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) <parri.andrea@gmail.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210201144814.2701-5-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
This commit is contained in:
Andrea Parri (Microsoft) 2021-02-01 15:48:14 +01:00 committed by Wei Liu
parent 7ef4b2f0d9
commit 96854bbda2
1 changed files with 16 additions and 2 deletions

View File

@ -22,6 +22,7 @@
#include <linux/prefetch.h>
#include <asm/sync_bitops.h>
#include <asm/mshyperv.h>
#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;
}
}