Yuji Shimada writes ("[Xen-devel] [PATCH 2/2] ioemu: Enable guest OS to program
D0-D3hot states of an assigned device"):
> This patch enables guest OS to program D0-D3hot states of assigned
> device.
I applied this patch but unfortunately it broke the automatic test
(and thus the staging propagation) because our automatic test system
has a very old version of libpci. I have applied a band-aid - see
below - but would you please review it and consider whether a
different fix would be correct ? For example, we might copy the
definitions of PCI_ERR_* from the libpci headers into pass-through.h
protected by an #ifdef, or something.
Also, this logic is very very strange:
> + int aer_size = 0x2c;
> +
> + for (i=0; i < aer_size; i+=4)
> + {
> + switch (i) {
> + /* after reset, following register values should be restored.
> + * So, save them.
> + */
> + case PCI_ERR_UNCOR_MASK:
> + case PCI_ERR_UNCOR_SEVER:
> + case PCI_ERR_COR_MASK:
> + case PCI_ERR_CAP:
> + *(uint32_t*)(d->config + (aer_base + i))
> + = pci_read_long(ptdev->pci_dev, (aer_base + i));
> + break;
> + default:
> + break;
> + }
> + }
What purpose does the loop serve ? Is there an ordering constraint ?
There are two copies of this construct, too - one in the save and one
in the restore. That duplication is rather unfortunate.
Thanks,
Ian.
commit b80fc65b715099ee28465f6571eb5242588ef246
Author: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Date: Fri Feb 6 16:16:06 2009 +0000
hw/pass-through.c: workaround for old libpci
Old versions of libpci (including the ones on the automatic tests
which control Xen staging propagation) do not define
PCI_LIB_VERSION or the PCI_ERR_{UNCOR_MASK,...} constants.
This means that change 8c771eb6294afc5b3754a9e3de51568d4e5986c2 breaks
the build. In this changeset I apply what is intended to be a
workaround for this problem but it may not be completely correct; this
is therefore perhaps an interim fix.
The potential problem is that the save/restore of some PCI passthrough
error handling registers (across suspend/resume) may not work properly
with old versions of libpci. However non-passthrough and non-suspect
use cases should now be fine.
Signed-off-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
diff --git a/hw/pass-through.c b/hw/pass-through.c
index 8dfae3c..29714c7 100644
--- a/hw/pass-through.c
+++ b/hw/pass-through.c
@@ -1503,7 +1503,7 @@ exit:
static void pt_libpci_fixup(struct pci_dev *dev)
{
-#if PCI_LIB_VERSION < 0x030100
+#if !defined(PCI_LIB_VERSION) || PCI_LIB_VERSION < 0x030100
int i;
FILE *fp;
char path[PATH_MAX], buf[256];
@@ -1850,6 +1850,7 @@ static void pt_aer_reg_save(struct pt_dev *ptdev)
/* Root Port and Root Complex Event Collector need size expansion */
int aer_size = 0x2c;
+#ifdef PCI_ERR_UNCOR_MASK
for (i=0; i < aer_size; i+=4)
{
switch (i) {
@@ -1867,6 +1868,7 @@ static void pt_aer_reg_save(struct pt_dev *ptdev)
break;
}
}
+#endif
}
/* restore AER register */
@@ -1879,6 +1881,7 @@ static void pt_aer_reg_restore(struct pt_dev *ptdev)
/* Root Port and Root Complex Event Collector need size expansion */
int aer_size = 0x2c;
+#ifdef PCI_ERR_UNCOR_MASK
for (i=0; i < aer_size; i+=4)
{
switch (i) {
@@ -1899,6 +1902,7 @@ static void pt_aer_reg_restore(struct pt_dev *ptdev)
break;
}
}
+#endif
}
/* reset Interrupt and I/O resource */
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