From 96854bbda24febe2cc9231e1f6ffbd3059dc57fc Mon Sep 17 00:00:00 2001 From: "Andrea Parri (Microsoft)" Date: Mon, 1 Feb 2021 15:48:14 +0100 Subject: [PATCH] hv_netvsc: Restrict configurations on isolated guests Restrict the NVSP protocol version(s) that will be negotiated with the host to be NVSP_PROTOCOL_VERSION_61 or greater if the guest is running isolated. Moreover, do not advertise the SR-IOV capability and ignore NVSP_MSG_4_TYPE_SEND_VF_ASSOCIATION messages in isolated guests, which are not supposed to support SR-IOV. This reduces the footprint of the code that will be exercised by Confidential VMs and hence the exposure to bugs and vulnerabilities. Signed-off-by: Andrea Parri (Microsoft) Acked-by: Jakub Kicinski Reviewed-by: Haiyang Zhang Cc: "David S. Miller" Cc: Jakub Kicinski Cc: netdev@vger.kernel.org Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20210201144814.2701-5-parri.andrea@gmail.com Signed-off-by: Wei Liu --- drivers/net/hyperv/netvsc.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c index 1510a236aa34..51005f2d4a82 100644 --- a/drivers/net/hyperv/netvsc.c +++ b/drivers/net/hyperv/netvsc.c @@ -22,6 +22,7 @@ #include #include +#include #include "hyperv_net.h" #include "netvsc_trace.h" @@ -544,7 +545,10 @@ static int negotiate_nvsp_ver(struct hv_device *device, init_packet->msg.v2_msg.send_ndis_config.capability.ieee8021q = 1; if (nvsp_ver >= NVSP_PROTOCOL_VERSION_5) { - init_packet->msg.v2_msg.send_ndis_config.capability.sriov = 1; + if (hv_is_isolation_supported()) + netdev_info(ndev, "SR-IOV not advertised by guests on the host supporting isolation\n"); + else + init_packet->msg.v2_msg.send_ndis_config.capability.sriov = 1; /* Teaming bit is needed to receive link speed updates */ init_packet->msg.v2_msg.send_ndis_config.capability.teaming = 1; @@ -591,6 +595,13 @@ static int netvsc_connect_vsp(struct hv_device *device, goto cleanup; } + if (hv_is_isolation_supported() && net_device->nvsp_version < NVSP_PROTOCOL_VERSION_61) { + netdev_err(ndev, "Invalid NVSP version 0x%x (expected >= 0x%x) from the host supporting isolation\n", + net_device->nvsp_version, NVSP_PROTOCOL_VERSION_61); + ret = -EPROTO; + goto cleanup; + } + pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version); /* Send the ndis version */ @@ -1357,7 +1368,10 @@ static void netvsc_receive_inband(struct net_device *ndev, break; case NVSP_MSG4_TYPE_SEND_VF_ASSOCIATION: - netvsc_send_vf(ndev, nvmsg, msglen); + if (hv_is_isolation_supported()) + netdev_err(ndev, "Ignore VF_ASSOCIATION msg from the host supporting isolation\n"); + else + netvsc_send_vf(ndev, nvmsg, msglen); break; } }