTOR_CTRL) {
+        if (msix->enabled && !(val & PCI_MSIX_ENTRY_CTRL_MASKBIT)) {
+            xen_pt_msix_update_one(s, entry_nr);
+        }
+    }
+}
+
+static uint64_t pci_msix_read(void *opaque, target_phys_addr_t addr,
+                              unsigned size)
+{
+    XenPCIPassthroughState *s = opaque;
+    XenPTMSIX *msix = s->msix;
+    int entry_nr, offset;
+
+    entry_nr = addr / PCI_MSIX_ENTRY_SIZE;
+    if (entry_nr < 0) {
+        XEN_PT_ERR(&s->dev, "asked MSI-X entry '%i' invalid!\n", entry_nr);
+        return 0;
+    }
+
+    offset = addr % PCI_MSIX_ENTRY_SIZE;
+
+    if (addr < msix->total_entries * PCI_MSIX_ENTRY_SIZE) {
+        return get_entry_value(&msix->msix_entry[entry_nr], offset);
+    } else {
+        /* Pending Bit Array (PBA) */
+        return *(uint32_t *)(msix->phys_iomem_base + addr);
+    }
+}
+
+static const MemoryRegionOps pci_msix_ops = {
+    .read = pci_msix_read,
+    .write = pci_msix_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+    .valid = {
+        .min_access_size = 4,
+        .max_access_size = 4,
+        .unaligned = false,
+    },
+};
+
+int xen_pt_msix_init(XenPCIPassthroughState *s, uint32_t base)
+{
+    uint8_t id = 0;
+    uint16_t control = 0;
+    uint32_t table_off = 0;
+    int i, total_entries, bar_index;
+    XenHostPCIDevice *hd = &s->real_device;
+    PCIDevice *d = &s->dev;
+    int fd = -1;
+    XenPTMSIX *msix = NULL;
+    int rc = 0;
+
+    rc = xen_host_pci_get_byte(hd, base + PCI_CAP_LIST_ID, &id);
+    if (rc) {
+        return rc;
+    }
+
+    if (id != PCI_CAP_ID_MSIX) {
+        XEN_PT_ERR(d, "Invalid id %#x base %#x\n", id, base);
+        return -1;
+    }
+
+    xen_host_pci_get_word(hd, base + PCI_MSIX_FLAGS, &control);
+    total_entries = control & PCI_MSIX_FLAGS_QSIZE;
+    total_entries += 1;
+
+    s->msix = g_malloc0(sizeof (XenPTMSIX)
+                        + total_entries * sizeof (XenPTMSIXEntry));
+    msix = s->msix;
+
+    msix->total_entries = total_entries;
+    for (i = 0; i < total_entries; i++) {
+        msix->msix_entry[i].pirq = XEN_PT_UNASSIGNED_PIRQ;
+    }
+
+    memory_region_init_io(&msix->mmio, &pci_msix_ops, s, "xen-pci-pt-msix",
+                          (total_entries * PCI_MSIX_ENTRY_SIZE
+                           + XC_PAGE_SIZE - 1)
+                          & XC_PAGE_MASK);
+
+    xen_host_pci_get_long(hd, base + PCI_MSIX_TABLE, &table_off);
+    bar_index = msix->bar_index = table_off & PCI_MSIX_FLAGS_BIRMASK;
+    table_off = table_off & ~PCI_MSIX_FLAGS_BIRMASK;
+    msix->table_base = s->real_device.io_regions[bar_index].base_addr;
+    XEN_PT_LOG(d, "get MSI-X table BAR base 0x%"PRIx64"\n", msix->table_base);
+
+    fd = open("/dev/mem", O_RDWR);
+    if (fd == -1) {
+        rc = -errno;
+        XEN_PT_ERR(d, "Can't open /dev/mem: %s\n", strerror(errno));
+        goto error_out;
+    }
+    XEN_PT_LOG(d, "table_off = %#x, total_entries = %d\n",
+               table_off, total_entries);
+    msix->table_offset_adjust = table_off & 0x0fff;
+    msix->phys_iomem_base =
+        mmap(NULL,
+             total_entries * PCI_MSIX_ENTRY_SIZE + msix->table_offset_adjust,
+             PROT_READ,
+             MAP_SHARED | MAP_LOCKED,
+             fd,
+             msix->table_base + table_off - msix->table_offset_adjust);
+    close(fd);
+    if (msix->phys_iomem_base == MAP_FAILED) {
+        rc = -errno;
+        XEN_PT_ERR(d, "Can't map physical MSI-X table: %s\n", strerror(errno));
+        goto error_out;
+    }
+    msix->phys_iomem_base = (char *)msix->phys_iomem_base
+        + msix->table_offset_adjust;
+
+    XEN_PT_LOG(d, "mapping physical MSI-X table to %p\n",
+               msix->phys_iomem_base);
+
+    memory_region_add_subregion_overlap(&s->bar[bar_index], table_off,
+                                        &msix->mmio,
+                                        2); /* Priority: pci default + 1 */
+
+    return 0;
+
+error_out:
+    memory_region_destroy(&msix->mmio);
+    g_free(s->msix);
+    s->msix = NULL;
+    return rc;
+}
+
+void xen_pt_msix_delete(XenPCIPassthroughState *s)
+{
+    XenPTMSIX *msix = s->msix;
+
+    if (!msix) {
+        return;
+    }
+
+    /* unmap the MSI-X memory mapped register area */
+    if (msix->phys_iomem_base) {
+        XEN_PT_LOG(&s->dev, "unmapping physical MSI-X table from %p\n",
+                   msix->phys_iomem_base);
+        munmap(msix->phys_iomem_base, msix->total_entries * PCI_MSIX_ENTRY_SIZE
+               + msix->table_offset_adjust);
+    }
+
+    memory_region_del_subregion(&s->bar[msix->bar_index], &msix->mmio);
+    memory_region_destroy(&msix->mmio);
+
+    g_free(s->msix);
+    s->msix = NULL;
+}