On Fri, Feb 06, 2026 at 06:54:55PM +0000, Michael Kelley wrote: > From: Stanislav Kinsburskii <[email protected]> Sent: > Thursday, February 5, 2026 10:42 AM > > To: [email protected]; [email protected]; [email protected]; > > [email protected]; [email protected] > > Cc: [email protected]; [email protected] > > Subject: [PATCH v3 4/4] mshv: Handle insufficient root memory hypervisor > > statuses > > > > When creating guest partition objects, the hypervisor may fail to > > allocate root partition pages and return an insufficient memory status. > > In this case, deposit memory using the root partition ID instead. > > > > Note: This error should never occur in a guest of L1VH partition context. > > > > Signed-off-by: Stanislav Kinsburskii <[email protected]> > > --- > > drivers/hv/hv_common.c | 2 + > > drivers/hv/hv_proc.c | 14 ++++++++++ > > include/hyperv/hvgdk_mini.h | 58 > > ++++++++++++++++++++++--------------------- > > 3 files changed, 46 insertions(+), 28 deletions(-) > > > > diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c > > index f20596276662..6b67ac616789 100644 > > --- a/drivers/hv/hv_common.c > > +++ b/drivers/hv/hv_common.c > > @@ -794,6 +794,8 @@ static const struct hv_status_info hv_status_infos[] = { > > _STATUS_INFO(HV_STATUS_PROPERTY_VALUE_OUT_OF_RANGE, -EIO), > > _STATUS_INFO(HV_STATUS_INSUFFICIENT_MEMORY, -ENOMEM), > > _STATUS_INFO(HV_STATUS_INSUFFICIENT_CONTIGUOUS_MEMORY, -ENOMEM), > > + _STATUS_INFO(HV_STATUS_INSUFFICIENT_ROOT_MEMORY, -ENOMEM), > > + _STATUS_INFO(HV_STATUS_INSUFFICIENT_CONTIGUOUS_ROOT_MEMORY, > > -ENOMEM), > > _STATUS_INFO(HV_STATUS_INVALID_PARTITION_ID, -EINVAL), > > _STATUS_INFO(HV_STATUS_INVALID_VP_INDEX, -EINVAL), > > _STATUS_INFO(HV_STATUS_NOT_FOUND, -EIO), > > diff --git a/drivers/hv/hv_proc.c b/drivers/hv/hv_proc.c > > index 181f6d02bce3..5f4fd9c3231c 100644 > > --- a/drivers/hv/hv_proc.c > > +++ b/drivers/hv/hv_proc.c > > @@ -121,6 +121,18 @@ int hv_deposit_memory_node(int node, u64 partition_id, > > case HV_STATUS_INSUFFICIENT_CONTIGUOUS_MEMORY: > > num_pages = HV_MAX_CONTIGUOUS_ALLOCATION_PAGES; > > break; > > + > > + case HV_STATUS_INSUFFICIENT_CONTIGUOUS_ROOT_MEMORY: > > + num_pages = HV_MAX_CONTIGUOUS_ALLOCATION_PAGES; > > + fallthrough; > > + case HV_STATUS_INSUFFICIENT_ROOT_MEMORY: > > + if (!hv_root_partition()) { > > + hv_status_err(hv_status, "Unexpected root memory > > deposit\n"); > > + return -ENOMEM; > > + } > > + partition_id = HV_PARTITION_ID_SELF; > > + break; > > + > > Per the discussion in v1 of this patch set, if the number of pages that > should be > deposited in a particular situation is different from what this function > provides, > the fallback is to use hv_call_deposit_pages() directly. From what I see, > there's > only one such fallback case after a hypercall failure -- in > hv_do_map_gpa_hcall(). > The other uses of hv_call_deposit_pages() are initial deposits when creating a > VP or partition. > > But if hv_call_deposit_pages() is used directly, the logic added here to > detect > insufficient root memory and deposit to HV_PARTITION_ID_SELF isn't applied. > So if the hypercall in hv_do_map_gpa_hcall() fails with insufficient root > memory, the deposit is done to the wrong partition ID. If that case can > actually happen, then some additional logic is needed in > hv_do_map_gpa_hcall() to handle it. Or there needs to be a fallback > function that contains the logic.
Stanislav, how about this comment? Please submit a follow-up patch if necessary. Wei > > Other than that, everything else in this patch set looks good to me. > > Michael > > > default: > > hv_status_err(hv_status, "Unexpected!\n"); > > return -ENOMEM;
