domain_validate: Check for domain address conflicts fully

Current implementation of virDomainMemoryDefCheckConflict() does
only a one way comparison, i.e. if there's a memory device within
def->mems[] which address falls in [mem->address, mem->address +
mem->size] range (mem is basically an iterator within
def->mems[]). And for static XML this works just fine. Problem is
with hot/cold plugging of a memory device. Then mem points to
freshly parsed memory device and these half checks are
insufficient. Not only we must check whether an existing memory
device doesn't clash with freshly parsed memory device, but also
whether freshly parsed memory device does not fall into range of
already existing memory device.

Resolves: https://issues.redhat.com/browse/RHEL-4452
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>

diff --git a/src/conf/domain_validate.c b/src/conf/domain_validate.c
index d485ec4fb1131b6af5670fd6ffacc52fd4603eb3..46479f10f2a6884842d4d295f00e91f2d24d2c23 100644 (file)
--- a/src/conf/domain_validate.c
+++ b/src/conf/domain_validate.c
@@ -2264,6 +2264,7 @@ virDomainMemoryDefCheckConflict(const virDomainMemoryDef *mem,
     for (i = 0; i < def->nmems; i++) {
         const virDomainMemoryDef *other = def->mems[i];
         unsigned long long otherStart = 0;
+        unsigned long long otherEnd = 0;
 
         if (other == mem)
             continue;
@@ -2315,7 +2316,10 @@ virDomainMemoryDefCheckConflict(const virDomainMemoryDef *mem,
         if (thisStart == 0 || otherStart == 0)
             continue;
 
-        if (thisStart <= otherStart && thisEnd > otherStart) {
+        otherEnd = otherStart + other->size * 1024;
+
+        if ((thisStart <= otherStart && thisEnd > otherStart) ||
+            (otherStart <= thisStart && otherEnd > thisStart)) {
             virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                            _("memory device address [0x%1$llx:0x%2$llx] overlaps with other memory device (0x%3$llx)"),
                            thisStart, thisEnd, otherStart);