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From: Mukesh R <mrathor@linux.microsoft.com>
To: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Cc: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org,
	decui@microsoft.com, longli@microsoft.com,
	linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/4] mshv: Introduce hv_deposit_memory helper functions
Date: Mon, 26 Jan 2026 18:06:23 -0800	[thread overview]
Message-ID: <df21ce10-3cd5-9d78-a3ce-84c4b1ff9275@linux.microsoft.com> (raw)
In-Reply-To: <aXacAQP3gjZ1gSLs@skinsburskii.localdomain>

On 1/25/26 14:41, Stanislav Kinsburskii wrote:
> On Fri, Jan 23, 2026 at 04:33:39PM -0800, Mukesh R wrote:
>> On 1/22/26 17:35, Stanislav Kinsburskii wrote:
>>> Introduce hv_deposit_memory_node() and hv_deposit_memory() helper
>>> functions to handle memory deposition with proper error handling.
>>>
>>> The new hv_deposit_memory_node() function takes the hypervisor status
>>> as a parameter and validates it before depositing pages. It checks for
>>> HV_STATUS_INSUFFICIENT_MEMORY specifically and returns an error for
>>> unexpected status codes.
>>>
>>> This is a precursor patch to new out-of-memory error codes support.
>>> No functional changes intended.
>>>
>>> Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
>>> ---
>>>    drivers/hv/hv_proc.c           |   22 ++++++++++++++++++++--
>>>    drivers/hv/mshv_root_hv_call.c |   25 +++++++++----------------
>>>    drivers/hv/mshv_root_main.c    |    3 +--
>>>    include/asm-generic/mshyperv.h |   10 ++++++++++
>>>    4 files changed, 40 insertions(+), 20 deletions(-)
>>>
>>> diff --git a/drivers/hv/hv_proc.c b/drivers/hv/hv_proc.c
>>> index 80c66d1c74d5..c0c2bfc80d77 100644
>>> --- a/drivers/hv/hv_proc.c
>>> +++ b/drivers/hv/hv_proc.c
>>> @@ -110,6 +110,23 @@ int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages)
>>>    }
>>>    EXPORT_SYMBOL_GPL(hv_call_deposit_pages);
>>> +int hv_deposit_memory_node(int node, u64 partition_id,
>>> +			   u64 hv_status)
>>> +{
>>> +	u32 num_pages;
>>> +
>>> +	switch (hv_result(hv_status)) {
>>> +	case HV_STATUS_INSUFFICIENT_MEMORY:
>>> +		num_pages = 1;
>>> +		break;
>>> +	default:
>>> +		hv_status_err(hv_status, "Unexpected!\n");
>>> +		return -ENOMEM;
>>> +	}
>>> +	return hv_call_deposit_pages(node, partition_id, num_pages);
>>> +}
>>> +EXPORT_SYMBOL_GPL(hv_deposit_memory_node);
>>> +
>>
>> Different hypercalls may want to deposit different number of pages in one
>> shot. As feature evolves, page sizes get mixed, we'd almost need that
>> flexibility. So, imo, either we just don't do this for now, or add num pages
>> parameter to be passed down.
>>
> 
> What you do mean by "page sizes get mixed"?
> A helper to deposit num pages already exists: its
> hv_call_deposit_pages().

My point, you are removing number of pages, and we may want to keep
that so one can quickly play around and change them.

-                       ret = hv_call_deposit_pages(NUMA_NO_NODE,
-                                                   pt_id, 1);
+                       ret = hv_deposit_memory(pt_id, status);

For example, in hv_call_initialize_partition() we may realize after
some analysis that depositing 2 pages or 4 pages is much better.

> Thanks,
> Stanislav
> 
>> Thanks,
>> -Mukesh
>>
>>
>>
>>>    bool hv_result_oom(u64 status)
>>>    {
>>>    	switch (hv_result(status)) {
>>> @@ -155,7 +172,8 @@ int hv_call_add_logical_proc(int node, u32 lp_index, u32 apic_id)
>>>    			}
>>>    			break;
>>>    		}
>>> -		ret = hv_call_deposit_pages(node, hv_current_partition_id, 1);
>>> +		ret = hv_deposit_memory_node(node, hv_current_partition_id,
>>> +					     status);
>>>    	} while (!ret);
>>>    	return ret;
>>> @@ -197,7 +215,7 @@ int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags)
>>>    			}
>>>    			break;
>>>    		}
>>> -		ret = hv_call_deposit_pages(node, partition_id, 1);
>>> +		ret = hv_deposit_memory_node(node, partition_id, status);
>>>    	} while (!ret);
>>> diff --git a/drivers/hv/mshv_root_hv_call.c b/drivers/hv/mshv_root_hv_call.c
>>> index 58c5cbf2e567..06f2bac8039d 100644
>>> --- a/drivers/hv/mshv_root_hv_call.c
>>> +++ b/drivers/hv/mshv_root_hv_call.c
>>> @@ -123,8 +123,7 @@ int hv_call_create_partition(u64 flags,
>>>    			break;
>>>    		}
>>>    		local_irq_restore(irq_flags);
>>> -		ret = hv_call_deposit_pages(NUMA_NO_NODE,
>>> -					    hv_current_partition_id, 1);
>>> +		ret = hv_deposit_memory(hv_current_partition_id, status);
>>>    	} while (!ret);
>>>    	return ret;
>>> @@ -151,7 +150,7 @@ int hv_call_initialize_partition(u64 partition_id)
>>>    			ret = hv_result_to_errno(status);
>>>    			break;
>>>    		}
>>> -		ret = hv_call_deposit_pages(NUMA_NO_NODE, partition_id, 1);
>>> +		ret = hv_deposit_memory(partition_id, status);
>>>    	} while (!ret);
>>>    	return ret;
>>> @@ -465,8 +464,7 @@ int hv_call_get_vp_state(u32 vp_index, u64 partition_id,
>>>    		}
>>>    		local_irq_restore(flags);
>>> -		ret = hv_call_deposit_pages(NUMA_NO_NODE,
>>> -					    partition_id, 1);
>>> +		ret = hv_deposit_memory(partition_id, status);
>>>    	} while (!ret);
>>>    	return ret;
>>> @@ -525,8 +523,7 @@ int hv_call_set_vp_state(u32 vp_index, u64 partition_id,
>>>    		}
>>>    		local_irq_restore(flags);
>>> -		ret = hv_call_deposit_pages(NUMA_NO_NODE,
>>> -					    partition_id, 1);
>>> +		ret = hv_deposit_memory(partition_id, status);
>>>    	} while (!ret);
>>>    	return ret;
>>> @@ -573,7 +570,7 @@ static int hv_call_map_vp_state_page(u64 partition_id, u32 vp_index, u32 type,
>>>    		local_irq_restore(flags);
>>> -		ret = hv_call_deposit_pages(NUMA_NO_NODE, partition_id, 1);
>>> +		ret = hv_deposit_memory(partition_id, status);
>>>    	} while (!ret);
>>>    	return ret;
>>> @@ -722,8 +719,7 @@ hv_call_create_port(u64 port_partition_id, union hv_port_id port_id,
>>>    			ret = hv_result_to_errno(status);
>>>    			break;
>>>    		}
>>> -		ret = hv_call_deposit_pages(NUMA_NO_NODE, port_partition_id, 1);
>>> -
>>> +		ret = hv_deposit_memory(port_partition_id, status);
>>>    	} while (!ret);
>>>    	return ret;
>>> @@ -776,8 +772,7 @@ hv_call_connect_port(u64 port_partition_id, union hv_port_id port_id,
>>>    			ret = hv_result_to_errno(status);
>>>    			break;
>>>    		}
>>> -		ret = hv_call_deposit_pages(NUMA_NO_NODE,
>>> -					    connection_partition_id, 1);
>>> +		ret = hv_deposit_memory(connection_partition_id, status);
>>>    	} while (!ret);
>>>    	return ret;
>>> @@ -848,8 +843,7 @@ static int hv_call_map_stats_page2(enum hv_stats_object_type type,
>>>    			break;
>>>    		}
>>> -		ret = hv_call_deposit_pages(NUMA_NO_NODE,
>>> -					    hv_current_partition_id, 1);
>>> +		ret = hv_deposit_memory(hv_current_partition_id, status);
>>>    	} while (!ret);
>>>    	return ret;
>>> @@ -885,8 +879,7 @@ static int hv_call_map_stats_page(enum hv_stats_object_type type,
>>>    			return ret;
>>>    		}
>>> -		ret = hv_call_deposit_pages(NUMA_NO_NODE,
>>> -					    hv_current_partition_id, 1);
>>> +		ret = hv_deposit_memory(hv_current_partition_id, status);
>>>    		if (ret)
>>>    			return ret;
>>>    	} while (!ret);
>>> diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c
>>> index f4697497f83e..5fc572e31cd7 100644
>>> --- a/drivers/hv/mshv_root_main.c
>>> +++ b/drivers/hv/mshv_root_main.c
>>> @@ -264,8 +264,7 @@ static int mshv_ioctl_passthru_hvcall(struct mshv_partition *partition,
>>>    		if (!hv_result_oom(status))
>>>    			ret = hv_result_to_errno(status);
>>>    		else
>>> -			ret = hv_call_deposit_pages(NUMA_NO_NODE,
>>> -						    pt_id, 1);
>>> +			ret = hv_deposit_memory(pt_id, status);
>>>    	} while (!ret);
>>>    	args.status = hv_result(status);
>>> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
>>> index b73352a7fc9e..c8e8976839f8 100644
>>> --- a/include/asm-generic/mshyperv.h
>>> +++ b/include/asm-generic/mshyperv.h
>>> @@ -344,6 +344,7 @@ static inline bool hv_parent_partition(void)
>>>    }
>>>    bool hv_result_oom(u64 status);
>>> +int hv_deposit_memory_node(int node, u64 partition_id, u64 status);
>>>    int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages);
>>>    int hv_call_add_logical_proc(int node, u32 lp_index, u32 acpi_id);
>>>    int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags);
>>> @@ -353,6 +354,10 @@ static inline bool hv_root_partition(void) { return false; }
>>>    static inline bool hv_l1vh_partition(void) { return false; }
>>>    static inline bool hv_parent_partition(void) { return false; }
>>>    static inline bool hv_result_oom(u64 status) { return false; }
>>> +static inline int hv_deposit_memory_node(int node, u64 partition_id, u64 status)
>>> +{
>>> +	return -EOPNOTSUPP;
>>> +}
>>>    static inline int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages)
>>>    {
>>>    	return -EOPNOTSUPP;
>>> @@ -367,6 +372,11 @@ static inline int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u3
>>>    }
>>>    #endif /* CONFIG_MSHV_ROOT */
>>> +static inline int hv_deposit_memory(u64 partition_id, u64 status)
>>> +{
>>> +	return hv_deposit_memory_node(NUMA_NO_NODE, partition_id, status);
>>> +}
>>> +
>>>    #if IS_ENABLED(CONFIG_HYPERV_VTL_MODE)
>>>    u8 __init get_vtl(void);
>>>    #else
>>>
>>>


  reply	other threads:[~2026-01-27  2:06 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-01-23  1:35 [PATCH 0/4] Improve Hyper-V memory deposit error handling Stanislav Kinsburskii
2026-01-23  1:35 ` [PATCH 1/4] mshv: Introduce hv_result_oom() helper function Stanislav Kinsburskii
2026-01-24  0:31   ` Mukesh R
2026-01-23  1:35 ` [PATCH 2/4] mshv: Introduce hv_deposit_memory helper functions Stanislav Kinsburskii
2026-01-24  0:33   ` Mukesh R
2026-01-25 22:41     ` Stanislav Kinsburskii
2026-01-27  2:06       ` Mukesh R [this message]
2026-01-27 18:30         ` Stanislav Kinsburskii
2026-01-27 19:44           ` Mukesh R
2026-01-28 23:18             ` Stanislav Kinsburskii
2026-01-30  2:49               ` Mukesh R
2026-01-23  1:35 ` [PATCH 3/4] mshv: Handle insufficient contiguous memory hypervisor status Stanislav Kinsburskii
2026-01-23  1:35 ` [PATCH 4/4] mshv: Handle insufficient root memory hypervisor statuses Stanislav Kinsburskii

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