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authorJuergen Gross <jgross@suse.com>2022-06-22 08:38:36 +0200
committerJuergen Gross <jgross@suse.com>2022-08-01 07:42:49 +0200
commita603002eea8213eec5211be5a85db8340aea06d0 (patch)
tree5154e240ad4f487a866e74a055671d66b8b12b6d /drivers/virtio
parentxen: Fix spelling mistake (diff)
downloadlinux-dev-a603002eea8213eec5211be5a85db8340aea06d0.tar.xz
linux-dev-a603002eea8213eec5211be5a85db8340aea06d0.zip
virtio: replace restricted mem access flag with callback
Instead of having a global flag to require restricted memory access for all virtio devices, introduce a callback which can select that requirement on a per-device basis. For convenience add a common function returning always true, which can be used for use cases like SEV. Per default use a callback always returning false. As the callback needs to be set in early init code already, add a virtio anchor which is builtin in case virtio is enabled. Signed-off-by: Juergen Gross <jgross@suse.com> Tested-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> # Arm64 guest using Xen Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Link: https://lore.kernel.org/r/20220622063838.8854-2-jgross@suse.com Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'drivers/virtio')
-rw-r--r--drivers/virtio/Kconfig4
-rw-r--r--drivers/virtio/Makefile1
-rw-r--r--drivers/virtio/virtio.c4
-rw-r--r--drivers/virtio/virtio_anchor.c18
4 files changed, 25 insertions, 2 deletions
diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index e1556d2a355a..56c77f63cd22 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -1,6 +1,10 @@
# SPDX-License-Identifier: GPL-2.0-only
+config VIRTIO_ANCHOR
+ bool
+
config VIRTIO
tristate
+ select VIRTIO_ANCHOR
help
This option is selected by any driver which implements the virtio
bus, such as CONFIG_VIRTIO_PCI, CONFIG_VIRTIO_MMIO, CONFIG_RPMSG
diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
index 0a82d0873248..8e98d24917cc 100644
--- a/drivers/virtio/Makefile
+++ b/drivers/virtio/Makefile
@@ -1,5 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_VIRTIO) += virtio.o virtio_ring.o
+obj-$(CONFIG_VIRTIO_ANCHOR) += virtio_anchor.o
obj-$(CONFIG_VIRTIO_PCI_LIB) += virtio_pci_modern_dev.o
obj-$(CONFIG_VIRTIO_PCI_LIB_LEGACY) += virtio_pci_legacy_dev.o
obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 7deeed30d1f3..14c142d77fba 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -2,10 +2,10 @@
#include <linux/virtio.h>
#include <linux/spinlock.h>
#include <linux/virtio_config.h>
+#include <linux/virtio_anchor.h>
#include <linux/module.h>
#include <linux/idr.h>
#include <linux/of.h>
-#include <linux/platform-feature.h>
#include <uapi/linux/virtio_ids.h>
/* Unique numbering for virtio devices. */
@@ -174,7 +174,7 @@ static int virtio_features_ok(struct virtio_device *dev)
might_sleep();
- if (platform_has(PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS)) {
+ if (virtio_check_mem_acc_cb(dev)) {
if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) {
dev_warn(&dev->dev,
"device must provide VIRTIO_F_VERSION_1\n");
diff --git a/drivers/virtio/virtio_anchor.c b/drivers/virtio/virtio_anchor.c
new file mode 100644
index 000000000000..4d6a5d269b55
--- /dev/null
+++ b/drivers/virtio/virtio_anchor.c
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/virtio.h>
+#include <linux/virtio_anchor.h>
+
+bool virtio_require_restricted_mem_acc(struct virtio_device *dev)
+{
+ return true;
+}
+EXPORT_SYMBOL_GPL(virtio_require_restricted_mem_acc);
+
+static bool virtio_no_restricted_mem_acc(struct virtio_device *dev)
+{
+ return false;
+}
+
+bool (*virtio_check_mem_acc_cb)(struct virtio_device *dev) =
+ virtio_no_restricted_mem_acc;
+EXPORT_SYMBOL_GPL(virtio_check_mem_acc_cb);