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pcie_sriov: Reuse SR-IOV VF device instances

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Disable SR-IOV VF devices by reusing code to power down PCI devices
instead of removing them when the guest requests to disable VFs. This
allows to realize devices and report VF realization errors at PF
realization time.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-Id: <20250116-reuse-v20-8-7cb370606368@daynix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Akihiko Odaki 2025-01-16 18:00:59 +09:00 • committed by Michael S. Tsirkin
parent 3391d68e90
commit cab1398a60
3 changed files with 51 additions and 58 deletions
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94
hw/pci/pcie_sriov.c
View file

@ -20,9 +20,16 @@
#include "qapi/error.h"
#include "trace.h"
static PCIDevice *register_vf(PCIDevice *pf, int devfn,
const char *name, uint16_t vf_num);
static void unregister_vfs(PCIDevice *dev);
static void unparent_vfs(PCIDevice *dev, uint16_t total_vfs)
{
for (uint16_t i = 0; i < total_vfs; i++) {
PCIDevice *vf = dev->exp.sriov_pf.vf[i];
object_unparent(OBJECT(vf));
object_unref(OBJECT(vf));
}
g_free(dev->exp.sriov_pf.vf);
dev->exp.sriov_pf.vf = NULL;
}
bool pcie_sriov_pf_init(PCIDevice *dev, uint16_t offset,
const char *vfname, uint16_t vf_dev_id,
@ -30,6 +37,7 @@ bool pcie_sriov_pf_init(PCIDevice *dev, uint16_t offset,
uint16_t vf_offset, uint16_t vf_stride,
Error **errp)
{
BusState *bus = qdev_get_parent_bus(&dev->qdev);
int32_t devfn = dev->devfn + vf_offset;
uint8_t *cfg = dev->config + offset;
uint8_t *wmask;
@ -44,7 +52,6 @@ bool pcie_sriov_pf_init(PCIDevice *dev, uint16_t offset,
offset, PCI_EXT_CAP_SRIOV_SIZEOF);
dev->exp.sriov_cap = offset;
dev->exp.sriov_pf.num_vfs = 0;
dev->exp.sriov_pf.vfname = g_strdup(vfname);
dev->exp.sriov_pf.vf = NULL;
pci_set_word(cfg + PCI_SRIOV_VF_OFFSET, vf_offset);
@ -78,14 +85,34 @@ bool pcie_sriov_pf_init(PCIDevice *dev, uint16_t offset,
qdev_prop_set_bit(&dev->qdev, "multifunction", true);
dev->exp.sriov_pf.vf = g_new(PCIDevice *, total_vfs);
for (uint16_t i = 0; i < total_vfs; i++) {
PCIDevice *vf = pci_new(devfn, vfname);
vf->exp.sriov_vf.pf = dev;
vf->exp.sriov_vf.vf_number = i;
if (!qdev_realize(&vf->qdev, bus, errp)) {
unparent_vfs(dev, i);
return false;
}
/* set vid/did according to sr/iov spec - they are not used */
pci_config_set_vendor_id(vf->config, 0xffff);
pci_config_set_device_id(vf->config, 0xffff);
dev->exp.sriov_pf.vf[i] = vf;
devfn += vf_stride;
}
return true;
}
void pcie_sriov_pf_exit(PCIDevice *dev)
{
unregister_vfs(dev);
g_free((char *)dev->exp.sriov_pf.vfname);
dev->exp.sriov_pf.vfname = NULL;
uint8_t *cfg = dev->config + dev->exp.sriov_cap;
unparent_vfs(dev, pci_get_word(cfg + PCI_SRIOV_TOTAL_VF));
}
void pcie_sriov_pf_init_vf_bar(PCIDevice *dev, int region_num,
@ -151,38 +178,11 @@ void pcie_sriov_vf_register_bar(PCIDevice *dev, int region_num,
}
}
static PCIDevice *register_vf(PCIDevice *pf, int devfn, const char *name,
uint16_t vf_num)
{
PCIDevice *dev = pci_new(devfn, name);
dev->exp.sriov_vf.pf = pf;
dev->exp.sriov_vf.vf_number = vf_num;
PCIBus *bus = pci_get_bus(pf);
Error *local_err = NULL;
qdev_realize(&dev->qdev, &bus->qbus, &local_err);
if (local_err) {
error_report_err(local_err);
return NULL;
}
/* set vid/did according to sr/iov spec - they are not used */
pci_config_set_vendor_id(dev->config, 0xffff);
pci_config_set_device_id(dev->config, 0xffff);
return dev;
}
static void register_vfs(PCIDevice *dev)
{
uint16_t num_vfs;
uint16_t i;
uint16_t sriov_cap = dev->exp.sriov_cap;
uint16_t vf_offset =
pci_get_word(dev->config + sriov_cap + PCI_SRIOV_VF_OFFSET);
uint16_t vf_stride =
pci_get_word(dev->config + sriov_cap + PCI_SRIOV_VF_STRIDE);
int32_t devfn = dev->devfn + vf_offset;
assert(sriov_cap > 0);
num_vfs = pci_get_word(dev->config + sriov_cap + PCI_SRIOV_NUM_VF);
@ -190,18 +190,10 @@ static void register_vfs(PCIDevice *dev)
return;
}
dev->exp.sriov_pf.vf = g_new(PCIDevice *, num_vfs);
trace_sriov_register_vfs(dev->name, PCI_SLOT(dev->devfn),
PCI_FUNC(dev->devfn), num_vfs);
for (i = 0; i < num_vfs; i++) {
dev->exp.sriov_pf.vf[i] = register_vf(dev, devfn,
dev->exp.sriov_pf.vfname, i);
if (!dev->exp.sriov_pf.vf[i]) {
num_vfs = i;
break;
}
devfn += vf_stride;
pci_set_enabled(dev->exp.sriov_pf.vf[i], true);
}
dev->exp.sriov_pf.num_vfs = num_vfs;
}
@ -214,12 +206,8 @@ static void unregister_vfs(PCIDevice *dev)
trace_sriov_unregister_vfs(dev->name, PCI_SLOT(dev->devfn),
PCI_FUNC(dev->devfn), num_vfs);
for (i = 0; i < num_vfs; i++) {
PCIDevice *vf = dev->exp.sriov_pf.vf[i];
object_unparent(OBJECT(vf));
object_unref(OBJECT(vf));
pci_set_enabled(dev->exp.sriov_pf.vf[i], false);
}
g_free(dev->exp.sriov_pf.vf);
dev->exp.sriov_pf.vf = NULL;
dev->exp.sriov_pf.num_vfs = 0;
}
@ -241,14 +229,10 @@ void pcie_sriov_config_write(PCIDevice *dev, uint32_t address,
PCI_FUNC(dev->devfn), off, val, len);
if (range_covers_byte(off, len, PCI_SRIOV_CTRL)) {
if (dev->exp.sriov_pf.num_vfs) {
if (!(val & PCI_SRIOV_CTRL_VFE)) {
unregister_vfs(dev);
}
if (val & PCI_SRIOV_CTRL_VFE) {
register_vfs(dev);
} else {
if (val & PCI_SRIOV_CTRL_VFE) {
register_vfs(dev);
}
unregister_vfs(dev);
}
}
}