Re: [PATCH 06/17] mshv: SynIC port and connection hypercalls

[Wei Liu <wei.liu@kernel.org>]

On Wed, Jun 02, 2021 at 05:20:51PM +0000, Vineeth Pillai wrote:
> Hyper-V enables inter-partition communication through the port and
> connection constructs. More details about ports and connections in
> TLFS chapter 11.
> 
> Implement hypercalls related to ports and connections for enabling
> inter-partiion communication.
> 
> Signed-off-by: Vineeth Pillai <viremana@linux.microsoft.com>
> ---
>  drivers/hv/hv_call.c                   | 161 +++++++++++++++++++++++++
>  drivers/hv/mshv.h                      |  12 ++
>  include/asm-generic/hyperv-tlfs.h      |  55 +++++++++
>  include/linux/hyperv.h                 |   9 --
>  include/uapi/asm-generic/hyperv-tlfs.h |  76 ++++++++++++
>  5 files changed, 304 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/hv/hv_call.c b/drivers/hv/hv_call.c
> index 025d4e2b892f..57db3a8ac94a 100644
> --- a/drivers/hv/hv_call.c
> +++ b/drivers/hv/hv_call.c
> @@ -742,3 +742,164 @@ int hv_call_translate_virtual_address(
>  	return hv_status_to_errno(status);
>  }
>  
> +
> +int
> +hv_call_create_port(u64 port_partition_id, union hv_port_id port_id,
> +		    u64 connection_partition_id,
> +		    struct hv_port_info *port_info,
> +		    u8 port_vtl, u8 min_connection_vtl, int node)
> +{
> +	struct hv_create_port *input;
> +	unsigned long flags;
> +	int ret = 0;
> +	int status;
> +
> +	do {
> +		local_irq_save(flags);
> +		input = (struct hv_create_port *)(*this_cpu_ptr(
> +				hyperv_pcpu_input_arg));
> +		memset(input, 0, sizeof(*input));
> +
> +		input->port_partition_id = port_partition_id;
> +		input->port_id = port_id;
> +		input->connection_partition_id = connection_partition_id;
> +		input->port_info = *port_info;
> +		input->port_vtl = port_vtl;
> +		input->min_connection_vtl = min_connection_vtl;
> +		input->proximity_domain_info =
> +			numa_node_to_proximity_domain_info(node);

This misses the check for NUMA_NO_NODE, so does the function for port
connection (see below).

I think it would actually be better to leave the check in
numa_node_to_proximity_domain_info to avoid problems like this.

Of course, adapting this approach means some call sites for that
function will need to be changed too.

---8<---
From 8705857c62b3e5f13d415736ca8b508c22e3f5ba Mon Sep 17 00:00:00 2001
From: Wei Liu <wei.liu@kernel.org>
Date: Wed, 30 Jun 2021 11:08:31 +0000
Subject: [PATCH] numa_node_to_proximity_domain_info should cope with
 NUMA_NO_NODE

Signed-off-by: Wei Liu <wei.liu@kernel.org>
---
 include/asm-generic/mshyperv.h | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index d9b91b8f63c8..44552b7a02ef 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -31,10 +31,14 @@ numa_node_to_proximity_domain_info(int node)
 {
 	union hv_proximity_domain_info proximity_domain_info;
 
-	proximity_domain_info.domain_id = node_to_pxm(node);
-	proximity_domain_info.flags.reserved = 0;
-	proximity_domain_info.flags.proximity_info_valid = 1;
-	proximity_domain_info.flags.proximity_preferred = 1;
+	proximity_domain_info.as_uint64 = 0;
+
+	if (node != NUMA_NO_NODE) {
+		proximity_domain_info.domain_id = node_to_pxm(node);
+		proximity_domain_info.flags.reserved = 0;
+		proximity_domain_info.flags.proximity_info_valid = 1;
+		proximity_domain_info.flags.proximity_preferred = 1;
+	}
 
 	return proximity_domain_info;
 }
-- 
2.30.2


[...]
> +int
> +hv_call_connect_port(u64 port_partition_id, union hv_port_id port_id,
> +		     u64 connection_partition_id,
> +		     union hv_connection_id connection_id,
> +		     struct hv_connection_info *connection_info,
> +		     u8 connection_vtl, int node)
> +{
> +	struct hv_connect_port *input;
> +	unsigned long flags;
> +	int ret = 0, status;
> +
> +	do {
> +		local_irq_save(flags);
> +		input = (struct hv_connect_port *)(*this_cpu_ptr(
> +				hyperv_pcpu_input_arg));
> +		memset(input, 0, sizeof(*input));
> +		input->port_partition_id = port_partition_id;
> +		input->port_id = port_id;
> +		input->connection_partition_id = connection_partition_id;
> +		input->connection_id = connection_id;
> +		input->connection_info = *connection_info;
> +		input->connection_vtl = connection_vtl;
> +		input->proximity_domain_info =
> +			numa_node_to_proximity_domain_info(node);

Here...