Introduce a per-device fixed-bars property that allows users to provide
fixed PCI BAR addresses for PCI endpoint devices.
The fixed-bars property cannot be supported on hot-plugged PCI devices.
PCI BARs for the hot-plugged device are programmed by the guest at the
time the device appears.
Property format:
- Comma-separated list of BAR entries, each as:
barN@<addr>[,barM@<addr>]*
- Example:
-device vfio-pci,...,fixed-bars=bar2@0x6b8000000000
- Multiple BARs:
-device vfio-pci,host=...,id=dev0
-set dev0.fixed-bars=bar0@0x400000000000,bar4@0x410000000000
Signed-off-by: Tushar Dave <tdave@nvidia.com>
---
hw/pci/pci.c | 108 ++++++++++++++++++++++++++++++++++++
include/hw/pci/pci_device.h | 10 ++++
2 files changed, 118 insertions(+)
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 2c3657d00d..054fc2c0fa 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -50,6 +50,7 @@
#include "hw/core/boards.h"
#include "hw/nvram/fw_cfg.h"
#include "qapi/error.h"
+#include "qapi/util.h"
#include "qemu/cutils.h"
#include "pci-internal.h"
@@ -81,6 +82,7 @@ static const Property pci_props[] = {
DEFINE_PROP_STRING("romfile", PCIDevice, romfile),
DEFINE_PROP_UINT32("romsize", PCIDevice, romsize, UINT32_MAX),
DEFINE_PROP_INT32("rombar", PCIDevice, rom_bar, -1),
+ DEFINE_PROP_STRING("fixed-bars", PCIDevice, fixed_bars),
DEFINE_PROP_BIT("multifunction", PCIDevice, cap_present,
QEMU_PCI_CAP_MULTIFUNCTION_BITNR, false),
DEFINE_PROP_BIT("x-pcie-lnksta-dllla", PCIDevice, cap_present,
@@ -218,6 +220,103 @@ static void pci_bus_unrealize(BusState *qbus)
vmstate_unregister(NULL, &vmstate_pcibus, bus);
}
+#define FIXED_BARS_ERR "fixed-bars: expected barN@<addr>[,barM@<addr>]*; "
+
+static int pci_parse_bar_token(const char *tok, Error **errp)
+{
+ int v = qapi_enum_parse(&OffAutoPCIBAR_lookup, tok, -1, errp);
+
+ if (v < 0) {
+ return -1;
+ }
+ if (v < OFF_AUTO_PCIBAR_BAR0) {
+ error_setg(errp, FIXED_BARS_ERR "invalid BAR '%s', expected bar0..bar5", tok);
+ return -1;
+ }
+ return v - OFF_AUTO_PCIBAR_BAR0;
+}
+
+/*
+ * Parse fixed-bars=barN@<addr>[,barM@<addr>]*
+ * BAR type, size, and alignment validation is deferred to the allocator,
+ * which has the full device context needed to perform those checks.
+ * On error, sets *@errp.
+ */
+static void pci_parse_fixed_bars(PCIDevice *pci_dev, Error **errp)
+{
+ Error *local_err = NULL;
+ char **entries = NULL;
+ char **parts = NULL;
+ const char *endp;
+ char **e;
+ uint64_t bar_addr;
+ int index;
+ int i, ret;
+
+ if (!pci_dev->fixed_bars || !*pci_dev->fixed_bars) {
+ return;
+ }
+ if (DEVICE(pci_dev)->hotplugged) {
+ error_setg(&local_err,
+ "fixed-bars is not supported on hot-plugged PCI devices");
+ goto out;
+ }
+
+ entries = g_strsplit(pci_dev->fixed_bars, ",", -1);
+ for (e = entries; e && *e; e++) {
+ const char *entry = g_strstrip(*e);
+ if (*entry == '\0') {
+ error_setg(&local_err, FIXED_BARS_ERR "empty field in list");
+ goto out;
+ }
+
+ parts = g_strsplit(entry, "@", 2);
+ if (!parts[0] || !parts[1]) {
+ error_setg(&local_err, FIXED_BARS_ERR "not '%s'", entry);
+ goto out;
+ }
+
+ index = pci_parse_bar_token(parts[0], &local_err);
+ if (index < 0) {
+ goto out;
+ }
+
+ ret = qemu_strtou64(parts[1], &endp, 0, &bar_addr);
+ if (ret) {
+ error_setg(&local_err, FIXED_BARS_ERR "unparseable address in '%s'",
+ entry);
+ goto out;
+ }
+ if (*endp != '\0') {
+ error_setg(&local_err, FIXED_BARS_ERR "trailing data after address in '%s'",
+ entry);
+ goto out;
+ }
+ g_clear_pointer(&parts, g_strfreev);
+
+ if (!pci_dev->fixed_bar_addrs) {
+ pci_dev->fixed_bar_addrs = g_new(pcibus_t, PCI_NUM_REGIONS - 1);
+ for (i = 0; i < PCI_NUM_REGIONS - 1; i++) {
+ pci_dev->fixed_bar_addrs[i] = PCI_BAR_UNMAPPED;
+ }
+ }
+ if (pci_dev->fixed_bar_addrs[index] != PCI_BAR_UNMAPPED) {
+ error_setg(&local_err, FIXED_BARS_ERR "bar%d specified more than once",
+ index);
+ goto out;
+ }
+ pci_dev->fixed_bar_addrs[index] = (pcibus_t)bar_addr;
+ }
+
+out:
+ g_clear_pointer(&parts, g_strfreev);
+ g_strfreev(entries);
+ if (local_err) {
+ g_clear_pointer(&pci_dev->fixed_bar_addrs, g_free);
+ error_propagate(errp, local_err);
+ }
+}
+
static int pcibus_num(PCIBus *bus)
{
if (pci_bus_is_root(bus)) {
@@ -1473,6 +1572,8 @@ static void pci_qdev_unrealize(DeviceState *dev)
pci_del_option_rom(pci_dev);
pcie_sriov_unregister_device(pci_dev);
+ g_clear_pointer(&pci_dev->fixed_bar_addrs, g_free);
+
if (pc->exit) {
pc->exit(pci_dev);
}
@@ -2369,6 +2470,13 @@ static void pci_qdev_realize(DeviceState *qdev, Error **errp)
is_default_rom = true;
}
+ pci_parse_fixed_bars(pci_dev, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ pci_qdev_unrealize(DEVICE(pci_dev));
+ return;
+ }
+
pci_add_option_rom(pci_dev, is_default_rom, &local_err);
if (local_err) {
error_propagate(errp, local_err);
diff --git a/include/hw/pci/pci_device.h b/include/hw/pci/pci_device.h
index 5cac6e1688..3e46876985 100644
--- a/include/hw/pci/pci_device.h
+++ b/include/hw/pci/pci_device.h
@@ -179,6 +179,16 @@ struct PCIDevice {
char *failover_pair_id;
uint32_t acpi_index;
+ /*
+ * When fixed-bars property is in use, fixed_bar_addrs is non-NULL
+ * and has PCI_NUM_REGIONS - 1 elements (bar0..bar5); each slot is
+ * either PCI_BAR_UNMAPPED (no fixed address for that BAR) or the
+ * fixed address for that BAR. NULL if the property is unused/empty
+ * or the map is not yet allocated.
+ */
+ char *fixed_bars;
+ pcibus_t *fixed_bar_addrs;
+
/*
* Indirect DMA region bounce buffer size as configured for the device. This
* is a configuration parameter that is reflected into bus_master_as when
--
2.34.1