[libvirt] [PATCH 02/14] Retain disk PCI address across libvirtd restarts
Mark McLoughlin
markmc at redhat.com
Mon Jul 20 17:05:40 UTC 2009
On Mon, 2009-07-20 at 16:38 +0200, Daniel Veillard wrote:
> On Mon, Jul 20, 2009 at 03:05:31PM +0100, Mark McLoughlin wrote:
> > On Mon, 2009-07-20 at 14:42 +0100, Daniel P. Berrange wrote:
> > > On Mon, Jul 20, 2009 at 12:51:12PM +0100, Mark McLoughlin wrote:
> > > > When we hot-plug a disk device into a qemu guest, we need to retain its
> > > > PCI address so that it can be removed again later. Currently, we do
> > > > retain the slot number, but not across libvirtd restarts.
> > > >
> > > > Add <state devaddr="xxxx:xx:xx"/> to the disk device XML config when the
> > > > VIR_DOMAIN_XML_INTERNAL_STATUS flag is used. We still don't parse the
> > > > domain and bus number, but the format allows us to do that in future.
> > > >
> > > > * src/domain_conf.h: replace slotnum with pci_addr
> > > >
> > >
> > >
> > > > diff --git a/src/domain_conf.h b/src/domain_conf.h
> > > > index 6e111fa..1766b61 100644
> > > > --- a/src/domain_conf.h
> > > > +++ b/src/domain_conf.h
> > > > @@ -106,7 +106,7 @@ struct _virDomainDiskDef {
> > > > int cachemode;
> > > > unsigned int readonly : 1;
> > > > unsigned int shared : 1;
> > > > - int slotnum; /* pci slot number for unattach */
> > > > + char *pci_addr; /* for detach */
> > > > };
> > >
> > > I think it'd be nicer to store the parsed address here as a
> > > nested struct with domain, bus, slot.
>
> I understand dan 'here' as in the C struct not in the XML
>
> > > It is not really saving us trouble by using a string, since most
> > > of the places using this field end up asprintf'ing it into another
> > > string, or even having to extract pieces out of it again.
> >
> > It's saving us trouble because you don't have to code the equivalent of
> > virDomainHostdevSubsysPciDefParseXML() and have e.g.
> >
> > <state>
> > <address domain="0" bus="0" slot="5"/>
> > </state>
> >
> > I just now started to do it and then realized how much extra hassle the
> > XML parsing was going to be. All for some internal data that we use in
> > textual format anyway. Are you sure? :-)
>
> Well a single string in the XML is fine, but in the parsed Def let's
> keep the bits as fully parsed, i.e. the set of ints we extract in patch
> 12/14
> Agreed with Dan,
> Agreed that separating them in the XML will make the code way more
> complex especially for error handling.
Okay, here's how that looks.
Personally, I think even this much adds complexity (parsing the devaddr
param from the XML, re-formatting it in several places, not being able
to just check pci_addr != NULL) without much benefit.
Cheers,
Mark.
From: Mark McLoughlin <markmc at redhat.com>
Subject: [PATCH 02/14] Retain disk PCI address across libvirtd restarts
When we hot-plug a disk device into a qemu guest, we need to retain its
PCI address so that it can be removed again later. Currently, we do
retain the slot number, but not across libvirtd restarts.
Add <state devaddr="xxxx:xx:xx"/> to the disk device XML config when the
VIR_DOMAIN_XML_INTERNAL_STATUS flag is used. We still don't parse the
domain and bus number, but the format allows us to do that in future.
* src/domain_conf.h: replace slotnum with pci_addr struct, add helper
for testing whether the address is valid
* src/domain_conf.c: handle formatting and parsing the address
* src/qemu_driver.c: store the parsed slot number as a full PCI address,
and use this address with the pci_del monitor command
* src/vbox/vbox_tmpl.c: we're debug printing slotnum here even though
it can never be set, just delete it
---
src/domain_conf.c | 33 ++++++++++++++++++++++++++++++---
src/domain_conf.h | 12 +++++++++++-
src/qemu_driver.c | 36 ++++++++++++++++++++++++------------
src/vbox/vbox_tmpl.c | 1 -
4 files changed, 65 insertions(+), 17 deletions(-)
diff --git a/src/domain_conf.c b/src/domain_conf.c
index 10e6ac6..91a6c6e 100644
--- a/src/domain_conf.c
+++ b/src/domain_conf.c
@@ -643,7 +643,7 @@ int virDomainDiskCompare(virDomainDiskDefPtr a,
static virDomainDiskDefPtr
virDomainDiskDefParseXML(virConnectPtr conn,
xmlNodePtr node,
- int flags ATTRIBUTE_UNUSED) {
+ int flags) {
virDomainDiskDefPtr def;
xmlNodePtr cur;
char *type = NULL;
@@ -654,6 +654,7 @@ virDomainDiskDefParseXML(virConnectPtr conn,
char *target = NULL;
char *bus = NULL;
char *cachetag = NULL;
+ char *devaddr = NULL;
if (VIR_ALLOC(def) < 0) {
virReportOOMError(conn);
@@ -708,6 +709,9 @@ virDomainDiskDefParseXML(virConnectPtr conn,
def->readonly = 1;
} else if (xmlStrEqual(cur->name, BAD_CAST "shareable")) {
def->shared = 1;
+ } else if ((flags & VIR_DOMAIN_XML_INTERNAL_STATUS) &&
+ xmlStrEqual(cur->name, BAD_CAST "state")) {
+ devaddr = virXMLPropString(cur, "devaddr");
}
}
cur = cur->next;
@@ -807,6 +811,17 @@ virDomainDiskDefParseXML(virConnectPtr conn,
goto error;
}
+ if (devaddr &&
+ sscanf(devaddr, "%x:%x:%x",
+ &def->pci_addr.domain,
+ &def->pci_addr.bus,
+ &def->pci_addr.slot) < 3) {
+ virDomainReportError(conn, VIR_ERR_INTERNAL_ERROR,
+ _("Unable to parse devaddr parameter '%s'"),
+ devaddr);
+ goto error;
+ }
+
def->src = source;
source = NULL;
def->dst = target;
@@ -825,6 +840,7 @@ cleanup:
VIR_FREE(driverType);
VIR_FREE(driverName);
VIR_FREE(cachetag);
+ VIR_FREE(devaddr);
return def;
@@ -3388,7 +3404,8 @@ virDomainLifecycleDefFormat(virConnectPtr conn,
static int
virDomainDiskDefFormat(virConnectPtr conn,
virBufferPtr buf,
- virDomainDiskDefPtr def)
+ virDomainDiskDefPtr def,
+ int flags)
{
const char *type = virDomainDiskTypeToString(def->type);
const char *device = virDomainDiskDeviceTypeToString(def->device);
@@ -3446,6 +3463,16 @@ virDomainDiskDefFormat(virConnectPtr conn,
if (def->shared)
virBufferAddLit(buf, " <shareable/>\n");
+ if (flags & VIR_DOMAIN_XML_INTERNAL_STATUS) {
+ virBufferAddLit(buf, " <state");
+ if (virDiskHasValidPciAddr(def))
+ virBufferVSprintf(buf, " devaddr='%.4x:%.2x:%.2x'",
+ def->pci_addr.domain,
+ def->pci_addr.bus,
+ def->pci_addr.slot);
+ virBufferAddLit(buf, "/>\n");
+ }
+
virBufferAddLit(buf, " </disk>\n");
return 0;
@@ -4048,7 +4075,7 @@ char *virDomainDefFormat(virConnectPtr conn,
def->emulator);
for (n = 0 ; n < def->ndisks ; n++)
- if (virDomainDiskDefFormat(conn, &buf, def->disks[n]) < 0)
+ if (virDomainDiskDefFormat(conn, &buf, def->disks[n], flags) < 0)
goto cleanup;
for (n = 0 ; n < def->nfss ; n++)
diff --git a/src/domain_conf.h b/src/domain_conf.h
index 69b665f..c0fdd65 100644
--- a/src/domain_conf.h
+++ b/src/domain_conf.h
@@ -111,9 +111,19 @@ struct _virDomainDiskDef {
int cachemode;
unsigned int readonly : 1;
unsigned int shared : 1;
- int slotnum; /* pci slot number for unattach */
+ struct {
+ unsigned domain;
+ unsigned bus;
+ unsigned slot;
+ } pci_addr;
};
+static inline int
+virDiskHasValidPciAddr(virDomainDiskDefPtr def)
+{
+ return def->pci_addr.domain || def->pci_addr.domain || def->pci_addr.slot;
+}
+
/* Two types of disk backends */
enum virDomainFSType {
diff --git a/src/qemu_driver.c b/src/qemu_driver.c
index 00dc6e5..a87ef70 100644
--- a/src/qemu_driver.c
+++ b/src/qemu_driver.c
@@ -4390,6 +4390,8 @@ try_command:
return -1;
}
+ VIR_FREE(cmd);
+
DEBUG ("%s: pci_add reply: %s", vm->def->name, reply);
/* If the command succeeds qemu prints:
* OK bus 0, slot XXX...
@@ -4399,22 +4401,25 @@ try_command:
if ((s = strstr(reply, "OK ")) &&
(s = strstr(s, "slot "))) {
char *dummy = s;
+ unsigned slot;
+
s += strlen("slot ");
- if (virStrToLong_i ((const char*)s, &dummy, 10, &dev->data.disk->slotnum) == -1)
+ if (virStrToLong_ui((const char*)s, &dummy, 10, &slot) == -1)
VIR_WARN("%s", _("Unable to parse slot number\n"));
+
/* XXX not neccessarily always going to end up in domain 0 / bus 0 :-( */
- /* XXX this slotnum is not persistant across restarts :-( */
+ dev->data.disk->pci_addr.domain = 0;
+ dev->data.disk->pci_addr.bus = 0;
+ dev->data.disk->pci_addr.slot = slot;
} else if (!tryOldSyntax && strstr(reply, "invalid char in expression")) {
VIR_FREE(reply);
- VIR_FREE(cmd);
tryOldSyntax = 1;
goto try_command;
} else {
qemudReportError (conn, dom, NULL, VIR_ERR_OPERATION_FAILED,
_("adding %s disk failed: %s"), type, reply);
VIR_FREE(reply);
- VIR_FREE(cmd);
return -1;
}
@@ -4423,7 +4428,7 @@ try_command:
virDomainDiskQSort);
VIR_FREE(reply);
- VIR_FREE(cmd);
+
return 0;
}
@@ -4660,21 +4665,24 @@ static int qemudDomainDetachPciDiskDevice(virConnectPtr conn,
goto cleanup;
}
- if (detach->slotnum < 1) {
+ if (!virDiskHasValidPciAddr(detach)) {
qemudReportError(conn, NULL, NULL, VIR_ERR_OPERATION_FAILED,
- _("disk %s cannot be detached - invalid slot number %d"),
- detach->dst, detach->slotnum);
+ _("disk %s cannot be detached - no PCI address for device"),
+ detach->dst);
goto cleanup;
}
try_command:
if (tryOldSyntax) {
- if (virAsprintf(&cmd, "pci_del 0 %d", detach->slotnum) < 0) {
+ if (virAsprintf(&cmd, "pci_del 0 %.2x", detach->pci_addr.slot) < 0) {
virReportOOMError(conn);
goto cleanup;
}
} else {
- if (virAsprintf(&cmd, "pci_del pci_addr=0:0:%d", detach->slotnum) < 0) {
+ if (virAsprintf(&cmd, "pci_del pci_addr=%.4x:%.2x:%.2x",
+ detach->pci_addr.domain,
+ detach->pci_addr.bus,
+ detach->pci_addr.slot) < 0) {
virReportOOMError(conn);
goto cleanup;
}
@@ -4698,8 +4706,12 @@ try_command:
if (strstr(reply, "invalid slot") ||
strstr(reply, "Invalid pci address")) {
qemudReportError (conn, NULL, NULL, VIR_ERR_OPERATION_FAILED,
- _("failed to detach disk %s: invalid slot %d: %s"),
- detach->dst, detach->slotnum, reply);
+ _("failed to detach disk %s: invalid PCI address %.4x:%.2x:%.2x: %s"),
+ detach->dst,
+ detach->pci_addr.domain,
+ detach->pci_addr.bus,
+ detach->pci_addr.slot,
+ reply);
goto cleanup;
}
diff --git a/src/vbox/vbox_tmpl.c b/src/vbox/vbox_tmpl.c
index 3208f03..a2b958a 100644
--- a/src/vbox/vbox_tmpl.c
+++ b/src/vbox/vbox_tmpl.c
@@ -2712,7 +2712,6 @@ static virDomainPtr vboxDomainDefineXML(virConnectPtr conn, const char *xml) {
DEBUG("disk(%d) cachemode: %d", i, def->disks[i]->cachemode);
DEBUG("disk(%d) readonly: %s", i, def->disks[i]->readonly ? "True" : "False");
DEBUG("disk(%d) shared: %s", i, def->disks[i]->shared ? "True" : "False");
- DEBUG("disk(%d) slotnum: %d", i, def->disks[i]->slotnum);
if (def->disks[i]->device == VIR_DOMAIN_DISK_DEVICE_CDROM) {
if (def->disks[i]->type == VIR_DOMAIN_DISK_TYPE_FILE) {
--
1.6.2.5
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