On Thu, Apr 10, 2014 at 04:29:40PM +0300, Marcel Apfelbaum wrote:
If a pci-2-pci bridge supports hot-plug functionality but there are no devices connected to it, reserve IO/mem in order to be able to attach devices later. Do not waste space, use minimum allowed.
Signed-off-by: Marcel Apfelbaum marcel.a@redhat.com
Looks good to me Reviewed-by: Michael S. Tsirkin mst@redhat.com
but let's apply with patch 2 (after it's fixed): otherwise there's no way for hypervisors to avoid wasting resources unnecessaily on bridges.
src/fw/pciinit.c | 3 +++ src/hw/pci.c | 19 +++++++++++++++++++ src/hw/pci.h | 1 + 3 files changed, 23 insertions(+)
diff --git a/src/fw/pciinit.c b/src/fw/pciinit.c index 64f1d41..9b5d7ad 100644 --- a/src/fw/pciinit.c +++ b/src/fw/pciinit.c @@ -677,12 +677,15 @@ static int pci_bios_check_devices(struct pci_bus *busses) continue; struct pci_bus *parent = &busses[pci_bdf_to_bus(s->bus_dev->bdf)]; int type;
u8 shpc_cap = pci_find_capability(s->bus_dev, PCI_CAP_ID_SHPC); for (type = 0; type < PCI_REGION_TYPE_COUNT; type++) { u64 align = (type == PCI_REGION_TYPE_IO) ? PCI_BRIDGE_IO_MIN : PCI_BRIDGE_MEM_MIN; if (pci_region_align(&s->r[type]) > align) align = pci_region_align(&s->r[type]); u64 sum = pci_region_sum(&s->r[type]);if (!sum && shpc_cap)sum = align; /* reserve min size for hot-plug */ u64 size = ALIGN(sum, align); int is64 = pci_bios_bridge_region_is64(&s->r[type], s->bus_dev, type);diff --git a/src/hw/pci.c b/src/hw/pci.c index caf9265..055353d 100644 --- a/src/hw/pci.c +++ b/src/hw/pci.c @@ -225,6 +225,25 @@ pci_find_init_device(const struct pci_device_id *ids, void *arg) return NULL; }
+u8 pci_find_capability(struct pci_device *pci, u8 cap_id) +{
- int i;
- u8 cap;
- u16 status = pci_config_readw(pci->bdf, PCI_STATUS);
- if (!(status & PCI_STATUS_CAP_LIST))
return 0;- for (i = 0, cap = pci_config_readb(pci->bdf, PCI_CAPABILITY_LIST);
(i <= 0xff) && cap;i++, cap = pci_config_readb(pci->bdf, cap + PCI_CAP_LIST_NEXT))if (pci_config_readb(pci->bdf, cap + PCI_CAP_LIST_ID) == cap_id)return cap;- return 0;
+}
void pci_reboot(void) { diff --git a/src/hw/pci.h b/src/hw/pci.h index 167a027..e828225 100644 --- a/src/hw/pci.h +++ b/src/hw/pci.h @@ -116,6 +116,7 @@ int pci_init_device(const struct pci_device_id *ids , struct pci_device *pci, void *arg); struct pci_device *pci_find_init_device(const struct pci_device_id *ids , void *arg); +u8 pci_find_capability(struct pci_device *pci, u8 cap_id); void pci_reboot(void);
#endif
1.8.3.1