NuKVM/libvirt
3
0
Fork 0
mirror of https://github.com/libvirt/libvirt.git synced 2025-02-25 18:55:26 -06:00
Code Issues Packages Projects Releases Wiki Activity

xen: clean up the mess with cpumap

Browse Source 
Commit 8b55992f added some Coverity comments to silence what was
a real bug in the code.  Since then, we've had a miserable run
of trying to fix the underlying problem (commits c059cde and
ba5193c), and still have a problem on 32-bit machines.

This fixes the problem for once and for all, by realizing that
on older xen, cpumap_t is identical to uint64_t, and using the
new virendian.h to do the transformation from the API (documented
to be little-endian) to the host structure.

* src/xen/xen_hypervisor.c (virXen_setvcpumap): Do the conversion
correctly.  Finally.
This commit is contained in:
Eric Blake 2013-02-11 17:02:00 -07:00
parent 731ad69240
commit 069b5c5a58
1 changed files with 6 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
src/xen/xen_hypervisor.c
View File

@ -80,6 +80,7 @@
#include "virfile.h" #include "virfile.h"
#include "virnodesuspend.h" #include "virnodesuspend.h"
#include "virtypedparam.h" #include "virtypedparam.h"
#include "virendian.h"
#define VIR_FROM_THIS VIR_FROM_XEN #define VIR_FROM_THIS VIR_FROM_XEN
@ -1773,18 +1774,13 @@ virXen_setvcpumap(int handle,
ret = -1; ret = -1;
} else { } else {
cpumap_t xen_cpumap; /* limited to 64 CPUs in old hypervisors */ cpumap_t xen_cpumap; /* limited to 64 CPUs in old hypervisors */
uint64_t *pm = &xen_cpumap; char buf[8] = "";
int j;
if ((maplen > (int)sizeof(cpumap_t)) || (sizeof(cpumap_t) & 7)) if (maplen > sizeof(cpumap_t) || sizeof(cpumap_t) != sizeof(uint64_t))
return -1; return -1;
/* Supply trailing 0s if user's input array was short */
memset(&xen_cpumap, 0, sizeof(cpumap_t)); memcpy(buf, cpumap, maplen);
for (j = 0; j < maplen; j++) { xen_cpumap = virReadBufInt64LE(buf);
if ((j & 7) == 0)
pm = (uint64_t *)((uint64_t)&xen_cpumap + (j & ~0x7UL));
*pm |= (uint64_t)cpumap[j] << (8 * (j & 7));
}
if (hv_versions.hypervisor == 1) { if (hv_versions.hypervisor == 1) {
xen_op_v1 op; xen_op_v1 op;