vfio-pci: Test device reset capabilities

Not all resets are created equal.  PM reset is not very reliable,
especially for GPUs, so we might want to opt for a bus reset if a
standard reset will only do a D3hot->D0 transition.  We can also
use this to tell if the standard reset will do a bus reset (if
neither has_pm_reset or has_flr is probed, but the device still
supports reset).

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This commit is contained in:
Alex Williamson 2013-10-02 12:52:38 -06:00
parent c7679d450e
commit befe5176ef

View file

@ -185,6 +185,8 @@ typedef struct VFIODevice {
bool reset_works;
bool has_vga;
bool pci_aer;
bool has_flr;
bool has_pm_reset;
} VFIODevice;
typedef struct VFIOGroup {
@ -2513,6 +2515,42 @@ static int vfio_setup_pcie_cap(VFIODevice *vdev, int pos, uint8_t size)
return pos;
}
static void vfio_check_pcie_flr(VFIODevice *vdev, uint8_t pos)
{
uint32_t cap = pci_get_long(vdev->pdev.config + pos + PCI_EXP_DEVCAP);
if (cap & PCI_EXP_DEVCAP_FLR) {
DPRINTF("%04x:%02x:%02x.%x Supports FLR via PCIe cap\n",
vdev->host.domain, vdev->host.bus, vdev->host.slot,
vdev->host.function);
vdev->has_flr = true;
}
}
static void vfio_check_pm_reset(VFIODevice *vdev, uint8_t pos)
{
uint16_t csr = pci_get_word(vdev->pdev.config + pos + PCI_PM_CTRL);
if (!(csr & PCI_PM_CTRL_NO_SOFT_RESET)) {
DPRINTF("%04x:%02x:%02x.%x Supports PM reset\n",
vdev->host.domain, vdev->host.bus, vdev->host.slot,
vdev->host.function);
vdev->has_pm_reset = true;
}
}
static void vfio_check_af_flr(VFIODevice *vdev, uint8_t pos)
{
uint8_t cap = pci_get_byte(vdev->pdev.config + pos + PCI_AF_CAP);
if ((cap & PCI_AF_CAP_TP) && (cap & PCI_AF_CAP_FLR)) {
DPRINTF("%04x:%02x:%02x.%x Supports FLR via AF cap\n",
vdev->host.domain, vdev->host.bus, vdev->host.slot,
vdev->host.function);
vdev->has_flr = true;
}
}
static int vfio_add_std_cap(VFIODevice *vdev, uint8_t pos)
{
PCIDevice *pdev = &vdev->pdev;
@ -2557,13 +2595,21 @@ static int vfio_add_std_cap(VFIODevice *vdev, uint8_t pos)
ret = vfio_setup_msi(vdev, pos);
break;
case PCI_CAP_ID_EXP:
vfio_check_pcie_flr(vdev, pos);
ret = vfio_setup_pcie_cap(vdev, pos, size);
break;
case PCI_CAP_ID_MSIX:
ret = vfio_setup_msix(vdev, pos);
break;
case PCI_CAP_ID_PM:
vfio_check_pm_reset(vdev, pos);
vdev->pm_cap = pos;
ret = pci_add_capability(pdev, cap_id, pos, size);
break;
case PCI_CAP_ID_AF:
vfio_check_af_flr(vdev, pos);
ret = pci_add_capability(pdev, cap_id, pos, size);
break;
default:
ret = pci_add_capability(pdev, cap_id, pos, size);
break;