[PATCH v2 4/6] virtio: Initialize authorized attribute for confidential guest
From: Kuppuswamy Sathyanarayanan
<sathyanarayanan.kuppuswamy@linux.intel.com>
Date: 2021-09-30 01:05:45
Also in:
linux-pci, lkml
Subsystem:
the rest, virtio core · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", Jason Wang
Confidential guest platforms like TDX have a requirement to allow only trusted devices. By default the confidential-guest core will arrange for all devices to default to unauthorized (via dev_default_authorization) in device_initialize(). Since virtio driver is already hardened against the attack from the un-trusted host, override the confidential computing default unauthorized state Reviewed-by: Dan Williams <redacted> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> --- drivers/virtio/virtio.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 588e02fb91d3..377b0ccdc503 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c@@ -5,6 +5,8 @@ #include <linux/module.h> #include <linux/idr.h> #include <linux/of.h> +#include <linux/cc_platform.h> +#include <linux/device.h> #include <uapi/linux/virtio_ids.h> /* Unique numbering for virtio devices. */
@@ -390,6 +392,13 @@ int register_virtio_device(struct virtio_device *dev) dev->config_enabled = false; dev->config_change_pending = false; + /* + * For Confidential guest (like TDX), virtio devices are + * trusted. So set authorized status as true. + */ + if (cc_platform_has(CC_ATTR_GUEST_DEVICE_FILTER)) + dev->dev.authorized = true; + /* We always start by resetting the device, in case a previous * driver messed it up. This also tests that code path a little. */ dev->config->reset(dev);
--
2.25.1