On 11/01/2010 10:35 AM, Daniel P. Berrange wrote:
On Fri, Oct 29, 2010 at 11:19:50AM -0600, Eric Blake wrote:
diff --git a/src/xen/xend_internal.c b/src/xen/xend_internal.c index 974e96b..614c036 100644 --- a/src/xen/xend_internal.c +++ b/src/xen/xend_internal.c @@ -5770,10 +5770,11 @@ xenDaemonFormatSxpr(virConnectPtr conn, virBufferVSprintf(&buf, "(memory %lu)(maxmem %lu)", def->mem.cur_balloon/1024, def->mem.max_balloon/1024); virBufferVSprintf(&buf, "(vcpus %u)", def->maxvcpus); - /* Computing the vcpu_avail bitmask works because MAX_VIRT_CPUS is 32. */ - verify(MAX_VIRT_CPUS <= sizeof(1U) * CHAR_BIT); + /* Computing the vcpu_avail bitmask works because MAX_VIRT_CPUS is + either 32, or 64 on a platform where long is big enough. */ + verify(MAX_VIRT_CPUS <= sizeof(1UL) * CHAR_BIT); if (def->vcpus < def->maxvcpus) - virBufferVSprintf(&buf, "(vcpu_avail %u)", (1U << def->vcpus) - 1); + virBufferVSprintf(&buf, "(vcpu_avail %lu)", (1UL << def->vcpus) - 1);
if (def->cpumask) { char *ranges = virDomainCpuSetFormat(def->cpumask, def->cpumasklen);
This chunk causes a compile error for me
CC libvirt_driver_xen_la-xend_internal.lo cc1: warnings being treated as errors xen/xend_internal.c: In function 'xenDaemonFormatSxpr': xen/xend_internal.c:5775: error: nested extern declaration of 'verify_function2' [-Wnested-externs] make[3]: *** [libvirt_driver_xen_la-xend_internal.lo] Error 1
Which version of gcc? This may be a bug in gnulib's verify module. I tested successfully on F13, gcc 4.4.4.
Also, what was commited, looks different to this diff here
@@ -5770,9 +5770,11 @@ xenDaemonFormatSxpr(virConnectPtr conn, virBufferVSprintf(&buf, "(memory %lu)(maxmem %lu)", def->mem.cur_balloon/1024, def->mem.max_balloon/1024); virBufferVSprintf(&buf, "(vcpus %u)", def->maxvcpus); - /* Computing the vcpu_avail bitmask works because MAX_VIRT_CPUS is 32. */ + /* Computing the vcpu_avail bitmask works because MAX_VIRT_CPUS is + either 32, or 64 on a platform where long is big enough. */ + verify(MAX_VIRT_CPUS <= sizeof(1UL) * CHAR_BIT); if (def->vcpus < def->maxvcpus) - virBufferVSprintf(&buf, "(vcpu_avail %u)", (1U << def->vcpus) - 1); + virBufferVSprintf(&buf, "(vcpu_avail %lu)", (1UL << def->vcpus) - 1);
As Diego pointed out, the diff posted to this list was incomplete; it was a partial patch that I had forgotten to squash in to my first attempt. What I actually pushed was both patches squashed together; for reference, here's what the first patch was: From b67847f84d9d4e8dbad5200df247212bc14221ab Mon Sep 17 00:00:00 2001 From: Eric Blake <eblake@redhat.com> Date: Fri, 29 Oct 2010 10:51:01 -0600 Subject: [PATCH] xen: verify code assumption about MAX_VIRT_CPUS * src/xen/xend_internal.c (xenDaemonFormatSxpr): Detect if upstream xen ever changes to support 64 vcpus. * src/xen/xm_internal.c (xenXMDomainConfigFormat): Likewise. --- src/xen/xend_internal.c | 1 + src/xen/xm_internal.c | 2 ++ 2 files changed, 3 insertions(+), 0 deletions(-) diff --git a/src/xen/xend_internal.c b/src/xen/xend_internal.c index e96b762..974e96b 100644 --- a/src/xen/xend_internal.c +++ b/src/xen/xend_internal.c @@ -5771,6 +5771,7 @@ xenDaemonFormatSxpr(virConnectPtr conn, def->mem.cur_balloon/1024, def->mem.max_balloon/1024); virBufferVSprintf(&buf, "(vcpus %u)", def->maxvcpus); /* Computing the vcpu_avail bitmask works because MAX_VIRT_CPUS is 32. */ + verify(MAX_VIRT_CPUS <= sizeof(1U) * CHAR_BIT); if (def->vcpus < def->maxvcpus) virBufferVSprintf(&buf, "(vcpu_avail %u)", (1U << def->vcpus) - 1); diff --git a/src/xen/xm_internal.c b/src/xen/xm_internal.c index 430d40b..f80e252 100644 --- a/src/xen/xm_internal.c +++ b/src/xen/xm_internal.c @@ -2336,6 +2336,8 @@ virConfPtr xenXMDomainConfigFormat(virConnectPtr conn, if (xenXMConfigSetInt(conf, "vcpus", def->maxvcpus) < 0) goto no_memory; + /* Computing the vcpu_avail bitmask works because MAX_VIRT_CPUS is 32. */ + verify(MAX_VIRT_CPUS <= sizeof(1U) * CHAR_BIT); if (def->vcpus < def->maxvcpus && xenXMConfigSetInt(conf, "vcpu_avail", (1U << def->vcpus) - 1) < 0) goto no_memory; -- 1.7.2.3 -- Eric Blake eblake@redhat.com +1-801-349-2682 Libvirt virtualization library http://libvirt.org