linux-kernel - Re: [PATCH hyperv-next v3 13/15] Drivers: hv: Support confidential VMBus channels

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <eaf2687e-6054-4c54-9206-9dfdad56c3e9@oracle.com>
Date: Wed, 4 Jun 2025 19:45:43 +0530
From: ALOK TIWARI <alok.a.tiwari@...cle.com>
To: Roman Kisel <romank@...ux.microsoft.com>, arnd@...db.de, bp@...en8.de,
        corbet@....net, dave.hansen@...ux.intel.com, decui@...rosoft.com,
        haiyangz@...rosoft.com, hpa@...or.com, kys@...rosoft.com,
        mingo@...hat.com, mhklinux@...look.com, tglx@...utronix.de,
        wei.liu@...nel.org, linux-arch@...r.kernel.org,
        linux-doc@...r.kernel.org, linux-hyperv@...r.kernel.org,
        linux-kernel@...r.kernel.org, x86@...nel.org
Cc: apais@...rosoft.com, benhill@...rosoft.com, bperkins@...rosoft.com,
        sunilmut@...rosoft.com
Subject: Re: [PATCH hyperv-next v3 13/15] Drivers: hv: Support confidential
 VMBus channels



On 04-06-2025 06:13, Roman Kisel wrote:
> To run a confidential VMBus channels, one has to initialize the
> co_ring_buffers and co_external_memory fields of the channel
> structure.
> 
> Advertise support upon negoatiating the version and compute
> values for those fields and initialize them.
> 
> Signed-off-by: Roman Kisel <romank@...ux.microsoft.com>
> ---
>   drivers/hv/channel_mgmt.c | 19 +++++++++++++++++++
>   drivers/hv/connection.c   |  3 +++
>   2 files changed, 22 insertions(+)
> 
> diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
> index ca2fe10c110a..33bc29e826bd 100644
> --- a/drivers/hv/channel_mgmt.c
> +++ b/drivers/hv/channel_mgmt.c
> @@ -1021,6 +1021,7 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
>   	struct vmbus_channel_offer_channel *offer;
>   	struct vmbus_channel *oldchannel, *newchannel;
>   	size_t offer_sz;
> +	bool co_ring_buffer, co_external_memory;
>   
>   	offer = (struct vmbus_channel_offer_channel *)hdr;
>   
> @@ -1033,6 +1034,22 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
>   		return;
>   	}
>   
> +	co_ring_buffer = is_co_ring_buffer(offer);
> +	if (co_ring_buffer) {
> +		if (vmbus_proto_version < VERSION_WIN10_V6_0 || !vmbus_is_confidential()) {
> +			atomic_dec(&vmbus_connection.offer_in_progress);
> +			return;
> +		}
> +	}
> +
> +	co_external_memory = is_co_external_memory(offer);
> +	if (is_co_external_memory(offer)) {

  Redundant call for is_co_external_memory()
  if(co_external_memory)

> +		if (vmbus_proto_version < VERSION_WIN10_V6_0 || !vmbus_is_confidential()) {
> +			atomic_dec(&vmbus_connection.offer_in_progress);
> +			return;
> +		}
> +	}
> +
>   	oldchannel = find_primary_channel_by_offer(offer);
>   
>   	if (oldchannel != NULL) {
> @@ -1111,6 +1128,8 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
>   		pr_err("Unable to allocate channel object\n");
>   		return;
>   	}
> +	newchannel->co_ring_buffer = co_ring_buffer;
> +	newchannel->co_external_memory = co_external_memory;
>   
>   	vmbus_setup_channel_state(newchannel, offer);
>   
> diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
> index be490c598785..eeb472019d69 100644
> --- a/drivers/hv/connection.c
> +++ b/drivers/hv/connection.c
> @@ -105,6 +105,9 @@ int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version)
>   		vmbus_connection.msg_conn_id = VMBUS_MESSAGE_CONNECTION_ID;
>   	}
>   
> +	if (vmbus_is_confidential() && version >= VERSION_WIN10_V6_0)
> +		msg->feature_flags = VMBUS_FEATURE_FLAG_CONFIDENTIAL_CHANNELS;
> +
>   	/*
>   	 * shared_gpa_boundary is zero in non-SNP VMs, so it's safe to always
>   	 * bitwise OR it


Thanks,
Alok