On 12/2/19 9:26 AM, Michal Privoznik wrote:
We have this beautiful function that does crystal ball divination. The function is named qemuDomainGetMemLockLimitBytes() and it calculates the upper limit of how much locked memory is given guest going to need. The function bases its guess on devices defined for a domain. For instance, if there is a VFIO hostdev defined then it adds 1GiB to the guessed maximum. Since NVMe disks are pretty much VFIO hostdevs (but not quite), we have to do the same sorcery.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> ACKed-by: Peter Krempa <pkrempa@redhat.com> --- src/qemu/qemu_domain.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
For the patch as-is Reviewed-by: Cole Robinson <crobinso@redhat.com> But...
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index 59e98de2d2..7b515b9520 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -11920,6 +11920,9 @@ getPPC64MemLockLimitBytes(virDomainDefPtr def) } }
+ if (virDomainDefHasNVMeDisk(def)) + usesVFIO = true; +
We have qemuDomainNeedsVFIO which helpully captures these rules. Looks the logic has already diverged for ppc here because it doesn't consider IsMdev devices. Something for a future patch - Cole
memory = virDomainDefGetMemoryTotal(def);
if (def->mem.max_memory) @@ -12018,6 +12021,7 @@ unsigned long long qemuDomainGetMemLockLimitBytes(virDomainDefPtr def) { unsigned long long memKB = 0; + bool usesVFIO = false; size_t i;
/* prefer the hard limit */ @@ -12058,11 +12062,17 @@ qemuDomainGetMemLockLimitBytes(virDomainDefPtr def) for (i = 0; i < def->nhostdevs; i++) { if (virHostdevIsVFIODevice(def->hostdevs[i]) || virHostdevIsMdevDevice(def->hostdevs[i])) { - memKB = virDomainDefGetMemoryTotal(def) + 1024 * 1024; - goto done; + usesVFIO = true; + break; } }
+ if (virDomainDefHasNVMeDisk(def)) + usesVFIO = true; + + if (usesVFIO) + memKB = virDomainDefGetMemoryTotal(def) + 1024 * 1024; + done: return memKB << 10; }
- Cole